CN104009831A

CN104009831A - User special-purpose demodulation reference signal transmission and data demodulation methods and devices

Info

Publication number: CN104009831A
Application number: CN201310057622.3A
Authority: CN
Inventors: 高雪娟; 林亚男; 沈祖康
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2013-02-22
Filing date: 2013-02-22
Publication date: 2014-08-27
Anticipated expiration: 2033-02-22
Also published as: CN104009831B

Abstract

The embodiment of the invention discloses user special-purpose demodulation reference signal (DM-RS) transmission and data demodulation methods and devices and relates to the field of radio communication so as to improve a resource utilization rate. In the methods and devices, DM-RSs are transmitted on REs on one or two OFDM signs different with an OFDM sign, on which synchronous signal transmission is carried out, in first N OFDM signs of a subframe so that a problem of overlapping of DM-RS mapping resources and synchronous-signal mapping resources is prevented and thus a problem that in a synchronous-signal transmitting subframe, part of PRBs in a system bandwidth are incapable of transmitting downlink data is prevented. Therefore, the resource utilization rate is improved.

Description

Method and device for transmitting demodulation reference signal and demodulating data special for user

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a method and apparatus for transmitting a demodulation reference signal and demodulating data dedicated to a user.

Background

In order to reduce the system overhead and improve the resource utilization rate, a New Carrier Type (NCT) is defined in a Long Term Evolution-advanced (LTE-A) system version-11 (Release 11, Rel-11). On the NCT, there is no legacy control region, downlink data may be transmitted on all Orthogonal Frequency Division Multiplexing (OFDM) symbols in one subframe, and DeModulation is performed based on a DeModulation Reference Signal (DM-RS) dedicated to a User Equipment (UE); in order to improve the Resource utilization rate of NCT, it is necessary to support simultaneous transmission of DM-RS and downlink data demodulated based on DM-RS in a Physical Resource Block (PRB) in which the synchronization signal is transmitted.

On Legacy carriers (i.e. non-NCT carriers), the OFDM symbols in a downlink subframe are divided into two parts, namely a control region and a data region, where the control region is the first N OFDM symbols of the downlink subframe, as shown in fig. 1. Where N may be 1,2,3,4, and N =4 is only applicable to a carrier with a system bandwidth of 1.4MHz, and for a Time Division Duplex (TDD) special subframe, N may only be 1 or 2.

The Synchronization signals include Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS). In the frequency domain, PSS and SSS are mapped only on the 72 subcarriers in the middle of the bandwidth. In the time domain, for a Frequency Division Duplex (FDD) system, PSS is mapped to the last OFDM symbol of slot 0 (i.e., the first slot of subframe 0) and slot 10 (i.e., the first slot of subframe 5), and SSS is mapped to the second last OFDM symbol of slot 0 and slot 10, as shown in fig. 2 a; for TDD system, PSS is mapped to the third OFDM symbol in subframes 1 and 6 (i.e. in TDD uplink/Downlink configuration at 5ms uplink/Downlink switching point, both subframes 1 and 6 are special subframes; in TDD uplink/Downlink configuration at 10ms uplink/Downlink switching point, only subframe 1 is special subframe; for special subframe, PSS is mapped to the third OFDM symbol of Downlink Pilot Time Slot (DwPTS) contained in special subframe), SSS is mapped to the last OFDM symbol of Slot 1 (i.e. the second Slot of subframe 0) and Slot 11 (i.e. the second Slot of subframe 5), as shown in fig. 2 b.

The DM-RS special for the UE can support 1-8 antenna port transmission. The DM-RS is only sent on a PRB where a Physical Downlink Shared Channel (PDSCH) is transmitted, so as to reduce reference symbol overhead, save energy, and reduce interference between adjacent cells. Fig. 3a (under a normal Cyclic Prefix (CP)) and fig. 3b (under an extended CP) show a resource mapping manner of a DM-RS in units of one PRB pair, where mapping resources of the DM-RS on an antenna port 7/8/11/13 are the same, mapping resources on an antenna port 9/10/12/14 are the same, and orthogonality between DM-RSs of antenna ports using the same mapping resources is ensured by time-domain orthogonal sequences in table 1 and table 2. Under the extended CP, the DM-RS supports only 2 antenna ports. In addition, for the special subframe with DwPTS length of 3 OFDM symbols in TDD system (ii)I.e. DwPTS is 6592. T under the downlink normal CP_sIn the special subframe of (1), DwPTS is 7680. T under the downlink extended CP_sOf special subframes, wherein T_sTime intervals are adopted for the system), namely special subframes corresponding to special subframe configurations 0 and 5 in the case of a normal CP and special subframes corresponding to special subframe configurations 0 and 4 in the case of an extended CP, do not support DM-RS transmission.

Table 1: DM-RS orthogonal sequences of different antenna ports under normal CP

Table 2: DM-RS orthogonal sequences of different antenna ports under extended CP

According to the above DM-RS and synchronization signal mapping positions, when there is an overlap between the mapping resources of the UE-specific DM-RS and the mapping resources of the synchronization signal in the subframes where the synchronization signal is transmitted (subframes 0 and 5 for FDD and subframes 0, 1, 5, and 6 for TDD), in these subframes, the DM-RS and the downlink data demodulated by the DM-RS are not transmitted in the PRB pair (pair) where the synchronization signal mapping resources exist (i.e., in the 6 PRBs in the middle of the system bandwidth).

In order to further improve the utilization rate of system resources, Long Term Evolution-advanced (LTE-a) system version-12 (Release 11, Rel-12) determines to introduce a New Carrier Type (NCT) so as to enhance the utilization rate of system spectrum, better support heterogeneous networks and reduce power consumption. Currently on NCT: the legacy control region does not exist, the PDSCH can be transmitted on all OFDM symbols in one downlink subframe, and for TDD special subframes, the PDSCH can be transmitted on all OFDM symbols used for downlink transmission; currently, only Downlink transmission demodulated based on UE-specific DM-RS is supported on NCT, and since there is no legacy Control region and no legacy Physical Downlink Channel transmitted in the Control region on legacy Carrier, such as legacy Physical Downlink Control Channel (PDCCH), etc., PDSCH on NCT can only be scheduled through Enhanced Physical Downlink Control Channel (E-PDCCH) transmitted on NCT, or can also be cross-Carrier scheduled through PDCCH/E-PDCCH transmitted on legacy Carrier aggregated with NCT (Carrier Aggregation, CA), where Downlink transmission such as PDSCH and E-PDCCH on NCT needs to be demodulated based on UE-specific DM-RS; the main difference between the E-PDCCH and legacy PDCCH is that the E-PDCCH is frequency division multiplexed with the PDSCH, so the E-PDCCH on NCT can also be transmitted on all OFDM symbols for downlink transmission, and the transmission structure is shown in fig. 4; furthermore, NCT currently only supports Cell-specific pilot signals (CRS) transmitted on a single antenna port (antenna port p = 0) with a period of 5ms, and CRS is only used for measurement and tracking, not for demodulation.

NCTs can be divided into synchronous NCTs and asynchronous NCTs; for synchronous NCT, the NCT cannot work independently and needs to work together with legacy carrier waves, the synchronous information of the NCT is considered to be consistent with the aggregated legacy carrier waves, and the synchronous information can be obtained from the legacy carrier waves and can also be obtained by detecting synchronous signals sent on the NCT; for asynchronous NCTs, synchronization needs to be achieved by detecting the synchronization signal sent on the NCT; i.e. at least for non-synchronized NCTs, on which a synchronization signal transmission needs to be present.

In summary, the resource mapping manner of UE-specific DM-RS defined in Rel-10 has a problem that DM-RS mapping resources overlap with synchronization signal mapping subframes in synchronization signal transmission subframes. If the downlink data cannot be transmitted in 6 PRBs in the middle of the system bandwidth of the NCT in the synchronous signal transmission subframe according to the UE-dedicated DM-RS resource mapping mode of Rel-10, the resource utilization rate of the NCT is reduced.

Disclosure of Invention

The embodiment of the invention provides a method and equipment for transmitting a demodulation reference signal and demodulating data special for a user, which are used for improving the resource utilization rate.

A method for user-specific demodulation reference signal, DM-RS, transmission, the method comprising:

a network side determines physical resources for transmitting DM-RS in a current subframe;

respectively mapping the DM-RS corresponding to each DM-RS antenna port in the current subframe to a DM-RS resource unit RE corresponding to the DM-RS antenna port on the physical resource for transmitting the DM-RS by the network side according to the DM-RS resource mapping mode of each DM-RS antenna port, wherein the DM-RS RE corresponding to each DM-RS antenna port is the RE on one or two OFDM symbols which are different from the OFDM symbols where the synchronous signals are transmitted in the first N orthogonal frequency division multiplexing OFDM symbols in the subframe; wherein N is an integer of not less than 1;

and the network side sends the DM-RS after resource mapping to the terminal through the antenna port for transmitting the DM-RS in the subframe on the physical resource for transmitting the DM-RS in the subframe.

A method of data demodulation, the method comprising:

the terminal determines physical resources used for transmitting a user dedicated demodulation reference signal DM-RS in a current subframe;

the terminal respectively acquires the DM-RS corresponding to each DM-RS antenna port in the current subframe on a DM-RS resource unit RE corresponding to the physical resource for transmitting the DM-RS according to the DM-RS resource mapping mode of each DM-RS antenna port, wherein the DM-RS RE corresponding to each DM-RS antenna port is the RE on one or two OFDM symbols which are different from the OFDM symbols where the synchronous signals are transmitted in the first N orthogonal frequency division multiplexing OFDM symbols in the subframe; wherein N is an integer of not less than 1 and not more than 6;

and the terminal demodulates the downlink data received on the corresponding antenna port according to the DM-RS corresponding to each DM-RS antenna port.

A base station, the base station comprising:

a transmission resource determining unit, configured to determine a physical resource used for transmitting the DM-RS in a current subframe;

a DM-RS mapping unit, configured to map, according to a DM-RS resource mapping manner of each DM-RS antenna port, a DM-RS corresponding to each DM-RS antenna port in a current subframe to a DM-RS resource unit RE, corresponding to the DM-RS antenna port, on the physical resource used for transmitting the DM-RS, respectively, where the DM-RS RE corresponding to each DM-RS antenna port is a RE, different from one or two OFDM symbols where a synchronization signal is transmitted, in the first N orthogonal frequency division multiplexing OFDM symbols in the subframe; wherein N is an integer of not less than 1;

and the transmission unit is used for sending the DM-RS after resource mapping to the terminal through the antenna port used for transmitting the DM-RS in the subframe on the physical resource used for transmitting the DM-RS in the subframe.

A terminal, the terminal comprising:

a DM-RS obtaining unit, configured to obtain, at each DM-RS antenna port in a current subframe, a DM-RS corresponding to the DM-RS antenna port on a corresponding DM-RS resource unit RE on the physical resource for transmitting the DM-RS, respectively, according to a DM-RS resource mapping manner of each DM-RS antenna port, where the DM-RS RE corresponding to each DM-RS antenna port is a RE on one or two OFDM symbols, which are different from an OFDM symbol where a synchronization signal is transmitted, in the first N orthogonal frequency division multiplexing OFDM symbols in the subframe; wherein N is an integer of not less than 1 and not more than 6;

and the demodulation unit is used for demodulating the downlink data received on the corresponding antenna port according to the DM-RS corresponding to each DM-RS antenna port.

In the scheme provided by the embodiment of the invention, a network side determines physical resources for transmitting DM-RS in a current subframe, respectively maps DM-RS corresponding to each DM-RS antenna port in the current subframe to DM-RS RE corresponding to the DM-RS antenna port on the physical resources for transmitting DM-RS according to a DM-RS resource mapping mode of each DM-RS antenna port, and transmits the resource-mapped DM-RS to a terminal through the antenna port for transmitting DM-RS in the subframe on the physical resources for transmitting DM-RS in the subframe; the terminal determines physical resources used for transmitting user-specific demodulation reference signals DM-RS in a current subframe, acquires DM-RS corresponding to each DM-RS antenna port in the current subframe on a DM-RS RE corresponding to the physical resources used for transmitting DM-RS according to a DM-RS resource mapping mode of each DM-RS antenna port, and demodulates downlink data received on the corresponding antenna port according to the DM-RS corresponding to each DM-RS antenna port. The DM-RS RE corresponding to each DM-RS antenna port is the RE on one or two OFDM symbols different from the OFDM symbols where the synchronous signals are transmitted in the first N OFDM symbols in the subframe, so that the problem that DM-RS mapping resources and synchronous signal mapping resources are overlapped is avoided, the problem that downlink data cannot be transmitted in 6 PRBs in the middle of the system bandwidth in the synchronous signal transmission subframe is further avoided, and the resource utilization rate is improved.

Drawings

Fig. 1 is a schematic diagram illustrating a multiplexing relationship between a carrier control region and a data region in the prior art;

fig. 2a is a diagram illustrating a mapping position of a synchronization signal in an FDD system in the prior art;

FIG. 2b is a diagram illustrating the mapping positions of synchronization signals in a TDD system according to the prior art;

FIG. 3a is a diagram illustrating a DM-RS resource mapping method under a conventional CP in the prior art;

FIG. 3b is a diagram illustrating a DM-RS resource mapping method under an extended CP in the prior art;

FIG. 4 is a diagram illustrating a multiplexing relationship between a control region and a data region of an NCT in the prior art;

FIG. 5 is a schematic flow chart of a method provided by an embodiment of the present invention;

FIG. 6 is a schematic flow chart of another method provided by the embodiments of the present invention;

fig. 7a to fig. 7e are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =6 and 8 antenna ports in the embodiment of the present invention;

fig. 8a to 8d are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =4 and 8 antenna ports in an embodiment of the present invention;

fig. 9 a-9 b are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =4 and 8 antenna ports according to an embodiment of the present invention;

fig. 10 a-10 b are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =4 and 8 antenna ports according to an embodiment of the present invention;

fig. 11a to 11d are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =2 and 8 antenna ports in an embodiment of the present invention;

fig. 12a to 12d are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =2 and 8 antenna ports according to an embodiment of the present invention;

fig. 13a to 13d are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =3 and 8 antenna ports in an embodiment of the present invention;

fig. 14a to fig. 14d are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =2 and 8 antenna ports in an embodiment of the present invention;

fig. 15 a-15 b are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =2 and 8 antenna ports according to an embodiment of the present invention;

fig. 16a to fig. 16d are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =3 and 4 antenna ports according to an embodiment of the present invention;

fig. 17a is a schematic diagram of a DM-RS resource mapping manner under a normal CP and at a =4 and 4 antenna ports in the embodiment of the present invention;

fig. 17b is a schematic diagram of a DM-RS resource mapping manner under a normal CP and at a =6 and 4 antenna ports in the embodiment of the present invention;

fig. 18a to 18c are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =4 and 2 antenna ports according to an embodiment of the present invention;

fig. 19 a-19 b are schematic diagrams illustrating a DM-RS resource mapping method under a conventional CP when a =6 and 2 antenna ports according to an embodiment of the present invention;

fig. 20 is a schematic structural diagram of a base station according to an embodiment of the present invention;

fig. 21 is a schematic structural diagram of a terminal according to an embodiment of the present invention.

Detailed Description

In order to improve the resource utilization rate, embodiments of the present invention provide a method for transmitting a user specific DM-RS and a method for demodulating data using the user specific DM-RS.

Referring to fig. 5, the method for transmitting a DM-RS dedicated to a user according to an embodiment of the present invention includes the following steps:

step 50: a network side determines physical resources for transmitting DM-RS in a current subframe; here, the physical resource is specifically represented as a physical resource block pair (PRB pair), that is, a physical resource configured or scheduled by the network side for the terminal to receive downlink data, where the downlink data includes downlink data carried by channels such as PDSCH and E-PDCCH;

step 51: respectively mapping the DM-RS corresponding to each DM-RS antenna port in the current subframe to a DM-RS resource unit (RE) corresponding to the DM-RS antenna port on a physical resource for transmitting the DM-RS by the network side according to a DM-RS resource mapping mode of each DM-RS antenna port, wherein the DM-RS RE corresponding to each DM-RS antenna port is the RE on one or two OFDM symbols which are different from the OFDM symbols where the synchronous signals are transmitted in the first N Orthogonal Frequency Division Multiplexing (OFDM) symbols in the subframe; wherein N is an integer of not less than 1;

step 52: and the network side sends the DM-RS after resource mapping to the terminal through the antenna port for transmitting the DM-RS in the subframe on the physical resource for transmitting the DM-RS in the subframe.

Specifically, for a conventional Cyclic Prefix (CP), the maximum value of N is 6; for extended CP, the maximum value of N is 5; alternatively, the maximum value of N is 3 for normal CP and extended CP.

Specifically, in a Time Division Duplex (TDD) system, a subframe for transmitting a DM-RS is a special subframe corresponding to special subframe configuration 9 under a normal CP, or a special subframe corresponding to special subframe configuration 7 under an extended CP; or, the subframe for transmitting the DM-RS is a downlink subframe in a Frequency Division Duplex (FDD) system; or, in the TDD system, the subframe for transmitting the DM-RS is a special subframe corresponding to a special subframe configuration other than the special subframe configuration 9 under the normal CP, or a special subframe corresponding to a special subframe configuration other than the special subframe configuration 7 under the extended CP; or, in the TDD system, the subframe for transmitting the DM-RS is a special subframe configured to correspond to any special subframe under the normal CP, or a special subframe configured to correspond to any special subframe under the extended CP.

Further, if the subframe for transmitting the DM-RS is a synchronization signal transmission subframe, the synchronization signal is transmitted on the 3 rd OFDM symbol in the subframe. The synchronization signal may be a Primary Synchronization Signal (PSS).

Specifically, when the DM-RS RE corresponding to each DM-RS antenna port is an RE on two OFDM symbols different from the OFDM symbol on which the synchronization signal is transmitted in the first N OFDM symbols in the subframe, the two OFDM symbols are continuous or discontinuous OFDM symbols; preferably, when the two OFDM symbols are consecutive OFDM symbols, the two OFDM symbols are the 1 st OFDM symbol and the 2 nd OFDM symbol in the current subframe, or the 4 th OFDM symbol and the 5 th OFDM symbol in the current subframe, or the 5 th OFDM symbol and the 6 th OFDM symbol in the current subframe; when the two OFDM symbols are discontinuous OFDM symbols, the two OFDM symbols are the 2 nd OFDM symbol and the 4 th OFDM symbol in the current subframe, or the 4 th OFDM symbol and the 6 th OFDM symbol in the current subframe, or any two discontinuous OFDM symbols in the 1 st, 2 nd, 4 th, 5 th and 6 th OFDM symbols in the current subframe;

or,

when the DM-RS RE corresponding to each DM-RS antenna port is an RE on one of the first N OFDM symbols in the subframe, which is different from the OFDM symbol in which the synchronization signal is transmitted, the one OFDM symbol is any one of the first N OFDM symbols except the OFDM symbol in which the synchronization signal is transmitted. Preferably, the one OFDM symbol is any one of a 1 st OFDM symbol, a 2 nd OFDM symbol, a 4 th OFDM symbol, a 5 th OFDM symbol, and a 6 th OFDM symbol in the current subframe. When the N max under the extended CP does not exceed 5, the case of including the 6 th OFDM symbol is applicable only to the normal CP, and the case of not including the 6 th OFDM symbol is applicable to the extended CP.

Specifically, the DM-RS RE corresponding to each DM-RS antenna port is an RE corresponding to a number a of subcarriers with different numbers included in each PRB pair on one or two OFDM symbols to which the DM-RS is mapped, in a PRB pair set corresponding to physical resources for transmitting the DM-RS, where a is an integer greater than 1 and less than 12.

Specifically, when a maximum of 8 DM-RS antenna ports are supported, the DM-RS RE corresponding to each DM-RS antenna port is determined according to the following method:

dividing 8 DM-RS antenna ports into 2 groups, wherein each group comprises 4 DM-RS antenna ports, and the 4 DM-RS antenna ports in the same group correspond to the same DM-RS RE; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; taking REs corresponding to the A subcarriers determined in each PRB pair on the one or two OFDM symbols as DM-RS antenna ports in the corresponding group, wherein the REs correspond to the DM-RS antenna ports in each PRB pair; or,

dividing 8 DM-RS antenna ports into 4 groups, wherein each group comprises 2 DM-RS antenna ports, and the 2 DM-RS antenna ports in the same group correspond to the same DM-RS RE; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; and taking the corresponding REs of the A subcarriers determined in each PRB pair on the one or two OFDM symbols as the corresponding DM-RS REs of the DM-RS antenna port in the corresponding group in each PRB pair.

Specifically, the 8 DM-RS antenna ports are divided into 2 groups, each group includes 4 DM-RS antenna ports, and the 4 DM-RS antenna ports in the same group correspond to the same DM-RSRE; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; taking REs corresponding to the a subcarriers determined in each PRB pair on the one or two OFDM symbols as DM-RS REs corresponding to DM-RS antenna ports in the corresponding group in each PRB pair, which may specifically include the following three examples:

example 1:

when a =6 and DM-RS is mapped to two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 3 rd, 4 th, 7 th, 8 th, 11 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in another group are the 1 st, 2 nd, 5 th, 6 th, 9 th and 10 th REs corresponding to the two OFDM symbols in the order from the lower subcarrier number to the higher subcarrier number in each PRB pair; as shown in fig. 7 a-7 e;

example 2:

when a =4 and DM-RS is mapped to one or two OFDM symbols, the determination manner of the DM-RS RE includes one of the following methods 1 to 5:

the method comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are 12-b-a, 12-b +1-a, 12-b and 12-b +1 REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the b-th, b + 1-th, b + a-th and b +1+ a-th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; wherein a =8 or 7 or 6 or 4 or 3 or 2 when b =1, a =6 or 5 or 3 or 2 when b =2, and a =4 or 2 when b = 3;

in this method, for a =4, DM-RS is mapped to two OFDM symbols, b =1, and a =8 corresponds to fig. 8 a-8 d;

for the case of a =4, DM-RS mapped to one OFDM symbol, when b =3, a =2 corresponds to fig. 9 a-9 b;

for the case where a =4, DM-RS is mapped to one OFDM symbol, when b =1, a =8 corresponds to fig. 10 a-fig. 10 b.

When b =1, the following is specifically described:

the DM-RS REs corresponding to the antenna ports for transmitting the DM-RS in one group are 12-a, 11-11 and 12-th REs corresponding to the two OFDM symbols in the PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the antenna ports for transmitting the DM-RS in the other group are the 1 st, the 2 nd, the 1+ a th and the 2+ a th REs corresponding to the two OFDM symbols in the PRB pair according to the sequence of the subcarrier numbers from low to high; wherein, a =8 or 7 or 6 or 4 or 3 or 2;

b =2, specifically described as:

the DM-RS REs corresponding to the antenna ports for transmitting the DM-RS in one group are the 10-a th, 11-a th, 10 th and 11 th REs corresponding to the two OFDM symbols in the PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the antenna ports for transmitting the DM-RS in the other group are the 2 nd, the 3 rd, the 2+ a nd and the 3+ a th REs corresponding to the two OFDM symbols in the PRB pair according to the sequence of the subcarrier numbers from low to high; wherein a is 6 or 5 or 3 or 2;

b =3, specifically described as:

the DM-RS REs corresponding to the antenna ports for transmitting the DM-RS in one group are the 9-a th, 10-a th, 9 th and 10 th REs corresponding to the two OFDM symbols in the PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the antenna ports for transmitting the DM-RS in the other group are the 3 rd, the 4 th, the 3+ a th and the 4+ a th REs corresponding to the two OFDM symbols in the PRB pair according to the sequence of the subcarrier numbers from low to high; wherein a is 4 or 2.

The method 2 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 5 th, 6 th, 11 th and 12 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 3 rd, 4 th, 9 th and 10 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier numbers, or the 2 nd, 3 rd, 8 th and 9 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier numbers;

the method 3 comprises the following steps: taking the 1 st, 4 th, 7 th and 10 th REs corresponding to the one or two OFDM symbols in the sequence from the low to the high subcarrier numbers in each PRB pair as a set of DM-RS REs, the 3 rd, 6 th, 9 th and 12 th REs as a set of DM-RS REs, the 2 nd, 5 th, 8 th and 11 th REs as a set of DM-RS REs, and the DM-RS REs corresponding to the DM-RS antenna ports in one group are one of the 3 sets of DM-RS REs; the DM-RS RE corresponding to the DM-RS antenna port in the other group is the other group in the 3 groups of DM-RS REs;

the method 4 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 12-b-c +1-a, 12-b-c +1 and 12-b +1 REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the b-th, b + c-th, b + a-th and b + c + a-th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; wherein b =1, c =3, a =6, or, b =1, c =2, a =4, or b =2, c =2, a = 4;

the method 5 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 2 nd, 5 th, 8 th and 11 th REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, 4 th, 7 th, and 10 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair, or the 3 rd, 6 th, 9 th, and 12 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair;

example 3:

when a =2 and DM-RS is mapped to two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are 12-b +1-a and 12-b +1 REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the b-th and b + a-th REs corresponding to the two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair, wherein, when b =1, a is any integer from 1 to 10 including 1 and 10 (fig. 11 a-11 d correspond to the case of b =1, a = 8), when b =2, a is any integer other than 9 including 1 and 10 from 1 to 10 (fig. 12a to 12d correspond to the case of b =2, a = 8), when b =3, a is any integer other than 7 including 1 and 9 from 1 to 9, when b =4, a is any integer other than 5 including 1 and 8 from 1 to 8, when b =5, a is any integer other than 3 including 1 and 7 from 1 to 7.

For the resource mapping manner of the 8 ports (for example, the specific resource mapping manner given in examples 1 to 3), on the physical resource used for transmitting the DM-RS in the subframe on the network side, before the DM-RS after resource mapping is sent to the terminal through the antenna port used for transmitting the DM-RS in the subframe, the following spreading operation of the DM-RS needs to be performed:

when A is not an integer multiple of 4 and DM-RS mapping is at two OFDM symbols: for each DM-RS antenna port, taking 4 DM-RSs on two subcarriers adjacent to or closest to the two OFDM symbols on the DM-RS antenna port as a group, and respectively performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port; or,

when A is an integer multiple of 4: and for each DM-RS antenna port, taking 4 DM-RSs on 4 subcarriers adjacent to or closest to each OFDM symbol mapped with the DM-RS on the DM-RS antenna port as a group, and respectively performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port.

The above spreading process is described in detail as follows:

when a =6 and DM-RS maps to two OFDM symbols:

for each antenna port for transmitting the DM-RS, taking 4 DM-RSs on two subcarriers adjacent to or closest to the two OFDM symbols on the antenna port as a group, and respectively performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port;

when a =4 and DM-RS maps to two OFDM symbols:

for each DM-RS antenna port, taking 4 DM-RSs on two subcarriers adjacent to or closest to the two OFDM symbols on the antenna port as a group, and respectively performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port; or,

for each DM-RS antenna port, taking 4 DM-RSs on each OFDM symbol mapped with the DM-RS on the antenna port as a group, and respectively performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port;

when a =4 and DM-RS maps to one OFDM symbol:

for each DM-RS antenna port, taking 4 DM-RSs on an OFDM symbol mapped with the DM-RS on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port;

when a =2 and DM-RS maps to two OFDM symbols:

and for each DM-RS antenna port, taking 4 DM-RSs on the two OFDM symbols on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port.

Specifically, the 8 DM-RS antenna ports are divided into 4 groups, each group includes 2 DM-RS antenna ports, and 2 DM-RS ports in the same group correspond to the same DM-RS RE; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; when the REs corresponding to the a subcarriers determined in each PRB pair on the one or two OFDM symbols are used as the DM-RS REs corresponding to the DM-RS antenna ports in the corresponding group in each PRB pair, the following two examples may be specifically included:

example 1:

when a =3 and DM-RS is mapped to two OFDM symbols:

the DM-RS REs corresponding to the DM-RS antenna port in the first group are the 4 th, 8 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high;

the DM-RS REs corresponding to the DM-RS antenna ports in the second group are the 1 st, 5 th and 9 th REs corresponding to the two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair;

the DM-RS REs corresponding to the DM-RS antenna ports in the third group are the 3 rd, 7 th and 11 th REs corresponding to the two OFDM symbols in the order from the low subcarrier number to the high subcarrier number in each PRB pair;

the DM-RS REs corresponding to the DM-RS antenna ports in the fourth group are the 2 nd, 6 th and 10 th REs corresponding to the two OFDM symbols in the sequence from the low subcarrier number to the high subcarrier number in each PRB pair;

example 2:

when a =2 and DM-RS is mapped to one or two OFDM symbols, one of the following methods 1 to 3 is included:

the method comprises the following steps: taking the corresponding b-th and b + a-th REs on the one or two OFDM symbols in each PRB pair in the sequence from low to high according to the subcarrier number as a group to obtain a (12-a) group of REs, wherein a is any integer from 2 to 8 including 2 and 8, and b is any integer from 1 to (12-a) including 1 and (12-a); the DM-RS REs corresponding to the DM-RS antenna ports in the first, second, third and fourth groups are respectively one group of REs in the (12-a) group of REs, and the RE group corresponding to each group is different;

namely:

when a =8, b = 1-4, obtaining 4 groups of REs, which are respectively the 1 st and 9 th REs, the 2 nd and 10 th REs, the 3 rd and 11 th REs, and the 4 th and 12 th REs corresponding to the one or two OFDM symbols in a PRB pair according to the sequence of subcarrier numbers from low to high, that is, corresponding to fig. 14 a-14 d;

when a =7, b = 1-5, obtaining 5 groups of REs, which are respectively the 1 st and 8 th REs, the 2 nd and 9 th REs, the 3 rd and 10 th REs, the 4 th and 11 th REs, and the 5 th and 12 th REs corresponding to one or two OFDM symbols in one PRB pair in the sequence from the subcarrier number from low to high, wherein each of the 4 DM-RS antenna port groups respectively corresponds to one group of REs in the RE group, and preferably, the 4 DM-RS antenna port groups respectively correspond to the 1 st and 8 th REs, the 5 th and 12 th REs, the 4 th and 11 th REs, the 2 nd and 9 th REs corresponding to one or two OFDM symbols in one PRB pair in the sequence from the subcarrier number from low to high;

when a =6, b = 1-6, obtaining 6 groups of REs, which are respectively the 1 st and 7 th REs, the 2 nd and 8 th REs, the 3 rd and 9 th REs, the 4 th and 10 th REs, the 5 th and 11 th REs, and the 6 th and 12 th REs corresponding to one or two OFDM symbols in a PRB pair in the sequence from the subcarrier number from low to high, wherein each of the 4 DM-RS antenna port groups respectively corresponds to one group of REs in the RE groups, preferably, the 4 DM-RS antenna port groups respectively correspond to the 1 st and 7 th REs, the 6 th and 12 th REs, the 2 nd and 8 th REs, the 5 th and 11 th REs corresponding to one or two OFDM symbols in the sequence from the subcarrier number from low to high in one PRB pair, or respectively correspond to the 1 st and 7 th REs corresponding to one or two OFDM symbols in the sequence from the subcarrier number from low to high in one PRB pair, The 6 th and 12 th REs, the 3 rd and 9 th REs, and the 4 th and 10 th REs correspond to the 2 nd and 8 th REs, the 5 th and 11 th REs, the 3 rd and 9 th REs, and the 4 th and 10 th REs, respectively, in one PRB pair corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers;

when a =5, b =1~7, obtaining 7 groups of REs, which are respectively the 1 st and 6 th REs, the 2 nd and 7 th REs, the 3 rd and 8 th REs, the 4 th and 9 th REs, the 5 th and 10 th REs, the 6 th and 11 th REs, and the 7 th and 12 th REs corresponding to the subcarrier numbers in the sequence from low to high in one PRB pair on the one or two OFDM symbols, wherein each of the 4 DM-RS antenna port groups respectively corresponds to one group of REs in the RE groups, preferably, the 4 DM-RS antenna port groups respectively correspond to the 1 st and 6 th REs, the 7 th and 12 th PRBs, the 3 th and 8 th REs, the 5 th and 10 th REs corresponding to the subcarrier numbers in the sequence from low to high in one PRB pair on the one or two OFDM symbols, or respectively correspond to the 1 st and 6 th REs, the 7 th and 12 th PRBs, the 3 th and 8 th REs, the 5 th and 10 th REs corresponding to the subcarrier numbers in one PRB pair in the sequence from low to high on the OFDM symbols, 6 th and 11 th REs, 3 rd and 8 th REs, and 5 th and 10 th REs;

when a =4, b =1~8, obtaining 8 groups of REs, which are respectively the 1 st and 5 th REs, the 2 nd and 6 th REs, the 3 rd and 7 th REs, the 4 th and 8 th REs, the 5 th and 9 th R, the 6 th and 10 th REs, the 7 th and 11 th REs, and the 8 th and 12 th REs corresponding to the one or two OFDM symbols in the sequence from the low to the high of the subcarrier number in one PRB pair, wherein each group of the 4 DM-RS antenna port groups respectively corresponds to one group of REs in the RE groups, preferably, the 4 DM-RS antenna port groups respectively correspond to the 1 st and 5 th REs, the 8 th and 12 th REs, the 2 nd and 6 th REs, the 7 th and 11 th REs corresponding to the one or two OFDM symbols in the sequence from the low to the high of the subcarrier number in one PRB pair, or respectively correspond to the 1 st and two PRBs in the sequence from the low to the high of the subcarrier number in one PRB pair The 5 th RE, the 8 th and 12 th REs, the 3 rd and 7 th REs, the 6 th and 10 th REs correspond to the 2 nd and 6 th REs, the 7 th and 11 th REs, the 4 th and 8 th REs, the 5 th and 9 th REs in one PRB pair respectively corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high, or correspond to the 3 rd and 7 th REs, the 6 th and 10 th REs, the 4 th and 8 th REs, the 5 th and 9 th REs in one PRB pair respectively corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high;

when a =3, b = 1-9, obtaining 9 groups of REs, which are respectively the 1 st and 4 th REs, the 2 nd and 5 th REs, the 3 rd and 6 th REs, the 4 th and 7 th REs, the 5 th and 8 th REs, the 6 th and 9 th REs, the 7 th and 10 th REs, the 8 th and 11 th REs, and the 9 th and 12 th REs corresponding to the one or two OFDM symbols in the sequence from the lower subcarrier number to the higher subcarrier number in one PRB pair, wherein each group of the 4 DM-RS antenna port groups respectively corresponds to one group of REs in the RE groups, preferably, the 4 DM-RS antenna port groups respectively correspond to the 1 st and 4 th REs, the 9 th and 12 th REs, the 2 nd and 5 th REs, the 8 th and 11 th REs corresponding to the one or two OFDM symbols in the sequence from the lower subcarrier number to the higher subcarrier number in one PRB pair, or respectively correspond to the 1 st and 4 th REs, the 9 th and 12 th REs, the 2 nd and 5 th REs, the 8 th and 11 th REs corresponding to one PRB pair in the sequence from the lower subcarrier number or two OFDM symbols in the sequence from the higher subcarrier number Corresponding 1 st and 4 th REs, 9 th and 12 th REs, 3 rd and 6 th REs, and 7 th and 10 th REs, or corresponding 2 nd and 5 th REs, 8 th and 11 th REs, 3 rd and 6 th REs, and 3 rd and 10 th REs, which correspond to the one or two OFDM symbols in a PRB pair in the order of subcarrier numbers from low to high, respectively, or corresponding 2 nd and 5 th REs, 8 th and 11 th REs, 4 th and 7 th REs, and 6 th and 9 th REs, which correspond to the one or two OFDM symbols in a PRB pair in the order of subcarrier numbers from low to high, respectively;

when a =2, b =1~10, obtaining 10 groups of REs, which are respectively the 1 st and 3 rd REs, the 2 nd and 4 th REs, the 3 rd and 5 th REs, the 4 th and 6 th REs, the 5 th and 7 th REs, the 6 th and 8 th REs, the 7 th and 9 th REs, the 8 th and 10 th REs, the 9 th and 11 th REs, and the 10 th and 12 th REs corresponding to the one or two OFDM symbols in the order from the subcarrier number from the low to the high in one PRB pair, wherein each of the 4 DM-RS antenna port groups respectively corresponds to one group of REs in the RE groups, preferably, the 4 DM-RS antenna port groups respectively correspond to the 1 st and 3 rd REs, the 10 th and 12 th REs, the 2 nd and 4 th REs, the 9 th and 11 th REs corresponding to the one or two OFDM symbols in the order from the subcarrier number from the low to the high in one PRB pair, or respectively correspond to the 1 st and 3 rd REs, the 10 th and 12 th REs, the 4 th and 6 th REs, and the 7 th and 9 th REs corresponding to the one or two OFDM symbols in the order from the subcarrier numbers to the high in one PRB pair, or respectively correspond to the 1 st and 3 rd REs, the 10 th and 12 th REs, the 5 th and 7 th REs, the 6 th and 8 th REs corresponding to the one or two OFDM symbols in the order from the subcarrier numbers to the high in one PRB pair, or respectively correspond to the 2 nd and 4 th REs, the 9 th and 11 th REs, the 3 rd and 5 th REs, the 8 th and 10 th REs corresponding to the one or two OFDM symbols in the order from the subcarrier numbers to the high in one PRB pair, or respectively correspond to the 2 nd and 4 th REs corresponding to the one or two OFDM symbols in the order from the subcarrier numbers to the high in one PRB pair, 9 th and 11 th REs, 5 th and 7 th REs, and 6 th and 8 th REs, or respectively corresponding to 3 rd and 5 th REs, 8 th and 10 th REs, 4 th and 6 th REs, and 7 th and 9 th REs in one PRB pair corresponding to the one or two OFDM symbols in the order of subcarrier numbers from low to high;

the method 2 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna port in the first group are the corresponding b-th and b + 1-th REs on the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the second group are 12-b th and 12-b +1 th REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the third group are the b + a th and b +1+ a th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; the DM-RS REs corresponding to the DM-RS antenna ports in the fourth group are 12-b-a th and 12-b +1-a th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; wherein b =1, a =2 or 3 or 4, or, b =2, a =2 or 3, or b =3, a =2 (corresponding to fig. 15 a-15 b);

the method 3 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna port in the first group are the corresponding b-th and b + 1-th REs on the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the second group are the b + a th and b + a +1 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the third group are the b +2a th and b +2a +1 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; the DM-RS REs corresponding to the DM-RS antenna ports in the fourth group are the b +3a th and b +3a +1 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; wherein a =2 and b is any integer from 1 to 5 including 1 and 5, or a =3 and b =1 or 2.

Specifically, when the maximum 4 DM-RS antenna ports are supported, the 4 DM-RS antenna ports are divided into 2 groups, each group includes 2 DM-RS antenna ports, 2 DM-RS antenna ports in the same group correspond to the same DM-RS RE, and the DM-RS RE corresponding to each DM-RS antenna port is determined according to the following method:

when a =3 (corresponding to fig. 16 a-16 d) and DM-RS is mapped to two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 2 nd, 7 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high, and the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, 6 th and 11 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high; or,

when a =4 (corresponding to fig. 17 a) and DM-RS is mapped to one OFDM symbol: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 3 rd, the 4 th, the 11 th and the 12 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high, and the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, the 2 nd, the 9 th and the 10 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high; or,

when a =6 (corresponding to fig. 17 b) and DM-RS is mapped to one or two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 3 rd, 4 th, 7 th, 8 th, 11 th and 12 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair; the DM-RS REs corresponding to the DM-RS antenna ports in another group are the 1 st, 2 nd, 5 th, 6 th, 9 th and 10 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair.

Specifically, when a maximum of 2 DM-RS antenna ports are supported (in this case, under an extended CP generally), the DM-RS REs corresponding to each DM-RS antenna port are the same, and the DM-RS RE corresponding to each DM-RS antenna port is determined according to the following method:

when a =2 and DM-RS is mapped to one or two OFDM symbols: the DM-RS RE corresponding to each DM-RS antenna port is the corresponding b-th and b + a-th REs on the one or two OFDM symbols in the sequence of the subcarrier numbers from low to high in each PRB pair, wherein a is any integer from 1 to 11 including 1 and 11, and b is any integer from 1 to (12-a) including 1 and (12-a); or,

when a =3 and DM-RS is mapped to two OFDM symbols: the DM-RS RE corresponding to each DM-RS antenna port is the 2 nd, 7 th and 12 th REs corresponding to the two OFDM symbols in the sequence of the subcarrier numbers from low to high in each PRB pair, or the DM-RS RE corresponding to each DM-RS antenna port is the 1 st, 6 th and 11 th REs corresponding to the two OFDM symbols in the sequence of the subcarrier numbers from low to high in each PRB pair; or,

when a =4 and DM-RS is mapped to one or two OFDM symbols: the DM-RS REs corresponding to each DM-RS antenna port are the b-th, b + a-th, b +2 a-th and b +3 a-th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair, where a =1 and b is any integer from 1 to 9 inclusive (b =2, a =3, when the DM-RS is mapped to two OFDM symbols, corresponding to fig. 18 a-fig. 18 c), or a =2 and b is any integer from 1 to 6 inclusive, or a =3, b =1 or 2 or 3 or 4; or, the DM-RS REs corresponding to each DM-RS antenna port are the b-th, b + 1-th, b + a-th and b +1+ a-th REs corresponding to the one or two OFDM symbols in the order from the lower subcarrier number to the higher subcarrier number in each PRB pair, where a is any integer from 3 to 10, including 3 and 10, and is any integer from 1 to (11-a), including 1 and (11-a) (a =10, b =1, and when a DM-RS is mapped to one OFDM symbol, it corresponds to fig. 19 a); or,

when a =6 and DM-RS is mapped to one or two OFDM symbols: the DM-RS REs corresponding to each DM-RS antenna port are the 2 nd, 3 rd, 6 th, 7 th, 10 th and 11 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair.

For the above two examples that the 8 DM-RS antenna ports are divided into 4 groups and the maximum 4 and 2 DM-RS antenna ports are supported, on the physical resource used for transmitting the DM-RS in the subframe on the network side, before the DM-RS after the resource mapping is sent to the terminal through the antenna port used for transmitting the DM-RS in the subframe, the following spreading processing of the DM-RS needs to be performed:

when mapping DM-RS to two OFDM symbols: for each DM-RS antenna port, taking 2 DM-RSs corresponding to the same subcarrier on the two OFDM symbols on the antenna port as a group, and performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port; or,

when A is an integer multiple of 2: and for each DM-RS antenna port, taking 2 DM-RSs on the OFDM symbol mapped with the DM-RSs on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port.

The above-described specific description of the spreading process is as follows:

for the two examples described above where 8 DM-RS antenna ports are divided into 4 groups:

when a =3 and DM-RS is mapped to two OFDM symbols: for each DM-RS antenna port, taking 2 DM-RSs corresponding to the same subcarrier on the two OFDM symbols on the antenna port as a group, and performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port;

when a =2 and DM-RS is mapped to one OFDM symbol: for each DM-RS antenna port, taking 2 DM-RSs on the OFDM symbol on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port;

when a =2 and DM-RS is mapped to two OFDM symbols: and for each DM-RS antenna port, taking 2 DM-RSs corresponding to the same subcarrier on the two OFDM symbols on the antenna port as a group, or taking 2 DM-RSs on each OFDM symbol containing the DM-RSs on the antenna port as a group, and performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port.

For the case of supporting a maximum of 4 DM-RS antenna ports:

when a =4 and DM-RS is mapped to one OFDM symbol: for each DM-RS antenna port, taking 2 DM-RSs on two subcarriers adjacent to or closest to the OFDM symbol on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port;

when a =6 and DM-RS is mapped to one OFDM symbol: for each DM-RS antenna port, taking 2 DM-RSs on two subcarriers adjacent to or closest to the OFDM symbol on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port;

when a =6 and DM-RS is mapped to two OFDM symbols: for each DM-RS antenna port, taking 2 DM-RSs on two adjacent or nearest subcarriers on each OFDM symbol mapped with the DM-RSs on the antenna port as a group, or taking 2 DM-RSs corresponding to the same subcarrier on the two OFDM symbols on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port;

for the case of supporting a maximum of 2 DM-RS antenna ports:

when a =2 or 4 or 6, and DM-RS is mapped to two OFDM symbols: for each DM-RS antenna port, taking 2 DM-RSs corresponding to the same subcarrier on the two OFDM symbols on the antenna port as a group, or taking 2 DM-RSs on two subcarriers adjacent to or closest to each OFDM symbol mapped with the DM-RSs on the antenna port as a group, and performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port;

when a =2 or 4 or 6 and DM-RS is mapped to one OFDM symbol: for each DM-RS antenna port, taking 2 DM-RSs on the OFDM symbol on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port;

when a =3 and DM-RS is mapped to two OFDM symbols: and for each DM-RS antenna port, taking 2 DM-RSs corresponding to the same subcarrier on the two OFDM symbols on the antenna port as a group, and performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port.

Referring to fig. 6, an embodiment of the present invention provides a data demodulation method, including the following steps:

step 60: the terminal determines physical resources for transmitting the user dedicated DM-RS in the current subframe;

step 61: the terminal respectively acquires DM-RS corresponding to each DM-RS antenna port in the current subframe on the corresponding DM-RS RE on the physical resource for transmitting the DM-RS according to the DM-RS resource mapping mode of each DM-RS antenna port, wherein the DM-RS RE corresponding to each DM-RS antenna port is the RE on one or two OFDM symbols which are different from the OFDM symbols where the synchronous signals are transmitted in the first N OFDM symbols in the subframe; wherein N is an integer of not less than 1 and not more than 6;

step 62: and the terminal demodulates the downlink data received on the corresponding antenna port according to the DM-RS corresponding to each DM-RS antenna port.

Specifically, for a conventional CP, the maximum value of N is 6; for extended CP, the maximum value of N is 5; alternatively, the maximum value of N is 3 for normal CP and extended CP.

Specifically, in the TDD system, the subframe for transmitting the DM-RS is a special subframe corresponding to special subframe configuration 9 under the normal CP, or a special subframe corresponding to special subframe configuration 7 under the extended CP; or, the subframe for transmitting the DM-RS is a downlink subframe in the FDD system; or, in the TDD system, the subframe for transmitting the DM-RS is a special subframe corresponding to a special subframe configuration other than the special subframe configuration 9 under the normal CP, or a special subframe corresponding to a special subframe configuration other than the special subframe configuration 7 under the extended CP; or, in the TDD system, the subframe for transmitting the DM-RS is a special subframe configured to correspond to any special subframe under the normal CP, or a special subframe configured to correspond to any special subframe under the extended CP.

Further, if the subframe transmitting the DM-RS is a synchronization signal transmission subframe, the terminal also receives a synchronization signal on the 3 rd OFDM symbol in the current subframe.

Specifically, when the DM-RS RE corresponding to each DM-RS antenna port is an RE on two OFDM symbols different from the OFDM symbol on which the synchronization signal is transmitted in the first N OFDM symbols in the subframe, the two OFDM symbols are continuous or discontinuous OFDM symbols; preferably, the two OFDM symbols are the 1 st OFDM symbol and the 2 nd OFDM symbol in the current subframe, or the 4 th OFDM symbol and the 5 th OFDM symbol in the current subframe, or the 5 th OFDM symbol and the 6 th OFDM symbol in the current subframe, or the 2 nd OFDM symbol and the 4 th OFDM symbol in the current subframe, or the 4 th OFDM symbol and the 6 th OFDM symbol in the current subframe, or any two discontinuous OFDM symbols in the 1 st, 2 nd, 4 th, 5 th, and 6 th OFDM symbols in the current subframe;

or,

when the DM-RS RE corresponding to each DM-RS antenna port is an RE on one OFDM symbol, which is different from the OFDM symbol where the synchronization signal is transmitted, in the first N OFDM symbols in the subframe, the one OFDM symbol is any one OFDM symbol, which is not the OFDM symbol where the synchronization signal is transmitted, in the first N OFDM symbols. Preferably, the one OFDM symbol is any one of a 1 st OFDM symbol, a 2 nd OFDM symbol, a 4 th OFDM symbol, a 5 th OFDM symbol, and a 6 th OFDM symbol in the current subframe.

example 1:

when a =6 and DM-RS is mapped to two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 3 rd, 4 th, 7 th, 8 th, 11 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in another group are the 1 st, 2 nd, 5 th, 6 th, 9 th and 10 th REs corresponding to the two OFDM symbols in the order from the lower subcarrier number to the higher subcarrier number in each PRB pair; or,

example 2:

the method 5 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 2 nd, 5 th, 8 th and 11 th REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, 4 th, 7 th, and 10 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair, or the 3 rd, 6 th, 9 th, and 12 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; or,

example 3:

when a =2 and DM-RS is mapped to two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are 12-b +1-a and 12-b +1 REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the b-th and b + a-th REs corresponding to the two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair, where a is any integer from 1 to 10 including 1 and 10 when b =1, a is any integer from 1 to 10 including 1 and 10 except 9 when b =2, a is any integer from 1 to 9 including 1 and 9 when b =3, a is any integer from 1 to 9 except 7 including 1 and 9 when b =4, a is any integer from 1 to 8 including 1 and 8 except 5 when b =5, and a is any integer from 1 to 7 including 1 and 7 except 3 when b = 5.

For the above examples 1 to 3, the specific implementation of the terminal acquiring the DM-RS in step 61 may be as follows:

Specifically, the 8 DM-RS antenna ports are divided into 4 groups, each group includes 2 DM-RS antenna ports, and 2 DM-RS ports in the same group correspond to the same DM-RS RE; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; when the REs corresponding to the a subcarriers determined in each PRB pair on the one or two OFDM symbols are used as the DM-RS REs corresponding to the DM-RS antenna ports in the corresponding group in each PRB pair, the following two examples may be specifically included: :

example 1:

when a =3 and DM-RS is mapped to two OFDM symbols:

example 2:

the method 2 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna port in the first group are the corresponding b-th and b + 1-th REs on the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the second group are 12-b th and 12-b +1 th REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the third group are the b + a th and b +1+ a th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; the DM-RS REs corresponding to the DM-RS antenna ports in the fourth group are 12-b-a th and 12-b +1-a th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; wherein b =1, a =2 or 3 or 4, or, b =2, a =2 or 3, or b =3, a = 2;

when a =3 and DM-RS is mapped to two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 2 nd, 7 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high, and the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, 6 th and 11 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high; or,

when a =4 and DM-RS is mapped to one OFDM symbol: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 3 rd, the 4 th, the 11 th and the 12 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high, and the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, the 2 nd, the 9 th and the 10 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high; or,

when a =6 and DM-RS is mapped to one or two OFDM symbols: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 3 rd, 4 th, 7 th, 8 th, 11 th and 12 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair; the DM-RS REs corresponding to the DM-RS antenna ports in another group are the 1 st, 2 nd, 5 th, 6 th, 9 th and 10 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair.

Specifically, when the maximum 2 DM-RS antenna ports are supported, the DM-RS REs corresponding to each DM-RS antenna port are the same, and the DM-RS RE corresponding to each DM-RS antenna port is determined according to the following method:

when a =4 and DM-RS is mapped to one or two OFDM symbols: the DM-RS REs corresponding to each DM-RS antenna port are the b-th, b + a-th, b +2 a-th and b +3 a-th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair, where a =1 and b is any integer from 1 to 9 including 1 and 9, or a =2 and b is any integer from 1 to 6 including 1 and 6, or a =3, b =1 or 2 or 3 or 4; or, the DM-RS REs corresponding to each DM-RS antenna port are the b-th, b + 1-th, b + a-th and b +1+ a-th REs corresponding to the one or two OFDM symbols in the order from the lower subcarrier number to the higher subcarrier number in each PRB pair, where a is any integer from 3 to 10, including 3 and 10, and is any integer from 1 to (11-a), including 1 and (11-a); or,

For the above two examples of dividing 8 DM-RS antenna ports into 4 groups and supporting maximum 4 and 2 DM-RS antenna ports, the method for the terminal to acquire the DM-RS in step 61 may be as follows:

The resource mapping manner of DM-RS is further illustrated below:

the RE corresponding to each DM-RS antenna port is, in one PRB pair as a unit, corresponding to a (1 < a < 12) subcarriers that are different in number among the subcarriers included in the PRB pair and are distributed as uniformly as possible on the 1 or 2 OFDM symbols; for the DM-RS special for the UE with 1-8 antenna ports, the following two resource mapping methods can be adopted:

the method comprises the following steps: each 4 ports of the 8 antenna ports are divided into 2 groups, and a plurality of different antenna ports in each group correspond to the same DM-RS RE;

for example, when a =6 and DM-RS occupies two OFDM symbols: the DM-RSREs of the first set of antenna ports are the 3 rd, 4 th, 7 th, 8 th, 11 th, and 12 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order of the subcarrier numbers, and the DM-RS REs of the second set of antenna ports are the 1 st, 2 th, 5 th, 6 th, 9 th, and 10 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order of the subcarrier numbers, as shown in fig. 7a to fig. 7 e;

for each antenna port, taking 4 DM-RSs corresponding to two subcarriers (preferably, adjacent or closest subcarriers) on two OFDM symbols on the antenna port as a group, spreading by using an orthogonal sequence (shown in table 1) with a length of 4, that is, spreading by using a DM-RS group in a circle in fig. 7a to 7 e;

wherein, the case of the non-continuous OFDM symbols only takes the 2 nd and 4 th as examples, and when the non-continuous OFDM symbols are other combination cases in the 1 st, 2 nd, 4 th, 5 th and 6 th, the frequency domain position of the DM-RS RE on each OFDM symbol is the same as that in fig. 7d, which is not repeated;

for another example, when a =4 and DM-RS occupies 2 OFDM symbols: the DM-RS REs of the first set of antenna ports are the 3 rd, 4 th, 11 th, 12 th REs corresponding to the two OFDM symbols in a PRB pair from a low to a high order of subcarrier number, and the DM-RS REs of the second set of antenna ports are the 1 st, 2 nd, 9 th, 10 th REs corresponding to the two OFDM symbols in a PRB pair from a low to a high order of subcarrier number, as shown in fig. 8 a-8 d, or the DM-RS REs of the first set of antenna ports are the 5 th, 6 th, 11 th, 12 th REs corresponding to the two OFDM symbols in a PRB pair from a low to a high order of subcarrier number, and the DM-RS REs of the second set of antenna ports are the 3 rd, 4 th, 9 th, 10 th REs corresponding to the two OFDM symbols in a PRB pair from a low to a high order of subcarrier number, or, for example, the DM-RS REs of the first group of antenna ports are the 5 th, 6 th, 11 th and 12 th REs corresponding to the two OFDM symbols in a PRB pair according to the sequence of the subcarrier numbers from low to high, and the DM-RS REs of the second group of antenna ports are the 2 nd, 3 rd, 8 th and 9 th REs corresponding to the two OFDM symbols in a PRB pair according to the sequence of the subcarrier numbers from low to high; or, the 4 DM-RS REs on each OFDM symbol may also be 4 REs that are discontinuous with each other in the frequency domain;

for each antenna port, 4 DM-RSs corresponding to two subcarriers (preferably, adjacent or closest subcarriers) on two OFDM symbols on the antenna port are used as a group, and an orthogonal sequence (shown in table 1) with a length of 4 is used for spreading, such as the DM-RSs in the circle in fig. 8a to 8d are used as a group for spreading; or, taking 4 DM-RSs on each OFDM symbol on the antenna port as a group, spreading using an orthogonal sequence with a length of 4, for example, spreading with DM-RSs in the square blocks in fig. 8a to 8d as a group;

wherein, the case of the non-continuous OFDM symbols only takes the 2 nd and 4 th as examples, and when the non-continuous OFDM symbols are other combination cases in the 1 st, 2 nd, 4 th, 5 th and 6 th, the frequency domain position of the DM-RS RE on each OFDM symbol is the same as that in fig. 8d, which is not described again;

for another example, when a =4 and DM-RS occupies 1 OFDM symbol: the DM-RS REs of the first group of antenna ports are the 7 th, 8 th, 9 th, and 10 th REs corresponding to the 1 OFDM symbol in a PRB pair according to the sequence from the low to the high of the subcarrier number, and the DM-RS REs of the second group of antenna ports are the 3 rd, 4 th, 5 th, and 6 th REs corresponding to the 1 OFDM symbol in a PRB pair according to the sequence from the low to the high of the subcarrier number, as shown in fig. 9a to 9b (other continuous 4 RE positions may also be used, for example, the first group corresponds to the 8 th, 9 th, 10 th, and 11 th REs, and the second group corresponds to the 2 th, 3 th, 4 th, and 5 th REs, or the first group corresponds to the 9 th, 10 th, 11 th, and 12 th REs, and the second group corresponds to the 1 st, 2 nd, 3 th, and 4 th REs); or, the DM-RS REs of the first group of antenna ports are the 3 rd, 4 th, 11 th, and 12 th REs corresponding to the 1 OFDM symbol in a PRB pair according to the sequence from the low to the high of the subcarrier number, and the DM-RS REs of the second group of antenna ports are the 1 st, 2 th, 9 th, and 10 th REs corresponding to the 1 OFDM symbol in a PRB pair according to the sequence from the low to the high of the subcarrier number, as shown in fig. 10a to fig. 10 b; or, the 4 DM-RS REs on the 1 OFDM symbol may also be 4 REs that are discontinuous with each other in the frequency domain;

for each antenna port, 4 DM-RSs on an OFDM symbol where the DM-RS on the antenna port is located are grouped, and an orthogonal sequence (shown in table 1) with the length of 4 is used for spreading; i.e. spreading as a set of DM-RSs within the circles in fig. 9 a-9 b and fig. 10 a-10 b;

it should be noted that fig. 9 a-9 b and fig. 10 a-10 b only show that the 1 OFDM symbol is the 2 nd or 4 th OFDM symbol, and when the 1 OFDM symbol is the 1 st or 5 th or 6 th OFDM symbol, the structure is also applicable, except that the DM-RS RE is moved to the corresponding OFDM symbol.

For another example, when a =2 and DM-RS occupies 2 OFDM symbols: the DM-RSREs of the first set of antenna ports are the 4 th REs and the 12 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order of the subcarrier numbers, and the DM-RS REs of the second set of antenna ports are the 1 st REs and the 9 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order of the subcarrier numbers, as shown in fig. 11a to fig. 11 d; or, the DM-RS REs of the first group of antenna ports are the 3 rd REs and the 11 th REs corresponding to the two OFDM symbols in a PRB pair according to the sequence from the low subcarrier number to the high subcarrier number, and the DM-RS REs of the second group of antenna ports are the 2 nd REs and the 10 th REs corresponding to the two OFDM symbols in a PRB pair according to the sequence from the low subcarrier number to the high subcarrier number, as shown in fig. 12a to fig. 12 d;

for each antenna port, taking 4 DM-RSs on two OFDM symbols on the antenna port as a group, spreading using an orthogonal sequence with a length of 4 (shown in table 1), that is, spreading with a DM-RS group in a circle in fig. 11a to 11d and fig. 12a to 12 d;

here, the case of the non-continuous OFDM symbols only takes the 2 nd and 4 th as examples, and when the non-continuous OFDM symbols are other combination cases in the 1 st, 2 nd, 4 th, 5 th and 6 th, the frequency domain position of the DM-RS RE on each OFDM symbol is the same as that in fig. 11d, which is not described again.

The method 2 comprises the following steps: each 2 ports of the 8 antenna ports are divided into 4 groups, and a plurality of different antenna ports in each group correspond to the same DM-RS RE;

for example, when a =3 and DM-RS occupies 2 OFDM symbols: the DM-RS REs of the first group of antenna ports are the 4 th, 8 th, and 12 th REs corresponding to the two OFDM symbols in a PRB pair from low to high in sequence according to the subcarrier numbers, the DM-RS REs of the second group of antenna ports are the 1 st, 5 th, and 9 th REs corresponding to the two OFDM symbols in a PRB pair from low to high in sequence according to the subcarrier numbers, the DM-RS REs of the third group of antenna ports are the 3 rd, 7 th, and 11 th REs corresponding to the two OFDM symbols in a PRB pair from low to high in sequence according to the subcarrier numbers, and the DM-RS REs of the fourth group of antenna ports are the 2 nd, 6 th, and 10 th REs corresponding to the two OFDM symbols in a PRB pair from low to high in sequence according to the subcarrier numbers, as shown in fig. 13 a-13 d;

for each antenna port, taking 2 DM-RSs corresponding to the same subcarrier on two OFDM symbols on the antenna port as a group, spreading using an orthogonal sequence (shown in table 2) with a length of 2, that is, spreading with DM-RSs in a circle in fig. 13a to 13d as a group;

here, the case of the non-continuous OFDM symbols only takes the 2 nd and 4 th as examples, and when the non-continuous OFDM symbols are other combinations in the 1 st, 2 nd, 4 th, 5 th and 6 th, the frequency domain position of the DM-RS RE on each OFDM symbol is the same as that in fig. 13d, which is not described again.

For another example, when a =2 and DM-RS occupies 2 OFDM symbols: the DM-RS REs of the first group of antenna ports are the 4 th REs and the 12 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order according to the subcarrier number, the DM-RS REs of the second group of antenna ports are the 1 st REs and the 9 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order according to the subcarrier number, the DM-RS REs of the third group of antenna ports are the 3 rd REs and the 11 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order according to the subcarrier number, and the DM-RS REs of the fourth group of antenna ports are the 2 nd REs and the 10 th REs corresponding to the two OFDM symbols in a PRB pair from the low to the high order according to the subcarrier number, as shown in fig. 14a to fig. 14 d; other frequency domain position combinations without changing the number of DM-RS REs are also included in the method;

for each antenna port, using 2 DM-RSs corresponding to the same subcarrier on two OFDM symbols on the antenna port as a group, spreading using an orthogonal sequence with length 2 (shown in table 2), that is, spreading using a DM-RS group in a circle in fig. 14 a-14 d, or using 2 DM-RSs on each OFDM symbol on the antenna port as a group, spreading using an orthogonal sequence with length 2 (shown in table 2), that is, spreading using a DM-RS group in a block in fig. 14 a-14 d;

here, the case of the non-continuous OFDM symbols only takes the 2 nd and 4 th as examples, and when the non-continuous OFDM symbols are other combinations in the 1 st, 2 nd, 4 th, 5 th and 6 th, the frequency domain position of the DM-RS RE on each OFDM symbol is the same as that in fig. 14d, which is not described again.

For another example, when a =2 and DM-RS occupies 1 OFDM symbol: the DM-RS REs of the first group of antenna ports are 9 th REs and 10 th REs corresponding to the 1 OFDM symbol in a PRB pair from low to high in order of subcarrier number, the DM-RS REs of the second group of antenna ports are 3 rd REs and 4 th REs corresponding to the 1 OFDM symbol in a PRB pair from low to high in order of subcarrier number, the DM-RS REs of the third group of antenna ports are 5 th REs and 6 th REs corresponding to the 1 OFDM symbol in a PRB pair from low to high in order of subcarrier number, and the DM-RS REs of the fourth group of antenna ports are 7 th REs and 8 th REs corresponding to the 1 OFDM symbol in a PRB pair from low to high in order of subcarrier number, as shown in fig. 15 a-15 b (other continuous 2 RE positions may also be used, for example, the first group corresponds to the 11 th RE, 12 REs, the second group corresponds to the 1 st and 2 RE, the third group corresponds to the 9 th and 10 RE, the fourth group corresponds to the 3 rd and 4 RE, or the first group corresponds to the 11 th and 12 RE, the second group corresponds to the 1 st and 2 RE, the third group corresponds to the 8 th and 9 RE, the fourth group corresponds to the 4 th and 5 RE, or the first group corresponds to the 11 th and 12 RE, the second group corresponds to the 1 st and 2 RE, the third group corresponds to the 7 th and 8 RE, the fourth group corresponds to the 5 th and 6 RE, or the first group corresponds to the 11 th and 12 RE, the second group corresponds to the 2 nd and 3 RE, the third group corresponds to the 8 th and 9 RE, the fourth group corresponds to the 4 th and 5 RE, or the first group corresponds to the 10 th and 11 RE, the second group corresponds to the 2 th and 3 RE, the third group corresponds to the 8 th and 9 RE, the fourth group corresponds to the 4 th and 5 RE, or the first group corresponds to the 10 th and 11 RE, the second group corresponds to the 2 nd and 9 RE, 3 REs, the third group for 7, 8 REs, the fourth group for 5, 6 REs, etc.); for example, the resource mapping manner obtained by only reserving DM-RS on one of the OFDM symbols in fig. 14a to 14 d;

for each antenna port, using 2 DM-RSs on the 1 OFDM symbol on the antenna port as a group, spreading using an orthogonal sequence with length of 2 (shown in table 2), that is, spreading using a DM-RS group as a group in a circle in fig. 15 a-15 b;

wherein, the case of the non-continuous OFDM symbol only takes the 2 nd or 4 th OFDM symbol as an example, and when the 1 OFDM symbol is other symbols in the 1 st, 2 nd, 4 th, 5 th and 6 th OFDM symbols, the frequency domain position of the DM-RS RE on the 1 OFDM symbol is the same as that in fig. 15 a-15 b, which is not described again.

Particularly, for the DM-RS special for the UE of 1-4 antenna ports:

4 antenna ports are used as 1 group, 4 different antenna ports correspond to the same DM-RS RE, and the resource mapping mode corresponding to any one of the two groups of ports in the resource mapping mode in the method 1 adopted in the above figure can be used, and the spreading mode is the same as the above 8 antenna port mode (that is, the spreading sequence with the length of 4 is adopted);

or, every two of the 4 antenna ports are 1 group, and are divided into 2 groups, 4 different antenna ports correspond to the same DM-RS RE, and each group respectively adopts the resource mapping mode in the method 1 adopted in the previous figure, the resource mapping mode corresponding to any one of the two groups of antenna ports, and the spreading mode is the same as the 8 antenna port mode (that is, the spreading sequence with the length of 4 is adopted), or 2 DM-RSs corresponding to the same subcarrier on the OFDM symbol are spread by using the spreading sequence with the length of 2; or, each group respectively adopts the resource mapping mode corresponding to any one of the 4 groups of antenna ports in each resource mapping mode in the method 1, and the spreading mode is the same as the 8-antenna port mode (namely, a spreading sequence with the length of 2 is adopted);

preferably, for 1-4 antenna port DM-RS transmission, the resource mapping method is not limited to the 8-antenna port mapping method, but for the 8-antenna port mapping method with a =6, 4, 3, 2, 1, the number of DM-RS REs on 1 OFDM symbol is not changed, but the method of changing the frequency domain position is also included in the present invention,

for example, for a =3 and when DM-RS REs occupy two OFDM symbols, the manners shown in fig. 16 a-16 d may also be adopted, that is, every two ports in 4 antenna ports are grouped into 2 groups, the DM-RS REs of the first group of antenna ports are the 2 nd, 7 th, and 12 th REs corresponding to the two OFDM symbols in a PRB pair according to the sequence of subcarrier numbers from low to high, and the DM-RSRE of the second group of antenna ports are the 1 st, 6 th, and 11 th REs corresponding to the two OFDM symbols in a PRB pair according to the sequence of subcarrier numbers from low to high;

for each antenna port, taking 2 DM-RSs corresponding to the same subcarrier on two OFDM symbols on the antenna port as a group, and performing spreading by using an orthogonal sequence (shown in table 2) with a length of 2;

in other combination situations of non-continuous OFDM, the frequency domain position of the DM-RS on each OFDM is the same as that in fig. 16a to 16d, which is not described herein again.

For another example, when a =4 and the DM-RS REs occupy 1 OFDM symbol, the method shown in fig. 17a may be further adopted, that is, every two ports in the 4 antenna ports are a group and are divided into 2 groups, the DM-RS REs of the first group of antenna ports are the 3 rd, 4 th, 11 th, and 12 th REs corresponding to the 1 OFDM symbol in a PRB pair in the order from the lower subcarrier number to the higher subcarrier number, and the DM-RS REs of the second group of antenna ports are the 1 st, 2 th, 9 th, and 10 th REs corresponding to the two OFDM symbols in a PRB pair in the order from the lower subcarrier number to the higher subcarrier number (a resource mapping method obtained by shifting any one group of DM-RS REs formed by two consecutive REs in fig. 17a in the frequency domain, and a case where the DM-RS REs respectively occupy 4 discontinuous frequency domains are also included in the present invention); for another example, when a =6 and DM-RS RE occupies 1 OFDM symbol, the manner shown in fig. 17a may also be adopted, that is, every two ports of the 4 antenna ports are a group and divided into 2 groups, the DM-RS REs of the first group of antenna ports are the 3 rd, 4 th, 7 th, 8 th, 11 th, and 12 th REs corresponding to the 1 OFDM symbol in a PRB pair according to the sequence of the subcarrier numbers from low to high, and the DM-RS REs of the second group of antenna ports are the 1 st, 2 nd, 5 th, 6 th, 9 th, and 10 th REs corresponding to the two OFDM symbols in a PRB pair according to the sequence of the subcarrier numbers from low to high (a resource mapping manner obtained by shifting any one group of DM-RS REs formed by two continuous REs in frequency domain in fig. 17a in frequency domain, and a case that 6 discontinuous REs are respectively occupied are also included in the present invention);

for each antenna port, taking 2 DM-RSs on the 1 OFDM symbol on the antenna port as a group, spreading using an orthogonal sequence with length 2 (shown in table 2);

in fig. 17a, only the 2 nd OFDM symbol is used, and the placement of the frequency domain position of the corresponding DM-RS RE on the 1 st, 4 th, 5 th, and 6 th OFDM symbols on the OFDM symbol is also applicable, so that a new resource mapping manner can be obtained;

for the extended CP, the method is also applicable, and can support 1-8 antenna port DM-RS transmission, because each slot (slot) in the extended CP includes 6 OFDM symbols, each slot of the conventional CP includes 7 OFDM symbols, the specific resource map may be a resource map obtained by removing the last OFDM symbol in each slot in fig. 7 a-17 b, and 2 DM-RSs adjacent or adjacent to the time domain or the frequency domain are grouped, and the orthogonal sequence with the length of 2 is used for spreading.

Particularly, when only supporting 2-antenna port transmission under the extended CP, it may only select mapping resources corresponding to 2 antenna ports in the resource mapping manner of the above method to perform DM-RS mapping, preferably, the DM-RS mapping resources of the two antenna ports are the same, for example, when a =4 and DM-RS occupies two OFDM symbols, it may also use the resource mapping manner shown in fig. 18 a-18 c, where, when the two OFDM symbols are the 4 th and 5 th OFDM symbols or two non-consecutive OFDM symbols, the frequency domain position of the DM-RS RE on each OFDM symbol is the same as that in fig. 18 a-18 c, and is not described again; the case of a =3, 2 is similar to a =4, and it is possible to reduce 1 or 2 REs corresponding to the same subcarrier simultaneously on two OFDM symbols, preferably, reduce REs in the middle of the frequency domain; when a =4 and DM-RS occupies 1 OFDM symbol, the resource mapping method shown in fig. 19a may be further used, and when a =6 and DM-RS occupies 1 OFDM symbol, the resource mapping method shown in fig. 19b may be further used, where when two OFDM symbols are 1\4\5, the frequency domain position of DM-RS on the symbol is the same as that in fig. 19a and fig. 19b, which is not described herein again.

It should be noted that: the above antenna port grouping manner may not be limited to the grouping manner shown in the figure, and any antenna port grouping manner may be applied to the resource mapping manner shown in the figure, for example, the ports 7, 8, 9, and 10 may be further divided into 1 group, and the ports 11, 12, 13, and 14 may be divided into 1 group, as long as the UE and the base station group the antenna ports, and the correspondence between each group of antenna ports and the resource mapping manner in the figure are understood to be consistent; while the number of DM-RS REs is not changed, other ways of changing the frequency domain mapping position in the above embodiments are also included in the method.

It should be noted that: in the above process, when defining the DM-RS resource mapping method according to the maximum supported 8 antenna ports, for DM-RS transmission at the UE and the base station side, the number of actually used DM-RS antenna ports in the current subframe may be 1 port, for example, port 7 or port 8, or v ports, for example, ports 7 to 7+ v, where v is a positive integer greater than 1 and less than or equal to 7; when the number of the DM-RS antenna ports actually used by the UE and the base station for transmitting the DM-RS is less than 8, performing resource mapping (base station side) and receiving (UE side) on the DM-RS according to a resource mapping method defined under different grouping formulas of the 8 antenna ports, for example, the resource mapping method in fig. 7a to 15b, using the resource mapping method corresponding to the antenna port actually used for transmitting the DM-RS in the method, for example, when only the antenna ports 7 and 8 are applied to transmit the DM-RS in the current subframe, performing DM-RS mapping (base station side) and receiving (UE side) only according to the resource mapping method corresponding to the antenna ports 7 and 8; for the case that the DM-RS resource mapping method is defined according to the maximum 4 port or the maximum 2 port, the DM-RS transmission less than the maximum port number may also be supported, which is similar to the above process and is not described again.

Referring to fig. 20, an embodiment of the present invention provides a base station, where the base station includes:

a transmission resource determining unit 201, configured to determine a physical resource used for transmitting the DM-RS in the current subframe;

a DM-RS mapping unit 202, configured to map, according to a DM-RS resource mapping manner of each DM-RS antenna port, a DM-RS corresponding to each DM-RS antenna port in a current subframe to a DM-RS resource unit RE corresponding to the DM-RS antenna port on the physical resource used for transmitting the DM-RS, where the DM-RS RE corresponding to each DM-RS antenna port is a RE on one or two OFDM symbols, which are different from an OFDM symbol where a synchronization signal is transmitted, in the first N orthogonal frequency division multiplexing OFDM symbols in the subframe; wherein N is an integer of not less than 1;

a transmission unit 203, configured to send the resource-mapped DM-RS to the terminal through the antenna port in the subframe for transmitting the DM-RS on the physical resource used for transmitting the DM-RS in the subframe.

Further, the DM-RS mapping unit 202 is specifically configured to: for a normal Cyclic Prefix (CP), determining the maximum value of the N to be 6; for the extended CP, determining the maximum value of N to be 5; or,

and determining the maximum value of the N to be 3 for the normal CP and the extended CP.

Further, the DM-RS mapping unit 202 is specifically configured to: in a Time Division Duplex (TDD) system, determining that the subframe is a special subframe corresponding to special subframe configuration 9 under a normal CP or a special subframe corresponding to special subframe configuration 7 under an extended CP; or,

determining the subframe as a downlink subframe in a Frequency Division Duplex (FDD) system; or,

in a TDD system, determining that the subframe is a special subframe corresponding to other special subframe configurations except special subframe configuration 9 under a normal CP or a special subframe corresponding to other special subframe configurations except special subframe configuration 7 under an extended CP; or,

in the TDD system, the subframe is determined to be a special subframe corresponding to any special subframe configuration under a normal CP, or a special subframe corresponding to any special subframe configuration under an extended CP.

Further, the transmission unit 203 is further configured to:

and when the subframe is a synchronization signal transmission subframe, transmitting a synchronization signal on the 3 rd OFDM symbol in the subframe.

Further, the DM-RS mapping unit 202 is specifically configured to: when the DM-RS RE corresponding to each DM-RS antenna port is the RE on two OFDM symbols which are different from the OFDM symbol on which the synchronous signal is transmitted in the first N OFDM symbols in the subframe, determining that the two OFDM symbols are continuous or discontinuous OFDM symbols; or,

when the DM-RS RE corresponding to each DM-RS antenna port is an RE on one OFDM symbol, which is different from the OFDM symbol in which the synchronous signal is transmitted, in the first N OFDM symbols in the subframe, determining that the one OFDM symbol is any one OFDM symbol, except the OFDM symbol in which the synchronous signal is transmitted, in the first N OFDM symbols.

Further, the DM-RS mapping unit 202 is further configured to: determining the two OFDM symbols to be a 1 st OFDM symbol and a 2 nd OFDM symbol in the subframe, or a 4 th OFDM symbol and a 5 th OFDM symbol in the subframe, or a 5 th OFDM symbol and a 6 th OFDM symbol in the subframe, or a 2 nd OFDM symbol and a 4 th OFDM symbol in the subframe, or a 4 th OFDM symbol and a 6 th OFDM symbol in the subframe, or any two discontinuous OFDM symbols in the 1 st, 2 nd, 4 th, 5 th and 6 th OFDM symbols in the subframe;

and determining the OFDM symbol to be any one of the 1 st OFDM symbol, the 2 nd OFDM symbol, the 4 th OFDM symbol, the 5 th OFDM symbol and the 6 th OFDM symbol in the subframe.

Further, the DM-RS mapping unit 202 is specifically configured to: and determining the DM-RS REs corresponding to each DM-RS antenna port, where a is an integer greater than 1 and less than 12, and a number of subcarriers with different numbers included in each PRB pair corresponds to an RE on the one or two OFDM symbols in the PRB pair set corresponding to the physical resource for transmitting the DM-RS.

Further, the DM-RS mapping unit 202 is further configured to:

when the maximum 8 DM-RS antenna ports are supported, determining the DM-RS RE corresponding to each DM-RS antenna port according to the following method:

Further, when the DM-RS mapping unit 202 divides 8 DM-RS antenna ports into 2 groups, the DM-RS mapping unit 202 is further configured to:

when A =6 and DM-RS is mapped to two OFDM symbols, determining that DM-RS REs corresponding to DM-RS antenna ports in a group are 3 rd, 4 th, 7 th, 8 th, 11 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the other group are the 1 st, 2 nd, 5 th, 6 th, 9 th and 10 th REs corresponding to the two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair; or,

when a =4 and DM-RS is mapped to one or two OFDM symbols, determining DM-RS REs corresponding to DM-RS antenna ports in two packets according to one of the following methods 1 to 5:

the method comprises the following steps: determining the DM-RS REs corresponding to the DM-RS antenna ports in one group to be 12-b-a, 12-b +1-a, 12-b and 12-b +1 REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the other group are the b-th, b + 1-th, b + a-th and b +1+ a-th REs corresponding to the one or two OFDM symbols in each PRB pair in the sequence from the low subcarrier number to the high subcarrier number; wherein a =8 or 7 or 6 or 4 or 3 or 2 when b =1, a =6 or 5 or 3 or 2 when b =2, and a =4 or 2 when b = 3;

the method 2 comprises the following steps: determining that the DM-RS REs corresponding to the DM-RS antenna ports in one group are the corresponding 5 th, 6 th, 11 th and 12 th REs on the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna ports in the other packet are the 3 rd, 4 th, 9 th and 10 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier numbers, or the 2 nd, 3 rd, 8 th and 9 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier numbers;

the method 3 comprises the following steps: determining, in each PRB pair, the 1 st, 4 th, 7 th, and 10 th REs corresponding to the one or two OFDM symbols according to a sequence of subcarrier numbers from low to high as a set of DM-RS REs, the 3 rd, 6 th, 9 th, and 12 th REs as a set of DM-RS REs, and the 2 nd, 5 th, 8 th, and 11 th REs as a set of DM-RS REs, and determining a DM-RS RE corresponding to a DM-RS antenna port in one packet as one of the 3 sets of DM-RS REs; determining a DM-RS RE corresponding to a DM-RS antenna port in another group as another group in the 3 groups of DM-RS REs;

the method 4 comprises the following steps: determining the DM-RS REs corresponding to the DM-RS antenna ports in one group to be 12-b-c +1-a, 12-b-c +1 and 12-b +1 REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the other group are the b-th, b + c-th, b + a-th and b + c + a-th REs corresponding to the one or two OFDM symbols in each PRB pair in the sequence from the low subcarrier number to the high subcarrier number; wherein b =1, c =3, a =6, or, b =1, c =2, a =4, or b =2, c =2, a = 4;

the method 5 comprises the following steps: determining that the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 2 nd, 5 th, 8 th and 11 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna ports in the other packet are the 1 st, 4 th, 7 th, and 10 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair, or the 3 rd, 6 th, 9 th, and 12 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; or,

when A =2 and DM-RS is mapped to two OFDM symbols, determining that DM-RS REs corresponding to DM-RS antenna ports in a group are 12-b +1-a and 12-b +1 REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of subcarrier numbers from low to high; determining DM-RS REs corresponding to DM-RS antenna ports in another packet as the b-th and b + a-th REs corresponding to the two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair, wherein when b =1, a is any integer from 1 to 10 including 1 and 10, when b =2, a is any integer from 1 to 10 including 1 and 10 except 9, when b =3, a is any integer from 1 to 9 including 1 and 9 except 7, when b =4, a is any integer from 1 to 8 including 1 and 8 except 5, and when b =5, a is any integer from 1 to 7 including 1 and 7 except 3.

Further, the base station further includes:

a first spreading unit 204, configured to, on the physical resource used for transmitting the DM-RS in the subframe, before the resource-mapped DM-RS is sent to the terminal through the antenna port used for transmitting the DM-RS in the subframe:

Further, when the DM-RS mapping unit divides 8 DM-RS antenna ports into 4 groups, the DM-RS mapping unit 202 is further configured to:

when A =3 and DM-RS is mapped to two OFDM symbols, determining that DM-RS REs corresponding to DM-RS antenna ports in a first group are 4 th, 8 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the second group are the 1 st, 5 th and 9 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RSRE corresponding to the DM-RS antenna port in the third group is the 3 rd, 7 th and 11 th REs corresponding to the two OFDM symbols in the sequence of the subcarrier numbers from low to high in each PRB pair; determining that the DM-RS REs corresponding to the DM-RS antenna port in the fourth group are the 2 nd, the 6 th and the 10 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; or,

when a =2 and DM-RS is mapped to one or two OFDM symbols, the DM-RS REs corresponding to the DM-RS antenna ports in the four packets are determined according to one of the following methods 1 to 3:

the method comprises the following steps: taking the corresponding b-th and b + a-th REs on the one or two OFDM symbols in each PRB pair in the sequence from low to high according to the subcarrier number as a group to obtain a (12-a) group of REs, wherein a is any integer from 2 to 8 including 2 and 8, and b is any integer from 1 to (12-a) including 1 and (12-a); determining that the DM-RS REs corresponding to DM-RS antenna ports in the first, second, third and fourth groups are respectively a group of REs in the (12-a) group of REs, wherein the group of REs corresponding to each group is different;

the method 2 comprises the following steps: determining that the DM-RS REs corresponding to the DM-RS antenna port in the first group are the b-th and b + 1-th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the second group are 12-b th and 12-b +1 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the third group are the b + a th and b +1+ a th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that DM-RS REs corresponding to DM-RS antenna ports in a fourth group are 12-b-a th and 12-b +1-a th REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of subcarrier numbers from low to high; wherein b =1, a =2 or 3 or 4, or, b =2, a =2 or 3, or b =3, a = 2;

the method 3 comprises the following steps: determining that the DM-RS REs corresponding to the DM-RS antenna port in the first group are the b-th and b + 1-th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the second group are the b + a th and b + a +1 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the third group are the b +2a th and b +2a +1 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the fourth group are the b +3a th and b +3a +1 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; wherein a =2 and b is any integer from 1 to 5 including 1 and 5, or a =3 and b =1 or 2.

Further, the DM-RS mapping unit 202 is further configured to:

when the maximum 4 DM-RS antenna ports are supported, dividing the 4 DM-RS antenna ports into 2 groups, wherein each group comprises 2 DM-RS antenna ports, the 2 DM-RS antenna ports in the same group correspond to the same DM-RS RE, and determining the DM-RS RE corresponding to each DM-RS antenna port according to the following method:

when a =3 and DM-RS is mapped to two OFDM symbols: determining that the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 2 nd, 7 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high, and determining that the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, 6 th and 11 th REs corresponding to the two OFDM symbols in each PRB pair in the sequence of the subcarrier numbers from low to high; or,

when a =4 and DM-RS is mapped to one OFDM symbol: determining that the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 3 rd, 4 th, 11 th and 12 th REs corresponding to the two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair, and determining that the DM-RS REs corresponding to the DM-RS antenna ports in another group are the 1 st, 2 nd, 9 th and 10 th REs corresponding to the two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; or,

when a =6 and DM-RS is mapped to one or two OFDM symbols: determining that the DM-RS REs corresponding to the DM-RS antenna ports in a packet are the 3 rd, 4 th, 7 th, 8 th, 11 th and 12 th REs corresponding to the one or two OFDM symbols in the order from the low subcarrier number to the high subcarrier number in each PRB pair; and determining that the DM-RS RE corresponding to the DM-RS antenna port in the other group is the 1 st, 2 nd, 5 th, 6 th, 9 th and 10 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair.

Further, the DM-RS mapping unit 202 is further configured to:

when the maximum 2 DM-RS antenna ports are supported, determining that the DM-RS RE corresponding to each DM-RS antenna port is the same, and determining the DM-RS RE corresponding to each DM-RS antenna port according to the following method:

when a =2 and DM-RS is mapped to one or two OFDM symbols: determining that the DM-RS RE corresponding to each DM-RS antenna port is the corresponding b-th and b + a-th REs on the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair, wherein a is any integer from 1 to 11 including 1 and 11, and b is any integer from 1 to (12-a) including 1 and (12-a); or,

when a =3 and DM-RS is mapped to two OFDM symbols: determining that the DM-RS RE corresponding to each DM-RS antenna port is the 2 nd, 7 th and 12 th REs corresponding to the two OFDM symbols in the sequence of the subcarrier numbers from low to high in each PRB pair, or determining that the DM-RS RE corresponding to each DM-RS antenna port is the 1 st, 6 th and 11 th REs corresponding to the two OFDM symbols in the sequence of the subcarrier numbers from low to high in each PRB pair; or,

when a =4 and DM-RS is mapped to one or two OFDM symbols: determining that a DM-RS RE corresponding to each DM-RS antenna port is a b-th, b + a-th, b +2 a-th and b +3 a-th RE corresponding to the one or two OFDM symbols in order of a subcarrier number from low to high in each PRB pair, where a ═ 1 and b are any integers from 1 to 9 including 1 and 9, or a =2 and b is any integer from 1 to 6 including 1 and 6, or a =3 and b =1 or 2 or 3 or 4; or, determining that the DM-RS REs corresponding to each DM-RS antenna port are the b-th, b + 1-th, b + a-th and b +1+ a-th REs corresponding to the one or two OFDM symbols in the order from the low subcarrier number to the high subcarrier number in each PRB pair, where a is any integer from 3 to 10, including 3 and 10, and is any integer from 1 to (11-a), including 1 and (11-a); or,

when a =6 and DM-RS is mapped to one or two OFDM symbols: and determining the DM-RS RE corresponding to each DM-RS antenna port to be the 2 nd, 3 rd, 6 th, 7 th, 10 th and 11 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair.

Further, the base station further includes:

a second spreading unit 205, configured to, on the physical resource used for transmitting the DM-RS in the subframe, before the resource-mapped DM-RS is sent to the terminal through the antenna port used for transmitting the DM-RS in the subframe:

Referring to fig. 21, an embodiment of the present invention further provides a terminal, where the terminal includes:

a transmission resource determining unit 211, configured to determine a physical resource used for transmitting the DM-RS in the current subframe;

a DM-RS obtaining unit 212, configured to obtain, according to a DM-RS resource mapping manner of each DM-RS antenna port in the current subframe, a DM-RS corresponding to each DM-RS antenna port on a corresponding DM-RS resource unit RE on the physical resource used for transmitting the DM-RS, where the DM-RS RE corresponding to each DM-RS antenna port is a RE on one or two OFDM symbols, which are different from an OFDM symbol where the synchronization signal is transmitted, in the first N orthogonal frequency division multiplexing OFDM symbols in the subframe; wherein N is an integer of not less than 1 and not more than 6;

the demodulation unit 213 is configured to demodulate the downlink data received at the corresponding antenna port according to the DM-RS corresponding to each DM-RS antenna port.

Further, the DM-RS obtaining unit 212 is specifically configured to: for a normal Cyclic Prefix (CP), determining the maximum value of the N to be 6; for the extended CP, determining the maximum value of N to be 5; or,

Further, the DM-RS obtaining unit 212 is specifically configured to: in a Time Division Duplex (TDD) system, determining that the subframe is a special subframe corresponding to special subframe configuration 9 under a normal CP or a special subframe corresponding to special subframe configuration 7 under an extended CP; or,

Further, the DM-RS obtaining unit 212 is further configured to:

and when the subframe is a synchronous signal transmission subframe, receiving a synchronous signal on the 3 rd OFDM symbol in the subframe.

Further, when the DM-RS RE corresponding to each DM-RS antenna port is an RE on two OFDM symbols of the first N OFDM symbols in the subframe, which are different from the OFDM symbol where the synchronization signal is transmitted, the DM-RS obtaining unit 212 is specifically configured to: determining the two OFDM symbols to be continuous or discontinuous OFDM symbols; or,

when the DM-RS RE corresponding to each DM-RS antenna port is an RE on one OFDM symbol, which is different from the OFDM symbol where the synchronization signal is transmitted, in the first N OFDM symbols in the subframe, the DM-RS obtaining unit 212 is specifically configured to: and determining the OFDM symbol as any one of the first N OFDM symbols except the OFDM symbol where the synchronous signal is transmitted.

Further, the DM-RS obtaining unit 212 is further configured to: determining the two OFDM symbols to be a 1 st OFDM symbol and a 2 nd OFDM symbol in the subframe, or a 4 th OFDM symbol and a 5 th OFDM symbol in the subframe, or a 5 th OFDM symbol and a 6 th OFDM symbol in the subframe, or a 2 nd OFDM symbol and a 4 th OFDM symbol in the subframe, or a 4 th OFDM symbol and a 6 th OFDM symbol in the subframe, or any two discontinuous OFDM symbols in the 1 st, 2 nd, 4 th, 5 th and 6 th OFDM symbols in the subframe;

Further, the DM-RS obtaining unit 212 is specifically configured to: and determining the DM-RS REs corresponding to each DM-RS antenna port, where a is an integer greater than 1 and less than 12, and a number of subcarriers with different numbers included in each PRB pair corresponds to an RE on the one or two OFDM symbols in the PRB pair set corresponding to the physical resource for transmitting the DM-RS.

Further, the DM-RS obtaining unit 212 is further configured to:

Further, when the DM-RS obtaining unit 212 divides 8 DM-RS antenna ports into 2 groups, the DM-RS obtaining unit 212 is further configured to:

Further, the DM-RS obtaining unit 212 is configured to:

Further, when the DM-RS obtaining unit 212 divides 8 DM-RS antenna ports into 4 groups, the DM-RS obtaining unit 212 is further configured to:

when A =3 and DM-RS is mapped to two OFDM symbols, determining that DM-RS REs corresponding to DM-RS antenna ports in a first group are 4 th, 8 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the second group are the 1 st, 5 th and 9 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the third group are the 3 rd, 7 th and 11 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS REs corresponding to the DM-RS antenna port in the fourth group are the 2 nd, the 6 th and the 10 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; or,

Further, the DM-RS obtaining unit 212 is further configured to:

when a =6 and DM-RS is mapped to one or two OFDM symbols: determining the DM-RS RE corresponding to each DM-RS antenna port is the 2 nd, 3 rd, 6 th, 7 th, 10 th and 11 th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair.

Further, the DM-RS obtaining unit 212 is configured to:

The scheme of the invention can be applied to NCT.

In conclusion, the beneficial effects of the invention include:

in the scheme provided by the embodiment of the invention, a network side determines physical resources for transmitting DM-RS in a current subframe, respectively maps DM-RS corresponding to each DM-RS antenna port in the current subframe to DM-RS RE corresponding to the DM-RS antenna port on the physical resources for transmitting DM-RS according to a DM-RS resource mapping mode of each DM-RS antenna port, and transmits the resource-mapped DM-RS to a terminal through the antenna port for transmitting DM-RS in the subframe on the physical resources for transmitting DM-RS in the subframe; the terminal determines physical resources used for transmitting user-specific demodulation reference signals DM-RS in a current subframe, acquires DM-RS corresponding to each DM-RS antenna port in the current subframe on a DM-RS RE corresponding to the physical resources used for transmitting DM-RS according to a DM-RS resource mapping mode of each DM-RS antenna port, and demodulates downlink data received on the corresponding antenna port according to the DM-RS corresponding to each DM-RS antenna port. The DM-RS RE corresponding to each DM-RS antenna port is the RE on one or two OFDM symbols which are different from the OFDM symbols where the synchronous signals are transmitted in the first N OFDM symbols in the subframe, so that the problem that DM-RS mapping resources and synchronous signal mapping resources are overlapped is avoided, the problem that downlink data cannot be transmitted in 6 PRBs in the middle of the system bandwidth in the synchronous signal transmission subframe is further avoided, and the resource utilization rate is improved.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for transmitting a user-specific demodulation reference signal (DM-RS), the method comprising:

2. The method of claim 1, wherein the maximum value of N is 6 for a normal cyclic prefix CP; for the extended CP, the maximum value of N is 5; or,

for normal CP and extended CP, the maximum value of N is 3.

3. The method of claim 1, wherein in a time division duplex, TDD, system, the subframe is a special subframe corresponding to special subframe configuration 9 under normal CP or a special subframe corresponding to special subframe configuration 7 under extended CP; or,

the subframe is a downlink subframe in a frequency division duplex FDD system; or,

in the TDD system, the subframe is a special subframe corresponding to other special subframe configurations except special subframe configuration 9 under normal CP, or is a special subframe corresponding to other special subframe configurations except special subframe configuration 7 under extended CP; or,

in the TDD system, the subframe is a special subframe corresponding to any special subframe configuration under a normal CP, or a special subframe corresponding to any special subframe configuration under an extended CP.

4. The method of claim 1, wherein if the subframe is a synchronization signal transmission subframe, a synchronization signal is transmitted on a 3 rd OFDM symbol in the subframe.

5. The method of claim 1, wherein the DM-RS REs corresponding to each DM-RS antenna port are consecutive or non-consecutive OFDM symbols when REs on two OFDM symbols of the first N OFDM symbols in the subframe that are different from the OFDM symbol on which the synchronization signal is transmitted; or,

when the DM-RS RE corresponding to each DM-RS antenna port is an RE on one OFDM symbol, which is different from the OFDM symbol where the synchronization signal is transmitted, in the first N OFDM symbols in the subframe, the one OFDM symbol is any one OFDM symbol, which is not the OFDM symbol where the synchronization signal is transmitted, in the first N OFDM symbols.

6. The method of claim 5, wherein the two OFDM symbols are the 1 st and 2 nd OFDM symbols in the subframe, or the 4 th and 5 th OFDM symbols in the subframe, or the 5 th and 6 th OFDM symbols in the subframe, or the 2 nd and 4 th OFDM symbols in the subframe, or the 4 th and 6 th OFDM symbols in the subframe, or any two discontinuous OFDM symbols in the 1 st, 2 nd, 4 th, 5 th and 6 th OFDM symbols in the subframe;

the one OFDM symbol is any one of a 1 st OFDM symbol, a 2 nd OFDM symbol, a 4 th OFDM symbol, a 5 th OFDM symbol, and a 6 th OFDM symbol in the subframe.

7. The method of claim 1, wherein the DM-RS REs corresponding to each DM-RS antenna port are REs corresponding to a number a of different numbered subcarriers included in each PRB pair in a set of PRB pairs corresponding to the physical resources for transmitting DM-RS, where a is an integer greater than 1 and less than 12, on the one or two OFDM symbols.

8. The method of claim 7, wherein when a maximum of 8 DM-RS antenna ports are supported, the DM-RS RE corresponding to each DM-RS antenna port is determined as follows:

9. The method of claim 8, wherein 8 DM-RS antenna ports are divided into 2 groups, each group containing 4 DM-RS antenna ports, the 4 DM-RS antenna ports in the same group corresponding to the same DM-RS RE; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; taking REs corresponding to the a subcarriers determined in each PRB pair on the one or two OFDM symbols as DM-RS REs corresponding to DM-RS antenna ports in a corresponding group in each PRB pair, which specifically includes:

the method comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are 12-b-a, 12-b +1-a, 12-b and 12-b +1 REs corresponding to one or two OFDM symbols in each PRBpair in the order of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the b-th, b + 1-th, b + a-th and b +1+ a-th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; wherein, when b =1, a =8 or 7 or 6 or 4 or 3 or 2, when b =2, a =6 or 5 or 3 or 2, and when b =3, a =4 or 2;

the method 2 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 5 th, 6 th, 11 th and 12 th REs corresponding to the one or two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high; the DM-RS R corresponding to the DM-RS antenna port in another group is the 3 rd, 4 th, 9 th and 10 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier number, or the 2 nd, 3 rd, 8 th and 9 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier number;

the method 4 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are 12-b-c +1-a, 12-b-c +1 and 12-b +1 REs corresponding to one or two OFDM symbols in each PRBpair in the order of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the b-th, b + c-th, b + a-th and b + c + a-th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; wherein b =1, c =3, a =6, or, b =1, c =2, a =4, or b =2, c =2, a = 4;

the method 5 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 2 nd, 5 th, 8 th and 11 th REs corresponding to one or two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 1 st, 4 th, 7 th, and 10 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair, or the 3 rd, 6 th, 9 th, and 12 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; or,

10. The method according to any of claims 7 to 9, wherein before the network side sends the resource-mapped DM-RS to the terminal through the antenna port for transmitting DM-RS in the subframe on the physical resource for transmitting DM-RS in the subframe, the method further comprises:

when A is not an integer multiple of 4 and DM-RS mapping is at two OFDM symbols:

for each DM-RS antenna port, taking 4 DM-RSs on two subcarriers adjacent to or closest to the two OFDM symbols on the DM-RS antenna port as a group, and respectively performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port; or,

when A is an integer multiple of 4:

and for each DM-RS antenna port, taking 4 DM-RSs on 4 subcarriers adjacent to or closest to each OFDM symbol mapped with the DM-RS on the DM-RS antenna port as a group, and respectively performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 4 corresponding to the antenna port.

11. The method of claim 8, wherein 8 DM-RS antenna ports are divided into 4 groups, each group containing 2 DM-RS antenna ports, and 2 DM-RS off-the-day ports in the same group correspond to the same DM-RS REs; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; when the REs corresponding to the a subcarriers determined in each PRB pair on the one or two OFDM symbols are used as the DM-RS antenna ports in the corresponding packet and are corresponding to the DM-RS REs in each PRB pair, the method specifically includes:

when a =3 and DM-RS is mapped to two OFDM symbols:

the DM-RS REs corresponding to the DM-RS antenna ports in the first group are the 4 th, 8 th and 12 th REs corresponding to the two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high;

the DM-RS REs corresponding to the DM-RS antenna ports in the second group are the 1 st, 5 th and 9 th REs corresponding to the two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high;

the DM-RS REs corresponding to the DM-RS antenna ports in the third group are the 3 rd, the 7 th and the 11 th REs corresponding to the two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high;

the DM-RS REs corresponding to the DM-RS antenna ports in the fourth group are the 2 nd, 6 th and 10 th REs corresponding to the two OFDM symbols in the order from the low to the high subcarrier numbers in each PRBpair; or,

the method 2 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna port in the first group are the corresponding b-th and b + 1-th REs on the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the second group are 12-b th and 12-b +1 th REs corresponding to one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the third group are the b + a th and b +1+ a th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; the DM-RS REs corresponding to the DM-RS antenna ports in the fourth group are 12-b-a and 12-b +1-a REs corresponding to the one or two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high; wherein b =1, a =2 or 3 or 4, or, b =2, a =2 or 3, or b =3, a = 2;

the method 3 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna port in the first group are the corresponding b-th and b + 1-th REs on the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the second group are the b + a th and b + a +1 th REs corresponding to the one or two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the third group are the b +2a th and b +2a +1 th REs corresponding to the one or two OFDM symbols in the order from the low to the high subcarrier numbers in each PRB pair; the DM-RS REs corresponding to the DM-RS antenna ports in the fourth group are the b +3a th and b +3a +1 th REs corresponding to the one or two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high; wherein a =2 and b is any integer from 1 to 5 including 1 and 5, or a =3 and b =1 or 2.

12. The method of claim 7, wherein when a maximum of 4 DM-RS antenna ports are supported, the 4 DM-RS antenna ports are divided into 2 groups, each group includes 2 DM-RS antenna ports, 2 DM-RS antenna ports in a same group correspond to the same DM-RS RE, and the DM-RS RE corresponding to each DM-RS antenna port is determined according to the following method:

13. The method of claim 7, wherein when a maximum of 2 DM-RS antenna ports are supported, the DM-RS RE corresponding to each DM-RS antenna port is the same, and the DM-RS RE corresponding to each DM-RS antenna port is determined as follows:

when a =4 and DM-RS is mapped to one or two OFDM symbols: the DM-RS REs corresponding to each DM-RS antenna port are the b-th, b + a-th, b +2 a-th and b +3 a-th REs corresponding to the one or two OFDM symbols in the order of the subcarrier numbers from low to high in each PRB pair, where a =1 and b is any integer from 1 to 9 including 1 and 9, or a =2 and b is any integer from 1 to 6 including 1 and 6, or a =3, b =1 or 2 or 3 or 4; or, the DM-RS REs corresponding to each DM-RS antenna port are the b-th, b + 1-th, b + a-th and b +1+ a-th REs corresponding to the one or two OFDM symbols in the order from the low subcarrier number to the high subcarrier number in each PRB pair, where a is any integer from 3 to 10, including 3 and 10, and b is any integer from 1 to (11-a), including 1 and (11-a); or,

14. The method according to any of claims 11 to 13, wherein before the network side sends the resource-mapped DM-RS to the terminal through the antenna port for transmitting DM-RS in the subframe on the physical resource for transmitting DM-RS in the subframe, the method further comprises:

when mapping DM-RS to two OFDM symbols:

for each DM-RS antenna port, taking 2 DM-RSs corresponding to the same subcarrier on the two OFDM symbols on the antenna port as a group, and performing spread spectrum processing on each group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port; or,

when A is an integer multiple of 2:

and for each DM-RS antenna port, taking 2 DM-RSs on the OFDM symbol mapped with the DM-RSs on the antenna port as a group, and performing spread spectrum processing on the group of DM-RSs by using an orthogonal sequence with the length of 2 corresponding to the antenna port.

15. A method for demodulating data, the method comprising:

16. The method of claim 15, wherein the maximum value of N is 6 for a normal cyclic prefix CP; for the extended CP, the maximum value of N is 5; or,

for normal CP and extended CP, the maximum value of N is 3.

17. The method of claim 15, wherein in a time division duplex TDD system, the subframe is a special subframe corresponding to special subframe configuration 9 under normal CP or a special subframe corresponding to special subframe configuration 7 under extended CP; or,

18. The method of claim 15, wherein if the subframe is a synchronization signal transmission subframe, further comprising:

and the terminal receives the synchronization signal on the 3 rd OFDM symbol in the subframe.

19. The method of claim 15, wherein the DM-RS REs for each DM-RS antenna port are consecutive or non-consecutive OFDM symbols when the REs on two OFDM symbols of the first N OFDM symbols in the subframe that are different from the OFDM symbol on which the synchronization signal is transmitted; or,

20. The method of claim 19, wherein the two OFDM symbols are the 1 st OFDM symbol and the 2 nd OFDM symbol in the subframe, or the 4 th OFDM symbol and the 5 th OFDM symbol in the subframe, or the 5 th OFDM symbol and the 6 th OFDM symbol in the subframe, or the 2 nd OFDM symbol and the 4 th OFDM symbol in the subframe, or the 4 th OFDM symbol and the 6 th OFDM symbol in the subframe, or any two discontinuous OFDM symbols among the 1 st, 2 nd, 4 th, 5 th, and 6 th OFDM symbols in the subframe;

21. The method of claim 15, wherein the DM-RS REs corresponding to each DM-RS antenna port are REs corresponding to a number a of different numbered subcarriers included in each PRB pair on the one or two OFDM symbols in a PRB pair set corresponding to the physical resource for transmitting the DM-RS, where a is an integer greater than 1 and less than 12.

22. The method of claim 21, wherein when a maximum of 8 DM-RS antenna ports are supported, the DM-RS RE corresponding to each DM-RS antenna port is determined as follows:

23. The method of claim 22, wherein 8 DM-RS antenna ports are divided into 2 groups, each group containing 4 DM-RS antenna ports, and the 4 DM-RS antenna ports in the same group correspond to the same DM-RS RE; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; taking REs corresponding to the a subcarriers determined in each PRB pair on the one or two OFDM symbols as DM-RS REs corresponding to DM-RS antenna ports in a corresponding group in each PRB pair, which specifically includes:

the method 2 comprises the following steps: the DM-RS REs corresponding to the DM-RS antenna ports in one group are the 5 th, 6 th, 11 th and 12 th REs corresponding to the one or two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high; the DM-RS REs corresponding to the DM-RS antenna ports in the other group are the 3 rd, 4 th, 9 th and 10 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier numbers, or the 2 nd, 3 rd, 8 th and 9 th REs corresponding to the one or two OFDM symbols in each PRB pair from low to high according to the subcarrier numbers;

24. The method according to any one of claims 21 to 23, wherein the terminal, according to a DM-RS resource mapping manner of each DM-RS antenna port, respectively obtains, at a corresponding DM-RS RE on the physical resource for transmitting DM-RS, a DM-RS corresponding to the DM-RS antenna port at each DM-RS antenna port in a current subframe, specifically includes:

when A is an integer multiple of 4:

25. The method of claim 22, wherein 8 DM-RS antenna ports are divided into 4 groups, each group containing 2 DM-RS antenna ports, and 2 DM-RS off-the-day ports in the same group correspond to the same DM-RS REs; for each group, determining A subcarriers with different numbers in each PRB pair, wherein the subcarriers determined for different groups are different; when the REs corresponding to the a subcarriers determined in each PRB pair on the one or two OFDM symbols are used as the DM-RS antenna ports in the corresponding packet and are corresponding to the DM-RS REs in each PRB pair, the method specifically includes:

when a =3 and DM-RS is mapped to two OFDM symbols:

26. The method of claim 21, wherein when a maximum of 4 DM-RS antenna ports are supported, the 4 DM-RS antenna ports are divided into 2 groups, each group includes 2 DM-RS antenna ports, 2 DM-RS antenna ports in a same group correspond to the same DM-RS RE, and the DM-RS RE corresponding to each DM-RS antenna port is determined according to the following method:

27. The method of claim 21, wherein when a maximum of 2 DM-RS antenna ports are supported, the DM-RS RE corresponding to each DM-RS antenna port is the same, and the DM-RS RE corresponding to each DM-RS antenna port is determined as follows:

28. The method according to any one of claims 25 to 27, wherein the terminal obtains, according to the DM-RS resource mapping manner of each DM-RS antenna port, a DM-RS corresponding to the DM-RS antenna port on the corresponding DM-RS RE on the physical resource for transmitting the DM-RS at each DM-RS antenna port in the current subframe, specifically includes:

when mapping DM-RS to two OFDM symbols:

when A is an integer multiple of 2:

29. A base station, comprising:

30. The base station of claim 29, wherein the DM-RS mapping unit is specifically configured to: for a normal Cyclic Prefix (CP), determining the maximum value of the N to be 6; for the extended CP, determining the maximum value of N to be 5; or,

31. The base station of claim 29, wherein the DM-RS mapping unit is specifically configured to: in a Time Division Duplex (TDD) system, determining that the subframe is a special subframe corresponding to special subframe configuration 9 under a normal CP or a special subframe corresponding to special subframe configuration 7 under an extended CP; or,

32. The base station of claim 29, wherein the transmission unit is further configured to:

33. The base station of claim 29, wherein the DM-RS mapping unit is specifically configured to: when the DM-RS RE corresponding to each DM-RS antenna port is the RE on two OFDM symbols which are different from the OFDM symbol on which the synchronous signal is transmitted in the first N OFDM symbols in the subframe, determining that the two OFDM symbols are continuous or discontinuous OFDM symbols; or,

34. The base station of claim 33, wherein the DM-RS mapping unit is further configured to: determining the two OFDM symbols to be a 1 st OFDM symbol and a 2 nd OFDM symbol in the subframe, or a 4 th OFDM symbol and a 5 th OFDM symbol in the subframe, or a 5 th OFDM symbol and a 6 th OFDM symbol in the subframe, or a 2 nd OFDM symbol and a 4 th OFDM symbol in the subframe, or a 4 th OFDM symbol and a 6 th OFDM symbol in the subframe, or any two discontinuous OFDM symbols in the 1 st, 2 nd, 4 th, 5 th and 6 th OFDM symbols in the subframe;

35. The base station of claim 29, wherein the DM-RS mapping unit is specifically configured to: and determining the DM-RS REs corresponding to each DM-RS antenna port, where a is an integer greater than 1 and less than 12, and a number of subcarriers with different numbers included in each PRB pair corresponds to an RE on the one or two OFDM symbols in the PRB pair set corresponding to the physical resource for transmitting the DM-RS.

36. The base station of claim 35, wherein the DM-RS mapping unit is further configured to:

37. The base station of claim 36, wherein when the DM-RS mapping unit divides 8 DM-RS antenna ports into 2 groups, the DM-RS mapping unit is further to:

38. The base station of any of claims 35 to 37, further comprising:

a first spreading unit, configured to, on a physical resource used for transmitting the DM-RS in the subframe, before the DM-RS after resource mapping is sent to the terminal through an antenna port used for transmitting the DM-RS in the subframe:

39. The base station of claim 36, wherein when the DM-RS mapping unit divides 8 DM-RS antenna ports into 4 groups, the DM-RS mapping unit is further to:

when A =3 and DM-RS is mapped to two OFDM symbols, determining that DM-RS REs corresponding to DM-RS antenna ports in a first group are 4 th, 8 th and 12 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RS RE corresponding to the DM-RS antenna port in the second group is the 1 st, 5 th and 9 th REs corresponding to the two OFDM symbols in each PRBpair according to the sequence of the subcarrier numbers from low to high; determining that the DM-RSRE corresponding to the DM-RS antenna port in the third group is the 3 rd, 7 th and 11 th REs corresponding to the two OFDM symbols in the sequence of the subcarrier numbers from low to high in each PRB pair; determining that the DM-RS REs corresponding to the DM-RS antenna port in the fourth group are the 2 nd, the 6 th and the 10 th REs corresponding to the two OFDM symbols in each PRB pair according to the sequence of the subcarrier numbers from low to high; or,

40. The base station of claim 35, wherein the DM-RS mapping unit is further configured to:

41. The base station of claim 35, wherein the DM-RS mapping unit is further configured to:

when the maximum 2 DM-RS antenna ports are supported, determining that DM-RS RE corresponding to each DM-RS antenna port is the same, and determining DM-RSRE corresponding to each DM-RS antenna port according to the following method:

42. The base station of any of claims 39 to 41, further comprising:

a second spreading unit, configured to, on the physical resource used for transmitting the DM-RS in the subframe, before the DM-RS after resource mapping is sent to the terminal through the antenna port used for transmitting the DM-RS in the subframe:

43. A terminal, characterized in that the terminal comprises:

44. The terminal of claim 43, wherein the DM-RS acquiring unit is specifically configured to: for a normal Cyclic Prefix (CP), determining the maximum value of the N to be 6; for the extended CP, determining the maximum value of N to be 5; or,

45. The terminal of claim 43, wherein the DM-RS acquiring unit is specifically configured to: in a Time Division Duplex (TDD) system, determining that the subframe is a special subframe corresponding to special subframe configuration 9 under a normal CP or a special subframe corresponding to special subframe configuration 7 under an extended CP; or,

46. The terminal of claim 43, wherein the DM-RS acquisition unit is further configured to:

47. The terminal of claim 43, wherein when the DM-RS RE corresponding to each DM-RS antenna port is an RE on two OFDM symbols of the first N OFDM symbols in the subframe that are different from the OFDM symbol on which the synchronization signal is transmitted, the DM-RS obtaining unit is specifically configured to: determining the two OFDM symbols to be continuous or discontinuous OFDM symbols; or,

when the DM-RS RE corresponding to each DM-RS antenna port is an RE on one OFDM symbol, which is different from the OFDM symbol where the synchronization signal is transmitted, in the first N OFDM symbols in the subframe, the DM-RS obtaining unit is specifically configured to: and determining the OFDM symbol as any one of the first N OFDM symbols except the OFDM symbol where the synchronous signal is transmitted.

48. The terminal of claim 47, wherein the DM-RS acquisition unit is further configured to: determining the two OFDM symbols to be a 1 st OFDM symbol and a 2 nd OFDM symbol in the subframe, or a 4 th OFDM symbol and a 5 th OFDM symbol in the subframe, or a 5 th OFDM symbol and a 6 th OFDM symbol in the subframe, or a 2 nd OFDM symbol and a 4 th OFDM symbol in the subframe, or a 4 th OFDM symbol and a 6 th OFDM symbol in the subframe, or any two discontinuous OFDM symbols in the 1 st, 2 nd, 4 th, 5 th and 6 th OFDM symbols in the subframe;

49. The terminal of claim 43, wherein the DM-RS acquiring unit is specifically configured to: and determining the DM-RS REs corresponding to each DM-RS antenna port, where a is an integer greater than 1 and less than 12, and a number of subcarriers with different numbers included in each PRB pair corresponds to an RE on the one or two OFDM symbols in the PRB pair set corresponding to the physical resource for transmitting the DM-RS.

50. The terminal of claim 49, wherein the DM-RS acquisition unit is further configured to:

51. The terminal of claim 50, wherein when the DM-RS acquisition unit divides 8 DM-RS antenna ports into 2 groups, the DM-RS acquisition unit is further configured to:

52. The terminal of any of claims 49-51, wherein the DM-RS acquisition unit is configured to:

53. The terminal of claim 50, wherein when the DM-RS acquisition unit divides 8 DM-RS antenna ports into 4 groups, the DM-RS acquisition unit is further configured to:

54. The terminal of claim 49, wherein the DM-RS acquisition unit is further configured to:

55. The terminal of claim 49, wherein the DM-RS acquisition unit is further configured to:

56. The terminal of any one of claims 53-55, wherein the DM-RS acquisition unit is configured to: