CN111786916A - Channel estimation method and device, terminal, and storage medium - Google Patents

Abstract

An embodiment of the present application discloses a channel estimation method, including: determining a resource block that carries a PDCCH in an OFDM symbol according to a resource allocation method of a control channel; determining at least two associated blocks according to a frequency domain position of the resource block; Wherein, in the frequency domain, the associated block is a resource block within a specific frequency domain range from the resource block; the pilot signal borne by the resource block and the signal borne by the at least two associated blocks The pilot signal is processed to obtain the channel estimation value of the pilot position in the resource block. The embodiments of the present application also provide a channel estimation apparatus, device, and storage medium.

Description

Channel estimation method and device, terminal, and storage medium

technical field

The present application relates to wireless technologies, and relates to, but is not limited to, a channel estimation method and device, a terminal, and a storage medium.

Background technique

Using the full bandwidth DMRS (Demodulation Reference Signal, demodulation reference signal) in CORESET (Control Resource Set) for channel estimation can effectively improve the channel estimation MSE (Mean Square Error, mean square error) performance, thereby improving the system. Bit error rate and throughput performance.

However, on some physical resource blocks of CORESET, the REG (Resource Element Group, resource element group) corresponding to the PDCCH may not be allocated, and demodulation and decoding do not need to be performed on these physical resource blocks. Perform channel estimation. Therefore, how to effectively utilize the resource allocation mode of the control channel specified in the current protocol and achieve a compromise between the channel estimation performance and the computational complexity is an urgent problem to be solved.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a channel estimation method, device, terminal, and storage medium, which can effectively utilize the resource allocation mode of the control channel specified in the current protocol, and improve the MSE performance of channel estimation under the premise of limited increase in system complexity.

The technical solutions of the embodiments of the present application are implemented as follows:

In a first aspect, an embodiment of the present application provides a channel estimation method, including:

Determine the resource block that carries the PDCCH in the OFDM symbol according to the resource allocation method of the control channel;

According to the frequency domain position of the resource block, at least two associated blocks are determined; wherein, in the frequency domain, the associated block is a block within a specific frequency domain range from the resource block;

The pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks are processed to obtain the channel estimation value of the pilot position in the resource block.

In a second aspect, an embodiment of the present application provides a channel estimation device, including:

a first determining module, configured to determine a resource block that carries the PDCCH in each OFDM symbol according to the resource allocation mode of the control channel;

A second determining module, configured to determine at least two associated blocks according to the frequency domain positions of the resource blocks; wherein, in the frequency domain, the associated blocks are blocks located within a specific frequency domain range from the resource block ;

The processing module is configured to process the pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks to obtain the channel estimation value of the pilot position in the resource block.

In a third aspect, an embodiment of the present application provides a terminal, including a memory and a processor, where the memory stores a computer program that can be run on the processor, and when the processor executes the program, the above channel estimation method is implemented. step.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements the steps in the above channel estimation method.

The beneficial effects brought by the technical solutions provided in the embodiments of the present application include at least:

In the embodiment of the present application, firstly, the resource block corresponding to the PDCCH in the OFDM symbol is determined; then, according to the frequency domain position of the resource block, at least two associated blocks are determined; finally, the pilot signal carried by the resource block is determined. process with the pilot signals carried by the at least two associated blocks to obtain the channel estimation value of the pilot position in the resource block; in this way, the pilot signal participating in the channel estimation processing is determined by the resource block that currently needs to be detected. The pilot signal carried on the network is extended to the pilot signal jointly carried by the resource block that needs to be detected and the corresponding associated block to ensure that the channel estimation results at the resource block that needs to be detected in the subsequent processing are the results obtained by interpolation , to improve the MSE performance of channel estimation.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, under the premise of no creative work, other drawings can also be obtained from these drawings, wherein:

FIG. 1 is a schematic diagram of the architecture of a communication system provided by an embodiment of the present application;

Fig. 2 is the resource distribution pattern of wideband PDCCH DMRS in the related art;

FIG. 3 is an optional schematic flowchart of a channel estimation method provided by an embodiment of the present application;

FIG. 4 is another optional schematic flowchart of the channel estimation method provided by the embodiment of the present application;

FIG. 5 is another optional schematic flowchart of the channel estimation method provided by the embodiment of the present application;

6 is a schematic diagram of a PDCCH DMRS channel estimation process provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of channel estimation MSE performance results provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of the composition and structure of a channel estimation apparatus provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of a hardware entity of a terminal according to an embodiment of the present application.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of the present application, but not all of the embodiments. The following examples are used to illustrate the present application, but are not intended to limit the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

Before the detailed introduction of the channel estimation method provided by the embodiments of the present application, the communication systems and terms involved in the embodiments of the present application are briefly introduced.

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of a communication system provided by an embodiment of the present application, and exemplarily shows a network device 110 and a terminal 120 . In some embodiments, the communication system may include multiple network devices, and the coverage of each network device may include other numbers of terminals, which are not limited in this embodiment of the present application.

The network device 110 in the communication system can provide communication coverage for a specific geographic area, and can communicate with the terminals 120 located in the coverage area. In some embodiments, the network device 110 may be an eNB or an eNodeB (Evolutional Node B, evolved network device) in an LTE system, or a wireless controller in a CRAN (Cloud Radio Access Network, cloud radio access network), Or the network device 110 may be a mobile switching center, a relay station, an access point, an in-vehicle device, a wearable device, a hub, a switch, a bridge, a router, a network device in a 5G network, or a network device in a future communication system.

The communication system also includes at least one terminal 120 located within the coverage of the network device 110 . As used herein, "terminal" includes, but is not limited to, connection via wireline, such as via PSTN (Public Switched Telephone Networks), DSL (Digital Subscriber Line), digital cable, direct cable connection; and /or another data connection/network; and/or via a wireless interface, eg, for cellular networks, WLAN (Wireless Local Area Network), networks such as DVB-H (Digital Video Broadcasting Handheld) Digital TV network, satellite network, AM-FM (Amplitude Modulation-Frequency Modulation) broadcast transmitter; and/or a device of another terminal that is configured to receive/transmit communication signals; and/or IoT (Internet of Things) , IoT) devices. A terminal arranged to communicate through a wireless interface may be referred to as a "wireless communication terminal", "wireless terminal" or "mobile terminal". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; PCS (Personal Communications System) terminals that can combine cellular radio telephones with data processing, facsimile, and data communication capabilities; can include radio telephones, pagers, Internet/Intranet PDA (Personal Digital Assistant) with internet access, web browser, memo pad, calendar and/or GPS (Global Positioning System) receiver; and conventional laptop and/or palmtop receivers or other electronic devices including radiotelephone transceivers. A terminal may refer to an access terminal, UE (User Equipment, user equipment), a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a user device. The access terminal can be a cellular phone, a cordless phone, a SIP (Session Initiation Protocol) phone, a WLL (Wireless Local Loop) station, a PDA, a handheld device with wireless communication capabilities, a computing device, or a connection To other processing devices of wireless modems, in-vehicle devices, wearable devices, terminals in the 5G network or terminals in the future evolved PLMN (Public Land Mobile Network, Public Land Mobile Network), etc. For the convenience of description, the devices mentioned above are collectively referred to as terminals.

PDCCH (Physical Downlink Control Channel, physical downlink control channel) is mainly used to transmit DCI (Downlink Control Information, downlink control information) and UL Grant (Uplink Grant, uplink grant), so that the terminal can correctly receive PDSCH (Physical Downlink Shared Channel, physical downlink) shared channel) and allocate uplink resources for PUSCH (Physical Uplink Shared Channel, physical uplink shared channel).

A PDCCH is a set of physical resource elements, and a PDCCH may include one or more CCEs (Control Channel Element, control channel elements), where a CCE is the smallest resource unit for PDCCH transmission, occupying 6 REGs in the frequency domain. The actual physical resource to which a CCE is mapped includes 72 REs (Resource Element, resource element), that is, 6 RBs (Resource Block, resource block). Among them, 18 REs are used for demodulation reference signals, and 54 REs are used for DCI information transmission.

The REG is a physical resource unit that occupies one OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) symbol in the time domain and occupies one resource block (including 12 consecutive subcarriers in the frequency domain) in the frequency domain. In one REG, 3 REs are used for mapping PDCCH demodulation reference signals, and 9 REs are used for mapping DCI REs. The REs used for mapping the PDCCH demodulation reference signals are evenly distributed in the REG, and are located in subcarriers numbered 1, 5, and 9 in the REG.

The number of RE resources used as DMRS in each REG of each OFDM symbol in the NR (New Radio, new air interface) PDCCH is the same, and each REG of each OFDM symbol has 3 REs as DMRS resources.

A REG Bundle (REG bundle) is a plurality of REGs that are consecutive in the time domain and/or frequency domain. The number of REGs that constitute a REG Bundle may be 1, 2, 3, and 6, and the PDCCH mapped in one REG Bundle Using the same precoding, that is, the terminal can use the demodulation reference signals of all REGs in the REG Bundle to perform joint channel estimation in the time domain and/or frequency domain, which improves the channel estimation accuracy. The number of REGs included in the REG Bundle in the time domain and frequency domain is related to the configuration of the number of CORESET time domain symbols and the size of the REG Bundle.

CORESET indicates the number of symbols occupied by the PDCCH in the time domain and the number of RBs contained in the frequency domain. A CORESET is a time and frequency resource on which the terminal attempts to decode possible PDCCHs using one or more search spaces. The size and time-frequency location of CORESET are semi-statically configured by the network. It includes a plurality of physical resource blocks in the frequency domain, and includes 1-3 OFDM symbols in the time domain, and can be located at any position in the time slot. The CORESET frequency domain resource needs to match the frequency domain size of the REG Bundle as much as possible, thereby reducing the resource fragmentation of the PDCCH mapped in the CORESET. The granularity of CORESET frequency domain resource configuration is set to 6 REGs, which can be applied to the configuration of all REG Bundles. The time-frequency resources occupied by CORESET are semi-statically configured by high-level parameters, dynamic signaling is not supported, and data channels can be mapped in CORESET resources

Each CORESET has a related CCE to REG mapping method, which is described by the concept of REG Bundle. The REG Bundle means that the terminal can consider that the precoding of a group of REGs is the same, which helps to improve the performance of channel estimation. The CCE-to-REG mapping mode can be divided into interleaved mode and non-interleaved mode. The implementation of non-interleaved mapping is relatively simple, and the REG bundle size is fixed at 6, so that the terminal can consider that the precoding is unchanged on the entire CCE. 6 consecutive REGs are multiplied to form a CCE.

As part of the PDCCH reception process, the terminal needs to use the reference signals associated with the candidate PDCCHs for channel estimation. The PDCCH has its own demodulation reference signal, and the pseudo-random sequence corresponding to the demodulation reference signal is transmitted on the resource block where the PDCCH is sent. The demodulation reference signal of a candidate PDCCH is mapped to one of every 4 subcarriers in the REG, and the density of this reference signal is higher than that of LTE (the density of LTE is 1/6).

When the terminal attempts to decode a specific candidate PDCCH that occupies several CCEs, the terminal first designs the size of the REG Bundle, and then performs channel estimation. Considering that the network may use different precodings among different REG Bundles, channel estimation is performed separately for each REG Bundle. Generally speaking, this bundling can already provide better PDCCH channel estimation performance. But it is possible for the network to configure the terminal to assume that all consecutive resource blocks within a CORESET use the same precoding. In this case, the terminal can perform frequency domain interpolation to obtain better channel estimation performance. The terminal can use reference signals other than the PDCCH to estimate the channel.

Not all PDCCH signals are placed in CORESET, but only in CCE, and RBs with DMRS signals do not necessarily have PDCCH signals. The DMRS signal fills all CORESET only for accurate channel estimation. When deciphering the data, the entire CORESET should be taken out, then all the DMRS signals should be taken out for channel estimation and signal detection, and then all possible positions of the CCE starting position should be calculated for blind detection.

When each terminal of the PDCCH performs blind detection in the search space to receive its own DCI information, it can do channel estimation in each REG Bundle to obtain more accurate channel parameters, or it can do channel estimation in the entire PDCCH bandwidth, that is, without Channel estimation is limited to the bandwidth within its own CORESET.

The method for estimating a physical downlink control channel provided by the embodiment of the present application can be applied to a wireless communication system. The wireless communication system may adopt a fifth-generation (5th Generation, 5G) mobile communication technology system (hereinafter referred to as a 5G system).

Next, in order to facilitate the understanding of the solutions of the embodiments of the present application, the PDCCH channel estimation processing method in the related art is analyzed and explained:

In the 5G NR protocol design of 3GPP, for the DMRS of PDCCH, when the precoderGranularity (precoding granularity) parameter of CORSET in the RRC (Radio Resource Control, Radio Resource Control) configuration is configured as allContiguousRB (all continuous resource blocks), PDCCH DMRS solution The tuning reference signal is mapped to the entire CORSET, as shown in Figure 2 below. In this way, when the pilot points of the channel estimation are filtered in the frequency domain, the full-bandwidth DMRS can be used for processing, thereby improving the denoising performance of the channel estimation. When the precoderGranularity of CORSET in the RRC configuration is configured as sameAsREG-bundle (bundled with REG-bundle, resource element group), this scenario is equivalent to the narrowband mapping mentioned above, that is, PDCCH DRMS is only mapped on the REG with PDCCH, At this time, frequency domain channel estimation is usually performed inside a REG bundle (Resource Element Group bundle, resource element group bundle), that is, frequency domain filtering is performed by using the DMRS carried on all resource blocks in the REG Bundle.

When the parameter precoderGranularity in the RRC configuration is configured as allContiguousRB, using the full-bandwidth DMRS for channel estimation can effectively improve the channel estimation MSE performance, thereby improving the system bit error rate and throughput performance.

However, on some PRBs (Physical RBs, physical resource blocks) of CORSET, REGs mapped with PDCCH may not be allocated, and demodulation and decoding do not need to be performed on these PRBs, so there is no need to perform channels. estimate. When the bandwidth of CORSET itself is large, and the REGs that need to be detected in CORSET are few, if channel estimation is performed on all PRBs of COREST, the channel estimation process on the REGs that do not need to be detected will cause the system to be complicated. Waste of power and power consumption.

For example, when the CORESET bandwidth is 270 PRBs and the CORESET duration (control resource set duration) is 3 OFDM symbols (symbols), according to the protocol, the REG corresponding to the PDCCH that may exist in a single symbol can occupy a maximum of 112 PRBs. When all 270 PRBs are used for frequency-domain filtering, the increase in system complexity and power consumption is 1.4 times that of frequency-domain filtering for 112 PRBs. When the number of REGs allocated to the PDCCH is less than 112 PRBs, the system complexity and power consumption caused by using all 270 PRBs for filtering and denoising will increase as the number of REGs decreases.

Therefore, how to effectively utilize the resource allocation mode of the control channel specified by the current protocol is particularly important to achieve a compromise between the channel estimation performance and the computational complexity.

The embodiment of the present application provides a channel estimation method, which is applied to a terminal and can improve channel estimation performance on the premise of limited increase in system complexity. The functions implemented by the method can be implemented by the processor in the terminal calling program codes, and of course the program codes can be stored in a computer storage medium. It can be seen that the terminal includes at least a processor and a storage medium. FIG. 3 is an optional schematic flowchart of a channel estimation method provided by an embodiment of the present application. As shown in FIG. 3 , the method at least includes the following steps:

Step S310, according to the resource allocation mode of the control channel, determine the resource block that carries the PDCCH in the OFDM symbol.

Here, the resource allocation manner of the control channel includes the resource allocation manner of the uplink control channel and the resource allocation manner of the downlink control channel.

In some possible embodiments, the resource allocation mode of the control channel may be embodied as a pilot pattern, which represents the transmission rule of the pilot signal in time and/or space, frequency, and code channel, and may be represented by a graph, a table, or a sequence, etc. to express. The pilot pattern can be described by a series of parameters, such as Tcycle (the period of the pilot pattern), Tburst (the length of time for sending the pilot in each cycle), and Toffset (the time of the pilot relative to the start of a reference time system) offset). The parameters Tcycle, Tburst, and Toffset can be used to specify the transmission rule of a pilot signal in time.

In some possible embodiments, the resource allocation manner of the control channel may be understood as the time-frequency distribution of the reference signal on the physical resource, such as the time-frequency distribution of the PDCCH DMRS on the physical resource. It should be noted that the resource positions of the PDCCH DMRS are located on subcarriers numbered 1, 5, and 9 in one REG. Among them, the sequence of PDCCH DMRS can be generated according to the slot index, OFDM symbol index and cell ID; in addition, NR also supports the generation of PDCCH DMRS sequence without cell ID, and the generation parameters of the DMRS sequence can be configured by high-level parameters. PDCCH DMRS sequences are dedicated to channel estimation for a specific terminal and are only transmitted on resource blocks allocated to that terminal.

Here, the resource block carrying the PDCCH is the REG to which the PDCCH is mapped in the CORESET. It should be noted that the PDCCH here corresponds to several consecutive resource blocks in physical resources. In the implementation process, the terminal uses the resource allocation manner and resource mapping distribution of the control channel configured by the network to determine multiple consecutive resource blocks occupied by the PDCCH in each OFDM symbol. The following embodiments of the present application only describe how to perform channel estimation on a single resource block. In the case of multiple continuous resource blocks occupied by the PDCCH, each resource block in the multiple continuous resource blocks may be processed separately.

It is worth noting that the resource mapping of PDCCH DMRS supports both narrowband mapping and wideband mapping. Under narrowband mapping, PDCCH DMRS is only mapped on REGs with PDCCH; under wideband mapping, PDCCH DRMS is mapped on continuous resource blocks containing PDCCH.

It should be noted that the data of PDCCH in 5G NR is all placed in CORESET, but not all CORESET is full of PDCCH data, because PDCCH is aggregated from several CCEs, and only CCEs have PDCCH data. The terminal determines the resource block corresponding to the PDCCH according to the correspondence between a CCE index sent by the network device and the REG Bundle index.

Step S320: Determine at least two associated blocks according to the frequency domain positions of the resource blocks.

Here, in the frequency domain, the associated block is a block within a certain frequency domain range from the resource block. An association block may include one resource block or multiple resource blocks. Exemplarily, several resource blocks outside the REGBundle where the resource block is located may be used as associated blocks, or several resource blocks adjacent to the resource block in the frequency domain may be used as associated blocks.

Here, the resource block is any resource block corresponding to the physical resources of the PDCCH. When the REG Bundle contains multiple consecutive resource blocks, the corresponding resource block is determined according to the frequency domain position of each resource block. At least two associated blocks.

Step S330: Process the pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks to obtain the channel estimation value of the pilot position in the resource block.

Here, the pilot signal is a pre-defined reference signal, which is a special signal placed in the transmission data. The reference signal occupies a specific time-frequency resource unit and is used for channel estimation, channel measurement, channel sounding or channel demodulation. The NR standard specifies several different reference signals and different transmission modes, which are used for reception in different scenarios to obtain accurate channel state information. The pilot signal in this embodiment of the present application may be a PDCCH DMRS.

Here, the pilot location is the frequency location where the REs mapping the pilot signals in each resource block are located. In an example, the REs used for mapping the PDCCH DMRS are evenly distributed in the REG, and the numbers in the REG are 1, 5, 9 subcarriers.

It should be noted that the embodiment of the present application proposes a sliding filtering scheme based on the traditional fixed filtering scheme, that is, the resource block carrying the PDCCH and the DMRS carried on the associated block are used for processing, which increases the channel estimation performance while increasing a small amount of computational complexity.

In the embodiment of the present application, firstly, the resource block carrying the PDCCH in the OFDM symbol is determined; then, according to the frequency domain position of the resource block, at least two associated blocks are determined; finally, the pilot signal carried by the resource block is determined. process with the pilot signals carried by the at least two associated blocks to obtain the channel estimation value of the pilot position in the resource block; in this way, the pilot signal participating in the channel estimation processing is determined by the resource block that currently needs to be detected. The pilot signal carried on the network is extended to the pilot signal jointly carried by the resource block that needs to be detected and the corresponding associated block to ensure that the channel estimation results at the resource block that needs to be detected in the subsequent processing are the results obtained by interpolation , to improve the MSE performance of channel estimation.

FIG. 4 is an optional schematic flowchart of a channel estimation method provided by an embodiment of the present application. As shown in FIG. 4 , the method includes:

Step S410, according to the resource allocation mode of the control channel, determine the resource block that carries the PDCCH in the OFDM symbol.

Here, the resource allocation mode of the control channel is understood as the transmission rule of the pilot signal in time and/or space, frequency, and code channel, which can be expressed by a graph, a table, or a sequence. The resource allocation mode of the control channel can be described by a series of parameters, such as the cycle of the resource allocation mode of the control channel, the time length of sending the pilot frequency in each cycle, and the time offset of the pilot frequency relative to the start time of a certain reference time system. Wait.

Here, the resource block carrying the PDCCH is the REG to which the PDCCH is mapped in the CORESET. It should be noted that the PDCCH here corresponds to several consecutive resource blocks in physical resources. The terminal uses the resource allocation mode and resource mapping distribution of the control channel configured by the network to determine multiple consecutive resource blocks occupied by the PDCCH in each OFDM symbol.

Step S420: Determine the resource blocks adjacent to both sides of the frequency domain position of the resource block as the associated block.

Here, the associated block is a resource block adjacent to the resource block on both sides in the frequency domain, that is, the resource block and the corresponding associated block are consecutive resource blocks in the frequency domain, for example, the resource block is RB ₀ , the corresponding associated block may include several symmetric resource blocks adjacent to both sides of the resource block RB ₀ , or may be asymmetric several resource blocks adjacent to both sides of the resource block RB ₀ .

Exemplarily, the associated block of RB ₀ includes RB _-1 at the high frequency domain position adjacent to RB ₀ and RB ₁ at the low frequency domain position adjacent to RB ₀ ; or, the associated block of RB ₀ includes RB ₀ The RB _-2 and RB _-1 in the adjacent high frequency frequency domain positions also include RB ₁ in the low frequency frequency domain position adjacent to RB ₀ , and so on.

In some embodiments, the above-mentioned manner of determining the associated block may be implemented by the following steps:

Step S4201: Determine M high frequency frequency domain positions and N low frequency frequency domain positions adjacent to the frequency domain position where the resource block is located.

Here, several frequency domain positions adjacent to the frequency domain position where the resource block is located are respectively determined, including M high frequency frequency domain positions and N low frequency frequency domain positions. Wherein, both the M and the N are greater than or equal to 1. For example, M is 1, N is 1, or M is 2, N is 1, etc.

Step S4202: Use the M resource blocks in the high frequency frequency domain positions and the N resource blocks in the low frequency frequency domain positions as the associated blocks.

Here, a corresponding resource block is distributed in each frequency domain position, and the associated block corresponding to the resource block is finally determined by determining the frequency domain position satisfying a specific range.

In some embodiments, the M is the same as the N, that is, M is taken as 2 and N is taken as 2, so as to ensure that the result of channel estimation on the pilot signal carried by the resource block is the result of interpolation.

Step S430: Process the pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks to obtain the channel estimation value of the pilot position in the resource block.

In some embodiments, the pilot signal is distributed on resource blocks mapped with PDCCH and resource blocks without PDCCH mapping in the CORESET; wherein the resource blocks mapped with PDCCH and the resource blocks without PDCCH are mapped The resource blocks are contiguous in the frequency domain.

Here, the resource blocks to which the pilot signal, namely the PDCCH DRMS is mapped, include both the resource blocks to which the PDCCH is mapped and the resource blocks to which the PDCCH is not mapped, and the resource blocks to which the PDCCH is mapped and the resource blocks to which the PDCCH is not mapped are consecutive in the frequency domain .

In some embodiments, all resource blocks within the CORESET described above use the same precoding.

Here, the precoding granularity of the above CORESET is all consecutive resource blocks, and channel estimation can be performed on all resource blocks of the CORESET by using a DMRS with a full bandwidth. The channel estimation accuracy is improved by increasing the number of demodulated PDCCH DMRSs. Because the terminal can use the PDCCH and the PDCCH DMRS in its adjacent RBs to perform joint channel estimation in time domain and frequency domain under wideband mapping, the quality of channel estimation is improved.

FIG. 5 is an optional schematic flowchart of the channel estimation method provided by the embodiment of the present application. As shown in FIG. 5 , the method includes at least the following steps:

Step S510, according to the resource allocation mode of the control channel, determine the resource block that carries the PDCCH in the OFDM symbol.

Step S520: Determine the resource blocks adjacent to both sides of the frequency domain position of the resource block as associated blocks.

Here, in the frequency domain, the associated block is a block that satisfies a specific frequency domain range with the frequency domain position where the resource block is located. Exemplarily, several resource blocks outside the REG Bundle where the resource block is located may be used as associated blocks, or several resource blocks adjacent to the resource block in the frequency domain may be used as associated blocks.

Here, the resource blocks include all resource blocks in the REG Bundle corresponding to the PDCCH, and in the implementation process, the associated block corresponding to each resource block is determined.

Step S530: Process the pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks to obtain the channel estimation value of the pilot position in the resource block.

Here, the pilot location is a specific subcarrier on the resource block. The channel estimation value of the pilot position is the channel estimation value at the subcarrier where the PDCCH DMRS signal is located.

It should be noted that the basic process of the pilot-based channel estimation method is to insert the pilot at the appropriate position of the transmitting end, and the receiving end uses the pilot to recover the channel information H of the pilot position, and then uses a specific processing method (such as interpolation. , filtering, transforming, etc.) to obtain the channel information H of all time periods. That is to say, the channel estimation process for PDCCH is that the network device inserts a certain number of DMRS on a specific time-frequency domain resource, and the terminal obtains the frequency domain channel on the entire subframe through the frequency domain channel estimation and interpolation algorithm for the DMRS position. response.

Here, a possible implementation of the process of processing the pilot signal is to use the conjugate multiplication of the locally generated DMRS signal and the received DMRS signal to obtain the PDCCH channel at the subcarrier where the DMRS signal is located. Estimation; another possible implementation is to first perform frequency domain filtering and denoising on the DMRS signal, for example, to obtain the channel estimation value at the effective sub-carrier through the Wiener filtering algorithm.

Here, after obtaining the channel estimation value of the sub-carrier where the DMRS signal is located, in order to obtain the channel estimation value of the sub-carrier where the non-DMRS signal is located, it is necessary to measure the channel estimation value of the sub-carrier where the DMRS signal is located in the frequency domain and time domain of the time-frequency resource respectively. The channel estimation value at the subcarrier is further linearly interpolated to achieve the purpose of accurately estimating the PDCCH channel estimation value.

Step S540: Interpolate the channel estimation value of the pilot position in at least one of the resource blocks to obtain the channel estimation result of the PDCCH.

Here, for the case where the PDCCH corresponds to multiple resource blocks on the physical resource, after obtaining the channel estimation values of the pilot positions in each resource block respectively, these channel estimation values are interpolated to obtain the final PDCCH channel estimation result.

The above channel estimation method will be described below with reference to a specific embodiment. However, it should be noted that this specific embodiment is only for better description of the present application, and does not constitute an improper limitation of the present application.

In the existing 5G NR protocol, when the precoderGranularity parameter of CORSET in the RRC configuration is configured as allContiguousRB, the PDCCH DMRS will be mapped to the entire CORSET, that is, all REs with indexes 1, 5, and 9 in the CORESET carry DMRS signals. The REG bundle part in CERESET is mapped with PDCCH, and the REG bundle part needs to be detected, including demodulation and decoding.

This technical solution takes the REG bundle as the center, and extends the DMRS participating in the filtering to several RBs outside the REG bundle to be detected for frequency domain filtering, so as to ensure that during the filtering process, the channel estimation results of the PRBs in the REG bundle are all internal Interpolate the obtained result, thereby effectively improving the MSE performance of channel estimation, thereby achieving the effect of improving the bit error rate and throughput performance of the system.

FIG. 6 is a schematic diagram of a PDCCH DMRS channel estimation process provided by an embodiment of the present application. The left side of FIG. 6 represents the DMRS signal distribution of all PDCCHs in a CORESET, and the gray part shows the REGBundle corresponding to a certain PDCCH#n. The right side of Fig. 6 shows the frequency domain filtering scheme of PDCCH#n on one OFDM symbol. The channel estimation process for PRB ₀ , PRB ₁ , and PRB ₂ included in the REG Bundle corresponding to PDCCH#n is described as follows:

For PRB ₀ , as shown on the right side of Figure 6, the first group of pilot sequences is used for frequency domain filtering to obtain the channel estimation result of _{PRB 0} ; It can be _seen that _{PRB 0} is in the _middle of the _first group of pilot sequences in the frequency domain.

For PRB ₁ , as shown on the right side of Figure 6, the second group of pilot sequences is used for frequency domain filtering to obtain the channel estimation result of _{PRB 1 ;} The corresponding PDCCH DMRSs on PRB ₀ /PRB ₁ /PRB ₂ /PRB ₃ are composed, and it can be seen that in the frequency domain, PRB ₁ is in the middle of the second group of pilot sequences.

For PRB ₂ , as shown on the right side of FIG. 6 , the third group of pilot sequences is used for frequency domain filtering to obtain the channel estimation result of PRB ₂ ; the third group of pilot sequences is composed of continuous PRB ₀ /PRB ₁ /PRB ₂ /PRB ₃ /PRB ₄ is composed of the corresponding PDCCH DMRS, it can be seen that in the frequency domain, PRB ₂ is in the middle of the third group of pilot sequences.

After the PDCCH DMRS filtering is performed using the filtering scheme provided in the embodiment of the present application, all channel estimation positions output by the frequency domain filtering are the results of interpolation. Compared with the scheme of channel estimation within the REG bundle, the MSE performance of channel estimation is greatly improved. FIG. 7 is a schematic diagram of channel estimation MSE performance results provided by an embodiment of the present application. It can be seen from FIG. 7 that when frequency domain filtering is extended from 3RB fixed filtering to 5RB sliding filtering, when the SNR is around -5dB, the channel estimation MSE The performance gain is about 5dB. And the channel estimation MSE gain will continue to increase as the number of RBs participating in filtering increases.

When the CORESET bandwidth is 270 PRBs and the CORESET duration is 3 OFDM symbols, the REGs that may exist in a single symbol can occupy a maximum of 112 PRBs. Assuming that the filtering process of each PRB is extended from 3RB fixed filtering to 5RB sliding filtering, the number of PRBs involved in the calculation is 112/3*5=187, which saves 30% of the calculation amount compared to the full bandwidth calculation. When the number of allocated REGs is less than 112 PRBs, the computational complexity of the saved system will be greater than 30%.

In the embodiment of the present application, the DMRS that can be used in the system is effectively used, and the sliding filtering scheme is used, that is, the pilot DMRS participating in the filtering is extended to several PRBs outside the area that needs to be detected, so as to ensure that in the process of filtering, it is necessary to detect ( The channel estimation results at the PRBs of demodulation and decoding) are all obtained by interpolation, so that the channel estimation performance can be improved under the premise of limited increase in system complexity.

Based on the foregoing embodiments, the embodiments of the present application further provide a channel estimation apparatus. The apparatus includes each module included and each unit included in each module, which can be implemented by a processor in a terminal; of course, it can also be Realized by logic circuit; in the process of implementation, the processor can be CPU (Central Processing Unit, central processing unit), MPU (Micro Processing Unit, microprocessor), DSP (Digital Signal Processor, digital signal processor) or FPGA (Field Programmable Gate Array, Field Programmable Gate Array) and so on.

FIG. 8 is a schematic structural diagram of a channel estimation apparatus provided by an embodiment of the present application. As shown in FIG. 8 , the apparatus 800 includes a first determination module 801, a second determination module 802, and a processing module 803, wherein:

The first determining module 801 is configured to determine, according to the resource allocation mode of the control channel, the resource block that carries the PDCCH in the OFDM symbol;

The second determining module 802 is configured to determine at least two associated blocks according to the frequency domain positions of the resource blocks; wherein, in the frequency domain, the associated blocks are located in a specific frequency domain range away from the resource blocks block within;

The processing module 803 is configured to process the pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks to obtain the channel estimation value of the pilot position in the resource block.

In some embodiments, the second determining module is further configured to determine the resource blocks adjacent to both sides of the frequency domain position of the resource block as the associated blocks.

In some embodiments, the second determining module further includes a first determining sub-module and a second determining sub-module, wherein: the first determining sub-module is configured to determine the frequency domain position where the resource block is located The adjacent M high frequency frequency domain positions and N low frequency frequency domain positions; wherein, the M and the N are both greater than or equal to 1; the second determination sub-module is used for the M high frequency frequency domain positions The resource blocks at the location and the resource blocks at the N low-frequency frequency domain locations are used as the associated blocks.

In some embodiments, the M is the same as the N.

In some embodiments, the apparatus 800 further includes an interpolation module, configured to interpolate the channel estimation value of the pilot position in at least one of the resource blocks to obtain the channel estimation result of the PDCCH.

In some embodiments, the resource block carrying the PDCCH is a group of resource elements mapped with the PDCCH in the CORESET.

In some embodiments, all resource blocks within the CORESET use the same precoding.

In some embodiments, the pilot signal is distributed on resource blocks mapped with PDCCH and resource blocks not mapped with PDCCH in the CORESET; wherein, the resource blocks mapped with PDCCH and the non-mapped resource blocks Resource blocks with PDCCH are contiguous in the frequency domain.

It should be pointed out here that the descriptions of the above apparatus embodiments are similar to the descriptions of the above method embodiments, and have similar beneficial effects to the method embodiments. For technical details not disclosed in the device embodiments of the present application, please refer to the descriptions of the method embodiments of the present application for understanding.

Correspondingly, based on the same technical concept, an embodiment of the present application provides a terminal for implementing the channel estimation method described in the foregoing method embodiment. FIG. 9 is a schematic diagram of a hardware entity of a terminal provided by an embodiment of the present application. As shown in FIG. 9 , the hardware entity of the terminal 900 includes: a processor 901 , a receiver 902 , a transmitter 903 , a memory 904 and a bus 905 . It should be noted that FIG. 9 is only an exemplary architecture diagram. In addition to the functional units shown in FIG. 9 , the network architecture may further include other functional units, which are not limited in this embodiment of the present application.

The processor 901 includes one or more processing cores, and the processor 901 executes various functional applications and information processing by running software programs and modules.

The receiver 902 and the transmitter 903 may be implemented as a communication component, which may be a communication chip.

The memory 904 is connected to the processor 901 through the bus 905 .

The memory 904 can be used to store a computer program, and the processor 901 is used to execute the computer program, so as to implement each step of the channel estimation method performed by the terminal in the above method embodiments.

Additionally, memory 904 may be implemented by any type or combination of volatile or non-volatile storage devices including, but not limited to: magnetic or optical disks, EEPROM (electrically erasable) Programmable Read Only Memory), EPROM (Erasable Programmable Read Only Memory), SRAM (Static Anytime Access Memory), ROM (Read Only Memory), Magnetic Memory, Flash Memory, PROM (Programmable Read Only Memory) .

In an exemplary embodiment, the terminal includes a processor 901 and a memory 904, and the processor is configured to invoke a computer program stored in the memory 904 to execute the channel estimation method in the method embodiment, including: according to the control The resource allocation method of the channel is to determine the resource block that carries the PDCCH in the OFDM symbol; according to the frequency domain position of the resource block, at least two associated blocks are determined; wherein, in the frequency domain, the associated block is in the same The resource blocks are separated from the resource blocks within a specific frequency domain range; the pilot signals carried by the resource blocks and the pilot signals carried by the at least two associated blocks are processed to obtain the pilot positions in the resource blocks. channel estimate.

In some embodiments, the processor 901 is further configured to determine the resource blocks adjacent to both sides of the frequency domain position of the resource block as the associated blocks.

In some embodiments, the processor 901 is further configured to determine M high frequency frequency domain positions and N low frequency frequency domain positions adjacent to the frequency domain position where the resource block is located; wherein the M and all The above N is greater than or equal to 1; the resource blocks in the M high-frequency frequency domain positions and the N resource blocks in the low-frequency frequency domain positions are used as the associated blocks.

In some embodiments, the M is the same as the N.

In some embodiments, the processor 901 is further configured to interpolate the channel estimation value of the pilot position in at least one of the resource blocks to obtain the channel estimation result of the PDCCH.

In some embodiments, the resource block carrying the PDCCH is a group of resource elements mapped with the PDCCH in the CORESET.

In some embodiments, all resource blocks within the CORESET use the same precoding.

In some embodiments, the pilot signal is distributed on resource blocks mapped with PDCCH and resource blocks not mapped with PDCCH in the CORESET; wherein, the resource blocks mapped with PDCCH and the non-mapped resource blocks Resource blocks with PDCCH are contiguous in the frequency domain.

Correspondingly, the embodiments of the present application provide a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements the steps in the channel estimation method provided in the foregoing embodiments.

It should be pointed out here that the descriptions of the above storage medium and device embodiments are similar to the descriptions of the above method embodiments, and have similar beneficial effects to the method embodiments. For technical details not disclosed in the embodiments of the storage medium and device of the present application, please refer to the description of the method embodiments of the present application to understand.

Correspondingly, in the embodiment of the present application, a chip is also provided, the chip includes a programmable logic circuit and/or program instructions, when the chip is running, it is used to implement the channel described in any of the above embodiments estimation method.

Correspondingly, in the embodiment of the present application, a computer program product is also provided, and when the computer program product is executed by the processor of the terminal, the computer program product is used to implement the channel estimation method described in any of the foregoing embodiments.

It is to be understood that reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic associated with the embodiment is included in at least one embodiment of the present application. Thus, appearances of "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its functions and internal logic, and should not be dealt with in the embodiments of the present application. implementation constitutes any limitation. The above-mentioned serial numbers of the embodiments of the present application are only for description, and do not represent the advantages or disadvantages of the embodiments.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined, or Can be integrated into another system, or some features can be ignored, or not implemented. In addition, the coupling, or direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical or other forms. of.

The unit described above as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit; it may be located in one place or distributed to multiple network units; Some or all of the units may be selected according to actual needs to achieve the purpose of the solutions of the embodiments of the present application.

In addition, each functional unit in each embodiment of the present application may all be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above integration The unit can be implemented either in the form of hardware or in the form of hardware plus software functional units.

Alternatively, if the above-mentioned integrated units of the present application are implemented in the form of software function modules and sold or used as independent products, they may also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application may be embodied in the form of software products in essence or the parts that make contributions to related technologies. The computer software products are stored in a storage medium and include several instructions to make The automatic test line of the device performs all or part of the methods described in the various embodiments of the present application. The aforementioned storage medium includes various media that can store program codes, such as a removable storage device, a ROM, a magnetic disk, or an optical disk.

The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined under the condition of no conflict to obtain new method embodiments.

The features disclosed in several method or device embodiments provided in this application can be combined arbitrarily without conflict to obtain new method embodiments or device embodiments.

The above is only the embodiment of the present application, but the protection scope of the present application is not limited to this. Covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims (10)

1. A channel estimation method, characterized in that the method comprises: According to the resource allocation mode of the control channel, determine the resource block that carries the physical downlink control channel PDCCH in the OFDM symbol of the orthogonal frequency division multiplexing; According to the frequency domain position of the resource block, at least two associated blocks are determined; wherein, in the frequency domain, the associated block is a block within a specific frequency domain range from the resource block; The pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks are processed to obtain the channel estimation value of the pilot position in the resource block. 2. The method according to claim 1, wherein the determining at least two associated blocks according to the frequency domain positions of the resource blocks comprises: The resource blocks adjacent to both sides of the frequency domain position of the resource block are determined as the associated blocks. 3. The method according to claim 2, wherein the determining the resource blocks adjacent to both sides of the frequency domain position of the resource block as the associated block comprises: Determine M high frequency frequency domain positions and N low frequency frequency domain positions adjacent to the frequency domain position where the resource block is located; wherein, the M and the N are both greater than or equal to 1; The M resource blocks at high frequency frequency domain positions and the N resource blocks at low frequency frequency domain positions are used as the associated blocks. 4. The method of claim 3, wherein the M is the same as the N. 5. The method according to any one of claims 1 to 4, wherein the method further comprises: Interpolate the channel estimation value of the pilot position in at least one of the resource blocks to obtain the channel estimation result of the PDCCH. 6 . The method according to claim 1 , wherein the resource block bearing the PDCCH is a resource element group to which the PDCCH is mapped in the control resource set CORESET. 7 . 7. The method of claim 6, wherein all resource blocks within the CORESET use the same precoding. 8. A channel estimation device, characterized in that the device comprises a first determination module, a second determination module and a processing module, wherein: The first determining module is configured to determine, according to the resource allocation mode of the control channel, the resource block that carries the PDCCH in each OFDM symbol; The second determining module is configured to determine at least two associated blocks according to the frequency domain positions of the resource blocks; wherein, in the frequency domain, the associated blocks are located within a specific frequency domain range from the resource blocks the resource block; The processing module is configured to process the pilot signal carried by the resource block and the pilot signal carried by the at least two associated blocks to obtain a channel estimation value of the pilot position in the resource block. 9. A terminal, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein the processor implements any one of claims 1 to 7 when the processor executes the program. steps in the method described above. 10. A computer-readable storage medium on which a computer program is stored, characterized in that, when the computer program is executed by a processor, the steps in the method of any one of claims 1 to 7 are implemented.

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