CN106162907B - Method and device for transmitting DCI in communication system based on machine type communication - Google Patents

Abstract

The present invention provides a method for transmitting DCI in a base station of a communication system based on machine type communication. DCI, and transmitting a second type of DCI at a second plurality of time points; wherein the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the second type of DCI The scheduling information and supplementary information of the PDSCH/PUSCH or only the supplementary information, and the frequency of the second plurality of time instants is lower than that of the first plurality of time instants.

Description

Method and device for transmitting DCI in a communication system based on machine type communication

technical field

The present invention relates to a communication system based on machine type communication, in particular to a method and apparatus for transmitting DCI in a communication system based on machine type communication.

Background technique

A Machine Type Communication (MTC) device is User Equipment (UE) used by a machine for a specific application. In 3GPPRel-12, a work project on low-complexity MTC UEs has been concluded, wherein the complexity (cost) of MTC UEs is reduced by about 50%. In 3GPP Rel-13, another work item has been decided to further reduce the complexity of the MTC UE, thereby increasing the coverage and improving the power consumption of the MTC UE.

It is assumed that the coverage enhancement for low-complexity MTC UEs reaches 18dB. To meet this higher coverage enhancement requirement, the most effective coverage enhancement technique is repetition. According to the applicant's simulation results, it can be known that about 180 to 330 times of repeated transmission of a data packet is required to achieve 18dB coverage enhancement. However, this has a dramatic effect on spectral efficiency.

The main technique for reducing the complexity of MTC UEs is to reduce the Radio Frequency (RF) bandwidth of low-complexity MTC UEs to 1.4MHz (operating in 6 physical resource blocks (PRBs), one of which is a resource allocation in the frequency domain) unit). Low complexity MTC UEs are expected to be able to operate on any system bandwidth and should be able to coexist with legacy UEs. In addition, low-complexity MTC UEs are expected to be able to retune their frequencies to operate on different subbands in a larger system bandwidth, allowing frequency reuse among low-complexity MTC UEs as well as with existing UEs. use.

SUMMARY OF THE INVENTION

In the current system, data transmission involves sending a Downlink Control Indicator (DCI). The downlink control indication is carried by the EPDCCH for scheduling the PDSCH. The MTC service is expected to be smaller, for example, 72 information bits are assumed in the current simulation research of 3GPP, while the existing DCI format 1A needs to occupy 42 bits, so if the current DCI format is used, it will consume a large overhead. In coverage enhancement operations, this DCI overhead may lead to a large loss of spectral efficiency, since the coverage enhancement operations require a large number of repetitions. It should be noted that there is no linear relationship between the required repetitions and the message size, ie larger packets may require more repetitions. Therefore, it is advantageous to use a compact DCI.

For low-complexity MTC or coverage enhancement operations, some fields in the current DCI are not needed and thus can be removed to reduce the DCI size. However, some additional bits of information are required, eg, the subband indication and the number of repetitions. Therefore, the present invention proposes two-level DCI dedicated to low-complexity MTC UEs.

In one embodiment, the first type of DCI in the two-level DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes scheduling information for scheduling PDSCH/PUSCH and supplementary information. The supplementary information includes, for example, subband configuration information.

In another embodiment, the first type of DCI in the two-level DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes only supplementary information. The supplementary information includes, for example, subband configuration information.

Based on this, according to an aspect of the present invention, there is provided a method for transmitting DCI in a base station of a communication system based on machine type communication, comprising the following steps: via the physical downlink control channel for MTC, At each time, the first type of DCI is transmitted, and at the second multiple times, the second type of DCI is transmitted; wherein, the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes scheduling information for scheduling PDSCH/PUSCH. The scheduling information for scheduling PDSCH/PUSCH and the supplementary information or only the supplementary information is included in the DCI, and the frequency of the second plurality of times is lower than that of the first plurality of times.

In one embodiment, the first plurality of times correspond to times when the physical downlink control channel for MTC is detected.

In one embodiment, the method further includes the step of: determining the second plurality of times based on predetermined parameters; wherein the predetermined parameters include any one or more of the following:

- the moment when the physical downlink control channel for MTC is detected;

- frequency hopping pattern;

- Channel estimation duration across subframes.

In one embodiment, when the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH and the second type of DCI includes only the supplementary information, the second plurality of time instants are the same as the Some of the first plurality of times overlap.

In an embodiment, when the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH and the second type of DCI includes the scheduling information for PDSCH/PUSCH scheduling and the supplementary information , and offset the second plurality of time instants by a predetermined offset amount.

In an embodiment, when the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the scheduling information for PDSCH/PUSCH scheduling and the supplementary information , the first multiple times correspond to the remaining times after the second multiple times are removed from the times when the physical downlink control channel for MTC is detected.

In one embodiment, the scheduling information for scheduling PDSCH/PUSCH includes resource block allocation information, and the length of the resource block allocation information is less than or equal to 6 bits.

In one embodiment, the supplemental information includes subband configuration information.

In one embodiment, the supplementary information further includes repetition control information.

According to another aspect of the present invention, there is provided a method for detecting DCI in a user equipment of a communication system based on machine type communication, comprising the steps of: receiving a physical downlink control channel for MTC; The first type of DCI and the second type of DCI perform blind decoding, wherein the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the scheduling information for scheduling PDSCH/PUSCH and Supplementary information or only the supplementary information is included.

According to another aspect of the present invention, there is provided an apparatus for transmitting DCI in a base station of a communication system based on machine type communication, comprising: a sending unit configured to, via a physical downlink control channel for MTC, transmit at a first At multiple times, the first type of DCI is transmitted, and at multiple second multiple times, the second type of DCI is transmitted; wherein, the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes scheduling information for scheduling PDSCH/PUSCH. The type of DCI includes the scheduling information for scheduling PDSCH/PUSCH and the supplementary information or only the supplementary information, and the frequency of the second plurality of times is lower than that of the first plurality of times.

According to another aspect of the present invention, there is provided an apparatus for detecting DCI in a user equipment of a communication system based on machine type communication, comprising: a receiving unit for receiving a physical downlink control channel for MTC; and detecting a unit, configured to perform blind decoding on the first type of DCI and the second type of DCI respectively, wherein the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the Scheduling information of PDSCH/PUSCH and supplementary information or only the supplementary information is included.

Various aspects of the present invention will become more apparent from the description of the specific embodiments hereinafter.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

1 shows a flowchart of a method for transmitting two-level DCI according to an embodiment of the present invention;

FIG. 2 shows a schematic diagram of repeated transmission of two-level DCI according to an embodiment of the present invention; and

FIG. 3 shows a schematic diagram of repeated transmission of two-level DCI according to another embodiment of the present invention.

In the figures, the same or similar reference numbers refer to the same or corresponding parts or features.

Detailed ways

The basic idea of the present invention is to define two levels of DCI for low-complexity MTC UEs, and for the two levels of DCI, the base station uses different frequencies for transmission. The first type of DCI in the two-level DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes scheduling information and supplementary information for scheduling PDSCH/PUSCH or only supplementary information, and the supplementary information may be Including, for example, subband configuration information and the like. The transmission frequency of the second type of DCI is lower than that of the first type of DCI.

In the following, the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, the second type of DCI includes scheduling information and supplementary information for scheduling PDSCH/PUSCH; and the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH; Scheduling information of /PUSCH, and the second type of DCI only includes supplementary information as examples to describe the method for transmitting DCI in a base station of a communication system based on machine type communication according to various embodiments of the present invention.

第一种DCI中包括用于调度PDSCH/PUSCH的调度信息，第二种DCI中包括用于调度PDSCH/PUSCH的调度信息和补充信息

The first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes scheduling information and supplementary information for scheduling PDSCH/PUSCH

Referring to FIG. 1 , in step S101 , the base station transmits the first type of DCI at the first plurality of times and transmits the second type of DCI at the second plurality of times via the physical downlink control channel for MTC. The frequency of the second plurality of times is lower than that of the first plurality of times.

It can be understood that the physical downlink control channel used for MTC may be an EPDCCH, or a physical downlink control channel specially used for MTC that will be newly defined in future discussions.

In the coverage enhancement operation, in order to ensure correct reception, the base station needs to repeat the transmission of DCI. In this case, each of the first multiple times and the second multiple times in this application may, for example, refer to repeated DCI transmission respectively. The process repeats at the end time.

In one example, the first plurality of time instants may correspond to the time instants/subframes at which the user equipment detects the physical downlink control channel for MTC. Considering that there is a transmission delay in the system, it can be understood that the first multiple times are slightly earlier than the time when the user equipment detects the physical downlink control channel for MTC on the time axis.

Generally, the supplementary information included in the second type of DCI is information that does not change frequently, and therefore, the frequency of the second plurality of times may be lower than the frequency of the first plurality of times. The second plurality of time instants may be pre-configured by the system or determined by the base station based on predetermined parameters. The predetermined parameters may include any one or more of the following:

- the moment when the physical downlink control channel of the MTC is detected;

- frequency hopping pattern;

- Channel estimation duration across subframes.

In one case, the second plurality of times may overlap with a portion of the first plurality of times. For example, as shown in FIG. 2, at time τ ₂ , the repetition end time of the first type of DCI is the same as the second time. The repetition end times of the two types of DCI overlap, so that, corresponding to time τ ₂ , the user equipment will perform blind decoding twice. In this case, the second plurality of time instants may be shifted, eg, as shown in FIG. 3, the second plurality of time instants may be shifted by a predetermined offset ΔT, such that each of the second plurality of time instants The times do not overlap with each of the first plurality of times, thereby reducing the number of times of blind decoding each time.

In addition, since the second type of DCI includes both scheduling information and supplementary information for scheduling PDSCH/PUSCH, when the second multiple times overlap with some of the first multiple times, the overlapping times can Consider transmitting only the second type of DCI and not the first type of DCI. For example, it is assumed that the original first multiple times correspond to the times when the physical downlink control channel for MTC is detected, then, in this embodiment, the first type of DCI may only correspond to the time when the physical downlink control channel for MTC is detected. The transmission is performed on the remaining time after the second plurality of time is removed from the time when the channel is detected. In this way, the number of blind decoding each time can be reduced to a certain extent.

第一种DCI中包括用于调度PDSCH/PUSCH的调度信息，第二种DCI中仅包括补充信息

The first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI only includes supplementary information

In this embodiment, similarly, the base station transmits the first type of DCI at the first plurality of times and transmits the second type of DCI at the second plurality of times via the physical downlink control channel for MTC. The frequency of the second plurality of times is lower than that of the first plurality of times.

The manners for determining the first plurality of times and the second plurality of times may be similar to those in the foregoing embodiments, and for the sake of brevity, details are not described herein. In addition, since the second type of DCI only includes supplementary information and does not include scheduling information for scheduling PDSCH/PUSCH, advantageously, the second plurality of times need to overlap with a part of the first plurality of times. It can be understood that, if the second plurality of times determined by the base station do not overlap with the first plurality of times, the second plurality of times may be offset from the first plurality of times to achieve the difference between the second plurality of times and the first plurality of times. part of the time overlap.

The first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and specifically, it may be expressed in various specific forms. In one embodiment, the format of the first DCI is shown in Table 1 below:

Table 1

The second type of DCI includes both scheduling information and supplementary information for scheduling PDSCH/PUSCH, and specifically, it can be expressed in multiple specific forms. In one embodiment, the format of the second DCI is shown in Table 2 below:

Table 2

For the situation where only supplementary information is included in the second type of DCI, in one embodiment, its format may be as shown in Table 3 below:

table 3

The resource allocation field in the format of the first type of DCI and/or the second type of DCI will be described below.

It is assumed that the six PRBs of the MTC subband are represented by a1, a2, a3, a4, a5, and a6, respectively. If the allocated MTC subband includes fewer PRBs, eg, in the case of overlapping PRBs, the unavailable PRBs are removed from the resource allocation field. The resource allocation bits are encoded to identify the allocation index.

- The resource block allocation field is 2bits

The 2bits resource block allocation scheme can be shown in the following table:

index Resource allocation 1 a1 2 a2,a3 3 a4,a5,a6 4 a1,a2,a3,a4,a5,a6

- The resource block allocation field is 3bits

The 3bits resource block allocation scheme can be shown in the following table:

index Resource allocation 1 a1 2 a2 3 a3,a4 4 a5,a6 5 a1,a2,a3 6 a4,a5,a6 7 a1,a2,a3,a4 8 a1,a2,a3,a4,a5,a6

- The resource block allocation field is 4bits

The 4bits resource block allocation scheme can be shown in the following table:

index Resource allocation 1 a1 2 a2 3 a3 4 a4 5 a5 6 a6 7 a1,a2 8 a3,a4 9 a5,a6 10 a1,a2,a3 11 a4,a5,a6 12 a1,a2,a3,a4 13 a3,a4,a5,a6 14 a1,a2,a3,a4,a5 15 a1,a2,a3,a4,a5,a6

In one or more exemplary designs, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium can be any available medium that can be accessed by a general purpose or special purpose computer. Such computer-readable media may include, for example and without limitation, RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, or may be used in a general purpose or special purpose computer or general purpose or special purpose Any other medium that carries or stores desired program code modules in the form of processor-accessible instructions or data structures. Also, any connection can be termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial Cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are also included in the definition of medium.

General purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or Any combination of the described functions implements or executes the various exemplary logical blocks, modules, and circuits described in connection with this disclosure. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, eg, a combination of a DSP and a microprocessor, multiple microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration.

It should also be understood by those of ordinary skill in the art that various exemplary logical blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments of the present application may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether this functionality is implemented in hardware or software depends on the specific application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in varying ways for each particular application, however, such implementation decisions should not be interpreted as a departure from the scope of the present invention.

The above description of the present disclosure is intended to enable any person of ordinary skill in the art to make or use the present invention. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other modifications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (16)

1. A method for transmitting DCI in a base station of a communication system based on machine type communication, comprising the following steps: - via the physical downlink control channel for MTC, at a first plurality of times, transmit a first type of DCI, and at a second plurality of times, transmit a second type of DCI; Wherein, the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the scheduling information for scheduling PDSCH/PUSCH and supplementary information or only the supplementary information, And the frequency of the second plurality of times is lower than that of the first plurality of times. 2 . The method according to claim 1 , wherein the first multiple times correspond to times when the physical downlink control channel for MTC is detected. 3 . 3. The method according to claim 1 or 2, wherein the method further comprises the steps of: - determining the second plurality of times based on predetermined parameters; Wherein, the predetermined parameters include any one or more of the following: - the moment when the physical downlink control channel for MTC is detected; - frequency hopping pattern; - Channel estimation duration across subframes. The method according to claim 1, wherein when the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH and the second type of DCI includes only the supplementary information, the The second plurality of times overlaps with a portion of the first plurality of times. The method according to claim 1, wherein when the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH and the second type of DCI includes the scheduling information for scheduling PDSCH/PUSCH When the scheduling information and the supplementary information are stored, the second plurality of time instants are offset by a predetermined offset. 6. The method according to claim 2, wherein when the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the scheduling information for scheduling PDSCH/PUSCH In the scheduling information of the PUSCH and the supplementary information, the first multiple times correspond to the remaining times after the second multiple times are removed from the times when the physical downlink control channel for MTC is detected. 7 . The method according to claim 1 , wherein the scheduling information for scheduling PDSCH/PUSCH comprises resource block allocation information, and the length of the resource block allocation information is less than or equal to 6 bits. 8 . 8. The method of claim 1, wherein the supplementary information comprises subband configuration information. 9. The method according to claim 8, wherein the supplementary information further comprises repetition control information. 10. The method according to claim 3, wherein when the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the scheduling information for scheduling PDSCH/PUSCH In the scheduling information of the PUSCH and the supplementary information, the first multiple times correspond to the remaining times after the second multiple times are removed from the times when the physical downlink control channel for MTC is detected. 11. A method for detecting DCI in a user equipment of a communication system based on machine type communication, comprising the steps of: - receiving the physical downlink control channel for MTC; - Perform blind decoding on the first type of DCI and the second type of DCI respectively, wherein the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the scheduling information for scheduling PDSCH/PUSCH The scheduling information and supplementary information of the PUSCH or only the supplementary information is included. 12. An apparatus for transmitting DCI in a base station of a communication system based on machine type communication, comprising: a sending unit, configured to transmit the first type of DCI at a first plurality of times and transmit the second type of DCI at a second plurality of times through the physical downlink control channel for MTC; wherein the first The second type of DCI includes scheduling information for scheduling PDSCH/PUSCH, the second type of DCI includes the scheduling information for scheduling PDSCH/PUSCH and supplementary information or only the supplementary information, and the second type of DCI The frequency of the time instants is lower than that of the first plurality of time instants. 13 . The apparatus according to claim 12 , wherein the first plurality of times correspond to times when the physical downlink control channel for MTC is detected. 14 . 14. The device of claim 12 or 13, further comprising: a determining unit, configured to determine the second plurality of moments based on predetermined parameters; Wherein, the predetermined parameters include any one or more of the following: - the moment when the physical downlink control channel for MTC is detected; - frequency hopping pattern; - Channel estimation duration across subframes. 15. The apparatus according to claim 12, wherein the supplementary information comprises subband configuration information. 16. An apparatus for detecting DCI in a user equipment of a communication system based on machine type communication, comprising: a receiving unit, configured to receive a physical downlink control channel for MTC; A detection unit, configured to perform blind decoding on the first type of DCI and the second type of DCI respectively, wherein the first type of DCI includes scheduling information for scheduling PDSCH/PUSCH, and the second type of DCI includes the The scheduling information and supplementary information for scheduling PDSCH/PUSCH or only the supplementary information is included.

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