CN117676547A

CN117676547A - Method, device and system for transmitting downlink control channel

Info

Publication number: CN117676547A
Application number: CN202210970267.8A
Authority: CN
Inventors: 花梦; 高飞; 颜冯尧; 丁梦颖; 彭金磷; 李�远
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-08-12
Filing date: 2022-08-12
Publication date: 2024-03-08
Also published as: WO2024032230A1

Abstract

The embodiment of the application provides a downlink control channel transmission method, a device and a system, which are used for a network device to determine a resource mapping scheme adopted when transmitting a downlink control channel. The method comprises the following steps: receiving capability information from a terminal, and determining a target resource mapping scheme according to the capability information; wherein the capability information may be used to indicate a first set of resource mapping schemes and/or a first set of reception schemes supported by the terminal on a first REG that overlaps with time-frequency resources configured for transmitting CRSs. In the above method, if there is a resource mapping scheme set and/or a receiving scheme set supported by the default by the terminal, the network device may also refer to when determining the target resource mapping scheme. Wherein, the target resource mapping scheme may be used to map modulation symbols of the first downlink control channel onto the first REG.

Description

Method, device and system for transmitting downlink control channel

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a downlink control channel transmission method, device, and system.

Background

In the scenario where the fourth generation (4th generation,4G) long term evolution (long term evolution, LTE) system and the fifth generation (5th generation,5G) New Radio (NR) system coexist, the time-frequency resources used for transmitting the cell specific reference signal (cell specific reference signal, CRS) in the LTE system may overlap with the time-frequency resources used for transmitting the physical downlink control channel (physical downlink control channel, PDCCH) or the demodulation reference signal (demodulation reference signal, DM-RS) in the NR system.

Disclosure of Invention

For the scenario that the time-frequency resource of LTE overlaps with the time-frequency resource of NR, there are multiple resource mapping schemes and multiple reception schemes. Wherein one resource mapping scheme may correspond to one or more reception schemes, and one reception scheme may also correspond to one or more resource mapping schemes. In a scenario where multiple resource mapping schemes and multiple receiving schemes coexist and the correspondence between the resource mapping schemes and the receiving schemes is complex, how the network device determines the adopted resource mapping scheme becomes a problem to be solved urgently. In order to achieve the above purpose, the embodiments of the present application adopt the following technical solutions:

in a first aspect, a downlink control channel transmission method is provided, where the method includes: receiving capability information from the terminal, the capability information including first indication information for indicating a first set of resource mapping schemes and/or a first set of reception schemes supported by the terminal on a first resource element group REG, the first REG being configured for transmitting downlink control channels and demodulation reference signals of the first downlink control channel, and the first REG overlapping with time-frequency resources configured for transmitting cell-specific reference signals CRS; determining a target resource mapping scheme according to the first indication information; and then, mapping the modulation symbol of the first downlink control channel to the first REG by adopting a target resource mapping scheme, and sending the first downlink control channel to the terminal.

In the downlink control channel transmission method provided in the embodiment of the present application, when the network device determines the target resource mapping scheme to be adopted, the first resource mapping scheme set and/or the first receiving scheme set supported by the terminal are referred to. Therefore, the target resource mapping scheme determined by the network equipment can meet the processing capability of the terminal, so that the terminal can normally receive the first downlink control channel, and further the communication efficiency is improved.

In one possible implementation manner, if the first resource mapping scheme set exists, determining the specific implementation of the target resource mapping scheme according to the first indication information is as follows:

determining one of the first set of resource mapping schemes as a target resource mapping scheme; or,

determining one of the first resource mapping scheme set and the resource mapping scheme set supported by the terminal in default on the first REG as a target resource mapping scheme; or,

if the first receiving scheme set still exists, determining a second resource mapping scheme set corresponding to the receiving scheme supported by the terminal by default on the first REG according to the corresponding relation between the resource mapping scheme and the receiving scheme; then, the same one of the first and second sets of resource mapping schemes is determined as the target resource mapping scheme.

In one possible implementation manner, if the first resource mapping scheme set does not exist and only the first receiving scheme set exists, determining the specific implementation of the target resource mapping scheme according to the first indication information is as follows:

according to the corresponding relation between the resource mapping scheme and the receiving scheme, determining one of one or more resource mapping schemes corresponding to the first receiving scheme set as a target resource mapping scheme; or,

determining a third resource mapping scheme set corresponding to the first receiving scheme set according to the corresponding relation between the resource mapping scheme and the receiving scheme; then, determining a resource mapping scheme set supported by the default of the terminal and one resource mapping scheme which is the same as the third resource mapping scheme set as a target resource mapping scheme; or determining the same one of the third resource mapping scheme set and the resource mapping scheme set corresponding to the receiving scheme set supported by the terminal by default as the target resource mapping scheme.

Specific implementations of the network device determining the target resource mapping scheme are given above. The method helps the network equipment to select a proper resource mapping scheme supported by the terminal, and avoids poor communication quality and even communication failure caused by the fact that the terminal cannot support the resource mapping scheme adopted by the network equipment, so that the communication efficiency can be improved. The specific implementation of the target resource mapping scheme is determined by the network equipment under the condition that the resource mapping scheme set and/or the receiving scheme set supported by the default of the terminal exists, so that the application scene of the downlink control channel transmission method provided by the embodiment of the application can be expanded.

In one possible implementation, the target resource mapping scheme when the aggregation level of the first downlink control channel is greater than the first threshold may be different from the target resource mapping scheme when the aggregation level of the first downlink control channel is less than or equal to the first threshold. In general, at different aggregation levels, the downlink control channel receiving performance corresponding to different resource mapping schemes may be different. In the scheme, the network equipment adopts different resource mapping schemes under different aggregation levels, so that the maximization of the receiving performance of the downlink control channel can be realized.

In a possible implementation manner, before the first downlink control channel is sent to the terminal, the downlink control channel transmission method provided in the embodiment of the present application further includes: and sending the corresponding relation between the resource mapping scheme and the aggregation level to the terminal. The scheme is helpful for the terminal to determine the adopted target receiving scheme according to the corresponding relation between the resource mapping scheme and the aggregation level.

In a possible implementation manner, the downlink control channel transmission method provided in the embodiment of the present application further includes: and transmitting second indication information for indicating the terminal to receive the first downlink control channel by adopting the target receiving scheme to the terminal, and/or transmitting second indication information for indicating that the modulation symbol of the first downlink control channel is mapped onto the time-frequency resource of the first downlink control channel by adopting the target resource mapping scheme to the terminal. In this scheme, the second indication information may explicitly indicate a target reception scheme adopted by the terminal, or the terminal may determine the target reception scheme according to the target resource mapping scheme indicated by the received second indication information and the correspondence between the resource mapping scheme and the reception scheme.

In one possible implementation, the resource mapping scheme differs in that: the rate matching parameters when mapping the downlink control channel by adopting different resource mapping schemes are different, and/or the usage of the time-frequency resources of the downlink control channel is different from that of RE#1 with overlapping time-frequency resources configured for transmitting CRS. For example, at least one of the following conditions may distinguish between different resource mapping schemes: whether re#1 can be used to map or carry modulation symbols of a downlink control channel or whether re#1 can be used to map or carry modulation symbols of a demodulation reference signal mapping the downlink control channel.

In one possible implementation, the reception scheme differs in that: the downlink control channel time-frequency resources are different in use from REs #2 configured for overlapping time-frequency resources for CRS transmission. For example, at least one of the following conditions may distinguish between different reception schemes: whether re#2 can be used for channel estimation, whether re#2 can be used for demodulation, or whether re#2 can be used for generating the input of a decoder.

In one possible implementation, the capability information further includes third indication information. If the first resource mapping scheme set exists and the first receiving scheme set does not exist, the third indication information is used for indicating the number of the CRS supported or the number of the CRS patterns supported when each resource mapping scheme in the first resource mapping scheme set is used. If the first reception scheme set exists and the first resource mapping scheme set does not exist, the third indication information is used for indicating the number of CRS supported or the number of CRS patterns supported when each reception scheme in the first reception scheme set is used. If the first resource mapping scheme set and the first reception scheme set exist at the same time, the third indication information is used for indicating the number of CRS supported or the number of CRS patterns supported when the resource mapping scheme M1 in the first resource mapping scheme set and the reception scheme R1 in the first reception scheme set are used.

In a possible implementation manner, the number of CRSs or the number of CRS patterns overlapping with the CRS time-frequency resource in the carrier where the first REG is located does not exceed the number of supported CRSs or the number of supported CRS patterns indicated in the third indication information, or the number of CRSs or the number of CRS patterns overlapping with the CRS time-frequency resource in the time-frequency domain resource in one CORESET where the first REG is located does not exceed the number of supported CRSs or the number of supported CRS patterns indicated in the third indication information, or the number of CRSs or the number of CRS patterns overlapping with the CRS time-frequency resource in one physical downlink control channel PDCCH candidate where the first REG is located does not exceed the number of supported CRSs or the number of supported CRS patterns indicated in the third indication information. For more possible overlapping situations, reference may be made to method embodiments, which are not described here in detail. In this scheme, the overlapping condition of the first REG and the time-frequency resource for transmitting the CRS may satisfy the processing capability of the terminal, so that the terminal may normally receive the first downlink control channel, thereby improving the communication efficiency.

In one possible implementation, sending a first downlink control channel to a terminal includes: and transmitting the first downlink control channel to the terminal on the second time-frequency resource. Wherein the second time-frequency resource is a resource for transmitting the first downlink control channel, and the second time-frequency resource is included in the first time-frequency resource. The first time-frequency resource includes a third time-frequency resource that cannot be used for transmitting the first downlink control channel in addition to the second time-frequency resource. The first time-frequency resource includes the same number of REs as the number of REs used for mapping the first downlink control channel in the second REG but different in position, and the second REG does not overlap with the time-frequency resource used for transmitting the CRS. In this scheme, since the number of REs included in the first time-frequency resource is the same as the number of REs used for mapping the first downlink control channel in the second REG, that is, the number of modulation symbols of the downlink control channel participating in decoding is not changed at the terminal side, it is not necessary to modify the decoding part on the basis of the 5G conventional reception scheme, thereby reducing modification at the terminal side.

In one possible implementation, the second time-frequency resources include REs in the first time-frequency resources other than the first set of REs, wherein the first set of REs consists of REs in which the first REG overlaps with time-frequency resources configured for transmitting CRS. In this scheme, all REs except for the RE with the overlapping resource in the first time-frequency resource are used to transmit the resource of the first downlink control channel, so that the time-frequency resource used to transmit the first downlink control channel can be increased as much as possible, and the corresponding receiving performance is better.

In one possible implementation, the third time-frequency resource includes at least one RE of the first set of REs that is non-adjacent and non-overlapping with REs configured for transmission of demodulation reference signals of the downlink control channel. In this scheme, at least one RE of the first set of REs that is not adjacent to and does not overlap with REs configured to transmit demodulation reference signals of a downlink control channel cannot be used to transmit the first downlink control channel, and the first downlink control channel on the at least one RE is punctured and only used to transmit CRS. Thus, the scheme can ensure the receiving and demodulating performance of the LTE system.

In a second aspect, a downlink control channel transmission method is provided, where the method includes: transmitting capability information to the network device, the capability information including first indication information for indicating a first set of resource mapping schemes and/or a first set of reception schemes supported by the terminal on a first resource element group REG, the first REG being configured for transmitting downlink control channels and demodulation reference signals of the downlink control channels, and the first REG overlapping with time-frequency resources configured for transmitting cell-specific reference signals CRS; thereafter, a first downlink control channel from the network device is received on the first REG.

In one possible implementation, receiving a first downlink control channel from a network device on a first REG includes: receiving a first downlink control channel from the network device on the first REG using a target reception scheme; the target reception scheme when the aggregation level of the first downlink control channel is greater than the first threshold may be different from the target reception scheme when the aggregation level of the first downlink control channel is less than or equal to the first threshold.

In one possible implementation, receiving a first downlink control channel from a network device on a first REG includes: receiving a first downlink control channel from the network device on the first REG using a target reception scheme; before receiving the first downlink control channel from the network device on the first REG using the target reception scheme, the method further comprises: receiving a corresponding relation between a resource mapping scheme and an aggregation level from network equipment; then, according to the aggregation level of the first downlink control channel and the corresponding relation between the resource mapping scheme and the aggregation level, determining a third resource mapping scheme corresponding to the aggregation level of the first downlink control channel; and finally, according to the third resource mapping scheme and the corresponding relation between the resource mapping scheme and the receiving scheme, determining one of the receiving schemes corresponding to the third resource mapping scheme as a target receiving scheme.

In one possible implementation, receiving a first downlink control channel from a network device on a first REG includes: receiving second indication information from the network equipment, wherein the second indication information indicates the terminal to receive the first downlink control channel by adopting a target receiving scheme; or the second indication information indicates that the modulation symbols of the first downlink control channel are mapped to the time-frequency resources of the first downlink control channel by adopting a target resource mapping scheme, and the terminal receives the first downlink control channel by adopting a target receiving scheme; at this time, the first downlink control channel from the network device may be directly received on the first REG using the target reception scheme indicated by the second indication information;

in one possible implementation, receiving a first downlink control channel from a network device on a first REG includes: receiving second indication information from the network equipment, wherein the second indication information indicates that a modulation symbol of the first downlink control channel is mapped to a time-frequency resource of the first downlink control channel by adopting a target resource mapping scheme; at this time, one of the receiving schemes corresponding to the target resource mapping scheme is determined as the target receiving scheme according to the corresponding relationship between the target resource mapping scheme and the receiving scheme; and then adopting the target receiving scheme to receive the first downlink control channel from the network equipment on the first REG.

In a possible implementation manner, the number of CRSs or the number of CRS patterns overlapping with the CRS time-frequency resource in the carrier where the first REG is located does not exceed the number of supported CRSs or the number of supported CRS patterns indicated in the third indication information, or the number of CRSs or the number of CRS patterns overlapping with the CRS time-frequency resource in the time-frequency domain resource in one CORESET where the first REG is located does not exceed the number of supported CRSs or the number of supported CRS patterns indicated in the third indication information, or the number of CRSs or the number of CRS patterns overlapping with the CRS time-frequency resource in one physical downlink control channel PDCCH candidate where the first REG is located does not exceed the number of supported CRSs or the number of supported CRS patterns indicated in the third indication information. For more possible overlapping situations, reference may be made to method embodiments, which are not described here in detail.

In one possible implementation, receiving a first downlink control channel from a network device on a first REG includes: a first downlink control channel is received from the network device on a second time-frequency resource. Wherein the second time-frequency resource is a resource for transmitting the first downlink control channel, and the second time-frequency resource is included in the first time-frequency resource. The first time-frequency resource includes a third time-frequency resource that cannot be used for transmitting the first downlink control channel in addition to the second time-frequency resource. The first time-frequency resource includes the same number of REs as the number of REs used for mapping the first downlink control channel in the second REG but different in position, and the second REG does not overlap with the time-frequency resource used for transmitting the CRS.

In one possible implementation, the second time-frequency resources include REs in the first time-frequency resources other than the first set of REs, wherein the first set of REs consists of REs in which the first REG overlaps with time-frequency resources configured for transmitting CRS.

In one possible implementation, the third time-frequency resource includes at least one RE of the first set of REs that is non-adjacent and non-overlapping with REs configured for transmission of demodulation reference signals of the downlink control channel.

The technical effects caused by any possible implementation manner of the second aspect may be referred to the technical effects caused by the foregoing first aspect or the different implementation manners of the first aspect, which are not described herein.

In a third aspect, a downlink control channel transmission method is provided, where the method includes: transmitting first configuration information to the terminal, the first configuration information being used to determine a first REG and/or a second REG, the first REG and/or the second REG being time-frequency resources configured to transmit downlink control channels and demodulation reference signals of the downlink control channels; transmitting second configuration information to the terminal, wherein the second configuration information is used for determining time-frequency resources for transmitting the CRS; determining a first time-frequency resource in the first REG in case there is an overlap of the first REG with time-frequency resources configured for transmitting CRSs; the first time-frequency resource is a resource for mapping the first downlink control channel, the first time-frequency resource comprises a second time-frequency resource and a third time-frequency resource, the second time-frequency resource is a resource for transmitting the first downlink control channel, the third time-frequency resource is a resource which cannot be used for transmitting the first downlink control channel, the number of REs included in the first time-frequency resource is the same as the number of REs used for mapping the first downlink control channel in the second REG but different in position, and the second REG is not overlapped with the time-frequency resource used for transmitting the CRS; and transmitting the first downlink control channel to the terminal on the second time-frequency resource.

The technical effects of any one of the possible implementation manners of the third aspect may be referred to the technical effects of one of the last three implementation manners of the first aspect, which are not described herein.

In a fourth aspect, a downlink control channel transmission method is provided, where the method includes: receiving first configuration information from a network device, the first configuration information being used to determine a first REG and/or a second REG, the first REG and/or the second REG being time-frequency resources configured to transmit downlink control channels and demodulation reference signals of the downlink control channels; receiving second configuration information from the network device, wherein the second configuration information is used for determining time-frequency resources for transmitting the CRS; determining a first time-frequency resource in the first REG in case there is an overlap of the first REG with time-frequency resources configured for transmitting CRSs; the first time-frequency resource is a resource for mapping the first downlink control channel, the first time-frequency resource comprises a second time-frequency resource and a third time-frequency resource, the second time-frequency resource is a resource for transmitting the first downlink control channel, the third time-frequency resource is a resource which cannot be used for transmitting the first downlink control channel, the number of REs included in the first time-frequency resource is the same as the number of REs used for mapping the first downlink control channel in the second REG but different in position, and the second REG is not overlapped with the time-frequency resource used for transmitting the CRS; a first downlink control channel is received from the network device on a second time-frequency resource.

The technical effects of any one of the possible implementation manners of the fourth aspect may be referred to the technical effects of one of the last three implementation manners of the first aspect, which are not described herein.

In a fifth aspect, a downlink control channel transmission method is provided, where the method includes: receiving first configuration information from a network device; and determining the aggregation level of the first control channel candidate as a first aggregation level according to the first configuration information. And determining whether the first downlink control channel candidate needs to be monitored according to the overlapping condition of the first downlink control channel candidate and the time-frequency resource configured for transmitting the CRS and the aggregation level of the first downlink control channel. In the case where the first downlink control channel candidate overlaps with time-frequency resources configured for transmitting CRS on each symbol in the first set of symbols, monitoring the downlink control channel on the first downlink control channel candidate if the first aggregation level belongs to the second set of aggregation levels, and not monitoring the downlink control channel on the first downlink control channel candidate if the first aggregation level does not belong to the second set of aggregation levels; the first symbol set is a symbol where a first downlink channel candidate is located; in case there is no overlap of the first downlink control channel with time-frequency resources configured for transmitting CRS on at least one symbol of the first set of symbols, the terminal monitors the downlink control channel on the first downlink control channel candidate if the first aggregation level belongs to the third aggregation level set, and does not monitor the downlink control channel on the first downlink control channel candidate if the first aggregation level does not belong to the third aggregation level set. Wherein the third set of polymerization levels is different from the second set of polymerization levels.

In the downlink control channel transmission method provided by the embodiment of the application, the downlink control channel can be monitored by selecting the proper aggregation level set according to the resource overlapping condition, so that the receiving performance of the downlink control channel can be improved.

In one possible implementation, the third set of aggregation levels includes each aggregation level included in the second set of aggregation levels.

In one possible implementation, each aggregation level in the second set of aggregation levels is greater than or equal to a first threshold value, and each aggregation level in the third set of aggregation levels is greater than or equal to a second threshold value, the second threshold value being less than the first threshold value.

In the case where there is resource overlap on all symbols, the second aggregation level set does not include the lower aggregation level in this scheme because the reception performance of the downlink control channel of the lower aggregation level is poor. Therefore, the terminal can only monitor the downlink control channel candidates with higher aggregation level, but not monitor the downlink control channel candidates with lower aggregation level, which are easy to generate receiving errors, so that the power consumption of the terminal can be saved. In addition, the scheme can also reduce the probability of false alarm and missed detection caused by error of the downlink channel receiving the lower aggregation level.

In a sixth aspect, there is provided a communication apparatus comprising: a processor; the processor is configured to implement the method according to any one of the first to fifth aspects through logic circuits or executing code instructions;

in one possible implementation, the communication device further includes a memory; the memory is used to store computer instructions.

In one possible implementation, the communication device further includes a communication interface; the communication interface is used for the communication device to communicate with other equipment. By way of example, the communication interface may be a transceiver, an input/output interface, an interface circuit, an output circuit, an input circuit, a pin or related circuit, or the like. For example, the interface circuit is used to receive signals from other communication devices and transmit to the processor or send signals from the processor to other communication devices,

in one possible implementation, the communication device may be a chip or a system-on-chip. When the communication device is a chip system, the communication device may be formed by a chip, or may include a chip and other discrete devices.

In a seventh aspect, there is provided a computer readable storage medium having instructions stored therein which, when run on a computer, cause the computer to perform the method of any of the first to fifth aspects described above.

In an eighth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any one of the first to fifth aspects above.

A ninth aspect provides a communication system comprising communication means for performing the method of the first aspect as described above, and communication means for performing the method of the second aspect as described above; or comprises performing the communication device according to the third aspect and performing the communication device according to the fourth aspect; or comprises a network device and a communication apparatus performing the method according to the fifth aspect described above.

The technical effects caused by any one of the possible implementation manners of the sixth aspect to the ninth aspect may be referred to the technical effects caused by the foregoing first aspect or the different implementation manners of the fifth aspect, which are not described herein.

Drawings

Fig. 1 is a schematic diagram of a first case of allocating resources for CRS in the prior art;

fig. 2 is a schematic diagram of a second case of allocating resources for CRS in the prior art;

FIG. 3 is a schematic diagram of a resource unit of a NR system according to the prior art;

FIG. 4 is a second diagram of a resource unit of a NR system according to the prior art;

FIG. 5 is a diagram showing the relationship between the time-frequency resources of CORESET and the time-frequency resources of the search space set in the prior art;

fig. 6 is a schematic diagram of a relationship between an NR system and an LTE system in a frequency domain in the prior art;

fig. 7 is a schematic diagram illustrating a case of allocating resources for PDCCH and DM-RS of PDCCH in the prior art;

fig. 8 is a schematic diagram of overlapping time-frequency resources used for mapping PDCCH or PDCCH DM-RS and time-frequency resources used for mapping CRS in the prior art;

FIG. 9 is a schematic diagram of a resource mapping scheme A in the prior art;

FIG. 10 is a diagram of a resource mapping scheme B in the prior art;

FIG. 11 is a diagram of a resource mapping scheme C in the prior art;

fig. 12 is a schematic architecture diagram of a mobile communication system applied in an embodiment of the present application;

fig. 13 is a flowchart of a downlink control channel transmission method provided in an embodiment of the present application;

fig. 14 is a schematic diagram of a resource mapping scheme provided in an embodiment of the present application;

fig. 15 is a flowchart of another downlink control channel transmission method according to an embodiment of the present application;

fig. 16 is a flowchart of another downlink control channel transmission method according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of a communication device according to an embodiment of the present application;

Fig. 18 is a schematic diagram of a second structure of the communication device according to the embodiment of the present application.

Detailed Description

For the convenience of understanding the technical solutions of the embodiments of the present application, a brief description of related technologies or terms of the present application is given below.

First, cell and carrier.

At a higher layer, i.e. at a protocol layer located above the physical layer, e.g. at a radio resource control layer or a medium access control layer, the cell is a concept described from the point of view of resource management or mobility management. The coverage of a network device may be divided into one or more cells. In the current NR system standard, one downlink carrier may be configured for one cell, and optionally, at least one uplink carrier may also be configured for one cell. For a terminal, the cell that serves it may be referred to as a serving cell. The "cell" in the embodiment of the present application may also be a "serving cell".

Second, bandwidth part (BWP).

In the NR system, the concept of BWP is introduced. A BWP may be a continuous length of frequency resources on one carrier. When a BWP is configured and activated, the BWP may be referred to as an activated BWP. In the current protocol, a terminal can only have one downlink active BWP on one downlink carrier and only one uplink active BWP on one uplink carrier. Wherein, the uplink active BWP is used for uplink data transmission and/or control signaling of the terminal, and the downlink active BWP is used for downlink data reception and/or control signaling of the terminal.

Third, resource units of LTE.

In the embodiment of the present application, mainly a scenario where an LTE system and an NR system coexist is discussed, and therefore, an LTE system and an NR system will be briefly described below. The LTE system is described in the "third" and "fourth" sections, and the NR system is described in the "fifth" to "tenth" sections, which are collectively described herein, and are not described in detail below.

In the LTE system, concepts in the time domain include subframes (subframes), slots (slots), and symbols (symbols). Wherein the symbols may also be referred to as orthogonal frequency division multiplexing (orthogonal frequency-division multiplexing, OFDM) symbols. 1 subframe contains two slots, each slot containing 6 or 7 OFDM symbols. That is, 1 subframe includes 12 or 14 OFDM symbols.

In the LTE system, the concept on the frequency domain includes subcarriers (subcarriers). Typically, the subcarrier spacing (subcarrier spacing, SCS) may be 15kHz.

In the LTE system, the concept of a time-frequency resource block includes a Resource Block (RB) and a Resource Element (RE). Wherein 1 RB contains 1 slot, i.e., 6 or 7 OFDM symbols in the time domain and 12 consecutive subcarriers in the frequency domain. 1 RE contains 1 OFDM symbol in the time domain and 1 subcarrier in the frequency domain.

Fourth, LTE cell-specific reference signals (cell specific reference signal, CRS).

In an LTE system, a network device may transmit CRS to a terminal. Typically, if an LTE cell is operating properly, CRS is transmitted periodically and continuously. Since no CRS is present in the existing NR system, the "CRS" in the embodiment of the present application may also be referred to as "LTE CRS".

The CRS supports 1 port (port), 2 ports, or 4 ports. Taking CRS supporting 4 ports as an example, fig. 1 shows a case where resources are allocated for CRS. Wherein, the minimum unit in the time domain is a symbol, 7 symbols constitute 1 LTE slot, and 2 LTE slots constitute 1 LTE subframe. The smallest unit in the frequency domain is a subcarrier. 1 RE contains 1 symbol in the time domain and 1 subcarrier in the frequency domain. 1 LTE RB contains 1 slot, i.e., 7 symbols, in the time domain and 12 consecutive subcarriers in the frequency domain. In fig. 1, REs with a fill pattern and marked with a number bear CRSs with a port index number corresponding to the number. Wherein the port index number may be 0,1,2 or 3. It can be seen that the locations of the CRS-bearing REs in the left LTE RB and the right LTE RB are the same. Typically, the locations of CRS-bearing REs in each LTE RB are the same.

It should be explained that, since the concept of "slot" in the current LTE system is different from the concept of "slot" in the NR system, the concept of "RB" in the current LTE system is also different from the concept of "RB" in the NR system, and "subframe" is not defined in the current NR system, the "LTE slot", "LTE RB" and "LTE subframe" are shown in fig. 1 for distinction.

In order to avoid mutual interference between CRSs of the same-frequency neighbor cells, different frequency domain Shift parameters (v-Shift) may be configured for the CRSs of the same-frequency neighbor cells, so that the CRSs of the neighbor cells are not located on the same frequency. Fig. 1 shows a case where CRS contains resources when v-shift=0, and is also represented on REs with the same filling pattern and reference numerals as fig. 1 in fig. 2. The case where CRS contains resources when v-shift=1 is also given in fig. 2. It can be seen that, in the frequency domain, the CRS contains REs that are shifted by one subcarrier when v-shift=1 compared to the CRS when v-shift=0. For example, cell a is adjacent to cell B, and v-shift=0 may be configured for the CRS of cell a, and v-shift=1 may be configured for the CRS of cell B, so that the CRSs of cell a and cell B are not in the same subcarrier in the frequency domain, and thus, mutual interference between the CRSs of cell a and cell B can be avoided.

Fifth, resource units of NR.

In an NR system, the concept in the time domain includes slots and symbols. Wherein the symbol may also be referred to as an OFDM symbol. 1 slot contains 12 or 14 OFDM symbols. It can be seen that the concept of "time slot" in the LTE system is different from that of "time slot" in the NR system at present, that is, the LTE time slot and the NR time slot contain different numbers of OFDM symbols. Illustratively, the NR slots shown in FIG. 3 contain 14 symbols. In addition, the concept of "symbol" in the LTE system is the same as that in the NR system at present.

In the NR system, the concept on the frequency domain includes RBs and subcarriers. Wherein, as shown in fig. 3, 1 RB contains 12 subcarriers. It can be seen that the concept of "RB" in the LTE system is different from that of "RB" in the NR system at present, that is, LTE RB is a concept of time-frequency resource block and NR RB is a concept on the frequency domain. In addition, the concept of "subcarrier" in the LTE system is the same as that of "subcarrier" in the NR system at present. However, there may be 5 SCSs in the NR system, with index numbers μ of 0 to 4, corresponding to 15kHz, 30kHz,60kHz,120kHz and 240kHz, respectively. In the embodiment of the present application, a scenario in which the LTE carrier overlaps with the NR carrier with SCS of 15kHz is described as an example, but this does not constitute a scenario limitation of the embodiment of the present application.

In an NR system, the concept of a time-frequency resource block includes REs. The concept of "RE" in the LTE system is currently the same as that of "RE" in the NR system. As shown in fig. 3, 1 RE contains 1 symbol in the time domain and 1 subcarrier in the frequency domain.

Sixth, PDCCH monitoring and PDCCH candidates.

In an NR system, the PDCCH may carry downlink control information (downlink control information, DCI).

The network device may configure a PDCCH candidate (PDCCH candidate) for the terminal. On one PDCCH candidate, the PDCCH of one terminal may or may not be transmitted. The terminal monitors (monitor) the PDCCH on the PDCCH candidate, and the monitoring result is that the PDCCH is monitored or not monitored. In the present embodiment, "monitoring" may be replaced with "detection (detect)". In the case that the PDCCH is detected, the terminal may decode the PDCCH according to a format (downlink control information format, DCI format) of downlink control information carried on the PDCCH.

Typically, 1 PDCCH candidate may contain L control channel elements (control channel element, CCEs). Where L may be referred to as an aggregation level (aggregation level, AL) of the PDCCH, and the value of L may be 1,2,4,8 or 16.1 CCE may contain 6 resource element groups (resource element group, REG). REGs belong to the concept of time-frequency resource blocks in NR systems, 1 REG contains 1 symbol in the time domain and 1 RB, i.e., 12 subcarriers, in the frequency domain, as shown in fig. 4. On the basis of fig. 3, fig. 4 illustrates the concept of REG.

Seventh, a search space set (search space set) and a control resource set (control resource set, CORESET).

How the network device configures PDCCH candidates for the terminal will be described below.

In an NR system, one search space set may be defined as a set of PDCCH candidates. Wherein the set of search spaces may also be referred to as a search space (search space). In the foregoing set of PDCCH candidates, the aggregation level of each PDCCH candidate may be the same, or there may be at least two PDCCH candidates with different aggregation levels. A search space set may be associated with a CORESET.

A CORESET may be defined on a cell. A CORESET contains a set of contiguous or non-contiguous RBs in the frequency domain and 1, 2 or 3 contiguous OFDM symbols in the time domain.

In general, one set of search spaces may be associated with, and only one CORESET, one CORESET may be associated with multiple sets of search spaces.

The network device may configure periodic, offset, etc. domain parameters for one set of search spaces. Based on the time domain parameters of a set of search spaces and the time-frequency resource parameters of CORESET associated with the set of search spaces, the network device may determine a set of time-frequency resources corresponding to the set of search spaces. Specifically, as shown in FIG. 5, one CORESET is associated with search space set 1, which is also associated with search space set 2. The time domain resources and frequency domain resources contained by the CORESET are shown in fig. 5. The network device may shift the CORESET to different positions in time according to the time domain resources and the frequency domain resources included in the CORESET and the time domain parameters of the search space set 1, so as to form a set of time-frequency resources corresponding to the search space set 1, such as a set of time-frequency resources without a filling pattern in fig. 5. Likewise, the network device may shift the CORESET to different positions in time according to the time domain resources and the frequency domain resources included in the CORESET and the time domain parameters of the search space set 2, so as to form a set of time-frequency resources corresponding to the search space set 2, such as a set of time-frequency resources with a filling pattern in fig. 5. It can be seen that the time domain parameters of search space set 1 are different from the time domain parameters of search space set 2.

The configuration information of the search space set may include an aggregation level, and the number of PDCCH candidates corresponding to the aggregation level; or, the configuration information of the search space set may include a plurality of aggregation levels, and the number of PDCCH candidates corresponding to each of the plurality of aggregation levels. The network device may determine, according to the configuration information of the search space set and the time-frequency resource corresponding to the search space set, the time-frequency resource location of the PDCCH candidate contained in the search space set in combination with a rule in the existing protocol.

Eighth, precoding of CORESET and PDCCH channel estimation.

In one possible implementation, the high-level parametric precoder granularity (precodier granularity) is configured to all neighbors RB (allContiguousRBs). Under this configuration, CORESET can be divided into at most 4 groups that are discontinuous in the frequency domain, and RBs in each group are continuous. The terminal may assume that the precoding of all REGs in CORESET containing consecutive RBs is the same and that no RE in CORESET overlaps with the synchronization signal and downlink broadcast channel module (synchronization signal and physical downlink broadcast channel block, SS & PBCH block, SSB) or LTE CRS indicated by higher layer parameters.

In another possible implementation, the higher-layer parameter pre-coding granularity is configured to be the same as the REG packet (sameAsREG-bundle). In this configuration, the terminal may assume that the precoding within one REG packet is the same. One REG packet contains REGs with REG packet size (REG bundle size) adjacent to each other in sequence number. Specifically, if one CORESET contains 1 OFDM symbol in the time domain, the REG packet size may be 2 or 6; if one CORESET contains 2 consecutive OFDM symbols in the time domain, the REG packet size may be 2 or 6; if one CORESET contains 3 consecutive OFDM symbols in the time domain, the REG packet size may be 3 or 6. If there is overlap between any RE in a PDCCH candidate and SSB or LTE CRS, then the terminal need not monitor this PDCCH candidate.

Ninth, configuration of LTE CRS in NR system.

As described in the previous "eighth" section, in the case where the higher layer parameter pre-coding granularity is configured as allcoeuousrbs, the network device needs to ensure that any RE in CORESET does not overlap with the LTE CRS indicated by the higher layer parameter. In the case where the higher layer parameter pre-coding granularity is configured as a sameiasreg-bundle, if there is overlap of any RE in one PDCCH candidate with the LTE CRS indicated by the higher layer parameter, then the terminal does not need to monitor this PDCCH candidate.

The higher layer parameters for indicating LTE CRS in an NR system are described below.

LTE CRS may be configured by higher layer information elements (information element, IE). Wherein, the IE includes LTE CRS match surrounding (LTE-CRS-ToMatchArnd), LTE CRS pattern list1 (LTE-CRS-Pattern List 1) or LTE CRS pattern list2 (LTE-CRS-Pattern List 2).

Specifically, 1 set of LTE CRS parameters can be configured in the LTE-CRS-ToMatchArnd, and at most 3 sets of LTE CRS parameters can be configured for each of two IEs, namely, the LTE-CRS-Pattern List1 and the LTE-CRS-Pattern List 2. The set of LTE CRS parameters includes at least one of downlink carrier location (carrier freqdl), downlink carrier bandwidth (carrier bandwidth dl), multicast and multicast single frequency network (multicast broadcast single frequency network, MBSFN) subframe configuration (MBSFN-subframe configlist), CRS port number (nrofCRS-Ports) or frequency shift (v-shift). Wherein, within the MBSFN subframe, there is no LTE CRS.

In release 18 (r 18) of the 5G NR standard, PDCCH candidates may overlap with LTE CRS, but PDCCH may also be carried on the PDCCH candidates. This is because the bandwidth of one CORESET may be wider than the bandwidth of one LTE CRS, i.e., there may be overlap of multiple bands of one CORESET with LTE CRS. Fig. 6 shows a relationship between an NR system and an LTE system in the frequency domain. Wherein, a partial frequency band of one 100M NR system may overlap with 3 20M LTE systems.

Tenth, mapping of DM-RS of PDCCH and PDCCH.

In the embodiment of the present application, the meanings indicated by "DM-RS of PDCCH", "PDCCH DM-RS" and "DM-RS" are the same and may be replaced with each other, and are collectively described herein, and are not described in detail.

In the embodiment of the present application, the nth RE in one REG is counted after being ordered from low to high according to frequency. DM-RS of PDCCH may be mapped on 3 REs in one REG, namely, 2 nd, 6 th and 10 th REs. The PDCCH may be mapped on 9 REs in one REG, i.e., 1 st, 3 rd, 4 th, 5 th, 7 th, 8 th, 9 th, 11 th and 12 th REs. Illustratively, as shown in fig. 7, the CORESET associated with one PDCCH candidate contains 3 symbols in the time domain, and these 3 symbols are the first 3 symbols of one NR slot. REs with diagonal fill patterns are used to map the DM-RS of the PDCCH, and REs with diamond fill patterns are used to map the PDCCH. Assuming that the 1 st RE of the 1 st REG is used to map the kth PDCCH modulation symbol, the 3 rd, 4 th, 5 th, 7 th, 8 th, 9 th, 11 th and 12 th REs of the REG are used to map the k+1th to k+8th PDCCH modulation symbols, respectively.

In fig. 7, since there is no overlap of REGs with time-frequency resources for transmitting CRSs, "REs for mapping PDCCHs" can be understood as "REs for transmitting PDCCHs" or "REs for transmitting PDCCHs"; similarly, "RE for mapping PDCCH DM-RS" may be understood as "RE for transmitting PDCCH DM-RS" or "RE for transmitting PDCCH DM-RS".

Eleventh, there are problems in the LTE system and NR system scenarios.

In view of the wide spread distribution of LTE, there are many stock terminals. The LTE system and the NR system coexist for a long time before the NR system completely replaces the LTE system.

However, as previously described, one PDCCH candidate is not allowed to overlap with the CRS in configuration, or is allowed to overlap with the CRS in configuration, but once overlapped, the PDCCH candidate cannot carry the PDCCH.

In an NR system, some PDCCHs for scheduling data must be carried on the first 3 symbols of one NR slot. However, in a scenario where the LTE system and the NR system coexist, CRS may exist on the 1 st symbol or the first 2 symbols of the NR slot. Referring to fig. 1 and fig. 7, fig. 8 shows a schematic diagram in which there is an overlap between time-frequency resources for mapping PDCCH or PDCCH DM-RS and time-frequency resources for mapping CRS in a scenario where an LTE system and an NR system coexist. In particular, in the case where CRS is present on the first 2 symbols of the NR slot, the PDCCH candidate can only be configured on the 3 rd symbol of the NR slot. Due to the limited resources of one symbol, the PDCCH resources may be insufficient. In the latest standard discussion, it is desirable to increase resources for transmitting the PDCCH in order to improve flexibility of PDCCH transmission.

When there is overlap between the time-frequency resources used for mapping PDCCH or PDCCH DM-RS and the time-frequency resources used for mapping CRS, how to transmit PDCCH and PDCCH DM-RS is a problem to be solved.

Twelfth, resource mapping scheme a and advantages and disadvantages.

In the embodiment of the present application, "overlap with CRS" may be understood as "overlap with time-frequency resources or REs used for mapping or transmitting CRS", which is generally described herein, and will not be described in detail herein.

In resource mapping scheme A, PDCCH, PDCCH DM-RS and CRS are both sent normally. That is, on REs where there is overlap of resources, both PDCCH and CRS are transmitted, or both PDCCH DM-RS and CRS are transmitted.

In the resource mapping scheme a, "for mapping PDCCH" may be understood as "RE for transmitting PDCCH" or "for transmitting PDCCH"; similarly, "RE for mapping PDCCH DM-RS" may be understood as "RE for transmitting PDCCH DM-RS" or "RE for transmitting PDCCH DM-RS".

Illustratively, fig. 9 shows a resource allocation schematic of the resource mapping scheme a when there is an overlap of 2 ports or 4 ports CRS and 2 symbols in length CORESET-associated PDCCH on one symbol with frequency shifts of 0,1 and 2. The following description will take, as an example, a case where the frequency shift is 0. In the two REGs with the same frequency domain resource and adjacent time domain resources, one REG overlaps with the CRS, and the other REG does not overlap with the CRS.

Let 1 st RE of REGs with CRS exist for mapping kth PDCCH modulation symbol, let 1 st RE of REGs with CRS without overlapping exist for mapping mth PDCCH modulation symbol. The mapping of the mth to the mth+8th PDCCH modulation symbols and the PDCCH DM-RS on REGs where there is no overlap with the CRS may refer to the mapping manner in the first three symbols in the embodiment shown in fig. 7, and will not be described here again. The Mth to M+8th PDCCH modulation symbols can be normally transmitted.

On REGs where there is overlap with CRS, the kth to k+8 th PDCCH modulation symbols are mapped, and the PDCCH DM-RS is mapped in the same manner as on REGs where there is no overlap with CRS. But there is overlap with the CRS on REs used to map the kth, k+2, and k+4 PDCCH modulation symbols. On these REs, PDCCH may be normally transmitted or CRS may be normally transmitted. In addition, there is also overlap with the CRS on one of the REs used to map PDCCH DM-RS. On this RE, the PDCCH DM-RS can be normally transmitted, or the CRS can be normally transmitted.

It is easy to see that in the resource mapping scheme a, 9 PDCCH modulation symbols are mapped on REGs overlapping with CRS, and all of the 9 PDCCH modulation symbols can be normally transmitted.

For the case of frequency shifts of 1 and 2, on REGs where there is overlap with CRS, the positions of REs where there is overlap are different, offset by 1 subcarrier and 2 subcarriers, respectively, with respect to the frequency shift of 0. However, the number of the REs where overlap exists is the same, and is 4, including 3 REs for mapping PDCCH modulation symbols and 1 RE for mapping PDCCH DM-RS. On the overlapped REs, the PDCCH may be normally transmitted, the CRS may be normally transmitted, or the PDCCH DM-RS may be normally transmitted, or the CRS may be normally transmitted.

For the resource mapping scheme a, the terminal may receive using a 5G legacy reception scheme. Wherein, the 5G legacy reception scheme refers to a reception scheme adopted when only the 5G NR system exists and the 4G LTE system does not exist. Optionally, the terminal may also use a receiving scheme for the resource mapping scheme a to receive, that is, perform special processing on the PDCCH and/or the PDCCH DM-RS on the RE overlapped with the CRS, where the specific processing manner is not unique, and the embodiment of the present application is not limited in any way. In general, when the network device transmits the PDCCH using the resource mapping scheme a, the reception performance of the terminal using the reception scheme for the resource mapping scheme a may be superior to that of the terminal using the 5G legacy reception scheme.

The advantage of resource mapping scheme a is the following:

1. the reception scheme corresponding to the resource mapping scheme a may be a 5G legacy reception scheme.

2. Since the PDCCH with higher AL is preferably transmitted in a scene with lower signal-to-noise ratio, i.e., higher noise, the CRS is superimposed on the basis of higher noise, and the influence on the noise is limited, and the influence on the receiving performance of the PDCCH is also limited. That is, when AL is high, the reception performance of the PDCCH corresponding to the resource mapping scheme a is good.

The disadvantage of resource mapping scheme a is the following:

1. since CRS and PDCCH or PDCCH DM-RS are transmitted on the same RE, which is equivalent to doping noise in CRS, resource mapping scheme a may affect the receiving performance of PDCCH in LTE system.

2. The CRS may be used for channel state estimation of the LTE system, and since the CRS is equivalent to noise doped, the channel state estimation of the LTE system is affected by the resource mapping scheme a.

3. Inaccurate channel state estimation of the LTE system may cause the resource mapping scheme a to further affect demodulation of data on the LTE physical downlink shared channel (physical downlink shared channel, PDSCH).

4. Because the PDCCH with lower AL is preferably transmitted in the scene of higher signal-to-noise ratio, i.e. lower noise, overlapping CRS on the basis of lower noise introduces significant noise, thereby affecting the receiving performance of PDCCH. That is, when AL is low, the reception performance of the PDCCH corresponding to the resource mapping scheme a is poor.

Thirteenth, resource mapping scheme B and advantages and disadvantages.

In the resource mapping scheme B, the mapping manner on REGs with overlapping CRSs is the same as the mapping manner on REGs with no overlapping CRSs. Then, the PDCCH or PDCCH DM-RS is punctured on the overlapped REs, i.e., the PDCCH or PDCCH DM-RS is not transmitted, and the CRS is normally transmitted.

In the resource mapping scheme B, "RE for mapping PDCCH" cannot be identical to "RE for transmitting PDCCH" or "RE for transmitting PDCCH", because PDCCH may be punctured on RE for mapping PDCCH, and cannot be used for transmitting or transmitting PDCCH. That is, the "RE for mapping PDCCH" includes "RE for transmitting PDCCH" or "RE for transmitting PDCCH". Similarly, "RE for mapping PDCCH DM-RS" includes "RE for transmitting PDCCH DM-RS" or "RE for transmitting PDCCH DM-RS".

Illustratively, fig. 10 shows a resource allocation schematic of resource mapping scheme B when there is an overlap of 2-port or 4-port CRS and 2-symbol-length CORESET-associated PDCCHs on one symbol with frequency shifts of 0,1, and 2. The following description will take, as an example, a case where the frequency shift is 0. In the two REGs with the same frequency domain resource and adjacent time domain resources, one REG overlaps with the CRS, and the other REG does not overlap with the CRS.

On REGs where there is overlap with CRS, the kth to k+8 th PDCCH modulation symbols are mapped, and the PDCCH DM-RS is mapped in the same manner as on REGs where there is no overlap with CRS. But there is overlap with the CRS on REs used to map the kth, k+2, and k+4 PDCCH modulation symbols. On these 3 REs, PDCCH modulation symbols are punctured and CRS is transmitted. In addition, there is also overlap with the CRS on one of the REs used to map PDCCH DM-RS. On this RE, PDCCH DM-RS is punctured and CRS is transmitted.

To count the number of REs available for transmitting PDCCH modulation symbols, the punctured PDCCH modulation symbols are denoted by "x" only in fig. 10, and the punctured PDCCH DM-RS is not similarly denoted. It is easy to see that in the resource mapping scheme B, 9 PDCCH modulation symbols are mapped on REGs overlapping with CRS, wherein 3 PDCCH modulation symbols are punctured and 6 PDCCH modulation symbols can be normally transmitted.

For the case of frequency shifts of 1 and 2, on REGs where there is overlap with CRS, the positions of REs where there is overlap are different, offset by 1 subcarrier and 2 subcarriers, respectively, with respect to the frequency shift of 0. However, the number of the REs where overlap exists is the same, and is 4, including 3 REs for mapping PDCCH modulation symbols and 1 RE for mapping PDCCH DM-RS. On overlapping REs, CRS is transmitted, while PDCCH or PDCCH DM-RS is punctured, i.e., not transmitted.

For resource mapping scheme B, the terminal may receive using a 5G legacy reception scheme. Optionally, the terminal may also use a receiving scheme for the resource mapping scheme B to receive, that is, perform special processing on the PDCCH and/or the PDCCH DM-RS on the RE overlapped with the CRS, where the specific processing manner is not unique, and the embodiment of the present application is not limited in any way. Illustratively, in the reception scheme for the resource mapping scheme B, the terminal uses DM-RS on REGs that do not overlap with the CRS, and does not use DM-RS on REGs that overlap with the CRS, because the terminal does not receive DM-RS on REGs that overlap with the CRS. This requires that at least one REG in one CORESET or PDCCH candidate or REG packet does not overlap with CRS. In general, when the network device transmits the PDCCH using the resource mapping scheme B, the reception performance of the terminal using the reception scheme for the resource mapping scheme B may be superior to that of the terminal using the 5G legacy reception scheme.

The advantage of resource mapping scheme B is the following:

1. the reception scheme corresponding to the resource mapping scheme B may be a 5G legacy reception scheme.

2. In the resource mapping scheme B, since the positions of the REs used for mapping the PDCCH modulation symbols on the REGs overlapping the CRS and the positions of the REs used for mapping the PDCCH modulation symbols on the REGs not overlapping the CRS are the same, and the number of the REs is 9, the decoding part or the rate matching part is not required to be modified for the receiving scheme of the resource mapping scheme B on the basis of the 5G conventional receiving scheme, and the modification is small.

3. Compared with the resource mapping scheme A, when the AL is lower, the receiving performance of the PDCCH corresponding to the resource mapping scheme B is better. The specific analysis is detailed at the 4 th point of the defects of the resource mapping scheme a, and is not repeated here.

The disadvantage of resource mapping scheme B is that:

when AL is higher, the reception performance of the PDCCH corresponding to the resource mapping scheme B is worse than that of the resource mapping scheme a. The specific analysis is detailed in the point 2 of the advantages of the resource mapping scheme a, and will not be described herein.

Fourteenth, resource mapping scheme C, advantages and disadvantages.

In resource mapping scheme C, on REGs that overlap with CRS, all REs are used to map PDCCH modulation symbols. The PDCCH is then punctured on the overlapping REs, i.e., the PDCCH is not transmitted, and the CRS is normally transmitted.

In the resource mapping scheme C, "RE for mapping PDCCH" cannot be identical to "RE for transmitting PDCCH" or "RE for transmitting PDCCH", because PDCCH may be punctured on RE for mapping PDCCH, and cannot be used for transmitting or transmitting PDCCH. That is, the "RE for mapping PDCCH" includes "RE for transmitting PDCCH" or "RE for transmitting PDCCH".

Illustratively, fig. 11 shows a resource allocation schematic of resource mapping scheme C when there is an overlap of 2-port or 4-port CRS and 2-symbol-length CORESET-associated PDCCHs on one symbol with frequency shifts of 0,1, and 2. The following description will take, as an example, a case where the frequency shift is 0. In the two REGs with the same frequency domain resource and adjacent time domain resources, one REG overlaps with the CRS, and the other REG does not overlap with the CRS.

On REGs that overlap with the CRS, each RE is used to map PDCCH modulation symbols, i.e., K-th to k+11-th PDCCH modulation symbols. But there is overlap with the CRS on REs used to map the kth, k+3, k+6, and k+9 PDCCH modulation symbols. On these 4 REs, PDCCH modulation symbols are punctured and CRS is transmitted.

The punctured PDCCH modulation symbols are marked with an "x" in fig. 11. It is easy to see that, in the resource mapping scheme C, 12 PDCCH modulation symbols are mapped on REGs overlapping with CRS, wherein 4 PDCCH modulation symbols are punctured and 8 PDCCH modulation symbols can be normally transmitted.

For the case of frequency shifts of 1 and 2, on REGs where there is overlap with CRS, the positions of REs where there is overlap are different, offset by 1 subcarrier and 2 subcarriers, respectively, with respect to the frequency shift of 0. However, the number of REs where overlap exists is the same as 4, that is, there are 4 REs where PDCCH modulation symbols are mapped and CRS overlap. On the overlapping REs, CRS is transmitted, while PDCCH is punctured, i.e., PDCCH is not transmitted.

For the resource mapping scheme C, the terminal can only use the receiving scheme for the resource mapping scheme C to receive, that is, perform special processing on the PDCCH and/or the PDCCH DM-RS on the RE overlapped with the CRS, and the specific processing manner is not unique, which is not limited in any way in the embodiment of the present application. Illustratively, in the reception scheme for the resource mapping scheme C, the terminal uses DM-RS on REGs that do not overlap with the CRS, and does not use DM-RS on REGs that overlap with the CRS, because the terminal does not receive DM-RS on REGs that overlap with the CRS. This requires that at least one REG in one CORESET or PDCCH candidate or REG packet does not overlap with CRS.

The resource mapping scheme C has the advantages that:

since the number of REs used for transmitting PDCCH in the resource mapping scheme B is 6 and the number of REs used for transmitting PDCCH in the resource mapping scheme C is 8, the resources used for transmitting PDCCH in the resource mapping scheme C are more than those in the resource mapping scheme B, and thus the PDCCH receiving performance corresponding to the resource mapping scheme C is better.

The disadvantage of resource mapping scheme C is that:

in the resource mapping scheme C, since the number of REs for mapping PDCCH modulation symbols on REGs overlapping with CRS is different from the number of REs for mapping PDCCH modulation symbols on REGs not overlapping with CRS, respectively, is 12 and 9, that is, the terminal needs to decode more PDCCH modulation symbols in the same time, the reception scheme for the resource mapping scheme C needs to modify the decoding part on the basis of the 5G legacy reception scheme. In addition, since the locations of REs on REGs overlapping with CRS for mapping PDCCH modulation symbols are also different from those on REGs not overlapping with CRS, the reception scheme for resource mapping scheme C also needs to modify the rate matching part on the basis of the 5G legacy reception scheme, resulting in a larger modification of the reception scheme for resource mapping scheme C on the basis of the 5G legacy reception scheme.

In order to more intuitively compare the above-mentioned resource mapping schemes, table 1 lists the correspondence between the resource mapping schemes and the reception schemes, and table 2 lists the advantages and disadvantages of the respective resource mapping schemes.

TABLE 1

TABLE 2

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the present application, "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a alone, a and B together, and B alone, wherein a, B may be singular or plural. In the text description of the present application, the character "/", generally indicates that the associated object is an or relationship; in the formulas of the present application, the character "/" indicates that the front and rear associated objects are a "division" relationship. "including at least one of A, B and C" may mean: comprises A; comprises B; comprising C; comprises A and B; comprises A and C; comprises B and C; including A, B and C.

Fig. 12 is a schematic architecture diagram of a communication system 1000 to which embodiments of the present application apply. As shown in fig. 12, the communication system includes a radio access network 100 and a core network 200, and optionally, the communication system 1000 may further include the internet 300. Wherein the radio access network 100 may include at least one radio access network device (e.g., 110a and 110b in fig. 12) and may also include at least one terminal (e.g., 120a-120j in fig. 12). The terminal is connected with the wireless access network equipment in a wireless mode, and the wireless access network equipment is connected with the core network in a wireless or wired mode. The core network device and the radio access network device may be separate physical devices, or may integrate the functions of the core network device and the logic functions of the radio access network device on the same physical device, or may integrate the functions of part of the core network device and part of the radio access network device on one physical device. The terminals and the radio access network device may be connected to each other by wired or wireless means. Fig. 12 is only a schematic diagram, and other network devices may be further included in the communication system, for example, a wireless relay device and a wireless backhaul device may also be included, which are not shown in fig. 12.

The radio access network device is an access device to which the terminal accesses the communication system by wireless. The radio access network device may be a base station (base station), an evolved NodeB (eNodeB), a transmission and reception point (transmission reception point, TRP), a next generation NodeB (gNB) in a fifth generation (5th generation,5G) mobile communication system, a next generation base station in a sixth generation (6th generation,6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc.; the present invention may also be a module or unit that performs a function of a base station part, for example, a Central Unit (CU) or a Distributed Unit (DU). The CU can complete the functions of a radio resource control protocol and a packet data convergence layer protocol (packet data convergence protocol, PDCP) of the base station and can also complete the functions of a service data adaptation protocol (service data adaptation protocol, SDAP); the DU performs the functions of the radio link control layer and the medium access control (medium access control, MAC) layer of the base station, and may also perform the functions of a part of the physical layer or the entire physical layer, and for a detailed description of the above protocol layers, reference may be made to the relevant technical specifications of the third generation partnership project (3rd generation partnership project,3GPP). The radio access network device may be a macro base station (e.g. 110a in fig. 12), a micro base station or an indoor station (e.g. 110b in fig. 12), a relay node or a donor node, etc. The embodiment of the application does not limit the specific technology and the specific equipment form adopted by the wireless access network equipment. For convenience of description, a base station will be described below as an example of a radio access network device.

A terminal is a device having a wireless transceiving function, and can transmit a signal to a base station or receive a signal from a base station. A terminal may also be referred to as a terminal device, user Equipment (UE), mobile station, mobile terminal, etc. The terminal may be widely applied to various scenes, for example, device-to-device (D2D), vehicle-to-device (vehicle to everything, V2X) communication, machine-type communication (MTC), internet of things (internet of things, IOT), virtual reality, augmented reality, industrial control, autopilot, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, and the like. The terminal can be a mobile phone, a tablet personal computer, a computer with a wireless receiving and transmitting function, a wearable device, a vehicle, an airplane, a ship, a robot, a mechanical arm, intelligent household equipment and the like. The embodiment of the application does not limit the specific technology and the specific equipment form adopted by the terminal.

The base station and the terminal may be fixed in position or movable. Base stations and terminals may be deployed on land, including indoors or outdoors, hand-held or vehicle-mounted; the device can be deployed on the water surface; but also on aircraft, balloons and satellites. The application scenes of the base station and the terminal are not limited in the embodiment of the application.

The roles of base station and terminal may be relative, e.g., helicopter or drone 120i in fig. 12 may be configured as a mobile base station, terminal 120i being the base station for those terminals 120j that access radio access network 100 through 120 i; but for base station 110a 120i is a terminal, i.e., communication between 110a and 120i is via a wireless air interface protocol. Of course, communication between 110a and 120i may be performed via an interface protocol between base stations, and in this case, 120i is also a base station with respect to 110 a. Thus, both the base station and the terminal may be collectively referred to as a communication device, 110a and 110b in fig. 12 may be referred to as a communication device having a base station function, and 120a-120j in fig. 12 may be referred to as a communication device having a terminal function.

Communication can be carried out between the base station and the terminal, between the base station and between the terminal and the terminal through the authorized spectrum, communication can be carried out through the unlicensed spectrum, and communication can also be carried out through the authorized spectrum and the unlicensed spectrum at the same time; communication can be performed through a frequency spectrum of 6 gigahertz (GHz) or less, communication can be performed through a frequency spectrum of 6GHz or more, and communication can be performed using a frequency spectrum of 6GHz or less and a frequency spectrum of 6GHz or more simultaneously. The embodiments of the present application do not limit the spectrum resources used for wireless communications.

In the embodiments of the present application, the functions of the base station may be performed by a module (such as a chip) in the base station, or may be performed by a control subsystem including the functions of the base station. The control subsystem comprising the base station function can be a control center in the application scenarios of smart power grids, industrial control, intelligent transportation, smart cities and the like. The functions of the terminal may be performed by a module (e.g., a chip or a modem) in the terminal, or by a device including the functions of the terminal.

In the application, a base station sends a downlink signal or downlink information to a terminal, and the downlink information is borne on a downlink channel; the terminal sends an uplink signal or uplink information to the base station, and the uplink information is carried on an uplink channel. In order for a terminal to communicate with a base station, it is necessary to establish a radio connection with a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the serving cell of the terminal. The terminal may also be interfered by signals from neighboring cells when communicating with the serving cell.

In the embodiments of the present application, the time domain symbols may be OFDM symbols or discrete fourier transform spread-OFDM (discrete fourier transform-spread-OFDM, DFT-s-OFDM) symbols. Symbols in embodiments of the present application all refer to time domain symbols, unless otherwise specified.

It should be understood that, in the embodiments of the present application, PDSCH and PDCCH are only examples of downlink data channels and downlink control channels, respectively, and that in different systems and different scenarios, the data channels and the control channels may have different names, and the embodiments of the present application are not limited thereto.

The downlink control channel transmission method provided in the embodiments of the present application will be specifically described below with reference to fig. 1 to 12.

Fig. 13 is a downlink control channel transmission method provided in the embodiment of the present application, where the downlink control channel transmission method includes the following steps:

step S1301, the terminal sends capability information to the network device. Accordingly, the network device receives capability information from the terminal device.

The capability information includes first indication information, where the first indication information indicates a first resource mapping scheme set and/or a first receiving scheme set supported by a terminal on a first resource element group REG, the first resource mapping scheme set includes one or more resource mapping schemes of downlink control channels, the first receiving scheme set includes one or more receiving schemes of downlink control channels, the first REG is configured to transmit the downlink control channels and demodulation reference signals of the downlink control channels, and the first REG overlaps with time-frequency resources configured to transmit CRSs.

In the embodiment of the present application, the time-frequency resource configured for transmitting CRS may be replaced by an RE configured for not allowing PDSCH transmission, an RE configured for not allowing PDSCH transmission and PDSCH DM-RS transmission, an RE configured for Reference Signal (RS) mapping for channel state measurement, an RE configured for RS mapping for beam measurement, an RE mapped for channel state indication reference signal (channel state information-reference signal, CSI-RS), an RE mapped for tracking reference signal (tracking reference signal, TRS), and an RE included in the rate matching resource are collectively described herein and will not be described herein. In the present embodiment, "configured for transmission" refers to the use of time-frequency resources in the case where only a single communication system is present. In the case where two communication systems coexist, "configured for transmission" is not necessarily equivalent to "used for transmission". In the embodiment of the present application, the "downlink control channel" does not include the "demodulation reference signal of the downlink control channel", and may be understood as "downlink control channel modulation symbol". The "resource mapping scheme" in the embodiment of the present application includes "mapping of modulation symbols and bearer scheme".

As described above, the resource mapping schemes and the receiving schemes are not in one-to-one correspondence, one resource mapping scheme may correspond to one or more receiving schemes, and one receiving scheme may also correspond to one or more resource mapping schemes, so that the terminal may report both the supported first set of resource mapping schemes and the supported first set of receiving schemes to the network device.

Optionally, the first resource mapping scheme set includes a different resource mapping scheme M1 and a resource mapping scheme M2, where the resource mapping scheme M1 and the resource mapping scheme M2 are:

the downlink control channel adopts different rate matching parameters when adopting a resource mapping scheme M1 and a resource mapping scheme M2; or,

one RE#1 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting the CRS, the RE#1 is used for mapping the modulation symbol of the downlink control channel in the resource mapping scheme M1, and the RE#1 is not used for mapping the modulation symbol of the downlink control channel in the resource mapping scheme M2; or,

one RE#1 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting the CRS, the RE#1 is used for bearing the modulation symbol of the downlink control channel in the resource mapping scheme M1, and the RE#1 is not used for bearing the modulation symbol of the downlink control channel in the resource mapping scheme M2; or,

One RE#1 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting the CRS, the RE#1 is used for bearing the modulation symbol of the demodulation reference signal of the downlink control channel in the resource mapping scheme M1, and the RE#1 is not used for bearing the modulation symbol of the demodulation reference signal of the downlink control channel in the resource mapping scheme M2; or,

one RE#1 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting the CRS, RE#1 is used for mapping modulation symbols of demodulation reference signals of the downlink control channel in a resource mapping scheme M1, and RE#1 is not used for mapping modulation symbols of demodulation reference signals of the downlink control channel in a resource mapping scheme M2. Illustratively, the different resource mapping schemes M1 and M2 may satisfy at least one of the above conditions. The scheme gives the case that the resource mapping scheme M1 is different from the resource mapping scheme M2, including different rate matching parameters, and different uses of re#1 where the resources overlap.

The "rate matching parameter" in the embodiment of the present application refers to a parameter adopted by the rate matching module when performing signal processing.

In the present embodiments, "bearer" may be understood as "transmission". If RE#1 is not punctured, then the concept of "bearer" is equivalent to "map". If RE#1 is punctured, then the concepts of "bearer" and "map" are not equivalent.

Optionally, the first receiving scheme set includes different receiving schemes R1 and R2, where the receiving schemes R1 and R2 are:

one RE#2 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting the CRS, and the received signal on the RE#2 is used for channel estimation in a receiving scheme R1, and is not used for channel estimation in the receiving scheme R2; or,

one RE#2 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting the CRS, and the received signal on RE#2 is used for demodulation in the receiving scheme R1 and is not used for demodulation in the receiving scheme R2; or,

one RE #2 of the REs where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting CRS is used to generate the input of the decoder in the receiving scheme R1, and the received signal on RE #2 is not used to generate the input of the decoder in the receiving scheme R2. Illustratively, the different reception schemes R1 and R2 may satisfy at least one of the above conditions. This scheme gives a case where the reception scheme R1 is different from the reception scheme R2, and uses of re#2 including resource overlap are different.

Optionally, the capability information further comprises third indication information, wherein,

The third indication information indicates the number of CRS supported or the number of CRS patterns supported when each resource mapping scheme in the first set of resource mapping schemes is used; or,

the third indication information indicates the number of CRS supported or the number of CRS patterns supported when each reception scheme in the first reception scheme set is used; or,

the third indication information indicates the number of CRS supported or the number of CRS patterns supported when the resource mapping scheme M1 in the first resource mapping scheme set and the reception scheme R1 in the first reception scheme set are used.

As described in the "ninth" of the preamble, 1 set of LTE CRS parameters may be configured in the LTE-CRS-to-matchbond, including: carrierFreqDL, carrierBandwidthDL, at least one of the group consisting of msfn-SubframeConfigList, nrofCRS-Ports and v-shift. In the embodiment of the application, the number of CRS can be understood as the number of lte-CRS-ToMatchArnd configurations. The first CRS and the second CRS are different as long as there is one difference in the above parameters.

For CRS patterns to be the same, it can be understood that:

the v-shift of the first CRS is the same as that of the second CRS, and the other four parameters except for the v-shift are different, so that the patterns of the first CRS and the second CRS are the same; or,

The v-shift and nrofCRS-Ports of the first CRS are the same as those of the second CRS, and the other three parameters except for the v-shift and nrofCRS-Ports are different, which is called that the patterns of the first CRS and the second CRS are the same; or,

the v-shift, nrofCRS-Ports and msfn-subframe configlist of the first CRS are the same as those of the second CRS, and the other two parameters except for the v-shift, nrofCRS-Ports and msfn-subframe configlist are different and are called that the patterns of the first CRS and the second CRS are the same.

For example, assuming that the first set of resource mapping schemes is the resource mapping scheme a and the resource mapping scheme C, the third indication information may indicate that the number of CRSs supported or the number of CRS patterns supported when the resource mapping scheme a is used is 3. The third indication information may also indicate that the number of CRSs supported or the number of CRS patterns supported when the resource mapping scheme C is used is 1.

For example, assuming that the first set of resource mapping schemes is the resource mapping scheme a and the first set of reception schemes is the 5G legacy reception scheme and the reception scheme for the resource mapping scheme a, the third indication information indicates that the number of CRSs supported or the number of CRS patterns supported when the resource mapping schemes a and 5G legacy reception schemes are used is 3. The third indication information may also indicate that the number of CRSs supported or the number of CRS patterns supported when using the resource mapping scheme a and the reception scheme for the resource mapping scheme a is 1.

Optionally, when the number of the CRS supported or the number of the CRS patterns supported is that one of the CRS time-frequency resources and the following time-frequency resources overlap, an upper limit of the number of the CRS supported by the terminal or an upper limit of the number of the CRS patterns supported by the terminal:

a carrier on which the first REG is located;

the first REG is located in a search space set and is used for concentrating time-frequency domain resources of a CORESET;

one PDCCH candidate where the first REG is located;

all search space sets on the carrier on which the first REG is located;

all PDCCH candidates on the carrier on which the first REG is located;

activating all search space sets on BWP by the downlink where the first REG is located;

all PDCCH candidates on the downlink active BWP where the first REG is located;

or one OFDM symbol where the first REG is located. In this scheme, the overlapping condition of the first REG and the time-frequency resource for transmitting the CRS may satisfy the processing capability of the terminal, so that the terminal may normally receive the first downlink control channel, thereby improving the communication efficiency.

For example, the subcarrier spacing of the carrier on which the first REG is located may be 15kHz.

Alternatively, it may be restricted that the PDCCH candidates corresponding to the above-mentioned one CORESET time-frequency domain resource, even if overlapped with CRS, need to be monitored by the terminal. Similarly, it may be restricted that one or all of the PDCCH candidates described above need to be monitored by the terminal even though they overlap with the CRS. Similarly, it may be restricted that PDCCH candidates in all search space sets described above need to be monitored by the terminal even though they overlap with CRS.

For example, assuming that the third indication information indicates that the number of CRSs supported or the number of CRS patterns supported when the resource mapping scheme a is used is 3, the number of CRSs or the number of CRS patterns supported overlapping with the carrier where the first REG is located must not exceed 3.

Step S1302, the network device determines a target resource mapping scheme according to the first indication information.

In one possible implementation, the first indication information indicates a first set of resource mapping schemes supported by the terminal on the first REG; or, the first indication information indicates a first set of resource mapping schemes and a first set of reception schemes supported by the terminal on the first REG; step S1302 includes: the network device determines one of the first set of resource mapping schemes as a target resource mapping scheme.

In another possible implementation, the first indication information indicates a first set of reception schemes supported by the terminal on the first REG; step S1302 includes: according to the corresponding relation between the resource mapping scheme and the receiving scheme, the network equipment determines one of one or more resource mapping schemes corresponding to the first receiving scheme set as a target resource mapping scheme.

The above two implementations give specific implementation of the network device to determine the target resource mapping scheme. The method helps the network equipment to select a proper resource mapping scheme supported by the terminal, and avoids poor communication quality and even communication failure caused by the fact that the terminal cannot support the resource mapping scheme adopted by the network equipment, so that the communication efficiency can be improved.

For example, if the first reception scheme set is a 5G legacy reception scheme, the resource mapping schemes corresponding to the 5G legacy reception scheme are a resource mapping scheme a and a resource mapping scheme B, and the target resource mapping scheme determined by the network device may be the resource mapping scheme a or the resource mapping scheme B.

The network device may further determine a target resource mapping scheme according to the first indication information reported by different terminals, and, for example, one terminal supports a receiving scheme set that is a 5G legacy receiving scheme, and another terminal supports a receiving scheme set that is a receiving scheme for the resource mapping scheme a, where the target resource mapping scheme determined by the network device may be the resource mapping scheme a. In this way, both terminals can normally receive the first downlink control channel sent by the network device.

In the embodiment of the application, there may be a resource mapping scheme set and/or a receiving scheme set supported by the terminal by default. The set of resource mapping schemes supported by the default of the terminal may correspond to the set of receiving schemes supported by the default of the terminal.

In one possible implementation, the first indication information indicates a first set of resource mapping schemes supported by the terminal on the first REG; or, the first indication information indicates a first set of resource mapping schemes and a first set of reception schemes supported by the terminal on the first REG; step S1302 includes:

the network equipment determines one resource mapping scheme in the first resource mapping scheme set and the resource mapping scheme set supported by the terminal in default on the first REG as a target resource mapping scheme;

or, the network device determines a second resource mapping scheme set corresponding to the receiving scheme supported by the terminal by default on the first REG according to the corresponding relation between the resource mapping scheme and the receiving scheme; and determining the same one of the first resource mapping scheme set and the second resource mapping scheme set as a target resource mapping scheme.

In another possible implementation, the first indication information indicates a first set of reception schemes supported by the terminal on the first REG; step S1302 includes:

The network equipment determines a third resource mapping scheme set corresponding to the first receiving scheme set according to the corresponding relation between the resource mapping scheme and the receiving scheme;

the network device determines one of the resource mapping schemes in the third resource mapping scheme set or the resource mapping scheme set corresponding to the receiving scheme set supported by the terminal in default on the first REG as a target resource mapping scheme; or, the network device determines a set of resource mapping schemes supported by the terminal by default on the first REG and one resource mapping scheme identical to that in the third set of resource mapping schemes as target resource mapping schemes.

The two implementation modes provide that the network equipment determines the specific implementation of the target resource mapping scheme under the condition that the resource mapping scheme set and/or the receiving scheme set supported by the default of the terminal exist, so that the application scene of the downlink control channel transmission method provided by the embodiment of the application can be expanded.

For example, if there is a receiving scheme set supported by the default by the terminal, which is a 5G legacy receiving scheme, and the first resource mapping scheme set is a resource mapping scheme a, then a second resource mapping scheme set corresponding to the receiving scheme supported by the default by the terminal is a resource mapping scheme a and a resource mapping scheme B, and the target resource mapping scheme determined by the network device may be the same one of the first resource mapping scheme set and the second resource mapping scheme set, that is, one of the intersections of the first resource mapping scheme set and the second resource mapping scheme set, specifically, the resource mapping scheme a.

In one possible implementation, when the aggregation level of the first downlink control channel is greater than a first threshold, the target resource mapping scheme is a first resource mapping scheme; when the aggregation level of the first downlink control channel is smaller than or equal to a first threshold value, the target resource mapping scheme is a second resource mapping scheme; the first resource mapping scheme is different from the second resource mapping scheme. In general, at different aggregation levels, the downlink control channel receiving performance corresponding to different resource mapping schemes may be different. In the scheme, the network equipment adopts different resource mapping schemes under different aggregation levels, so that the maximization of the receiving performance of the downlink control channel can be realized. Illustratively, the first threshold is al=2.

In another possible implementation manner, when the aggregation level of the first downlink control channel is smaller than the first threshold, the target resource mapping scheme is a first resource mapping scheme; when the aggregation level of the first downlink control channel is greater than or equal to a first threshold value, the target resource mapping scheme is a first resource mapping scheme or a second resource mapping scheme; the first resource mapping scheme is different from the second resource mapping scheme. Illustratively, the first threshold is al=2.

In step S1303, the network device adopts a target resource mapping scheme to map the modulation symbol of the first downlink control channel onto the first REG.

In the embodiment of the present application, "mapping the modulation symbols of the first downlink control channel onto the first REG" may be understood as "mapping the modulation symbols of the first downlink control channel onto some or all of the REs of the first REG". That is, it is not necessarily required that all REs on the first REG are mapped to.

In step S1304, the network device sends a first downlink control channel to the terminal. Accordingly, the terminal receives a first downlink control channel from the network device on the first REG.

Optionally, the terminal receives the first downlink control channel from the network device on the first REG, including: the terminal receives a first downlink control channel from the network device on the first REG using a target reception scheme.

In order to determine the target receiving scheme adopted by the terminal to receive the first downlink control channel, in a possible implementation manner, before step S1304, the downlink control channel transmission method provided in the embodiment of the present application further includes: and the network equipment sends the corresponding relation between the resource mapping scheme and the aggregation level to the terminal. Correspondingly, the terminal receives the corresponding relation between the resource mapping scheme and the aggregation level from the network equipment. The terminal determines a third resource mapping scheme corresponding to the aggregation level of the first downlink control channel according to the aggregation level of the first downlink control channel and the corresponding relation between the resource mapping scheme and the aggregation level; and the terminal determines one of the receiving schemes corresponding to the third resource mapping scheme as a target receiving scheme according to the third resource mapping scheme and the corresponding relation between the resource mapping scheme and the receiving scheme.

The implementation manner is beneficial to the terminal to determine the adopted target receiving scheme according to the corresponding relation between the resource mapping scheme and the aggregation level.

In order to determine a target receiving scheme adopted by the terminal for receiving the first downlink control channel, in another possible implementation manner, the downlink control channel transmission method provided in the embodiment of the present application further includes: the network device sends the second indication information to the terminal, and correspondingly, the terminal receives the second indication information from the network device. The second indication information indicates the terminal to receive the first downlink control channel by adopting a target receiving scheme; or, the second indication information indicates that the modulation symbols of the first downlink control channel are mapped to the time-frequency resources of the first downlink control channel by adopting a target resource mapping scheme, and the terminal receives the first downlink control channel by adopting a target receiving scheme. The terminal receives a first downlink control channel from the network device on the first REG using a target reception scheme indicated by the second indication information.

In the above implementation manner, the terminal may receive second indication information from the network device, where the second indication information may explicitly indicate a target receiving scheme adopted by the terminal.

In order to determine a target receiving scheme adopted by the terminal for receiving the first downlink control channel, in another possible implementation manner, the downlink control channel transmission method provided in the embodiment of the application further includes: the network device sends the second indication information to the terminal, and correspondingly, the terminal receives the second indication information from the network device. The second indication information indicates that the modulation symbol of the first downlink control channel is mapped to the time-frequency resource of the first downlink control channel by adopting a target resource mapping scheme. And the terminal determines one of the receiving schemes corresponding to the target resource mapping scheme as a target receiving scheme according to the corresponding relation between the resource mapping scheme and the receiving scheme.

In the above implementation manner, the terminal may determine the target receiving scheme according to the target resource mapping scheme indicated by the received second indication information and the corresponding relationship between the resource mapping scheme and the receiving scheme.

Optionally, when the aggregation level of the first downlink control channel is greater than a first threshold, the target receiving scheme is a first receiving scheme; when the aggregation level of the first downlink control channel is smaller than or equal to a first threshold value, the target receiving scheme is a second receiving scheme; the first reception scheme is different from the second reception scheme; wherein,

The first receiving scheme or the second receiving scheme is one receiving scheme in the first receiving scheme set; or,

the first receiving scheme or the second receiving scheme is one of a first receiving scheme set and a receiving scheme set supported by the terminal by default on the first REG; or,

the first receiving scheme or the second receiving scheme is one of the receiving schemes corresponding to the first resource mapping scheme set; or,

the first receiving scheme or the second receiving scheme is one of the receiving schemes corresponding to the first resource mapping scheme set and the resource mapping scheme set supported by the terminal by default on the first REG. In general, at different aggregation levels, the reception performance of different reception schemes may be different. In the scheme, the terminal adopts different receiving schemes under different aggregation levels, so that the maximization of the receiving performance of the downlink control channel can be realized. In addition, the scheme considers the situation that a resource mapping scheme set and/or a receiving scheme set supported by a default by a terminal exist, so that the application scene of the downlink control channel transmission method provided by the embodiment of the application can be expanded.

Optionally, the first time-frequency resource is a resource used for mapping the first downlink control channel in the first REG, the first time-frequency resource includes a second time-frequency resource and a third time-frequency resource, the second time-frequency resource is a resource used for transmitting the first downlink control channel, the third time-frequency resource is a resource which cannot be used for transmitting the first downlink control channel, the number of REs included in the first time-frequency resource is the same as the number of REs used for mapping the first downlink control channel in the second REG but the positions are different, and the second REG is not overlapped with the time-frequency resource used for transmitting the CRS; step S1304 includes: the network device sends the first downlink control channel to the terminal on the second time-frequency resource, and correspondingly, the terminal receives the first downlink control channel from the network device on the second time-frequency resource. In this scheme, since the number of REs included in the first time-frequency resource is the same as the number of REs used for mapping the first downlink control channel in the second REG, that is, the number of modulation symbols of the downlink control channel participating in decoding is not changed at the terminal side, it is not necessary to modify the decoding part on the basis of the 5G conventional reception scheme, thereby reducing modification at the terminal side.

In the embodiment of the present application, "the resource for mapping the first downlink control channel" may be understood as "the resource for mapping the modulation symbol of the first downlink control channel".

Optionally, the second time-frequency resource includes REs in the first time-frequency resource other than the first set of REs, the first set of REs consisting of REs where the first REG overlaps with time-frequency resources configured for transmitting CRS. In this scheme, all REs except for the RE with the overlapping resource in the first time-frequency resource are used to transmit the resource of the first downlink control channel, so that the time-frequency resource used to transmit the first downlink control channel can be increased as much as possible, and the corresponding receiving performance is better.

Optionally, the third time-frequency resource includes at least one RE of the first set of REs that is non-adjacent and non-overlapping with REs configured for transmission of demodulation reference signals of the downlink control channel.

For convenience of description and comparison, the resource mapping scheme provided in the embodiments of the present application may be referred to as resource mapping scheme D. Illustratively, fig. 14 shows a resource allocation schematic of the resource mapping scheme D when there is an overlap of 2-port or 4-port CRSs and 2-symbol-length CORESET-associated PDCCHs on one symbol with frequency shifts of 0,1, and 2. The following description will take, as an example, a case where the frequency shift is 0. In the two REGs with the same frequency domain resource and adjacent time domain resources, one REG overlaps with the CRS, and the other REG does not overlap with the CRS.

In the resource mapping scheme D, "RE for mapping PDCCH" cannot be identical to "RE for transmitting PDCCH" or "RE for transmitting PDCCH", because PDCCH may be punctured on RE for mapping PDCCH, and cannot be used for transmitting or transmitting PDCCH. That is, the "RE for mapping PDCCH" includes "RE for transmitting PDCCH" or "RE for transmitting PDCCH".

On REGs that overlap with CRS, all REs that do not overlap with CRS are used to map PDCCH modulation symbols, i.e., K, k+1th, k+3rd to k+8th PDCCH modulation symbols, for a total of 8 REs or PDCCH modulation symbols. Illustratively, the second time-frequency resource may be the 8 REs, and the first set of REs may be 4 REs on REGs that overlap with the CRS. That is, the second time-frequency resource may be REs in the first REG other than the first RE set. Further, PDCCH modulation symbols are mapped on at least one RE that overlaps with CRS and is not adjacent to and overlapping with REs configured for transmission of PDCCH DM-RS in the REG, but mapped PDCCH modulation symbols are punctured. That is, the k+2th modulation symbol is mapped on the 4 th RE but the k+2th PDCCH modulation symbol is punctured. Illustratively, the third time-frequency resource is the RE mapping the k+2th modulation symbol, and the first time-frequency resource may be the second time-frequency resource and the third time-frequency resource. Since the PDCCH modulation symbols are punctured, the third time-frequency resource cannot be used for transmitting PDCCH, but can only be used for transmitting CRS.

In the embodiment of the present application, "configured to transmit PDCCH DM-RS" refers to the use of time-frequency resources in the case where only NR system exists and LTE system does not exist.

In fig. 14, the punctured PDCCH modulation symbols are marked with "x". It is easy to see that in the resource mapping scheme D, 9 PDCCH modulation symbols are mapped on REGs overlapping with CRS, where 1 PDCCH modulation symbol is punctured and 8 PDCCH modulation symbols can be normally transmitted.

For the case of frequency shifts of 1 and 2, on REGs where there is overlap with CRS, the positions of REs where there is overlap are different, offset by 1 subcarrier and 2 subcarriers, respectively, with respect to the frequency shift of 0. However, the number of REs having overlap is the same and is 4. In one aspect, PDCCH modulation symbols are mapped on the remaining 8 non-overlapping REs. On the other hand, PDCCH modulation symbols are mapped on one RE that overlaps and is not adjacent to and overlaps with an RE configured to transmit PDCCH DM-RS, but mapped PDCCH modulation symbols are punctured, i.e., PDCCH is not transmitted, and CRS is transmitted. Specifically, when the frequency shift is 1, the 8 th RE is mapped with the (K+5) th modulation symbol, but the (K+5) th PDCCH modulation symbol is punctured; when the frequency shift is 2, the 12 th RE is mapped with the K+8 th modulation symbol, but the K+8 th PDCCH modulation symbol is punctured.

For the resource mapping scheme D, the terminal can only use the receiving scheme for the resource mapping scheme D to receive, that is, perform special processing on the PDCCH and/or the PDCCH DM-RS on the RE overlapped with the CRS, and the specific processing manner is not unique, which is not limited in any way in the embodiment of the present application. Illustratively, in the reception scheme for the resource mapping scheme D, the terminal uses DM-RS on REGs that do not overlap with the CRS, and does not use DM-RS on REGs that overlap with the CRS, because the terminal does not receive DM-RS on REGs that overlap with the CRS. This requires that at least one REG in one CORESET or PDCCH candidate or REG packet does not overlap with CRS.

The embodiment of the present application is described by taking a scenario where an LTE system and an NR system coexist as an example, but the embodiment of the present application may also be applied to a scenario where an NR system and another new system that faces the future coexist, or a scenario where two new systems that faces the future coexist, which is not specifically limited.

The resource mapping scheme D has the advantages that:

1. since the number of REs used for transmitting PDCCH in the resource mapping scheme B is 6 and the number of REs used for transmitting PDCCH in the resource mapping scheme D is 8, resources used for transmitting PDCCH in the resource mapping scheme D are more than those in the resource mapping scheme B, and thus, the PDCCH receiving performance corresponding to the resource mapping scheme D is better.

2. In the resource mapping scheme D, since the number of REs for mapping PDCCH modulation symbols on REGs overlapping with CRS and the number of REs for mapping PDCCH modulation symbols on REGs not overlapping with CRS are both 9, the decoding part does not need to be modified for the reception scheme of the resource mapping scheme D on the basis of the 5G legacy reception scheme. However, since the locations of REs on REGs where there is overlap with the CRS for mapping PDCCH modulation symbols are different from the locations of REs on REGs where there is no overlap with the CRS for mapping PDCCH modulation symbols, the reception scheme for resource mapping scheme D only needs to modify the rate matching section on the basis of the 5G legacy reception scheme. The resource mapping scheme D requires less modification of the corresponding reception scheme than the resource mapping scheme C.

The disadvantage of resource mapping scheme D is that:

the reception scheme corresponding to the resource mapping scheme B cannot be a 5G legacy reception scheme.

In connection with the above analysis, table 1 can be extended to table 3 below and table 2 can be extended to table 4 below.

TABLE 3 Table 3

TABLE 4 Table 4

Fig. 15 is a diagram of another downlink control channel transmission method according to an embodiment of the present application, where the downlink control channel transmission method includes the following steps:

In step S1501, the network device sends first configuration information to the terminal, and accordingly, the terminal receives the first configuration information from the network device.

The first configuration information is used for determining a first REG and/or a second REG, wherein the first REG and/or the second REG are time-frequency resources configured for transmitting downlink control channels and demodulation reference signals of the downlink control channels.

For example, the first configuration information may be PDCCH configuration information, and specific content of the PDCCH configuration information may refer to an existing protocol, which is not described herein.

In step S1502, the network device sends the second configuration information to the terminal, and accordingly, the terminal receives the second configuration information from the network device.

Wherein the second configuration information is used to determine time-frequency resources for transmitting the CRS.

For example, the second configuration information may be CRS configuration information, and specific content of the CRS configuration information may refer to an existing protocol, which is not described herein.

In the embodiment of the present application, step S1501 may be performed first and then step S1502 may be performed, or step S1502 may be performed first and then step S1501 may be performed, or step S1501 and step S1502 may be performed simultaneously, which is not limited in any way in the embodiment of the present application.

In step S1503a, in a case where there is an overlap between the first REG and the time-frequency resources configured for transmitting CRS, the network device determines the first time-frequency resources in the first REG.

In step S1503b, in the case where there is an overlap between the first REG and the time-frequency resources configured for transmitting CRS, the terminal determines the first time-frequency resources in the first REG.

The first time-frequency resource is a resource for mapping the first downlink control channel, the first time-frequency resource comprises a second time-frequency resource and a third time-frequency resource, the second time-frequency resource is a resource for transmitting the first downlink control channel, the third time-frequency resource is a resource which cannot be used for transmitting the first downlink control channel, the number of REs included in the first time-frequency resource is the same as the number of REs used for mapping the first downlink control channel in the second REG but different in position, and the second REG is not overlapped with the time-frequency resource used for transmitting the CRS.

In the embodiment of the present application, step S1503a may be performed first and then step S1503b may be performed, or step S1503b may be performed first and then step S1503a may be performed, or step S1503a and step S1503b may be performed simultaneously, which is not limited in this embodiment of the present application.

Optionally, the second time-frequency resource includes REs in the first time-frequency resource other than the first set of REs, the first set of REs consisting of REs where the first REG overlaps with time-frequency resources configured for transmitting CRS.

Optionally, the third time-frequency resource includes at least one RE of the first RE set that is not adjacent to and does not overlap with REs preset for transmitting demodulation reference signals of the downlink control channel.

In step S1504, the network device sends a first downlink control channel to the terminal on the second time-frequency resource, and correspondingly, the terminal receives the first downlink control channel from the network device on the second time-frequency resource.

In the embodiment of the present application, even if the network device does not send the first downlink control channel to the terminal on the second time-frequency resource, the terminal needs to perform the action of receiving the first downlink control channel from the network device on the second time-frequency resource. That is, the terminal monitors the downlink control channel even if the downlink control channel is not transmitted or carried on the second time-frequency resource.

The specific description and technical effects of the embodiment shown in fig. 15 can be found in the above embodiment, and will not be repeated here.

Fig. 16 is a schematic diagram of another downlink control channel transmission method according to an embodiment of the present application, where the downlink control channel transmission method includes the following steps:

in step S1601, the network device sends first configuration information to the terminal, and accordingly, the terminal receives the first configuration information from the network device. The first configuration information is used for indicating that the aggregation level of the first control channel candidate is a first aggregation level. And the terminal determines the aggregation level of the first control channel candidate as a first aggregation level according to the first configuration information.

In the embodiment of the present application, the terminal may determine whether to need to monitor the first downlink control channel candidate according to the overlapping situation of the first downlink control channel candidate and the time-frequency resource configured for transmitting CRS, and the aggregation level of the first downlink control channel.

Optionally, the configuration information of the first downlink control channel candidate is configuration information of a search space where the first downlink control channel is located, or the configuration information of the first downlink control channel candidate is configuration information of a search space set where the first downlink control channel is located.

In step S1602a, if the first downlink control channel candidate overlaps with the time-frequency resources configured for transmitting CRS on each symbol in the first symbol set, the terminal monitors the downlink control channel on the first downlink control channel candidate if the first aggregation level belongs to the second aggregation level set, and does not monitor the downlink control channel on the first downlink control channel candidate if the first aggregation level does not belong to the second aggregation level set. The first symbol set is a symbol where the first downlink channel candidate is located.

In step S1602b, if the first downlink control channel candidate does not overlap with the time-frequency resources configured for transmitting CRS on at least one symbol in the first symbol set, the terminal monitors the downlink control channel on the first downlink control channel candidate if the first aggregation level belongs to the third aggregation level set, and does not monitor the downlink control channel on the first downlink control channel candidate if the first aggregation level does not belong to the third aggregation level set. Wherein the third set of polymerization levels is different from the second set of polymerization levels.

In the embodiment of the present application, step S1602a or step S1602b may be performed.

Optionally, the third set of aggregation levels includes each aggregation level included in the second set of aggregation levels.

Optionally, the second aggregation level set does not contain all of the aggregation levels 1, 2, 4, 8, 16.

Optionally, the second aggregation level set comprises and only comprises aggregation levels 2, 4, 8, 16.

Optionally, the second aggregation level set comprises and only comprises aggregation levels 4, 8, 16.

Optionally, the second aggregation level set comprises and only comprises aggregation levels 8, 16.

Optionally, the second aggregation level set comprises and only comprises aggregation level 16.

Optionally, the third aggregation level set comprises and only comprises aggregation levels 1, 2, 4, 8, 16.

Optionally, each aggregation level in the second set of aggregation levels is greater than or equal to a first threshold, and each aggregation level in the third set of aggregation levels is greater than or equal to a second threshold, the second threshold being less than the first threshold. In the case where there is resource overlap on all symbols, the second aggregation level set does not include the lower aggregation level in this scheme because the reception performance of the downlink control channel of the lower aggregation level is poor. The UE does not monitor the first downlink control channel candidate when the aggregation level of the first downlink control channel candidate, i.e., the first aggregation level, is low. Therefore, the terminal can only monitor the downlink control channel candidates with higher aggregation level, but not monitor the downlink control channel candidates with lower aggregation level, which are easy to generate receiving errors, so that the power consumption of the terminal can be saved. In addition, the scheme can also reduce the probability of false alarm and missed detection caused by error of the downlink channel receiving the lower aggregation level.

Illustratively, the first threshold may be 4.

Illustratively, the second threshold may be 1.

In combination with the embodiment shown in fig. 16, the downlink control channel transmission method provided in the embodiment of the present application may further include the following steps:

For a specific description of step S1601, please refer to the specific description of step S1601 in the embodiment shown in fig. 6, which is not repeated here.

In step S1602c, if the first downlink control channel candidate overlaps with the time-frequency resource configured for transmitting CRS, the terminal monitors the downlink control channel on the first downlink control channel candidate if the first aggregation level belongs to the second aggregation level set, and does not monitor the downlink control channel on the first downlink control channel candidate if the first aggregation level does not belong to the second aggregation level set.

In step S1602d, the terminal monitors the downlink control channel with the first aggregation level on the first downlink control channel candidate if there is no overlap between the first downlink control channel candidate and the time-frequency resource configured for transmitting CRS.

In the embodiment of the present application, step S1602c or step S1602d may be performed.

Optionally, each aggregation level in the second set of aggregation levels is greater than or equal to a first threshold, the first threshold being greater than 1. In the case where there is an overlap between the first downlink control channel candidate and the time-frequency resource configured for CRS transmission, the second aggregation level set does not include the lower aggregation level because the reception performance of the downlink control channel of the lower aggregation level is poor. The UE does not monitor the first downlink control channel candidate when the aggregation level of the first downlink control channel candidate, i.e., the first aggregation level, is low. Therefore, the terminal can only monitor the downlink control channel candidates with higher aggregation level, but not monitor the downlink control channel candidates with lower aggregation level, which are easy to generate receiving errors, so that the power consumption of the terminal can be saved. In addition, the scheme can also reduce the probability of false alarm and missed detection caused by error of the downlink channel receiving the lower aggregation level.

Illustratively, the first threshold may be 2,4, or 8.

In connection with the embodiment shown in fig. 16, another downlink control channel transmission method is provided in the embodiment of the present application, which may include the following steps:

In step S1602e, if the first downlink control channel candidate overlaps with the time-frequency resources configured for transmitting CRS on each symbol in the first symbol set, the terminal monitors the downlink control channel on the first downlink control channel candidate if the first aggregation level belongs to the second aggregation level set, and does not monitor the downlink control channel on the first downlink control channel candidate if the first aggregation level does not belong to the second aggregation level set. The first symbol set is a symbol where the first downlink channel candidate is located.

In step S1602f, if the first downlink control channel does not overlap with the time-frequency resources configured for transmitting CRS on at least one symbol in the first symbol set, and the first downlink control channel overlaps with the time-frequency resources configured for transmitting CRS on at least one symbol in the first symbol set, the terminal monitors the downlink control channel on the first downlink control channel candidate if the first aggregation level belongs to the third aggregation level set, and if the first aggregation level does not belong to the third aggregation level set, the terminal does not monitor the downlink control channel on the first downlink control channel candidate. Wherein the third set of polymerization levels is different from the second set of polymerization levels.

In step S1602g, the terminal monitors the downlink control channel using the first aggregation level on the first downlink control channel candidate if there is no overlap between the first downlink control channel candidate and the time-frequency resource configured for transmitting CRS.

In the embodiment of the present application, step S1602a, or step S1602b may be performed.

Optionally, the third aggregation level set does not contain all of the aggregation levels 1, 2, 4, 8, 16.

Optionally, the third aggregation level set comprises and only comprises aggregation levels 2, 4, 8, 16.

Optionally, the third aggregation level set comprises and only comprises aggregation levels 4, 8, 16.

Optionally, the third aggregation level set comprises and only comprises aggregation levels 8, 16.

Optionally, the third aggregation level set comprises and only comprises aggregation level 16.

Optionally, each aggregation level in the second set of aggregation levels is greater than or equal to a first threshold, and each aggregation level in the third set of aggregation levels is greater than or equal to a second threshold, the second threshold being less than the first threshold. In the case where there is a resource overlap or a partial overlap on all symbols, the reception performance of the downlink control channel of the lower aggregation level is poor, and in particular, in the case where there is a resource overlap in its entirety, the reception performance of the downlink control channel of the lower aggregation level is particularly poor, and therefore, the second aggregation level set and the third aggregation level set do not include the lower aggregation level in this scheme. The second set of polymerization levels does not contain more low polymerization levels than the third set of polymerization levels. The UE does not monitor the first downlink control channel candidate when the aggregation level of the first downlink control channel candidate, i.e., the first aggregation level, is low. Therefore, the terminal can only monitor the downlink control channel candidates with higher aggregation level, but not monitor the downlink control channel candidates with lower aggregation level, which are easy to generate receiving errors, so that the power consumption of the terminal can be saved. In addition, the scheme can also reduce the probability of false alarm and missed detection caused by error of the downlink channel receiving the lower aggregation level.

Illustratively, the first threshold may be 4 or 8 and the second threshold may be 2.

Illustratively, the second threshold may be 8, the second threshold being 4 or 2.

It will be appreciated that, in order to implement the functions in the above embodiments, the network device and the terminal include corresponding hardware structures and/or software modules that perform the respective functions. Those of skill in the art will readily appreciate that the elements and method steps of the examples described in connection with the embodiments disclosed herein may be implemented as hardware or a combination of hardware and computer software. Whether a function is implemented as hardware or computer software driven hardware depends upon the particular application scenario and design constraints imposed on the solution.

Fig. 17 and 18 are schematic structural diagrams of possible communication devices according to embodiments of the present application. These communication devices may be used to implement the functions of the terminal or the network device in the above method embodiments, so that the beneficial effects of the above method embodiments may also be implemented. In the embodiment of the present application, the communication apparatus may be one of the terminals 120a-120j shown in fig. 12, or may be the radio access network device 110a or 110b shown in fig. 12, or may be a module (such as a chip) applied to the terminal or the network device.

As shown in fig. 17, the communication apparatus 1700 includes a processing unit 1710 and a transmitting-receiving unit 1720. The communication apparatus 1700 is used to implement the functions of the terminal or network device in the method embodiment shown in fig. 13 or fig. 15 described above.

When the communication apparatus 1700 is used to implement the functions of a terminal in the method embodiment shown in fig. 13: a transceiver unit 1720, configured to send capability information to a network device; the transceiver unit 1720 is further configured to receive a first downlink control channel from the network device on the first REG.

When the communication apparatus 1700 is used to implement the functionality of a network device in the method embodiment shown in fig. 13: a transceiving unit 1720 for receiving capability information from a terminal; a processing unit 1710, configured to determine a target resource mapping scheme according to the first indication information; the processing unit 1710 is further configured to map the modulation symbol of the first downlink control channel onto the first REG by using the target resource mapping scheme; the transceiver unit 1720 is further configured to send the first downlink control channel to the terminal.

For a more detailed description of the processing unit 1710 and the transceiving unit 1720 described above, reference is made to the relevant description in the method embodiment shown in fig. 13.

When the communication apparatus 1700 is used to implement the functions of a terminal in the method embodiment shown in fig. 15: a transceiver unit 1720 configured to receive first configuration information from a network device; a transceiver unit 1720, configured to receive second configuration information from the network device; a processing unit 1710, configured to determine, in a case where there is an overlap of the first REGs with time-frequency resources configured for transmitting CRSs, a first time-frequency resource in the first REGs; the transceiver unit 1720 is further configured to receive the first downlink control channel from the network device on the second time-frequency resource.

When the communication apparatus 1700 is used to implement the functionality of a network device in the method embodiment shown in fig. 15: a transceiver unit 1720, configured to send the first configuration information to the terminal device; a transceiver unit 1720, configured to send the second configuration information to the terminal device; a processing unit 1710, configured to determine, in a case where there is an overlap of the first REGs with time-frequency resources configured for transmitting CRSs, a first time-frequency resource in the first REGs; the transceiver unit 1720 is further configured to send the first downlink control channel to the terminal on the second time-frequency resource.

For a more detailed description of the processing unit 1710 and the transceiving unit 1720 described above, reference may be made to the relevant description in the method embodiment shown in fig. 15.

When the communication apparatus 1700 is used to implement the functions of a terminal in the method embodiment shown in fig. 16: a transceiver unit 1720 for receiving first lower configuration information from a network device; the processing unit 1710 is configured to determine whether the first downlink control channel candidate needs to be monitored according to the overlapping situation of the first downlink control channel candidate and the time-frequency resource configured for transmitting CRS, and the aggregation level of the first downlink control channel. The transceiver unit 1720 is further configured to monitor the downlink control channel on the first downlink control channel candidate if it is determined that the first downlink control channel candidate needs to be monitored.

When the communication apparatus 1700 is used to implement the functionality of a network device in the method embodiment shown in fig. 16: a transceiver unit 1720, configured to send configuration information of the first downlink control channel candidate to the terminal device.

For a more detailed description of the processing unit 1710 and the transceiving unit 1720 described above, reference is made to the relevant description in the method embodiment shown in fig. 16.

As shown in fig. 18, the communication device 1800 includes a processor 1810 and an interface circuit 1820. The processor 1810 and the interface circuit 1820 are coupled to each other. It is to be appreciated that interface circuit 1820 can be a transceiver or an input-output interface. Optionally, the communication device 1800 may also include a memory 1830 for storing instructions to be executed by the processor 1810 or for storing input data required by the processor 1810 to execute instructions or for storing data generated by the processor 1810 after executing instructions.

When the communication device 1800 is used to implement the method shown in fig. 13 or fig. 15, the processor 1810 is used to implement the functions of the processing unit 1710, and the interface circuit 1820 is used to implement the functions of the transceiver unit 1720.

When the communication device is a chip applied to the terminal, the terminal chip realizes the functions of the terminal in the embodiment of the method. The terminal chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal, and the information is sent to the terminal by the base station; alternatively, the terminal chip sends information to other modules in the terminal (e.g., radio frequency modules or antennas) that the terminal sends to the base station.

When the communication device is a module applied to the network device, the network device module implements the functions of the network device in the method embodiment. The network device module receives information from other modules (such as a radio frequency module or an antenna) in the network device, the information being transmitted to the network device by the terminal; alternatively, the network device module sends information to other modules in the network device (e.g., radio frequency modules or antennas) that the network device sends to the terminal. The network device module may be a baseband chip of the network device, or may be a DU or other module, where the DU may be a DU under an open radio access network (open radio access network, O-RAN) architecture.

It is to be appreciated that the processor in embodiments of the present application may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field Programmable Gate Array, FPGA) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general purpose processor may be a microprocessor, but in the alternative, it may be any conventional processor.

The method steps in the embodiments of the present application may be implemented in hardware, or in software instructions executable by a processor. The software instructions may be comprised of corresponding software modules that may be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, removable disk, compact disc-read only memory (CD-ROM), or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. The storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. In addition, the ASIC may reside in a base station or terminal. The processor and the storage medium may reside as discrete components in a base station or terminal.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, a network device, a user device, or other programmable apparatus. The computer program or instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer program or instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center by wired or wireless means. The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that integrates one or more available media. The usable medium may be a magnetic medium, e.g., floppy disk, hard disk, tape; but also optical media such as digital video discs; but also semiconductor media such as solid state disks. The computer readable storage medium may be volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage medium.

In the various embodiments of the application, if there is no specific description or logical conflict, terms and/or descriptions between the various embodiments are consistent and may reference each other, and features of the various embodiments may be combined to form new embodiments according to their inherent logical relationships.

Claims

1. A downlink control channel transmission method, comprising:

receiving capability information from a terminal, wherein the capability information comprises first indication information, the first indication information indicates a first resource mapping scheme set and/or a first receiving scheme set supported by the terminal on a first Resource Element Group (REG), wherein the first resource mapping scheme set comprises resource mapping schemes of one or more downlink control channels, the first receiving scheme set comprises receiving schemes of one or more downlink control channels, the first REG is configured to transmit downlink control channels and demodulation reference signals of the downlink control channels, and the first REG is overlapped with time-frequency resources configured to transmit cell specific reference signals (CRSs);

determining a target resource mapping scheme according to the first indication information;

And mapping the modulation symbol of the first downlink control channel to the first REG by adopting the target resource mapping scheme, and sending the first downlink control channel to the terminal.

2. The method of claim 1, wherein the step of determining the position of the substrate comprises,

the first indication information indicates the first set of resource mapping schemes supported by the terminal on the first REG; or, the first indication information indicates the first set of resource mapping schemes and the first set of reception schemes supported by the terminal on the first REG; the determining a target resource mapping scheme according to the first indication information includes:

determining one of the first set of resource mapping schemes as the target resource mapping scheme; or,

determining one of the first set of resource mapping schemes and the set of resource mapping schemes supported by the terminal by default on the first REG as the target resource mapping scheme; or,

determining a second resource mapping scheme set corresponding to a receiving scheme supported by the terminal by default on the first REG according to the corresponding relation between the resource mapping scheme and the receiving scheme; and determining the same one of the first resource mapping scheme set and the second resource mapping scheme set as the target resource mapping scheme.

3. The method of claim 1, wherein the first indication information indicates the first set of reception schemes supported by the terminal on the first REG; the determining a target resource mapping scheme according to the first indication information includes:

according to the corresponding relation between the resource mapping scheme and the receiving scheme, determining one of one or more resource mapping schemes corresponding to the first receiving scheme set as the target resource mapping scheme; or,

determining a third resource mapping scheme set corresponding to the first receiving scheme set according to the corresponding relation between the resource mapping scheme and the receiving scheme; determining one of the third resource mapping scheme set or the resource mapping scheme set corresponding to the receiving scheme set supported by the terminal by default on the first REG as the target resource mapping scheme; or determining a set of resource mapping schemes supported by the terminal by default on the first REG and one resource mapping scheme identical to that in the third set of resource mapping schemes as the target resource mapping scheme.

4. A method according to any one of claims 1-3, wherein the target resource mapping scheme is a first resource mapping scheme when the aggregation level of the first downlink control channel is greater than a first threshold; when the aggregation level of the first downlink control channel is smaller than or equal to the first threshold, the target resource mapping scheme is a second resource mapping scheme; the first resource mapping scheme is different from the second resource mapping scheme.

5. The method according to any of claims 1-4, wherein before said transmitting the first downlink control channel to the terminal, the method further comprises:

and sending the corresponding relation between the resource mapping scheme and the aggregation level to the terminal.

6. The method according to any one of claims 1-5, further comprising:

and sending second indication information to the terminal, wherein the second indication information indicates that the modulation symbols of the first downlink control channel are mapped to the time-frequency resources of the first downlink control channel by adopting the target resource mapping scheme, and/or indicates that the terminal receives the first downlink control channel by adopting a target receiving scheme.

7. The method according to any one of claims 1-6, wherein the first set of resource mapping schemes includes a different resource mapping scheme M1 and a resource mapping scheme M2, and the resource mapping scheme M1 and the resource mapping scheme M2 are:

the rate matching parameters of the downlink control channel when the resource mapping scheme M1 and the resource mapping scheme M2 are adopted are different; or,

one RE#1 is arranged in resource units RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting CRS, the RE#1 is used for mapping modulation symbols of the downlink control channel in the resource mapping scheme M1, and the RE#1 is not used for mapping modulation symbols of the downlink control channel in the resource mapping scheme M2; or,

one RE#1 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting CRS, the RE#1 is used for bearing the modulation symbol of the downlink control channel in the resource mapping scheme M1, and the RE#1 is not used for bearing the modulation symbol of the downlink control channel in the resource mapping scheme M2; or,

one RE#1 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting CRS, the RE#1 is used for bearing modulation symbols of demodulation reference signals of the downlink control channel in the resource mapping scheme M1, and the RE#1 is not used for bearing modulation symbols of demodulation reference signals of the downlink control channel in the resource mapping scheme M2; or,

And one RE#1 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting the CRS, the RE#1 is used for mapping modulation symbols of demodulation reference signals of the downlink control channel in the resource mapping scheme M1, and the RE#1 is not used for mapping modulation symbols of demodulation reference signals of the downlink control channel in the resource mapping scheme M2.

8. The method according to any of claims 1-7, wherein the first set of reception schemes includes a different reception scheme R1 and a reception scheme R2, the reception scheme R1 and the reception scheme R2 being:

one RE#2 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting CRS, and the received signal on the RE#2 is used for channel estimation in the receiving scheme R1 and is not used for channel estimation in the receiving scheme R2; or,

one RE#2 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting CRS, and the received signal on the RE#2 is used for demodulation in the receiving scheme R1 and is not used for demodulation in the receiving scheme R2; or,

And one RE #2 exists in the RE where the time-frequency resource of the downlink control channel overlaps with the time-frequency resource configured for transmitting CRS, and the received signal on the RE #2 is used for generating the input of the decoder in the receiving scheme R1, and is not used for generating the input of the decoder in the receiving scheme R2.

9. The method of any of claims 1-8, wherein the capability information further comprises third indication information, wherein,

the third indication information indicates the number of CRS supported or the number of CRS patterns supported when using the resource mapping scheme M1 in the first resource mapping scheme set and the reception scheme R1 in the first reception scheme set.

10. The method of claim 9, wherein the number of CRS supported or the number of CRS patterns supported is an upper limit of the number of CRS supported by the terminal or an upper limit of the number of CRS patterns supported by the terminal when there is an overlap in one of CRS time-frequency resources and:

A carrier on which the first REG is located;

the first REG is located in a search space set and is used for controlling time-frequency domain resources of a resource set CORESET;

a Physical Downlink Control Channel (PDCCH) candidate in which the first REG is located;

all search space sets on the carrier on which the first REG is located;

all PDCCH candidates on the carrier on which the first REG is located;

all search space sets on the downlink active bandwidth portion BWP where the first REG is located;

all PDCCH candidates on the downlink active bandwidth portion BWP where the first REG is located;

alternatively, the first REG is located in one orthogonal frequency division multiplexing OFDM symbol.

11. The method according to any one of claims 1-10, wherein a first time-frequency resource is a resource used for mapping the first downlink control channel in the first REG, the first time-frequency resource includes a second time-frequency resource and a third time-frequency resource, the second time-frequency resource is a resource used for transmitting the first downlink control channel, the third time-frequency resource is a resource that cannot be used for transmitting the first downlink control channel, the first time-frequency resource includes the same number of REs as the number of REs used for mapping the first downlink control channel in a second REG but is located differently, and the second REG does not overlap with the time-frequency resource used for transmitting the CRS;

The sending the first downlink control channel to the terminal includes:

and sending the first downlink control channel to the terminal on the second time-frequency resource.

12. The method of claim 11, wherein the second time-frequency resources comprise REs of the first time-frequency resources other than a first set of REs comprised of REs of the first REG that overlap with the time-frequency resources configured for transmission of the CRS.

13. The method of claim 12, wherein the third time-frequency resource comprises at least one RE of the first set of REs that is non-adjacent and non-overlapping with REs configured for transmission of demodulation reference signals of the first downlink control channel.

14. A downlink control channel transmission method, performed by a terminal or a module applied in the terminal, comprising:

transmitting capability information to a network device, wherein the capability information comprises first indication information, the first indication information indicates a first resource mapping scheme set and/or a first receiving scheme set supported by the terminal on a first resource unit group (REG), the first resource mapping scheme set comprises one or more resource mapping schemes of downlink control channels, the first receiving scheme set comprises one or more receiving schemes of downlink control channels, the first REG is configured to transmit downlink control channels and demodulation reference signals of the downlink control channels, and the first REG overlaps with time-frequency resources configured to transmit cell specific reference signals (CRSs);

A first downlink control channel from the network device is received on the first REG.

15. The method of claim 14, wherein the receiving a first downlink control channel from the network device on the first REG comprises:

receiving the first downlink control channel from the network device on the first REG using a target reception scheme; when the aggregation level of the first downlink control channel is greater than a first threshold, the target receiving scheme is a first receiving scheme; when the aggregation level of the first downlink control channel is smaller than or equal to the first threshold, the target receiving scheme is a second receiving scheme; the first reception scheme is different from the second reception scheme; wherein,

the first reception scheme or the second reception scheme is one of the first set of reception schemes and a set of reception schemes supported by the terminal by default on the first REG; or,

The first receiving scheme or the second receiving scheme is one of the first resource mapping scheme set and a receiving scheme corresponding to the resource mapping scheme set supported by the terminal by default on the first REG.

16. The method of claim 14 or 15, wherein the receiving the first downlink control channel from the network device on the first REG comprises:

receiving the first downlink control channel from the network device on the first REG using a target reception scheme;

the method further comprises, prior to the receiving the first downlink control channel from the network device on the first REG using the target reception scheme:

receiving a corresponding relation between a resource mapping scheme and an aggregation level from the network equipment;

determining a third resource mapping scheme corresponding to the aggregation level of the first downlink control channel according to the aggregation level of the first downlink control channel and the corresponding relation between the resource mapping scheme and the aggregation level;

and determining one of the receiving schemes corresponding to the third resource mapping scheme as the target receiving scheme according to the third resource mapping scheme and the corresponding relation between the resource mapping scheme and the receiving scheme.

17. The method of any of claims 14-16, wherein the receiving a first downlink control channel from the network device on the first REG comprises:

receiving second indication information from the network equipment, wherein the second indication information indicates the terminal to receive the first downlink control channel by adopting a target receiving scheme; or, the second indication information indicates that the modulation symbol of the first downlink control channel is mapped to the time-frequency resource of the first downlink control channel by adopting a target resource mapping scheme, and the terminal receives the first downlink control channel by adopting the target receiving scheme; receiving the first downlink control channel from the network device on the first REG using the target reception scheme indicated by the second indication information;

or,

receiving second indication information from the network equipment, wherein the second indication information indicates that a modulation symbol of the first downlink control channel is mapped to a time-frequency resource of the first downlink control channel by adopting a target resource mapping scheme; according to the target resource mapping scheme, determining one of the receiving schemes corresponding to the target resource mapping scheme as a target receiving scheme according to the corresponding relation between the resource mapping scheme and the receiving scheme; the first downlink control channel from the network device is received on the first REG using the target reception scheme.

18. The method according to any one of claims 14-17, wherein the first set of resource mapping schemes includes a different resource mapping scheme M1 and a resource mapping scheme M2, and the resource mapping scheme M1 and the resource mapping scheme M2 are:

19. The method according to any of claims 14-18, wherein the first set of reception schemes comprises a different reception scheme R1 and a reception scheme R2, the reception scheme R1 and the reception scheme R2 being:

20. The method of any of claims 14-19, wherein the capability information further comprises third indication information, wherein,

21. The method of claim 20, wherein the number of CRS supported or the number of CRS patterns supported is an upper limit of the number of CRS supported by the terminal or an upper limit of the number of CRS patterns supported by the terminal when there is overlap between CRS time-frequency resources and one of the following time-frequency resources:

A carrier on which the first REG is located;

all search space sets on the carrier on which the first REG is located;

all PDCCH candidates on the carrier on which the first REG is located;

22. The method according to any one of claims 14-21, wherein a first time-frequency resource is a resource used for mapping the first downlink control channel in the first REG, the first time-frequency resource includes a second time-frequency resource and a third time-frequency resource, the second time-frequency resource is a resource used for transmitting the first downlink control channel, the third time-frequency resource is a resource that cannot be used for transmitting the first downlink control channel, the first time-frequency resource includes the same number of REs as the number of REs used for mapping the first downlink control channel in a second REG but is located differently, and the second REG is not overlapped with the time-frequency resource used for transmitting the CRS;

The receiving the first downlink control channel from the network device on the first REG comprises:

the first downlink control channel from the network device is received on the second time-frequency resource.

23. The method of claim 22, wherein the second time-frequency resources comprise REs of the first time-frequency resources other than a first set of REs comprised of REs of the first REG that overlap with the time-frequency resources configured for transmission of the CRS.

24. The method of claim 23, wherein the third time-frequency resource comprises at least one RE of the first set of REs that is non-adjacent and non-overlapping with REs configured for transmission of demodulation reference signals of the first downlink control channel.

25. A communication device comprising a processor and interface circuitry for receiving signals from other communication devices and transmitting signals from the processor to the processor or for sending signals from the processor to other communication devices, the processor being configured to implement the method of any one of claims 1 to 13 by logic circuitry or execution of code instructions; alternatively, the processor is configured to implement the method of any one of claims 14 to 24 by logic circuitry or executing code instructions.

26. A computer readable storage medium, characterized in that the storage medium has stored therein a computer program or instructions which, when executed by a communication device, implement the method of any of claims 1 to 13; alternatively, the method of any one of claims 14 to 24 is implemented.