CN112788761B

CN112788761B - PDCCH resource configuration and search method, base station and terminal

Info

Publication number: CN112788761B
Application number: CN201911096170.3A
Authority: CN
Inventors: 王新玲; 李华栋; 方冬梅; 杨芸霞; 鲁志兵
Original assignee: Hytera Communications Corp Ltd
Current assignee: Hytera Communications Corp Ltd
Priority date: 2019-11-11
Filing date: 2019-11-11
Publication date: 2022-11-18
Anticipated expiration: 2039-11-11
Also published as: CN112788761A

Abstract

The application discloses a method for configuring and searching PDCCH resources, wherein a base station sends the information of the PDCCH resources: information of the control resource sets indicates that any one common control resource set maximally comprises 32 Control Channel Elements (CCEs); the information of the search spaces indicates that the start position of any one common search space in any one time slot is the second OFDM symbol, and the detection period of the common search space is one time slot. The terminal determines the initial position of any one public search space as the second OFDM symbol of the time slot according to the information of the PDCCH resources and the information of the search space, and searches the PDCCH from the public search space in the minimum detection period of one time slot, and the maximum number of CCEs which are detected by the terminal without overlapping is 64, so that the requirement of satellite communication can be met.

Description

PDCCH resource configuration and search method, base station and terminal

Technical Field

The present application relates to the field of satellite communications technologies, and in particular, to a PDCCH resource configuration and search method, a base station, and a terminal.

Background

A Physical Downlink Control Channel (PDCCH) carries scheduling and other Control information, which is the basis for communication between the base station and the terminal.

The satellite communication has the characteristics of single port, DFT-s-OFDM modulation and high aggregation level, and particularly aims at the characteristic of high aggregation level, and the existing resource configuration and method of the PDCCH are not suitable for the satellite communication.

Disclosure of Invention

In view of this, the present application provides a PDCCH resource configuration and search method, a base station, and a terminal, and aims to solve the problem that the existing PDCCH resource configuration and method are not suitable for satellite communication.

In order to achieve the purpose, the application provides the following technical scheme:

a method for configuring Physical Downlink Control Channel (PDCCH) resources comprises the following steps:

a base station sends information of PDCCH resources, wherein the information comprises information of a control resource set and information of a search space;

wherein, the information of the control resource sets indicates that any one common control resource set maximally includes 32 Control Channel Elements (CCEs); the information of the search space indicates that the starting position of any one public search space in any one time slot is a second OFDM symbol, and the detection period of the public search space is one time slot;

and the information of the PDCCH resources is used for searching the PDCCH by the terminal so as to obtain the downlink control information.

Optionally, the information for controlling the resource set further indicates:

the location offset of the common control resource set from the resource blocks RB of the SSB is any of [ -2,2 ].

Optionally, the information for controlling the resource set further indicates:

any one of the common control resource sets occupies 1 or 2 OFDM symbols.

Optionally, the method further includes:

and the base station numbers the REG by using a mode of firstly numbering a frequency domain and then numbering a time domain in any control resource set.

Optionally, the method further includes:

and under the condition that RBs occupied by other channels exist after the RB occupied by the REG with the number of N, the base station numbers a target RB as the (N + 1) th REG, wherein the target RB is the RB with the number of a second numerical value and no occupied 6 continuous RBs, the second numerical value is the minimum numerical value of numerical values which are larger than the first numerical value and are integral multiples of 6, and the first numerical value is the number of the RB occupied by the REG with the number of N in the control resource set.

Optionally, the any one common control resource set includes 32 CCEs at maximum, and includes:

the any one common control resource set occupies 96 RBs and 2 OFDM symbols; alternatively, the first and second electrodes may be,

the arbitrary one common control resource set occupies 192 RBs, and 1 OFDM symbol.

A searching method of PDCCH comprises the following steps:

the terminal determines the initial position of any one public search space as a second OFDM symbol of the time slot according to the information of the control resource set and the information of the search space;

the terminal searches PDCCH from the public search space in the minimum detection period of one time slot to acquire downlink control information, wherein the maximum number of CCEs (control channel elements) which are detected in a non-overlapping mode by the terminal is 64, the terminal searches 4 PDCCH candidate positions under the condition that the aggregation level of the CCEs is 8, the terminal searches two public PDCCH candidate positions under the condition that the aggregation level of the CCEs is 16, and the terminal searches one public PDCCH candidate position under the condition that the aggregation level of the CCEs is 32; the information of the control resource set and the information of the search space are issued to the terminal by the base station in advance, the information of the control resource set indicates that any one public control resource set maximally comprises 32 control channel elements CCE; the information of the search space indicates that the starting position of any one common search space in any one time slot is a second OFDM symbol, and the minimum detection period of the common search space is one time slot.

Optionally, the method further includes:

and in the process of searching the PDCCH, the terminal numbers the REG in a mode of firstly using a frequency domain and then using a time domain in any control resource set.

Optionally, the method further includes:

and the terminal numbers a target RB as an N +1 th REG after the RB occupied by the REG with the number of N and under the condition that the RB occupied by other channels exists, wherein the target RB is the RB with the number of a second numerical value and no occupied by 6 continuous RBs after the second numerical value, the second numerical value is the minimum numerical value in numerical values which are larger than the first numerical value and are integral multiples of 6, and the first numerical value is the number of the RB occupied by the REG with the number of N in the control resource set.

A base station, comprising:

the processor is used for operating the program to realize the configuration method of the physical downlink control channel PDCCH resource.

A terminal, comprising:

a processor and a memory, the memory is used for storing programs, and the processor is used for operating the programs so as to realize the PDCCH searching method.

According to the technical scheme, the base station sends the information of the PDCCH resources, wherein the information comprises the information of a control resource set and the information of a search space, and the information of the control resource set indicates that any one public control resource set maximally comprises 32 Control Channel Elements (CCEs); the information of the search space indicates that the start position of any one common search space in any one time slot is a second OFDM symbol, and the detection period of the common search space is one time slot. And the terminal determines the initial position of any one public search space as the second OFDM symbol of the time slot according to the information of the PDCCH resource and the information of the search space, and searches the PDCCH from the public search space in the minimum detection period of one time slot. Because any one common control resource set comprises 32 CCEs at most and the maximum number of CCEs detected by the terminal without overlapping is 64, the characteristic of high satellite communication aggregation level can be met. In addition, because the first OFDM symbol of any one time slot is occupied by the CRS in satellite communication, in this embodiment, the mode in which the starting position of the common search space is the second OFDM symbol of the time slot can adapt to the requirement of satellite communication.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only the embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on the provided drawings without creative efforts.

Fig. 1 is a flowchart of a PDCCH resource configuration and search method disclosed in an embodiment of the present application;

FIG. 2 is an exemplary diagram of a conventional REG numbering scheme;

FIG. 3 is an exemplary diagram of REG numbering disclosed in the present application;

fig. 4 is another example diagram of REG numbering disclosed in the present application.

Detailed Description

According to the method, aiming at the characteristics of satellite communication, the resource allocation method of the PDCCH of the base station is improved, and the method for searching the PDCCH by the terminal is correspondingly improved, so that the resource allocation and search of the PDCCH are suitable for satellite communication.

Fig. 1 is a method for configuring and searching PDCCH resources disclosed in an embodiment of the present application, including the following steps:

s101: the base station transmits information of the PDCCH resource.

The information of the PDCCH resource is used for the terminal to search the PDCCH to acquire downlink control information, thereby communicating with the base station.

Wherein the information of the PDCCH resources comprises information of a control resource set and information of a search space.

Specifically, the information of the Control resource sets indicates that any one common Control resource set includes 32 Control Channel Elements (CCEs) at maximum.

The information of the search space indicates that the start position of any one common search space in any one time slot is a second OFDM symbol, and the detection period of the common search space is one time slot.

S102: and the terminal determines the initial position of any one public search space as the second OFDM symbol of the time slot according to the information of the control resource set and the information of the search space.

S103: the terminal searches for the PDCCH from the common search space with a minimum detection period of one slot.

Since any one control resource set is carried on 32 CCEs, in this embodiment, the maximum number of CCEs detected by the terminal without overlapping is 64.

Therefore, the terminal searches for 4 PDCCH candidate positions when the aggregation level of CCE is 8, detects two PDCCH candidate positions when the aggregation level of CCE is 16, and detects one PDCCH candidate position when the aggregation level of CCE is 32.

As can be seen from the process shown in fig. 1, the base station uses 32 CCEs to carry the control resource set, and accordingly, the maximum number of CCEs detected by the terminal without overlapping is 64, so that compared with the prior art, the aggregation level of 32 can be satisfied, and the method is suitable for the characteristic of high aggregation level of satellite communication.

In addition, in satellite communication, since the first OFDM symbol of any one time slot is occupied by a Cell Reference Signal (CRS), the embodiment can adapt to the requirement of satellite communication in a manner that the initial position of the common search space is the second OFDM symbol of the time slot. The search space has a detection period of one slot, and can satisfy the (DCI) requirements for Random Access Response (RAR), MSG4 (Message 4), paging (Paging), and System Information (SI).

Furthermore, other limitations can be performed on the configuration of the PDCCH resource to better adapt to the characteristics of satellite communication. I.e. the controlling resource set further indicates at least one of:

1. the common control Resource set is offset from the location of Resource Blocks (RBs) of the SSBs by any of [ -2,2 ]. As in the prior art, the position offset value is an integer, so the position offset of the common resource set from the RBs of the SSB can be any one of-2, -1, 0, 1, and 2.

2. Any one common set of control resources occupies 1 or 2 OFDM symbols.

Optionally, the base station numbers the REGs in any control resource set (including the common control resource set and the dedicated common control resource set) by using a frequency domain before time domain.

In the prior art, the REGs are numbered in a time domain first and then a frequency domain manner, for example, as shown in fig. 2, the numbers of REGs on two symbols are in upper case, because CCEs are mapped to REGs with continuous numbers, so it is assumed that CCE0 is mapped to REGs with numbers one to six and CCE1 is mapped to REGs with numbers seven to twelve. Assuming that CORESET0 occupies 6 REGs in lower case numbers, in case CORESET1 is resource-overlapped with CORESET0, since REGs of numbers one, three, and five corresponding to CCE0 are occupied, other REGs corresponding to CCE0 cannot be used.

On the other hand, if the REGs are numbered in a manner of frequency domain first and time domain second, CCE0 is mapped to REGs numbered one to six and CCE1 is mapped to REGs numbered seven to twelve, as shown in fig. 3. Because the frequency domain numbering is preferred, CORESET0 occupies 6 REGs with lower case numbers, which just corresponds to one CCE, and CORESET1 can occupy another CCE under the condition that CORESET1 and CORESET0 resources are overlapped, thereby avoiding the waste of REGs.

As shown in fig. 4, which is an example of numbering REGs in a frequency domain first and then a time domain, it should be noted that, the gray part is an RB occupied by another channel (e.g., SSB), in this case, the RB occupied by a REG belonging to the control resource set is divided into two discontinuous parts by the RB occupied by another channel (e.g., SSB).

Therefore, further, in the case that there is an RB occupied by another channel after the RB occupied by the REG numbered N, the base station numbers the target RB as the N +1 th REG, the target RB is an RB numbered as the second value and then consecutive 6 RBs are all unoccupied, the second value is the minimum value among the values which are greater than the first value and are integer multiples of 6, and the first value is the number of the RB occupied by the REG numbered N in the controlled resource set. Taking fig. 4 as an example, the first value is 2A, and the second value, that is, the smallest value among the numbers of the target RBs that are greater than 2A and are integer multiples of 6. And 6 consecutive RBs after the target RB are all unoccupied.

Note that, in the process of searching for the PDCCH by the terminal, the REGs are also numbered as described above.

Optionally, in order to reduce the occupation of resources, the information of the PDCCH resource sent by the base station may be only an index value of a preset table, the preset table is preset in the base station and the terminal, and after receiving the index value, the terminal may determine the PDCCH resource configured by the base station by searching the preset table.

Take the scenario that the SSB subcarrier spacing is 120KHz, the PDCCH subcarrier spacing is 120KHz, and the downlink bandwidth is 400MHZ as an example:

table 1 is a CORESET0 table:

TABLE 1

In table 1, the configuration of index values 0 to 7 is the existing configuration mode in the existing PDCCH resource configuration standard, and index values 8 to 15 are the configuration modes provided by the present application.

In the configuration modes of 8-15, the configuration mode occupies 96 RBs and 2 OFDM symbols, or occupies 192 RBs and 1 OFDM symbol, that is, the case occupies 32 CCEs (note that 32 CCEs are labeled). The configuration mode that occupies 96 RBs and 1 OFDM symbol, or occupies 48 RBs and 2 OFDM symbols is the case that occupies 16 CCEs (note that 16 CCEs are labeled).

It should be noted that, when the DFT-s-FDMA waveform is used in the downlink, the SSB and CORESET0 can have single carrier gain if both start from CRB0, i.e., the offset of both is 0. As can be seen from table 1, index values 8 to 11 all correspond to such a configuration, and compared with the configuration in which only one of the configuration modes corresponding to index values 0 to 7 exists, the configuration mode provided by the present application is more favorable for obtaining a single carrier gain.

The arrangement patterns of 8 to 15 shown in table 1 are all preferable examples of the technical solutions provided in the present application, and the technical solutions provided in the present application are not limited thereto.

Table 2 is an example of a configuration table of the search space:

TABLE 2

Table 3 is an example of a rule for a terminal to search for PDCCH:

TABLE 3

μ in table 3 is a subcarrier spacing index, and it can be seen that, when the subcarrier spacing index is 0 to 3, the maximum number of non-overlapping CCEs detected in the blind PDCCH detection process is 64. Especially for the case that the subcarrier spacing index is 3, the terminal can search 64 CCEs and is suitable for a satellite communication scene.

Table 4 shows an example of correspondence between CCE aggregation levels and common PDCCH candidate locations:

TABLE 4

As can be seen from table 4, the terminal blindly detects 7 candidate locations at most, wherein CCE aggregation levels may be pre-configured in the terminal and the base station.

Table 5 shows an example of the correspondence between CCE aggregation levels and dedicated PDCCH candidate locations:

TABLE 5

Wherein, the base station can send down to the terminal through reconfiguration (RRC) signaling according to the CCE aggregation level of the dedicated control resource set.

In summary, the CORESET0 table includes a configuration manner of 32 CCEs, the maximum number of CCEs detected by the terminal without overlapping is 64, and the search of candidate positions of 32CCE aggregation levels is supported, so that the requirement of high satellite communication aggregation level can be met to the maximum extent.

The offset between CORESET0 and CRB0 (i.e., the first RB of the SSB) is [ -2,2], which can satisfy the single carrier property of PDCCH.

The initial position of the public search space is the second OFDM symbol in the time slot, and the detection period is one time slot, so that the symbol occupation characteristic of satellite communication can be met, and the detection complexity is reduced.

The search mode at the terminal side can not only ensure the allocation success rate of the PDCCH, but also reduce the complexity of terminal processing.

The numbering rule of the REG can reduce the resource overlapping of the public PDCCH and the special PDCCH and reduce the resource fragments under the condition that the special PDCCH and the SSB resource are overlapped. And the success rate of the dedicated PDCCH resource allocation when the PDCCH and the SSB resources are overlapped can be increased.

The embodiment of the present application further discloses a base station, including:

the processor is used for storing programs and running the programs so as to realize the following configuration method of Physical Downlink Control Channel (PDCCH) resources: sending information of PDCCH resources, wherein the information comprises information of a control resource set and information of a search space; wherein, the information of the control resource sets indicates that any one common control resource set maximally includes 32 Control Channel Elements (CCEs); the information of the search space indicates that the start position of any one common search space in any one time slot is a second OFDM symbol, and the detection period of the common search space is one time slot.

Optionally, the information for controlling the resource set further indicates:

any one of the common control resource sets occupies 1 or 2 OFDM symbols.

Optionally, the base station numbers REGs in any control resource set by using a frequency domain first and a time domain second manner.

Optionally, when there is an RB occupied by another channel after the RB occupied by the REG with the number N, the base station numbers a target RB as an N +1 th REG, where the target RB is an RB numbered as a second value and then 6 consecutive RBs are all unoccupied, the second value is a minimum value among values that are greater than the first value and are integer multiples of 6, and the first value is a number of the occupied RB numbered as an NREG in the control resource set.

Optionally, a specific implementation manner that any one common control resource set includes 32 CCEs at most includes:

the arbitrary one common control resource set occupies 96 RBs, and 2 OFDM symbols; alternatively, the any one common control resource set occupies 192 RBs, and 1 OFDM symbol.

The base station described in this embodiment enables communication with the base station to better conform to the characteristics of satellite communication through the configuration of the PDCCH resource, thereby making full use of the resource and improving the communication performance.

The embodiment of the application also discloses a terminal, which comprises: a processor and a memory, the memory for storing a program, the processor for executing the program to implement the PDCCH searching method: determining the initial position of any one public search space as a second OFDM symbol of the time slot according to the information of the control resource set and the information of the search space; searching PDCCH from the public search space in the minimum detection period of one time slot, wherein the maximum number of CCEs which are detected by the terminal in a non-overlapping mode is 64, the terminal searches 4 PDCCH candidate positions under the condition that the aggregation level of the CCEs is 8, the terminal searches two public PDCCH candidate positions under the condition that the aggregation level of the CCEs is 16, and the terminal searches one public PDCCH candidate position under the condition that the aggregation level of the CCEs is 32; the information of the control resource set and the information of the search space are issued to the terminal by the base station in advance, the information of the control resource set indicates that any one public control resource set maximally comprises 32 control channel elements CCE; the information of the search space indicates that the starting position of any one common search space in any one time slot is a second OFDM symbol, and the minimum detection period of the common search space is one time slot.

Optionally, in the process of searching the PDCCH, the terminal numbers the REGs in a frequency domain before time domain within any control resource set.

Optionally, the terminal numbers a target RB as an N +1 th REG when there is an RB occupied by another channel after the RB occupied by the REG with the number N, where the target RB is the RB numbered as a second value, the second value is a minimum value of values that are greater than a first value, are not occupied by subsequent 6 consecutive RBs, and are integer multiples of 6, and the first value is a number of a last RB occupied by the REG inside the control resource set.

The method for searching the PDCCH by the terminal disclosed by the embodiment is more suitable for the characteristics of satellite communication, so that resources are fully utilized, and the communication performance is improved.

The embodiment of the application also discloses a base station, which comprises a sending module, and the sending module is used for sending the information of the PDCCH resources, wherein the information comprises the information of the control resource set and the information of the search space. And the information of the PDCCH resources is used for searching the PDCCH by the terminal so as to obtain the downlink control information. Wherein, the information of the control resource sets indicates that any one common control resource set maximally includes 32 Control Channel Elements (CCEs); the information of the search space indicates that the start position of any one common search space in any one time slot is a second OFDM symbol, and the detection period of the common search space is one time slot.

For a specific implementation manner of the foregoing technical solution, reference may be made to the foregoing embodiment, which is not described herein again.

The embodiment of the application further discloses a terminal, which includes: the device comprises a determining module and a searching module.

The determining module is used for determining the starting position of any one public search space as the second OFDM symbol of the time slot according to the information of the control resource set and the information of the search space.

The search module is configured to search the PDCCH from the common search space in a minimum detection period of one time slot to obtain downlink control information.

Wherein the maximum number of CCEs detected by the search module without overlapping is 64, the search module searches 4 PDCCH candidate positions under the condition that the aggregation level of the CCEs is 8, the search module searches two common PDCCH candidate positions under the condition that the aggregation level of the CCEs is 16, and the search module searches one common PDCCH candidate position under the condition that the aggregation level of the CCEs is 32; the information of the control resource set and the information of the search space are issued to the terminal by the base station in advance, the information of the control resource set indicates that any one public control resource set maximally comprises 32 control channel elements CCE; the information of the search space indicates that the starting position of any one common search space in any one time slot is a second OFDM symbol, and the minimum detection period of the common search space is one time slot.

It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other. For the device-like embodiment, since it is basically similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

Finally, it should also be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a component of' 8230; \8230;" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. A method for configuring Physical Downlink Control Channel (PDCCH) resources is characterized by comprising the following steps:

the information of the PDCCH resources is used for searching the PDCCH by the terminal so as to obtain downlink control information;

further comprising:

2. The method of claim 1, wherein the information controlling the resource set further indicates:

the position offset of the common control resource set from the resource block RB of the SSB is any one of [ -2,2 ].

3. The method of claim 1, wherein the information controlling the resource set further indicates:

any one of the common control resource sets occupies 1 or 2 OFDM symbols.

4. The method of claim 1, further comprising:

5. The method of any one of claims 1-4, wherein any one of the common control resource sets comprises up to 32 CCEs, and comprises:

the any one common control resource set occupies 96 RBs and 2 OFDM symbols; alternatively, the first and second liquid crystal display panels may be,

6. A method for searching a PDCCH, comprising:

the terminal determines the initial position of any one public search space as the second OFDM symbol of the time slot according to the information of the control resource set and the information of the search space;

the terminal searches PDCCH from the public search space in the minimum detection period of one time slot to acquire downlink control information, wherein the maximum number of CCEs (control channel elements) which are detected in a non-overlapping mode by the terminal is 64, the terminal searches 4 PDCCH candidate positions under the condition that the aggregation level of the CCEs is 8, the terminal searches two public PDCCH candidate positions under the condition that the aggregation level of the CCEs is 16, and the terminal searches one public PDCCH candidate position under the condition that the aggregation level of the CCEs is 32; the information of the control resource set and the information of the search space are issued to the terminal by the base station in advance, the information of the control resource set indicates that any one public control resource set maximally comprises 32 control channel elements CCE; the information of the search space indicates that the starting position of any one public search space in any one time slot is a second OFDM symbol, and the minimum detection period of the public search space is one time slot;

further comprising:

7. The method of claim 6, further comprising:

8. A base station, comprising:

a processor and a memory, the memory being used for storing a program, and the processor being used for executing the program to implement the method for configuring physical downlink control channel, PDCCH, resources according to any of claims 1-5.

9. A terminal, comprising:

a processor and a memory, the memory being configured to store a program, the processor being configured to execute the program to implement the PDCCH searching method according to any of claims 6-7.