Communication method, apparatus, medium, chip system and product

Abstract

The application provides a communication method, device, medium, chip system and product, and belongs to the technical field of communication. The method comprises the following steps: a terminal device acquires a candidate precoding matrix based on a codebook subset restriction (CBSR) prohibited spatial domain basis vector group, and reports a candidate precoding matrix indicator (PMI) used for indicating the candidate precoding matrix to a network device in the case that the candidate precoding matrix is better than a main precoding matrix, so that the network device determines a precoding matrix used for communicating with the terminal device based on the candidate PMI, and the main precoding matrix is an optimal precoding matrix determined based on a CBSR allowed spatial domain basis vector group. In this way, in the case that the CBSR mis-masks some fine beam directions with good channel quality, the more optimal fine beam direction can be avoided to be missed, so that the signaling overhead and system performance can be balanced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of communication, and particularly relates to a communication method, device, medium, chip system and product. BACKGROUND

[0002] In the new radio (NR) of the 5th generation (5G) mobile communication technology, codebook subset restriction (CBSR) is a mechanism for limiting the subset of precoding vectors of a codebook selectable by a terminal device, configured by a network device through a radio resource control (RRC) layer. By controlling the subset of the codebook, CBSR can effectively reduce feedback overhead and improve resource configuration efficiency. In a type II codebook structure, the RRC configuration overhead of CBSR is positively correlated with the parameter combination N1N2O1O2, which leads to a significant increase in signaling burden under a large-scale array, where N1 represents the number of antenna ports in the horizontal direction of the antenna, N2 represents the number of antenna ports in the vertical direction of the antenna, O1 represents the oversampling factor of the antenna port in the horizontal direction, and O2 represents the oversampling factor of the second dimension in the vertical direction.

[0003] To this end, in Release 19 of the technical specification (TS) 38.214 of the 3rd generation partnership project (3GPP), the control granularity of CBSR is simplified, and it is specified that it is only configured for N1N2 coarse directions, which can significantly reduce the RRC configuration overhead. However, in the case where CBSR adopts a coarse-grained restriction method, the system performance may be reduced.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore does not constitute prior art known to those skilled in the art. SUMMARY

[0005] In view of this, the purpose of the present application is to provide a communication method, device, medium, chip system and product to balance the signaling overhead and system performance in the case where CBSR mis-masks fine beam directions with good channel quality.

[0006] Embodiments of the present application are implemented as follows:

[0007] Firstly, a communication method is provided. This method can be executed by a terminal device, by a component configured in the terminal device (such as a processor, circuit, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the terminal device. This application does not limit the scope of this method. The following description uses a terminal device as an example.

[0008] The method includes: obtaining a candidate precoding matrix, and, if the candidate precoding matrix is ​​superior to the master precoding matrix, sending a candidate precoding matrix indicator (PMI) to the network device to indicate the candidate precoding matrix; wherein the candidate precoding matrix is ​​the optimal precoding matrix determined based on the spatial basis vector set prohibited by the CBSR, and the master precoding matrix is ​​the optimal precoding matrix determined based on the spatial basis vector set allowed by the CBSR.

[0009] Based on the method described in the first aspect, when the CBSR employs a coarse-grained restriction approach, it may inadvertently block some fine beam directions with good channel quality. That is, among the spatial basis vector sets prohibited by the CBSR, there may be spatial basis vector sets that can be used to construct the precoding matrix corresponding to these fine beam directions. In this case, the terminal device determines the optimal precoding matrix (i.e., the aforementioned candidate precoding matrix) based on the spatial basis vector sets prohibited by the CBSR. If this optimal precoding matrix is ​​superior to the main precoding matrix, the terminal device reports a candidate PMI (Precoding Indicator Minute) to the network device to indicate this optimal precoding matrix. This allows the network device to determine the precoding matrix for communication with the terminal device based on the candidate precoding matrix corresponding to the candidate PMI. This avoids overlooking better fine beam directions, thus balancing signaling overhead and system performance.

[0010] In one possible implementation, the number of spatial basis vector groups prohibited by CBSR is M, and the number of spatial basis vector groups allowed by CBSR is N, where M and N are both positive integers. The sum of M and N is (N1·N2) / (X1·X2), where N1 is the number of antenna ports of the network device in the horizontal direction, N2 is the number of antenna ports of the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the horizontal direction, X1 is a positive integer less than or equal to N1, and N1 is divisible by X1, and X2 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the vertical direction, X2 is a positive integer less than or equal to N2, and N2 is divisible by X2. That is, CBSR can divide N1·N2 spatial basis vectors into (N1·N2) / (X1·X2) spatial basis vector groups. The terminal device can determine the candidate precoding matrix based on the M spatial basis vector groups in (N1·N2) / (X1·X2) indicated by CBSR, and determine the main precoding matrix based on the N spatial basis vector groups in (N1·N2) / (X1·X2) indicated by CBSR.

[0011] In one possible implementation, before obtaining the candidate precoding matrix, the method in the first aspect further includes: receiving first information from the network device, the first information indicating whether to report the candidate precoding matrix; obtaining the candidate precoding matrix includes: obtaining the candidate precoding matrix when the value of the first information is a first value. In this way, the network device can instruct the terminal device to report candidate PMIs according to the actual situation, thereby enabling global resource management on the network side and improving the overall system performance.

[0012] In one possible implementation, if the first information takes the value of the second value, the first information indicates that only the master precoding matrix (PMI) should be reported. In this way, the network device can instruct the terminal device to only report the master PMI based on the actual situation, thereby enabling global resource management on the network side and improving overall system performance.

[0013] In one possible implementation, the first information is carried in the downlink control information (DCI). This allows the first information to be sent by reusing existing messages, thereby improving resource utilization and reducing transmission latency.

[0014] In one possible implementation, the candidate PMI is related to the first spatial basis vector set used by the candidate precoding matrix, which belongs to the spatial basis vector set prohibited by the CBSR. It can be understood that after receiving the candidate PMI, the network device can determine the spatial basis vector set used by the candidate precoding matrix, i.e., the first spatial basis vector set, based on the relationship between the candidate PMI and the first spatial basis vector set. Furthermore, it can determine whether the candidate precoding matrix is ​​a precoding matrix generated based on a CBSR-prohibited spatial basis vector set based on whether the first spatial basis vector set belongs to the CBSR-prohibited spatial basis vector set. In this way, the network device does not need to fully decode the candidate PMI before determining whether the precoding matrix indicated by the candidate PMI is within the CBSR-prohibited range, thereby reducing the computational overhead incurred by the network device in verifying whether the precoding matrix indicated by the candidate PMI is within the CBSR-prohibited range.

[0015] In one possible implementation, the candidate PMI includes a first-level PMI and a second-level PMI. The first-level PMI indicates a first spatial basis vector group, and the second-level PMI indicates L spatial basis vectors in the first spatial basis vector group and a linear combination of the amplitude and phase of those L vectors, where L is less than or equal to the number of spatial basis vectors in the first spatial basis vector group, and L is a positive integer. By indicating the first spatial basis vector group through the first-level PMI of the candidate PMI, the CBSR control granularity and the PMI feedback granularity can be made consistent. This allows the network device to determine the first spatial basis vector group used by the candidate precoding matrix based on the first-level PMI of the candidate PMI, and to determine whether the candidate precoding matrix is ​​a precoding matrix generated based on a CBSR-prohibited spatial basis vector group based on whether the first spatial basis vector group belongs to a CBSR-prohibited spatial basis vector group.

[0016] In one possible implementation, candidate PMIs are carried in the Channel State Information (CSI) report. That is, when a terminal device reports the primary PMI to the network device via the CSI report, it can also report candidate PMIs along with the primary PMI. This improves resource utilization and makes it easier for the network device to obtain candidate PMIs.

[0017] In one possible implementation, the first part of the CSI report includes an indication symbol that indicates that a candidate PMI is included in the second part of the CSI report. This allows for the transmission of candidate PMIs based on the existing structure of the CSI report, thereby reducing the difficulty of transmitting candidate PMIs via the CSI report.

[0018] In one possible implementation, obtaining the candidate precoding matrix includes: obtaining a first set, and obtaining the candidate precoding matrix based on the first set; wherein the first set includes a set of spatial basis vectors prohibited by CBSR, or the first set includes a precoding matrix determined based on the set of spatial basis vectors prohibited by CBSR. Thus, the terminal device can quickly and accurately obtain the candidate precoding matrix based on the first set.

[0019] In one possible implementation, the method of the first aspect further includes: sending a primary PMI (Primary Indicator Missing) to the network device to indicate the primary precoding matrix, the primary PMI being related to a second spatial basis vector set used by the primary precoding matrix, the second spatial basis vector set being a spatial basis vector set permitted by the CBSR (Conventional Space Registry). It is understood that after receiving the primary PMI, the network device can determine the spatial basis vector set used by the primary precoding matrix, i.e., the second spatial basis vector set, based on the relationship between the primary PMI and the second spatial basis vector set; and can determine whether the primary precoding matrix is ​​a precoding matrix generated based on a spatial basis vector set permitted by the CBSR, based on whether the second spatial basis vector set is a spatial basis vector set permitted by the CBSR. Thus, the network device does not need to fully decode the primary PMI before determining whether the precoding matrix indicated by the primary PMI is within the CBSR-permitted range, thereby reducing the computational overhead incurred by the network device in verifying whether the precoding matrix indicated by the primary PMI is within the CBSR-permitted range.

[0020] In one possible implementation, the primary PMI includes a first-level PMI and a second-level PMI. The first-level PMI of the primary PMI indicates the second spatial basis vector group, and the second-level PMI indicates the L spatial basis vectors in the second spatial basis vector group and the linear combination of the amplitude and phase of the L spatial basis vectors, where L is less than or equal to the number of spatial basis vectors included in the second spatial basis vector group, and L is a positive integer. By indicating the second spatial basis vector group through the first-level PMI of the primary PMI, the CBSR control granularity can be made consistent with the PMI feedback granularity. This allows the network device to determine the second spatial basis vector group used by the candidate precoding matrix based on the first-level PMI of the primary PMI, and to determine whether the candidate precoding matrix is ​​a precoding matrix generated based on the spatial basis vector group allowed by the CBSR based on whether the second spatial basis vector group belongs to the spatial basis vector group allowed by the CBSR.

[0021] Secondly, a communication method is provided. This method can be executed by a network device, by a component configured in the network device (such as a processor, circuit, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the network device. This application does not limit this approach. The following description uses a network device as an example.

[0022] The method includes: receiving a candidate pre-PMI from a terminal device for indicating a candidate precoding matrix, and determining a precoding matrix for communicating with the terminal device based on the candidate PMI; wherein the candidate precoding matrix is ​​an optimal precoding matrix determined based on a spatial basis vector set prohibited by the CBSR, and the candidate precoding matrix is ​​superior to the master precoding matrix, which is an optimal precoding matrix determined based on a spatial basis vector set allowed by the CBSR.

[0023] In one possible implementation, the number of spatial basis vector groups prohibited by CBSR is M, and the number of spatial basis vector groups allowed by CBSR is N, where M and N are both positive integers. The sum of M and N is (N1·N2) / (X1·X2), where N1 is the number of antenna ports of the network device in the horizontal direction, N2 is the number of antenna ports of the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the horizontal direction, X1 is a positive integer less than or equal to N1, and N1 is divisible by X1, and X2 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the vertical direction, X2 is a positive integer less than or equal to N2, and N2 is divisible by X2.

[0024] In one possible implementation, before receiving the candidate PMI from the terminal device for indicating the candidate precoding matrix, the method of the second aspect further includes: sending first information to the terminal device, the first information indicating whether to report the candidate precoding matrix; the above-mentioned receiving the candidate PMI from the terminal device for indicating the candidate precoding matrix includes: receiving the candidate PMI if the value of the first information is a first value.

[0025] In one possible implementation, if the value of the first information is the second value, the first information indicates that only the master precoding matrix is ​​reported.

[0026] In one possible implementation, the first information is carried in the DCI.

[0027] In one possible implementation, the candidate PMI is associated with a first set of spatial basis vectors used by the candidate precoding matrix, which belongs to a set of spatial basis vectors prohibited by CBSR.

[0028] In one possible implementation, the candidate PMI includes a first-level PMI and a second-level PMI. The first-level PMI of the candidate PMI is used to indicate a first spatial basis vector group, and the second-level PMI of the candidate PMI is used to indicate L spatial basis vectors in the first spatial basis vector group and a linear combination of the magnitude and phase of the L spatial basis vectors. L is less than or equal to the number of spatial basis vectors included in the first spatial basis vector group, and L is a positive integer.

[0029] In one possible implementation, the candidate PMI is carried in the CSI report.

[0030] In one possible implementation, the first part of the CSI report includes an indicator symbol that indicates that a candidate PMI is included in the second part of the CSI report.

[0031] In one possible implementation, the method of the second aspect further includes: receiving a primary PMI from a terminal device for indicating the primary precoding matrix, the primary PMI being related to a second spatial basis vector set used by the primary precoding matrix, the second spatial basis vector set belonging to a spatial basis vector set permitted by the CBSR.

[0032] In one possible implementation, the main PMI includes a first-level PMI and a second-level PMI. The first-level PMI of the main PMI is used to indicate the second spatial basis vector group, and the second-level PMI of the main PMI is used to indicate the L spatial basis vectors in the second spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors, where L is less than or equal to the number of spatial basis vectors included in the second spatial basis vector group, and L is a positive integer.

[0033] In one possible implementation, the method in the second aspect further includes: updating the CBSR and sending the updated CBSR to the terminal device after receiving candidate PMIs multiple times consecutively from the terminal device; wherein the updated CBSR allows the use of the first spatial basis vector group. When the terminal device sends candidate PMIs to the network device multiple times consecutively, it can indicate that the beam direction corresponding to the candidate PMI is the optimal beam direction continuously measured by the terminal device. In this case, the network device can set the spatial basis vector group corresponding to the beam direction in the CBSR as the spatial basis vector group allowed by the terminal device. This improves the flexibility and accuracy of network scheduling.

[0034] It is understandable that the second aspect is the implementation on the network device side, which corresponds to the first aspect. The explanations, supplements, and descriptions of the beneficial effects of the first aspect also apply to the second aspect, and will not be repeated here.

[0035] Thirdly, a communication method is provided. This method can be executed by a terminal device, by a component configured in the terminal device (such as a processor, circuit, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the terminal device. This application does not limit this approach. The following description uses a terminal device as an example.

[0036] The method includes: obtaining the primary precoding vector and candidate precoding vector of the i-th spatial layer, and sending a set of PMIs to the network device; wherein, the primary precoding vector is the optimal precoding vector determined based on the spatial basis vector set allowed by the CBSR, the candidate precoding vector is the optimal precoding vector determined based on the spatial basis vector set prohibited by the CBSR, the set of PMIs includes the primary PMI used to indicate the primary precoding vector of the i-th spatial layer, and when the candidate precoding vector is better than the primary precoding vector, the set of PMIs also includes candidate PMIs used to indicate the candidate precoding vector of the i-th spatial layer, i taking values ​​from 1 to F, where the value of F is equal to the value of the rank indicator RI, and i is a positive integer.

[0037] Based on the third aspect of the method, it is known that when CBSR adopts a coarse-grained restriction approach, CBSR may inadvertently block some fine beam directions with good channel quality. That is, among the spatial basis vector sets prohibited by CBSR, there may be spatial basis vector sets that can be used to construct the precoding matrix corresponding to these fine beam directions. In this case, the terminal device determines the primary precoding vector and candidate precoding vector for the i-th spatial layer based on the spatial basis vector sets prohibited by CBSR. If the candidate precoding vector for the i-th spatial layer is superior to the primary precoding vector, the terminal device reports a candidate PMI (Predicted Precoding Matrix) to the network device to indicate the candidate precoding vector. This allows the network device to determine the precoding matrix for communication with the terminal device based on the candidate PMI. This avoids missing better fine beam directions, thus balancing signaling overhead and system performance. Furthermore, reporting candidate PMIs according to the spatial layer allows the network side to determine a precoding matrix with better performance for communication with the terminal device based on the PMI set.

[0038] In one possible implementation, before obtaining the master precoding vector of the i-th spatial layer, the method of the third aspect further includes: obtaining all precoding vectors determined based on the spatial basis vector set allowed by the CBSR; the above-mentioned obtaining the master precoding vector of the i-th spatial layer includes: determining the master precoding vector of the i-th spatial layer based on the channel response matrix and the all precoding vectors, wherein the master precoding vector is the precoding vector with the highest Reference Signal Received Power (RSRP) among the all precoding vectors. In this way, the master precoding vector of the i-th spatial layer can be accurately obtained.

[0039] In one possible implementation, before obtaining the candidate precoding vector for the i-th spatial layer, the method in the third aspect further includes: obtaining all precoding vectors determined based on the spatial basis vector set prohibited by CBSR; the above-mentioned obtaining the candidate precoding vector for the i-th spatial layer includes: determining the candidate precoding vector for the i-th spatial layer based on the channel response matrix and the all precoding vectors, wherein the candidate precoding vector is the precoding vector with the highest RSRP among the all precoding vectors. In this way, the candidate precoding vector for the i-th spatial layer can be accurately obtained.

[0040] In one possible implementation, the superiority of the candidate precoding vector of the i-th spatial layer over the master precoding vector of the i-th spatial layer specifically includes: the difference between the RSRP corresponding to the candidate precoding vector of the i-th spatial layer and the RSRP corresponding to the master precoding vector of the i-th spatial layer is greater than a preset threshold. This allows for an accurate determination of the relationship between the candidate precoding vector and the master precoding vector of the i-th spatial layer. It is understood that this preset threshold can be determined by the terminal device based on actual conditions.

[0041] In one possible implementation, the number of spatial basis vector groups prohibited by CBSR is M, and the number of spatial basis vector groups allowed by CBSR is N, where M and N are both positive integers. The sum of M and N is (N1·N2) / (X1·X2), where N1 is the number of antenna ports of the network device in the horizontal direction, N2 is the number of antenna ports of the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the horizontal direction, X1 is a positive integer less than or equal to N1, and N1 is divisible by X1, and X2 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the vertical direction, X2 is a positive integer less than or equal to N2, and N2 is divisible by X2. That is, CBSR can divide N1·N2 spatial basis vectors into (N1·N2) / (X1·X2) spatial basis vector groups. The terminal device can determine the candidate precoding vector of the i-th spatial layer based on the M spatial basis vector groups in (N1·N2) / (X1·X2) indicated by CBSR, and determine the main precoding vector of the i-th spatial layer based on the N spatial basis vector groups in (N1·N2) / (X1·X2) indicated by CBSR.

[0042] In one possible implementation, before obtaining the primary precoding vector and candidate precoding vector of the i-th spatial layer, the method of the third aspect further includes: receiving first information from the network device, the first information indicating whether to report the candidate precoding vector of the i-th spatial layer; the above-mentioned obtaining the candidate precoding vector includes: if the value of the first information is a first value, obtaining the primary precoding vector and candidate precoding vector of the i-th spatial layer. In this way, the network device can instruct the terminal device to report the candidate PMIs of each spatial layer according to the actual situation, thereby realizing global resource management on the network side and improving the overall system performance.

[0043] In one possible implementation, if the first information takes the value of the second value, the first information indicates that only the master precoding vector (PMI) indicating the i-th spatial layer is reported. In this way, the network device can instruct the terminal device to only report the master PMI for each spatial layer based on the actual situation, thereby achieving global resource management on the network side and improving the overall system performance.

[0044] In one possible implementation, the first message is carried in the DCI. This allows the first message to be sent by reusing existing messages, thereby improving resource utilization and reducing transmission latency.

[0045] In one possible implementation, the primary PMI of the i-th spatial layer is related to the first spatial basis vector set used by the primary precoding vector of the i-th spatial layer, which belongs to the spatial basis vector set allowed by CBSR; the candidate PMI of the i-th spatial layer is related to the second spatial basis vector set used by the candidate precoding vector of the i-th spatial layer, which belongs to the spatial basis vector set prohibited by CBSR. It is understandable that after receiving the primary PMI and candidate PMI of the i-th spatial layer, the network device can determine the spatial basis vector group used by the primary precoding vector, i.e., the first spatial basis vector group, based on the relationship between the primary PMI and the first spatial basis vector. Furthermore, it can determine whether the primary precoding vector is a precoding vector generated based on the spatial basis vector group allowed by the CBSR, based on whether the first spatial basis vector group belongs to the spatial basis vector group allowed by the CBSR. It can also determine the spatial basis vector group used by the candidate precoding vector, i.e., the second spatial basis vector group, based on the relationship between the candidate PMI and the second spatial basis vector. Furthermore, it can determine whether the candidate precoding vector is a precoding vector generated based on the spatial basis vector group prohibited by the CBSR, based on whether the second spatial basis vector group belongs to the spatial basis vector group prohibited by the CBSR. In this way, network devices do not need to fully decode the primary PMI and candidate PMI before determining whether the precoding vector indicated by the primary PMI is within the range allowed by the CBSR, or whether the precoding vector indicated by the candidate PMI is within the range prohibited by the CBSR. This reduces the computational overhead of network devices in verifying whether the precoding vector indicated by the candidate PMI is within the range prohibited by the CBSR, as well as the computational overhead in verifying whether the precoding vector indicated by the primary PMI is within the range allowed by the CBSR.

[0046] In one possible implementation, both the candidate PMI and the main PMI of the i-th spatial layer include a first-level PMI and a second-level PMI. The first-level PMI of the main PMI is used to indicate the first spatial basis vector group, and the second-level PMI of the main PMI is used to indicate the L spatial basis vectors in the first spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. The first-level PMI of the candidate PMI is used to indicate the second spatial basis vector group, and the second-level PMI of the candidate PMI is used to indicate the L spatial basis vectors in the second spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. L is less than or equal to the number of spatial basis vectors included in the spatial basis vector group, and L is a positive integer. By using the first-level PMI of the primary PMI to indicate the first spatial basis vector group, and the first-level PMI of the candidate PMI to indicate the second spatial basis vector group, the CBSR control granularity can be made consistent with the PMI feedback granularity. This enables network devices to determine the first spatial basis vector group used by the primary precoding vector based on the first-level PMI of the primary PMI, and to determine whether the primary precoding vector is a precoding vector generated based on the spatial basis vector group allowed by the CBSR based on the first spatial basis vector group. Furthermore, based on the first-level PMI of the candidate PMI, the device can determine the second spatial basis vector group used by the candidate precoding vector, and to determine whether the candidate precoding vector is a precoding vector generated based on the spatial basis vector group prohibited by the CBSR based on the second spatial basis vector group.

[0047] In one possible implementation, the PMI set is carried within the CSI report. That is, network devices can reuse existing CSI reports to send the PMI set to end devices. This improves resource utilization and facilitates the network device's acquisition of candidate PMIs.

[0048] In one possible implementation, the first part of the CSI report includes an indicator bitmap indicating whether the second part of the CSI report includes candidate PMIs for the i-th spatial layer. If the indicator bitmap indicates that the second part of the CSI report includes candidate PMIs for the i-th spatial layer, then both the candidate PMIs and the main PMI for the i-th spatial layer are included in the second part of the CSI report. This allows for the transmission of the PMI set based on the existing structure of the CSI report, thereby reducing the difficulty of transmitting the PMI set via the CSI report.

[0049] Fourthly, a communication method is provided. This method can be executed by a network device, by a component configured in the network device (such as a processor, circuit, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the network device. This application does not limit this approach. The following description uses a network device as an example.

[0050] The method includes: receiving a set of PMIs from a terminal device, and determining a precoding matrix for communicating with the terminal device based on the set of PMIs; wherein the set of PMIs includes a main PMI indicating the main precoding vector of the i-th spatial layer, and, if the candidate precoding vector of the i-th spatial layer is better than the main precoding vector of the i-th spatial layer, the set of PMIs also includes a candidate PMI indicating the candidate precoding vector of the i-th spatial layer, wherein the main precoding vector is the optimal precoding vector determined based on the spatial basis vector set allowed by the CBSR, the candidate precoding vector is the optimal precoding vector determined based on the spatial basis vector set prohibited by the CBSR, i takes values ​​from 1 to F, F is equal to the value of RI, and i is a positive integer.

[0051] In one possible implementation, the fact that the candidate precoding vector of the i-th spatial layer is better than the master precoding vector of the i-th spatial layer specifically includes: the difference between the reference signal received power (RSRP) corresponding to the candidate precoding vector of the i-th spatial layer and the RSRP corresponding to the master precoding vector of the i-th spatial layer is greater than a preset threshold.

[0052] In one possible implementation, the number of spatial basis vector groups prohibited by CBSR is M, and the number of spatial basis vector groups allowed by CBSR is N, where M and N are both positive integers. The sum of M and N is (N1·N2) / (X1·X2), where N1 is the number of antenna ports of the network device in the horizontal direction, N2 is the number of antenna ports of the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the horizontal direction, X1 is a positive integer less than or equal to N1, and N1 is divisible by X1, and X2 is the number of consecutive spatial basis vectors of the above spatial basis vector group in the vertical direction, X2 is a positive integer less than or equal to N2, and N2 is divisible by X2.

[0053] In one possible implementation, before receiving the PMI set from the terminal device, the method of the fourth aspect further includes: sending first information to the terminal device, the first information indicating whether to report the candidate precoding vector of the i-th spatial layer; the above receiving the PMI set from the terminal device includes: receiving the PMI set if the value of the first information is a first value.

[0054] In one possible implementation, if the value of the first information is the second value, the first information indicates that only the master precoding vector used to indicate the i-th spatial layer is reported.

[0055] In one possible implementation, the first information is carried in the DCI.

[0056] In one possible implementation, the primary PMI of the i-th spatial layer is related to the first spatial basis vector set used by the primary precoding vector of the i-th spatial layer, which belongs to the spatial basis vector set allowed by CBSR; the candidate PMI of the i-th spatial layer is related to the second spatial basis vector set used by the candidate precoding vector of the i-th spatial layer, which belongs to the spatial basis vector set prohibited by CBSR.

[0057] In one possible implementation, both the candidate PMI and the main PMI of the i-th spatial layer include a first-level PMI and a second-level PMI. The first-level PMI of the main PMI is used to indicate the first spatial basis vector group, and the second-level PMI of the main PMI is used to indicate the L spatial basis vectors in the first spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. The first-level PMI of the candidate PMI is used to indicate the second spatial basis vector group, and the second-level PMI of the candidate PMI is used to indicate the L spatial basis vectors in the second spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. L is less than or equal to the number of spatial basis vectors included in the spatial basis vector group, and L is a positive integer.

[0058] In one possible implementation, the PMI set is carried in the CSI report.

[0059] In one possible implementation, the first part of the CSI report includes an indicator bitmap that indicates whether the second part of the CSI report includes a candidate PMI for the i-th spatial layer; if the indicator bitmap indicates that the second part of the CSI report includes a candidate PMI for the i-th spatial layer, then the candidate PMI and the main PMI for the i-th spatial layer are included in the second part of the CSI report.

[0060] In one possible implementation, the method in the fourth aspect further includes: updating the CBSR upon receiving multiple candidate PMIs from the terminal device, wherein the updated CBSR allows the use of the second spatial basis vector group; and sending the updated CBSR to the terminal device. When the terminal device sends multiple candidate PMIs for the i-th spatial layer to the network device, it can indicate that the beam direction corresponding to the candidate PMI is the optimal beam direction for the i-th spatial layer measured by the terminal device. In this case, the network device can set the spatial basis vector group corresponding to the beam direction as the allowed spatial basis vector group in the CBSR. This improves the flexibility and accuracy of network scheduling.

[0061] It is understandable that the fourth aspect is the implementation on the network device side, which corresponds to the third aspect. The explanations, supplements, and descriptions of the beneficial effects of the third aspect also apply to the fourth aspect, and will not be repeated here.

[0062] A fifth aspect provides a communication device. The communication device includes: a module for performing the method in any possible implementation of any of the above aspects, such as a communication module and a processing module. For example, the communication module is used to instruct the transmission and reception functions of the communication device, and the processing module is used to perform functions of the communication device other than the transmission and reception functions.

[0063] Optionally, the communication module may include a transmitting module and a receiving module. The transmitting module implements the transmitting function of the communication device described in the fifth aspect, and the receiving module implements the receiving function of the communication device described in the fifth aspect.

[0064] Optionally, the communication device described in the fifth aspect may further include a storage module storing programs or instructions. When the processing module executes the program or instructions, the communication device can perform the methods in any of the possible implementations of any of the above aspects.

[0065] It is understood that the communication device described in the fifth aspect may be a terminal device or a network device, or it may be a chip (system) or other component or assembly that can be disposed in the terminal device or the network device, or it may be a device that includes the terminal device or the network device. This application does not limit it in this regard.

[0066] Furthermore, the technical effects of the communication device described in the fifth aspect can be referenced from the technical effects of the methods in any possible implementation of any of the above aspects, and will not be repeated here.

[0067] A sixth aspect provides a communication device including at least one processor. The at least one processor is coupled to a memory storing programs or instructions, and the processor executes the programs or instructions in the memory, causing the communication device to perform a method in any possible implementation of any of the above aspects. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0068] In one implementation, the communication interface may be a transceiver, or an input / output interface.

[0069] In another implementation, the communication device is a chip configured in a terminal device or network device. When the communication device is a chip configured in a terminal device or network device, the communication interface can be an input / output interface.

[0070] In a seventh aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive signals through the input circuit and transmit signals through the output circuit, causing the processor to execute a method in any possible implementation of any aspect.

[0071] In specific implementation, the processor can be one or more chips, the input circuit can be input pins, the output circuit can be output pins, and the processing circuit can be transistors, gate circuits, flip-flops, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to and transmitted by a transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as both the input circuit and the output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0072] Eighthly, a communication device is provided, including a processor and a memory. The processor is used to read instructions stored in the memory, receive signals via a receiver, and transmit signals via a transmitter to execute the method in any possible implementation of any of the preceding aspects.

[0073] Optionally, the processor may be one or more, and the memory may be one or more.

[0074] Ninthly, a computer-readable storage medium is provided that stores a computer program or instructions, which, when executed, cause a computer to perform the method in any possible implementation of any of the preceding aspects.

[0075] In a tenth aspect, embodiments of this application provide a chip system including one or more processors for calling and executing instructions stored in memory, causing the methods in any of the above aspects or possible implementations to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0076] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0077] Eleventhly, a computer program product is provided, the computer program product comprising: a computer program or instructions, which, when the computer program is run, causes the method in any possible implementation of any of the preceding aspects to be executed.

[0078] In a twelfth aspect, a communication system is provided, including the aforementioned terminal device and network device. Optionally, the communication system may further include other devices that communicate with the terminal device and / or network device. Attached Figure Description

[0079] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0080] Figure 1 A schematic diagram of the communication system provided in the embodiments of this application;

[0081] Figure 2 Flowchart of the communication method provided in the embodiments of this application Figure One ;

[0082] Figure 3 Flowchart of the communication method provided in the embodiments of this application Figure Two ;

[0083] Figure 4 Flowchart of the communication method provided in the embodiments of this application Figure Three ;

[0084] Figure 5 Flowchart of the communication method provided in the embodiments of this application Figure Four ;

[0085] Figure 6 A schematic diagram of the structure of the communication device provided in the embodiments of this application is shown. Figure One ;

[0086] Figure 7 A schematic diagram of the structure of the communication device provided in the embodiments of this application is shown. Figure Two . Detailed Implementation

[0087] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0088] The technical solutions provided in this application can be applied to various communication systems, such as: Global System for Mobile Communications (GSM) systems, General Packet Radio Service (GPRS), Wireless Local Area Network (WLAN), Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, non-terrestrial network (NTN) communication systems, 5th generation (5G) mobile communication systems, or new radio access technology (NR). Among these, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networking. The technical solutions provided in this application can also be applied to future communication systems. This application does not limit the scope of these applications.

[0089] Figure 1 This is a schematic diagram of a communication system 100 used in an embodiment of this application. The communication system 100 may include network devices, such as... Figure 1 The network device 110 is shown. The communication system 100 may also include terminal devices, such as... Figure 1 The terminal device 120 shown. The network device 110 and the terminal device 120 can communicate via a wireless link.

[0090] Figure 1 An exemplary network device 110 and a terminal device 120 are shown. Optionally, the communication system 100 may also include multiple network devices and / or multiple terminal devices.

[0091] The network equipment in this application can be network-side equipment such as access network equipment. Access network equipment is sometimes also called an access node. Access network equipment has wireless transceiver capabilities for communicating with terminals. Access network equipment includes, but is not limited to, base stations, evolved NodeBs (eNodeBs), transmission reception points (TRPs) in the aforementioned communication systems, next-generation NodeBs (gNBs) in 5G mobile communication systems, access network equipment or modules of access network equipment in open RAN (ORAN) systems, satellites in NTN communication systems, base stations in future mobile communication systems, or access nodes in WiFi systems. Access network equipment can also be modules or units capable of implementing some of the functions of a base station. Access network equipment can be a macro base station, micro base station, indoor station, relay node, donor node, or a wireless controller in a cloud radio access network (CRAN) scenario. Optionally, access network equipment can also be a server, wearable device, or vehicle-mounted equipment, etc. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). Multiple access network devices in a communication system can be base stations of the same type or different types. Base stations can communicate with terminals directly or via relay stations. Terminals can communicate with multiple base stations using different access technologies. The embodiments of this application do not limit the specific technology or device form used in the access network equipment. In this application, the access network equipment is referred to as a network device.

[0092] In this application, the means for implementing the functions of a network device can be a network device itself, or a means capable of supporting the network device in implementing those functions, such as a processor, circuit, chip, or chip system. This means can be installed in or connected to the network device. In the technical solutions provided in this application, the example of a network device being used to implement the functions of a network device is used to describe the technical solutions provided in this application.

[0093] The terminal device in this application can be a wireless terminal device capable of receiving network device scheduling and instruction information. The wireless terminal device can be a device providing voice and / or data connectivity to a user, a handheld device with wireless connectivity, or other processing devices connected to a wireless modem. For example, the terminal device can communicate with one or more core networks or the Internet via a radio access network (RAN). The terminal device can also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), ultra-reliable low-latency communication (URLLC), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, or satellite communication, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, wearable device, vehicle, aircraft (such as drone, helicopter, airplane), hot air balloon, ship, robot, robotic arm, or smart home device, etc. The embodiments of this application do not limit the form of the terminal device.

[0094] In this application, the apparatus for implementing the functions of a terminal device can be the terminal device itself, or any apparatus capable of supporting the terminal device in implementing those functions, such as a processor, circuit, chip, or chip system. This apparatus can be installed in or connected to the terminal device. In the technical solutions provided in this application, the example of a terminal device being used to implement the functions of a terminal device is used to describe the technical solutions provided in this application.

[0095] Access network equipment and / or terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. This application does not limit the application scenarios of the access network equipment and terminal equipment. They can be deployed in the same or different scenarios; for example, both can be deployed on land simultaneously; or the access network equipment can be deployed on land while the terminal equipment is deployed on water, etc., and so on.

[0096] In practical applications, multiple network devices can collaborate to assist terminals in achieving wireless access, with different network devices each implementing a portion of the base station's functions. For example, network devices can be central units (CUs), distributed units (DUs), CUs (control planes, CPs), CUs (user planes, UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0097] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (Open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU (or CU-CP and CU-UP), DU, and RU can implement different protocol layer functions.

[0098] To facilitate understanding of the embodiments of this application, the terminology used in this application is first briefly explained. Optionally, the explanation of some terms can also be found in the 3GPP standard protocols. It should be understood that the technical terms in this application are for illustrative purposes only and not as limiting. For example, as technology evolves, technical terms may also change; where the technical meaning remains the same, other technical terms should also apply to this application.

[0099] 1. Precoding technology refers to the process by which a transmitting device (such as a network device) processes the signal to be transmitted using a precoding matrix that matches the channel resources, given the channel conditions. This ensures that the precoded signal is compatible with the channel, reducing the equalization complexity required by the receiving device to eliminate inter-symbol interference caused by the channel. In other words, precoding the signal improves the quality of the received signal (e.g., signal-to-interference-plus-noise ratio, SINR). Furthermore, precoding technology enables network devices and multiple terminal devices to transmit on the same time-frequency resources, achieving multiple-user multiple-input multiple-output (MU-MIMO).

[0100] 2. PMI is an index value fed back to the network device by the terminal device after measuring the channel state information reference signal (CSI-RS). This index value indicates the precoding matrix that the terminal device recommends the network device to use during downlink transmission under the current channel conditions.

[0101] PMI feedback is determined and reported based on a codebook. A codebook is a set of finite precoding matrices; in codebook-based precoding, the available precoding matrices can only be selected from the codebook. In contrast, non-codebook-based precoding does not limit the number of available precoding matrices. Therefore, the precoding matrix can be any matrix that conforms to the design rules and application conditions, and is not limited to a specific matrix.

[0102] 3. Spatial domain basis vectors can also be called beam vectors, spatial beam basis vectors, spatial vectors, or spatial beams. Each element in the spatial basis vector represents a weighting coefficient for each antenna port. Based on the weighting coefficients of each antenna port represented by the elements in the spatial basis vector, the signals from each antenna port are linearly superimposed to form a region with a strong signal in a certain direction in space.

[0103] The aforementioned antenna ports can be understood as transmitting antennas recognized by network devices, or transmitting antennas that can be distinguished spatially. Each virtual antenna can be pre-configured with one antenna port. Each virtual antenna can be a weighted combination of multiple physical antennas. Each antenna port can correspond to a reference signal; therefore, each antenna port can be called a reference signal port, such as a CSI-RS port or a sounding reference signal (SRS) port. This reference signal can be an unencoded reference signal or a precoded reference signal; there is no limitation on this.

[0104] Spatial basis vectors can be Discrete Fourier Transform (DFT) vectors. A DFT vector can refer to a vector within a DFT matrix. Alternatively, spatial basis vectors can be the conjugate transpose of a DFT vector. The conjugate transpose of a DFT vector can refer to a column vector within the conjugate transpose of a DFT matrix. Or, spatial basis vectors can be oversampled DFT vectors. An oversampled DFT vector can refer to a vector within an oversampled DFT matrix.

[0105] 4. The spatial basis vector set can also be called a beam vector set, spatial beam vector set, or spatial basis vector set, etc. The spatial basis vector set can include various spatial basis vectors of different lengths to correspond to different numbers of antenna ports. In the embodiments of this application, the spatial basis vectors used to construct the precoding matrix or precoding vector can be determined from the spatial basis vector set.

[0106] 5. CBSR: Configured by the network device, it informs the terminal device of the codebook usage restrictions. Specifically, the CBSR restricts the precoding matrix candidate set that the terminal device can use in the Channel State Information (CSI) report. Furthermore, the network device can configure the CBSR bitmap during the RRC configuration phase to inform the terminal device of the codebook usage restrictions.

[0107] In the Type II codebook, the RRC configuration overhead of CBSR is positively correlated with the parameter combination N1N2O1O2, leading to a significant increase in signaling burden under large-scale arrays. For example, when the number of antenna ports is 32 (e.g., N1=N2=4, O1=O2=4), the CBSR configuration overhead is 256 bits; when the number of antenna ports is 128 (e.g., N1=N2=8, O1=O2=4), the CBSR configuration overhead is 1024 bits. It can be seen that when the number of antenna ports increases from 32 to 128, the signaling burden increases by a factor of four. This significant increase in overhead with the rapid increase in the number of antenna ports severely limits the practical application efficiency and configuration flexibility of CBSR in extremely large-scale antenna arrays (XL-MIMO) and narrow-beam scenarios.

[0108] To address this, 3GPP TS38.214 Rel-19 simplifies the control granularity of CBSR, specifying that it can only configure N1N2 coarse directions and can only restrict (N1·N2) / (X1·X2) spatial basis vector groups. This significantly reduces RRC configuration overhead, thereby improving the practicality and flexibility of CBSR in large-scale antenna arrays and narrow-beam precise control scenarios. Here, X1 and X2 are grouping factors. X1 indicates the number of consecutive spatial basis vectors in the horizontal direction (corresponding to antenna port dimension N1) of the spatial basis vector group. X1 is a positive integer less than or equal to N1, and N1 is divisible by X1. X2 indicates the number of consecutive spatial vectors in the vertical direction (corresponding to antenna port dimension N2) of the spatial basis vector group. X2 is a positive integer less than or equal to N2, and N2 is divisible by X2.

[0109] Research has revealed that when CBSR employs a coarse-grained constraint method, it may inadvertently block some fine beam directions with good channel quality, causing terminal devices to be unable to report the true optimal beam direction, which may reduce system performance.

[0110] To address the aforementioned technical issues, this application proposes a method to determine an optimal precoding matrix (i.e., a candidate precoding matrix) based on a spatial basis vector set prohibited by CBSR. If the candidate precoding matrix is ​​superior to the optimal precoding matrix determined based on a spatial basis vector set permitted by CBSR, the PMI of the candidate precoding matrix is ​​reported. This enables the terminal device to feedback the true optimal beam direction, thereby balancing signaling overhead and system performance.

[0111] The solution provided in this application will be described in detail below with reference to the corresponding flowcharts. It is understood that the illustrative flowcharts provided in this application primarily use different devices (such as terminal devices and network devices) as examples of the execution subjects of this interactive illustration to illustrate the method, but this application does not limit the execution subjects of the interactive illustrations. For example, the devices (such as terminal devices and network devices) in the illustrative flowcharts can also be chips, chip systems, or processors that support the implementation of this method on the device, or they can be logic modules or software that can implement all or part of the functions of the device.

[0112] It is hereby uniformly stated that the message or signaling interactions involved in the interaction process of the embodiments of this application can adopt standard messages or signaling, or they can be newly introduced messages or signaling. The embodiments of this application do not specifically limit this. The following embodiments are provided as examples to more clearly illustrate the technical solutions of this application, and should not be used to limit the scope of protection of this application. Those skilled in the art will understand that, without conflict, the following embodiments and features can be combined with each other.

[0113] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, relational terms such as "first," "second," etc., in the description of this application are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0114] Furthermore, the term "and / or" in this application is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0115] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "connection" can be a direct connection or an indirect connection through an intermediate medium.

[0116] Figure 2 Flowchart of the communication method provided in the embodiments of this application Figure One . Figure 2 The terminal device in the middle can be Figure 1Any terminal device in the context of network equipment can refer to any component within that terminal device (such as a processor, circuit, chip, or chip system). Network equipment can be... Figure 1 Any access network device, or a component within an access network device (such as a processor, circuit, chip, or chip system). For example... Figure 2 As shown, the communication method includes the following steps:

[0117] S201, The terminal device obtains the candidate precoding matrix.

[0118] The candidate precoding matrix is ​​the optimal precoding matrix determined based on the spatial basis vector set prohibited by CBSR.

[0119] The CBSR (Boundary Control Regulator) can restrict (N1·N2) / (X1·X2) spatial basis vector groups. Specifically, the CBSR indicates which spatial basis vector groups the terminal device can use and which are prohibited from use. The number of spatial basis vector groups prohibited by the CBSR can be M, and the number of spatial basis vector groups allowed by the CBSR can be N. Both M and N are positive integers, and the sum of M and N is (N1·N2) / (X1·X2). Here, N1 is the number of antenna ports on the network device in the horizontal direction, N2 is the number of antenna ports on the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors in the horizontal direction (a positive integer less than or equal to N1, divisible by X1), and X2 is the number of consecutive spatial basis vectors in the vertical direction (a positive integer less than or equal to N2, divisible by X2). In other words, the CBSR can divide the N1·N2 spatial basis vectors into (N1·N2) / (X1·X2) spatial basis vector groups. The CBSR can indicate M spatial basis vector groups out of (N1·N2) / (X1·X2) as spatial basis vector groups prohibited by the terminal device, and the CBSR can indicate N spatial basis vector groups out of (N1·N2) / (X1·X2) as spatial basis vector groups allowed by the terminal device. For the terminal device, it can determine the candidate precoding matrix from the M spatial basis vector groups and the main precoding matrix from the N spatial basis vector groups.

[0120] It is understood that in the embodiments of this application, X1 equals N1 and X2 equals N2 cannot coexist, that is, (N1·N2) / (X1·X2) is not 1. In other words, when X1 equals N1, X2 is not equal to N2; when X2 equals N2, X1 is not equal to N1.

[0121] CBSR can restrict (N1·N2) / (X1·X2) spatial basis vector groups using a bitmap. For example, the CBSR bitmap includes G bits, each corresponding to one of the G spatial vector groups, and each G bit is used to indicate whether a spatial vector group is allowed or not. G is the sum of M and N, and G = (N1·N2) / (X1·X2). For example, when a bit in the G bits is 1, it indicates that the corresponding spatial vector group is allowed; when a bit in the G bits is 0, it indicates that the corresponding spatial vector group is prohibited.

[0122] For example, if N1=N2=4, X1=2, X2=1, then G=8, resulting in 8 spatial vector groups. The CBSR bitmap is 00111110, indicating that the terminal device is allowed to use the 3rd to 7th spatial vector groups out of the G spatial vector groups, and is prohibited from using the 1st, 2nd, and 3rd spatial vector groups out of the G spatial vector groups. Furthermore, the CBSR details can be found in the Rel-19 section of "5. CBSR" above, and will not be repeated here.

[0123] The aforementioned optimal precoding matrix can be understood as the precoding matrix with the best index of the equivalent channel determined based on the spatial basis vector set prohibited by CBSR. This index may include at least one of the following: channel capacity and SINR; wherein, channel capacity can be used to indicate the maximum information rate that the equivalent channel can support for error-free transmission, and SINR can be used to represent the ratio of the target signal power to the sum of all non-target signal power and noise power. Of course, this index can also be other indices in the prior art, without limitation. The beam direction corresponding to the aforementioned optimal precoding matrix is ​​the fine beam direction with the best channel quality among the beam directions prohibited by CBSR.

[0124] During the process of acquiring candidate precoding matrices, the terminal device can either place the spatial basis vector set prohibited by CBSR into a first set, determine the precoding matrix prohibited by CBSR based on the first set, and determine the candidate precoding matrix based on the precoding matrix prohibited by CBSR; or it can place the precoding matrix determined based on the spatial basis vector set prohibited by CBSR into the first set and determine the candidate precoding matrix based on the first set.

[0125] For example, the above-mentioned acquisition of candidate precoding matrices may specifically include: acquiring a first set, and acquiring candidate precoding matrices based on the first set; wherein, the first set includes a set of spatial basis vectors prohibited by CBSR, or, the first set includes a precoding matrix determined based on a set of spatial basis vectors prohibited by CBSR. The following describes different cases.

[0126] Case 1.1: The first set includes the spatial basis vector set that is prohibited by CBSR.

[0127] In this case, the terminal device can determine the precoding matrix that CBSR prohibits based on the first set, and determine the candidate precoding matrix based on the precoding matrix.

[0128] For example, the spatial basis vector set prohibited by the CBSR mentioned above includes at least one spatial basis vector set, that is, the first set includes at least one spatial basis vector set. For each spatial basis vector set in the first set, the terminal device can select L different spatial basis vectors from the spatial basis vector set, and perform a linear combination of the amplitude and phase of the L spatial basis vectors based on the rank indicator (RI) to obtain a precoding matrix generated based on the L spatial basis vectors; where L is a positive integer, and the value of L is related to N1, N2, and RI. And the value of L can be determined by the network device, such as the network device sending the value of L to the terminal device. Each spatial basis vector set can correspond to at least one type of L spatial basis vectors. In other words, at least one precoding matrix can be determined based on a spatial basis vector set. It can be understood that the rules for the value of L and the method of linearly combining the amplitude and phase of the L spatial basis vectors can refer to existing technologies, such as selecting the L spatial basis vectors that best match the channel and can bring the strongest effective channel gain, which will not be elaborated here. In addition, the precoding matrix in the embodiments of this application may also include frequency domain related content (such as frequency domain basis vectors, etc.). The frequency domain related content can be referred to the prior art, and will not be described in detail here.

[0129] After determining at least one precoding matrix prohibited by CBSR, the terminal device can determine the optimal precoding matrix, i.e., the candidate precoding matrix, from among these at least one precoding matrices. For example, the terminal device can select the precoding matrix with the best index as the candidate precoding matrix based on the equivalent channel index corresponding to each precoding matrix in these at least one precoding matrices. This index can be referred to the aforementioned related descriptions and will not be repeated here. It is understood that the specific implementation of determining the optimal precoding matrix from at least one precoding matrix can refer to existing technologies, such as the prior art where the terminal device calculates the equivalent channel index corresponding to each precoding matrix based on the channel response matrix obtained by measuring CSI-RS, and determines the optimal precoding matrix based on this index. This will not be repeated here.

[0130] Case 1.2: The first set includes the precoding matrix determined based on the spatial basis vector set prohibited by CBSR.

[0131] In this case, the terminal device can first determine at least one precoding matrix that is prohibited by CBSR based on the spatial basis vector set that is prohibited by CBSR; and then determine the optimal precoding matrix based on the at least one precoding matrix.

[0132] There are several ways for a terminal device to determine at least one precoding matrix that is prohibited from use by CBSR based on a first set.

[0133] For example, when the terminal device uses an existing codebook (such as a type II codebook or an enhanced type II codebook), the terminal device can determine an orthogonal basis set prohibited by the CBSR based on a spatial basis vector set prohibited by the CBSR, and determine at least one corresponding precoding matrix based on the orthogonal basis vector set. It is understood that the specific implementation of determining the precoding matrix based on the orthogonal basis vector set can refer to existing technologies, and will not be elaborated here.

[0134] For example, the terminal device can select a variety of L different spatial basis vectors from each spatial basis vector group based on the spatial basis vector group prohibited by CBSR, and perform a linear combination of the amplitude and phase of the L spatial basis vectors to obtain a precoding matrix generated based on the L spatial basis vectors. For details, please refer to the relevant introduction in Case 1.1 above, which will not be repeated here.

[0135] The specific implementation of the terminal device determining the optimal precoding matrix based on at least one precoding matrix prohibited by CBSR can be found in the relevant introduction in Case 1.1 above, and will not be repeated here.

[0136] In this embodiment, after receiving the CBSR, the terminal device can obtain a first set based on the CBSR, and then obtain the candidate precoding matrix based on the first set. This allows the terminal device to quickly and accurately obtain the candidate precoding matrix.

[0137] S202, if the candidate precoding matrix is ​​superior to the main precoding matrix, the terminal device sends a candidate PMI indicating the candidate precoding matrix to the network device. Correspondingly, the network device receives the candidate PMI from the terminal device.

[0138] The master precoding matrix is ​​the optimal precoding matrix determined based on the spatial basis vector set allowed by CBSR. This optimal precoding matrix can be understood as the precoding matrix with the best equivalent channel performance based on the spatial basis vector set allowed by CBSR. This performance can be referred to in the relevant description in S201 above, and will not be repeated here. Furthermore, the beam direction corresponding to this optimal precoding matrix is ​​the fine beam direction with the best channel quality among the beam directions allowed by CBSR.

[0139] During the acquisition of the main precoding matrix, the terminal device may place the set of spatial basis vectors allowed by CBSR into a second set, determine at least one precoding matrix allowed by CBSR based on the second set, and determine the main precoding matrix based on the at least one precoding matrix; alternatively, it may place at least one precoding matrix determined based on the set of spatial basis vectors allowed by CBSR into the second set and determine the main precoding matrix based on the second set. That is, the second set may include the set of spatial basis vectors allowed by CBSR; or, the second set may include the precoding matrix determined based on the set of spatial basis vectors allowed by CBSR.

[0140] It is understandable that the specific implementation of the terminal device obtaining the main precoding matrix based on the spatial basis vector set allowed by CBSR is similar to the specific implementation of the terminal device obtaining the candidate precoding matrix based on the spatial basis vector set prohibited by CBSR. The difference is that the two use different spatial basis vector sets. That is, the terminal device uses the spatial basis vector set allowed by CBSR when obtaining the main precoding matrix, and uses the spatial basis vector set prohibited by CBSR when obtaining the candidate precoding matrix. The similarities can be understood by referring to the relevant introduction above, and will not be repeated here.

[0141] Furthermore, the terminal device can acquire the main precoding matrix and the candidate precoding matrix in a sequential manner, or it can acquire the main precoding matrix and the candidate precoding matrix simultaneously. In this embodiment, the order in which the terminal device acquires the main precoding matrix and the candidate precoding matrix is ​​not limited.

[0142] The superiority of the candidate precoding matrix over the master precoding matrix can specifically include: the equivalent channel metrics corresponding to the candidate precoding matrix are superior to those corresponding to the master precoding matrix. These metrics include at least one of the following: channel capacity and SINR. The channel capacity and SINR can be referenced in the aforementioned descriptions and will not be repeated here. Furthermore, the superiority of the candidate precoding matrix over the master precoding matrix indicates that the CBSR has mistakenly masked the fine beam direction with optimal channel quality.

[0143] After acquiring the primary precoding matrix and the candidate precoding matrix, the terminal device can compare them to determine whether the candidate precoding matrix is ​​superior to the primary precoding matrix. For example, it can determine whether the equivalent channel performance corresponding to the candidate precoding matrix is ​​superior to that corresponding to the primary precoding matrix. If the candidate precoding matrix is ​​superior to the primary precoding matrix, the terminal device sends a candidate PMI to the network device to indicate the fine beam direction with optimal channel quality for any CBSR mismasking.

[0144] It is understandable that the specific implementation of the terminal device comparing the main precoding matrix and the candidate precoding matrix can refer to existing technologies, such as the specific implementation of the terminal device determining the optimal precoding matrix from multiple precoding matrices in existing technologies, which will not be elaborated here.

[0145] S203, the network device determines the precoding matrix for communicating with the terminal device based on the candidate PMI.

[0146] After receiving a candidate PMI, the network device can determine the precoding matrix to communicate with the terminal device based on the candidate PMI, the main PMI used to indicate the main precoding matrix, and the actual situation (such as the service carried by the terminal device, channel quality, system policies, etc.).

[0147] For example, after receiving a candidate PMI, a network device can use the precoding matrix indicated by the candidate PMI to communicate with the terminal device based on the ultra-reliable low-latency communication (URLLC) service carried by the terminal device, thereby reducing the bit error rate and latency during transmission and improving SINR.

[0148] It is understandable that after receiving a candidate PMI, the network device can determine the candidate precoding matrix based on the content indicated by the candidate PMI. For example, when the terminal device reports the candidate PMI using the existing codebook, the network device can determine the candidate precoding matrix based on the existing method. For specific implementation, please refer to the existing technology, which will not be elaborated here.

[0149] In summary, in this embodiment, the terminal device determines a candidate precoding matrix based on the spatial basis vector set prohibited by CBSR. If the candidate precoding matrix is ​​superior to the main precoding matrix, the terminal device reports a candidate PMI (Precoding Indicator Machine) to the network device to indicate the candidate precoding matrix. This enables the network device to determine the precoding matrix for communication with the terminal device based on the candidate PMI. This avoids overlooking better fine beam directions, thereby balancing signaling overhead and system performance.

[0150] Furthermore, if the candidate precoding matrix is ​​not superior to the master precoding matrix, the terminal device only sends the master PMI to the network device. In other words, in this case, the terminal device does not send the candidate PMI to the network device.

[0151] The statement that a candidate precoding matrix is ​​not superior to the master precoding matrix can specifically include: the equivalent channel performance corresponding to the master precoding matrix is ​​superior to the equivalent channel performance corresponding to the candidate precoding matrix; or, the equivalent channel performance corresponding to the master precoding matrix is ​​equal to the equivalent channel performance corresponding to the candidate precoding matrix. This performance indicator can be found in the aforementioned related descriptions and will not be repeated here. Furthermore, the statement that a candidate precoding matrix is ​​not superior to the master precoding matrix indicates that there is no fine beam direction with better channel quality in the beam direction shielded by the CBSR.

[0152] When the candidate precoding matrix is ​​not superior to the master precoding matrix, the terminal device only sends the master PMI to the network device, which can avoid resource waste.

[0153] It is understandable that when the candidate precoding matrix is ​​superior to the master precoding matrix, the terminal device must send both the candidate PMI and the master PMI to the network device. Furthermore, the terminal device can send both the candidate PMI and the master PMI to the network device simultaneously.

[0154] Optionally, in conjunction with the above embodiments, before the terminal device obtains the candidate precoding matrix, the method may further include: the network device sending first information to the terminal device, and correspondingly, the terminal device receiving the first information from the network device, wherein the first information indicates whether to report the candidate precoding matrix; the terminal device obtaining the candidate precoding matrix may specifically include: the terminal device obtaining the candidate precoding matrix when the value of the first information is a first value; the network device receiving the candidate PMI from the terminal device for indicating the candidate precoding matrix may specifically include: the network device receiving the candidate PMI when the value of the first information is a first value.

[0155] The first information indicating whether to report the candidate precoding matrix can be replaced by: the first information indicating whether to enable the soft PMI function, which determines (or reports) the candidate precoding matrix based on the spatial vector group prohibited by CBSR; or, the first information indicating whether to determine the candidate precoding matrix based on the spatial vector group prohibited by CBSR; or, the first information indicating whether to acquire the candidate precoding matrix and report the candidate PMI when the candidate precoding matrix is ​​better than the main precoding matrix.

[0156] The first information can be represented by a 1-bit control field in the message carrying the first information. This control field can be `SoftPMI_enabled_flag` or other possible names, without restriction. The first information can be a first value or a second value (described below), such as a first value of 1 and a second value of 0, or a first value of 0 and a second value of 1. When the first information is the first value, it can indicate reporting a candidate precoding matrix, or it can indicate enabling the soft PMI function, or it can indicate determining the candidate precoding matrix based on the spatial vector group prohibited by CBSR, or it can indicate obtaining the candidate precoding matrix and reporting the candidate PMI when the candidate precoding matrix is ​​superior to the main precoding matrix. In this case, the terminal device needs to obtain the candidate precoding matrix and, based on the relationship between the candidate precoding matrix and the main precoding matrix, decide whether to report the candidate PMI. For example, if the candidate precoding matrix is ​​superior to the main precoding matrix, the candidate PMI is reported; if the candidate precoding matrix is ​​not superior to the main precoding matrix, the candidate PMI is not reported.

[0157] The aforementioned first piece of information can be carried in an existing message or in a newly defined message.

[0158] For example, the first information can be carried in the downlink control information (DCI).

[0159] Network devices can periodically broadcast DCI carrying initial information. In this case, terminals within the cell where the network device is located either report the candidate precoding matrix or not; in other words, terminals within the cell where the network device is located either enable or disable the soft PMI function.

[0160] Network devices can also send DCIs carrying first information to terminal devices in a targeted manner.

[0161] For example, when a user carrying a terminal device is at a street corner or in an area where line-of-sight (LOS) signals are blocked, the signal between the network device and the terminal device mainly comes from the reflection path. However, the CBSR configured on the network side limits the selection range of the spatial basis vector group based on the previous LOS direction, causing the terminal device to report a main PMI that deviates from the actual optimal direction to the network device based on the CBSR. In this case, the network device can send a DCI carrying the first information to the terminal device so that the terminal device can report the actual optimal beam direction.

[0162] For example, when the beams of a terminal device overlap or are highly correlated with those of other terminal devices, a network device may send a DCI carrying first information to the terminal device so that the terminal device may report a potentially better beam direction, thereby determining the precoding matrix for communicating with the terminal device based on the beam direction.

[0163] Network devices send the first message via DCI, which can reuse existing messages to send the first message, thereby improving resource utilization and reducing transmission latency.

[0164] In this embodiment, the network device can instruct the terminal device to report candidate PMIs via first information. In this way, the network device can control the terminal device to report candidate PMIs according to the actual situation, thereby achieving global resource management on the network side and improving overall system performance.

[0165] Furthermore, if the value of the first information is the second value, the first information indicates that only the main precoding matrix is ​​reported.

[0166] The first information instruction to report only the main precoding matrix can be replaced by: the first information instruction not to report candidate precoding matrices; or, the first information instruction to disable the soft PMI function; or, the first information instruction not to determine candidate precoding matrices based on spatial vector groups prohibited by CBSR; or, the first information instruction not to acquire candidate precoding matrices.

[0167] In this embodiment, the network device can instruct the terminal device to report only the primary PMI by taking the value of the first information as the second value. In this case, the terminal device does not need to obtain the candidate precoding matrix, nor does it need to report the candidate PMI to the network device; in other words, the terminal device does not perform the operation of obtaining the candidate precoding matrix. Thus, the network device can control the terminal device to only report the primary PMI according to the actual situation, thereby realizing global resource management on the network side and improving the overall system performance.

[0168] It is understood that the above content describes the network device instructing the terminal device to report candidate PMIs. In the embodiments of this application, the terminal device may also determine whether to report candidate PMIs to the network device according to the actual situation; or the protocol may stipulate or pre-set that the terminal device always reports candidate PMIs to the network device or reports candidate PMIs to the network device under certain specific circumstances. The specific settings can be flexibly configured according to the actual situation and are not limited.

[0169] Optionally, in conjunction with the above embodiments, the candidate PMI is related to the first spatial basis vector group used by the candidate precoding matrix, which belongs to the spatial basis vector group prohibited by CBSR.

[0170] When CBSR employs a coarse-grained restriction approach, the granularity of CBSR control differs from that of PMI feedback. This means that after receiving a PMI from a terminal device, the network device needs to fully decode the PMI before determining whether the precoding matrix indicated by the PMI is within the CBSR's permitted range. In this embodiment, after receiving a candidate PMI, the network device can determine the spatial basis vector group used by the candidate precoding matrix, i.e., the first spatial basis vector group, based on the relationship between the candidate PMI and the first spatial basis vector group. Furthermore, it can determine whether the candidate precoding matrix is ​​generated based on a spatial basis vector group prohibited by CBSR, based on whether the first spatial basis vector group belongs to such prohibited spatial basis vector groups. Thus, the network device does not need to fully decode the candidate PMI before determining whether the precoding matrix indicated by the candidate PMI is within the CBSR's prohibited range, thereby reducing the computational overhead incurred by the network device in verifying whether the precoding matrix indicated by the candidate PMI falls within the CBSR's prohibited range.

[0171] The relationship between a candidate PMI and the first spatial basis vector group can be either that the candidate PMI indicates the first spatial basis vector group, or that the candidate PMI and the first spatial basis vector group are correlated. These will be explained separately below.

[0172] Case 2.1: Candidate PMI indicates the first spatial basis vector group.

[0173] In this case, the candidate PMI can include a first-level PMI and a second-level PMI; wherein, the first-level PMI of the candidate PMI is used to indicate the first spatial basis vector group; the second-level PMI of the candidate PMI is used to indicate the L spatial basis vectors in the first spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors, where L is less than or equal to the number of spatial basis vectors included in the first spatial basis vector group, and L is a positive integer. It can be understood that the rules for determining the value of L can be referred to the aforementioned relevant introduction, and will not be repeated here.

[0174] The first-level PMI of a candidate PMI can be the index of the first spatial basis vector group within all spatial basis vector groups partitioned based on CBSR; in this case, the first-level PMI of the candidate PMI can be obtained through... Each bit indicates the number of spatial basis vector groups defined by the CBSR, where G is the total number of spatial basis vector groups. The first-level PMI of a candidate PMI can also be the index of the first spatial basis vector group within the spatial basis vector groups prohibited by the CBSR; in this case, the first-level PMI of the candidate PMI can be determined by... Each bit is used for indication, and M is the number of spatial basis vector groups that are prohibited in CBSR.

[0175] For example, there are 20 spatial basis vector groups based on CBSR. The first spatial basis vector group is the 8th spatial basis vector group among these 20 spatial basis vector groups. Then the first level PMI of the candidate PMI can be 8.

[0176] For example, there are 12 spatial basis vector groups that are prohibited from use by CBSR. The first spatial basis vector group is the 4th spatial basis vector group among these 12 spatial basis vector groups. Then the first level PMI of the candidate PMI can be 4.

[0177] The second-level PMI of the candidate PMI may include an index (denoted as index #1) indicating the L spatial basis vectors in the first spatial basis vector group, and an index (denoted as index #2) indicating the linear combination of the magnitude and phase of the L spatial basis vectors. That is, based on all spatial basis vector groups divided by the CBSR, the indices of all possible L spatial basis vectors, and the indices of all possible linear combinations of the magnitude and phase of each of the L spatial basis vectors, can be pre-set or pre-defined by protocol. Alternatively, based on each spatial basis vector group in all spatial basis vector groups divided by the CBSR, the indices of all possible L spatial basis vectors corresponding to that spatial basis vector group, and the indices of the linear combinations of the magnitude and phase of each of the L spatial basis vectors, can be pre-set or pre-defined by protocol. Alternatively, based on all spatial basis vector groups divided by the CBSR, the indices of all possible L spatial basis vectors corresponding to different values ​​of L, and the indices of the linear combinations of the magnitude and phase of each of the L spatial basis vectors, can be pre-set or pre-defined by protocol. After determining the candidate precoding matrix, the terminal device can use the indices corresponding to the L spatial basis vectors that make up the candidate precoding matrix and the index of the linear combination of the magnitude and phase of the L spatial basis vectors as the second-level PMI of the candidate PMI.

[0178] In this embodiment, after determining the value of L, the terminal device can determine all possible L spatial basis vectors and all possible linear combinations of amplitude and phase of the L spatial basis vectors based on the value and the spatial basis vector set prohibited by CBSR; and determine the precoding matrix prohibited by CBSR based on the L spatial basis vectors and the linear combinations. Then, the terminal device can determine the optimal precoding matrix based on the precoding matrix and the channel response matrix, and use the optimal precoding matrix as a candidate precoding matrix. After determining the candidate precoding matrix, the terminal device can determine the first-level PMI and the second-level PMI of the candidate PMI based on the candidate precoding matrix. For example, the candidate precoding matrix can be: ;in, For candidate precoding matrices, Select a matrix for broadband beams. For specific beam combining and quantization matrices. It corresponds to the first-level PMI of the candidate PMI; and It can represent the first spatial basis vector set, or in other words, It can be a matrix based on the first spatial basis vector group. It has a corresponding relationship with the second-level PMI of the candidate PMI; and It can characterize the linear combination of the magnitude and phase of the L spatial basis vectors in the first spatial basis vector set, or in other words, It can be a matrix used to characterize the L spatial basis vectors in the first spatial basis vector group and the linear combination of the magnitude and phase of these L spatial basis vectors. The terminal device determines... After that, the composition can be determined. of and and based on The first-level PMI for determining candidate PMIs, and based on... The second-level PMI is determined from the candidate PMI.

[0179] Furthermore, in this embodiment of the application, by indicating the first spatial basis vector group through the first-level PMI of the candidate PMI, the CBSR control granularity and the PMI feedback granularity can be made consistent. This enables the network device to determine the first spatial basis vector group used by the candidate precoding matrix based on the first-level PMI of the candidate PMI, and to determine whether the candidate precoding matrix is ​​a precoding matrix determined based on the spatial basis vector group prohibited by CBSR based on the first spatial basis vector group.

[0180] Case 2.2: The candidate PMI is correlated with the first spatial basis vector group.

[0181] In this scenario, different associations (or correspondences) between orthogonal basis vector groups and spatial basis vector groups partitioned based on CBSR can be established in existing codebooks (such as Type II codebooks or enhanced Type II codebooks). For example, orthogonal basis vector groups can be associated with their respective spatial basis vector groups. After receiving a candidate PMI, the network device can determine whether the spatial basis vector group corresponding to the orthogonal basis vector group indicated by the candidate PMI belongs to a spatial basis vector group prohibited by CBSR based on the correspondence between the orthogonal basis vector group indicated by the candidate PMI and the spatial basis vector group partitioned based on CBSR.

[0182] In this embodiment, the orthogonal basis vector group indicated by the candidate PMI is associated with the first spatial basis vector group, or in other words, the candidate PMI is associated with the first spatial basis vector group. After receiving the candidate PMI, the network device can determine its association with the first spatial basis vector group based on the candidate PMI, and determine whether the first spatial basis vector group belongs to the spatial basis vector group prohibited by CBSR.

[0183] It is understood that the above content describes two methods for network devices to determine the first spatial basis vector group based on candidate PMIs. In the embodiments of this application, the terminal device can also send additional information indicating the first spatial basis vector group when sending the candidate PMI to the network device, so that the network device can determine the spatial basis vector group used by the candidate precoding matrix based on the information, and determine whether the candidate precoding matrix is ​​a precoding matrix generated based on the spatial basis vector group prohibited by CBSR.

[0184] Optionally, in conjunction with the above embodiments, the candidate PMI is carried in the CSI report. That is, the terminal device sending the candidate PMI for indicating the candidate precoding matrix to the network device may specifically include: the terminal device sending a CSI report carrying the candidate PMI to the network device; the network device receiving the candidate PMI from the terminal device may specifically include: the network device receiving the CSI report from the terminal device.

[0185] CSI reports may also include information such as channel quality indicator (CQI), RI, primary PMI, and candidate PMI. The format of CQI, RI, and primary PMI in CSI reports can refer to existing technologies and will not be elaborated here.

[0186] In this embodiment, the terminal device can report candidate PMIs along with the primary PMI in the CSI report to the network device. This improves resource utilization and facilitates the network device's acquisition of candidate PMIs. It is understood that candidate PMIs can also be carried in other existing messages or newly defined messages; the specific settings can be flexibly configured according to actual circumstances without limitation.

[0187] In one possible implementation, the first part (part1) of the CSI report includes an indicator symbol that can be used to indicate that a candidate PMI is included in the second part (part2) of the CSI report.

[0188] For example, the terminal device may set a 1-bit indicator symbol in the first part of the CSI report. The indicator symbol may be used to indicate that the second part of the CSI report includes candidate PMIs; or, the indicator symbol may indicate whether an encoded field for candidate PMIs is used in the second part of the CSI report. The indicator symbol may be SoftPMI_indication or other names, without limitation.

[0189] When the candidate PMI includes a first-level PMI and a second-level PMI, as shown in Table 1 below, the second part of the CSI report can include the first-level PMI (SoftPMI_Level1 in Table 1 below) and the second-level PMI (SoftPMI_Level2 in Table 1 below). The first-level PMI and the second-level PMI can be set after the main PMI (PMI_Level1 and PMI_Level2 in Table 1 below, as described below). Table 1 shows the relevant content of the PMI field in the second part of the CSI report.

[0190] Table 1

[0191]

[0192] It is understandable that if the first part of the CSI report does not include an indicator symbol, it may indicate that the terminal device has not reported a candidate PMI to the network device. In this case, the second part of the CSI report will not include the candidate PMI.

[0193] In addition, different values ​​of the indicator symbol can be set to indicate whether the second part of the CSI report includes candidate PMIs. For example, when the value of the indicator symbol is 1 (or 0), it indicates that the second part of the CSI report includes candidate PMIs, and when the value of the indicator symbol is 0 (or 1), it indicates that the second part of the CSI report does not include candidate PMIs.

[0194] In this embodiment, after receiving a CSI report, the network device can first determine whether the second part of the CSI report includes candidate PMIs based on the indicator symbols in the first part of the CSI report. When the indicator symbol indicates that the second part of the CSI report includes candidate PMIs, the candidate precoding matrix can be determined based on the candidate PMIs in the second part of the CSI report. For example, it can be determined based on the first-level PMIs of the candidate PMIs. Determined based on the second-level PMI of the candidate PMI Based on and ,Sure This refers to the candidate precoding matrix. By setting indicator symbols in the first part of the CSI report and candidate PMIs in the second part of the CSI report, the candidate PMIs can be sent based on the existing structure of the CSI report, thereby reducing the difficulty of sending candidate PMIs through the CSI report.

[0195] In another possible implementation, the first part of the CSI report includes a decoding indicator symbol, which can be used to indicate the byte length of the second part of the CSI report; and the second part of the CSI report includes a candidate indicator symbol, which is used to indicate whether a candidate PMI exists, or, the candidate indicator symbol is used to indicate whether there is a candidate precoding matrix superior to the main precoding matrix in the direction prohibited by the CBSR.

[0196] The decoding indicator symbol can be SoftPMI_indication or any other name, without restriction. The candidate indicator symbol can use different bits to indicate the presence of a candidate PMI, or the presence of a candidate precoding matrix superior to the main precoding matrix in the CBSR-forbidden direction. For example, when the candidate indicator symbol is 0 (or 1), it indicates that there is no candidate PMI or that there is no candidate precoding matrix superior to the main precoding matrix in the CBSR-forbidden direction; when the candidate indicator symbol is 1 (or 0), it indicates that there is a candidate PMI or that there is a candidate precoding matrix superior to the main precoding matrix in the CBSR-forbidden direction. The candidate indicator symbol can be SoftPMI_Flag or any other name, without restriction.

[0197] For example, as shown in Table 2 below, the second part of the CSI report may include candidate indicator symbols (SoftPMI_Flag in Table 2 below), which can be located after the main PMI (PMI_Level1 and PMI_Level2 in Table 2 below, described below). Furthermore, when the candidate PMI includes a first-level PMI (SoftPMI_Level1 in Table 2 below) and a second-level PMI (SoftPMI_Level2 in Table 2 below), the first and second PMIs can be set after the candidate indicator symbols. Table 2 shows the relevant content of the PMI field in the second part of the CSI report.

[0198] Table 2

[0199]

[0200] In this embodiment, after receiving a CSI report, the network device can first determine the byte length for decoding the second part of the CSI report based on the decoding indicator symbols in the first part of the CSI report. After decoding the second part of the CSI report according to the byte length, it can determine whether there is a candidate PMI in the second part of the CSI report based on the candidate indicator symbols in the second part of the CSI report. When the candidate indicator symbol indicates the existence of a candidate PMI, the network device can determine the candidate precoding matrix based on the candidate PMI in the second part of the CSI report. For example, the network device can determine the first-level PMI of the candidate PMI. Determined based on the second-level PMI of the candidate PMI Based on and ,Sure This refers to the candidate precoding matrix. By setting the decoding indicator symbol in the first part of the CSI report and the candidate indicator symbol and candidate PMI in the second part of the CSI report, the candidate PMI can be sent based on the existing structure of the CSI report, thereby reducing the difficulty of sending candidate PMI through the CSI report.

[0201] Optionally, in conjunction with the above embodiments, the method may further include: the terminal device sending a main PMI for indicating the main precoding matrix to the network device, and correspondingly, the network device receiving the main PMI for indicating the main precoding matrix from the terminal device; wherein the main PMI is related to a second spatial basis vector set used by the main precoding matrix, and the second spatial basis vector set belongs to the spatial basis vector set allowed by CBSR.

[0202] The primary PMI is related to the second spatial basis vector group used by the primary precoding matrix. This could mean that the primary PMI indicates the second spatial basis vector group, or that the primary PMI and the second spatial basis vector group are related.

[0203] Case 3.1: The main PMI indicates the second spatial basis vector group.

[0204] In this case, the primary PMI includes a first-level PMI and a second-level PMI; wherein, the first-level PMI of the primary PMI is used to indicate the second spatial basis vector group, and the second-level PMI of the primary PMI is used to indicate the L spatial basis vectors in the second spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors, where L is less than or equal to the number of spatial basis vectors included in the second spatial basis vector group, and L is a positive integer.

[0205] The method of setting the first-level PMI and the second-level PMI in the main PMI is similar to the method of setting the first-level PMI and the second-level PMI in the candidate PMI. The difference is that the main PMI is determined based on the spatial basis vector group allowed by CBSR (such as the second spatial basis vector group), while the candidate PMI is determined based on the spatial basis vector group prohibited by CBSR (such as the first spatial basis vector group). The similarities can be understood by referring to the relevant introduction above, and will not be repeated here.

[0206] In this embodiment of the application, by instructing the second spatial basis vector group through the first-level PMI of the primary PMI, the CBSR control granularity can be made consistent with the PMI feedback granularity. This enables the network device to determine the second spatial basis vector group used by the candidate precoding matrix based on the first-level PMI of the primary PMI, and to determine whether the candidate precoding matrix is ​​a precoding matrix generated based on the spatial basis vector group allowed by the CBSR based on the second spatial basis vector group.

[0207] It is understood that when the primary PMI includes both the aforementioned first-level PMI and the aforementioned second-level PMI, the terminal device can send the primary PMI in the manner described in the prior art, such as setting the primary PMI in the second part of the CSI report, so as to send the primary PMI to the network device through the CSI report. Furthermore, the method by which the network device determines the primary precoding matrix based on the primary PMI after receiving it is similar to the method described above for determining the candidate precoding matrix based on the candidate PMI; this can be understood by referring to the aforementioned related content, and will not be repeated here.

[0208] Case 3.2: The main PMI is correlated with the second spatial basis vector group.

[0209] In this scenario, different associations (or correspondences) between orthogonal basis vector groups and spatial basis vector groups partitioned based on CBSR can be established in the existing codebook. For example, orthogonal basis vector groups can be associated with their respective spatial basis vector groups. After receiving the master PMI, the network device can determine whether the spatial basis vector group corresponding to the orthogonal basis vector group is a spatial basis vector group allowed by CBSR based on the correspondence between the orthogonal basis vector group indicated by the master PMI and the spatial basis vector group partitioned by CBSR.

[0210] In this embodiment, the orthogonal basis vector group indicated by the primary PMI is associated with the second spatial basis vector group; in other words, the primary PMI and the second spatial basis vector group are associated. After receiving the primary PMI, the network device can determine the associated second spatial basis vector group based on the primary PMI and determine whether the second spatial basis vector group belongs to the spatial basis vector groups allowed by CBSR.

[0211] It is understood that the above content describes two methods for network devices to determine the second spatial basis vector group based on the primary PMI. In the embodiments of this application, the terminal device can also send additional information indicating the second spatial basis vector group when sending the primary PMI to the network device, so that the network device can determine the spatial basis vector group used by the primary precoding matrix based on this information, and determine whether the primary precoding matrix is ​​a precoding matrix generated based on the spatial basis vector group allowed by CBSR.

[0212] Optionally, in conjunction with the above embodiments, the method may further include: when the network device receives candidate PMIs from the terminal device multiple times in a row, updating the CBSR, wherein the updated CBSR allows the use of the first spatial basis vector group; the network device sends the updated CBSR to the terminal device, and the terminal device receives the updated CBSR from the network device accordingly.

[0213] The first spatial basis vector group can be referred to the above-mentioned introduction, and will not be repeated here. When the terminal device sends candidate PMIs to the network device multiple times in a row, it can indicate that the beam direction corresponding to the candidate PMI is the optimal beam direction obtained by the terminal device through continuous measurement. In this case, the network device can set the spatial basis vector group corresponding to the beam direction as the allowed spatial basis vector group in the CBSR to improve the flexibility and accuracy of network scheduling.

[0214] The above, in conjunction with the method embodiments, provides an overall overview of the communication method provided in this application. For ease of understanding, the method will be described below using specific scenarios.

[0215] Figure 3 Flowchart of the communication method provided in the embodiments of this application Figure Two This method is applicable to Figure 1 The communication system shown primarily involves communication between terminal devices and network devices. In this scenario, the network device instructs the terminal to report a candidate PMI. If the candidate precoding matrix is ​​superior to the main precoding matrix, the terminal device reports both the main PMI and the candidate PMI to the network device. Based on the main PMI and the candidate PMI, the network device determines the precoding matrix used for communication with the terminal.

[0216] S301, the network device sends an RRC message to the terminal device. Correspondingly, the terminal device receives the RRC message from the network device.

[0217] RRC messages can be used to update the configuration parameters of terminal devices. RRC messages can include a CBSR bitmap and CSI configuration information.

[0218] The CBSR bitmap consists of 8 bits, namely 11110000; these 8 bits indicate that the terminal device is allowed to use the first to fourth spatial basis vector groups, and that the terminal device is prohibited from using the fifth to eighth spatial basis vector groups. This CBSR bitmap can be referred to in the relevant description in S201 above, and will not be repeated here.

[0219] CSI configuration information may include various information associated with CSI-RS resources, such as the CSI-RS resources that the terminal wants to measure. For details, please refer to existing technologies, which will not be elaborated here.

[0220] S302, the network device sends a DCI to the terminal device. Correspondingly, the terminal device receives the DCI from the network device.

[0221] The DCI carries first information, which takes the value of a first value. The first information can be referred to in the preceding text. Figure 2 The relevant descriptions in the illustrated embodiments will not be repeated here.

[0222] S303, the network device sends a CSI-RS to the terminal device. Correspondingly, the terminal device receives the CSI-RS from the network device.

[0223] The specific implementation of S303 can be found in existing technologies, and will not be elaborated here.

[0224] S304, the terminal device obtains the master PMI based on CSI-RS.

[0225] The terminal equipment measures CSI-RS to obtain the channel response matrix H and RI. The channel response matrix H can be used to describe the relationship between the various transmit and receive antennas during signal transmission; RI can be used to indicate the number of downlink data that the terminal equipment expects to spatially multiplex.

[0226] The terminal device can determine a second set based on the spatial basis vector set and RI allowed by the CBSR. This second set can be referred to in the relevant description in S202 above, and will not be repeated here. After determining at least one precoding matrix allowed by the CBSR based on the second set, the terminal device can determine the optimal precoding matrix, i.e., the master precoding matrix, from these at least one precoding matrix. For example, the terminal device can determine the optimal precoding matrix from these at least one precoding matrix based on the channel response matrix H; specific details can be found in existing technologies, and will not be repeated here.

[0227] Alternatively, the terminal device can determine the optimal precoding matrix from all precoding matrices corresponding to RI in the codebook (such as a type II codebook or an enhanced type II codebook) based on the channel response matrix H. After obtaining the optimal precoding matrix, the terminal device can determine the relationship between the optimal precoding matrix and the spatial vector groups allowed by the CBSR. If the spatial basis vector group used by the optimal precoding matrix belongs to the spatial vector groups allowed by the CBSR, then the optimal precoding matrix can be used as the master precoding matrix. If the spatial basis vector group used by the optimal precoding matrix does not belong to the spatial vector groups allowed by the CBSR, then the first precoding matrix that uses the spatial vector groups allowed by the CBSR can be used as the master precoding matrix, in descending order of quality.

[0228] After determining the master precoding matrix, the terminal device can determine the master PMI based on the master precoding matrix.

[0229] S305, terminal devices obtain candidate PMIs.

[0230] The terminal device can determine a first set based on the spatial basis vector set and RI prohibited by CBSR. This first set can be referred to in the relevant description in S202 above, and will not be repeated here. After determining at least one precoding matrix prohibited by CBSR based on the first set, the terminal device can determine the optimal precoding matrix, i.e., the candidate precoding matrix, from the at least one precoding matrix. For example, the terminal device can determine the optimal precoding matrix from the at least one precoding matrix based on the channel response matrix H; specific details can be found in existing technologies, and will not be repeated here.

[0231] Alternatively, the terminal device can determine the optimal precoding matrix from all precoding matrices corresponding to RI in the codebook based on the channel response matrix H. After obtaining the optimal precoding matrix, the terminal device can determine the relationship between the spatial vector groups prohibited by CBSR and the optimal precoding matrix. If the spatial basis vector group used by the optimal precoding matrix belongs to the CBSR-prohibited spatial vector group, then the optimal precoding matrix is ​​taken as a candidate precoding matrix. If the spatial basis vector group used by the optimal precoding matrix does not belong to the CBSR-prohibited spatial vector group, then the first precoding matrix that uses the CBSR-prohibited spatial vector group is taken as a candidate precoding matrix, in descending order of precoding matrix quality.

[0232] After determining the candidate precoding matrix, the terminal device can determine the candidate PMI based on the candidate precoding matrix.

[0233] It is understood that S304 and S305 can be performed simultaneously or in a specific order. The embodiments of this application do not restrict the order of S304 and S305.

[0234] S306, the terminal device sends a CSI report to the network device based on the primary PMI and candidate PMIs. Correspondingly, the network device receives the CSI report from the terminal device.

[0235] The first part of the CSI report includes indicator symbols, and the second part includes the main PMI and candidate PMIs, as detailed above. Figure 2 The relevant descriptions in the illustrated embodiments will not be repeated here.

[0236] S307, Network devices determine the precoding matrix for communication with terminal devices based on CSI reports.

[0237] The specific implementation of S307 can be found in the aforementioned introduction to S203, and will not be repeated here.

[0238] It is understandable that the specific implementations of S301-S507 can be referred to the aforementioned... Figure 2 The relevant descriptions of the embodiments shown will not be repeated here.

[0239] Figure 4 Flowchart of the communication method provided in the embodiments of this application Figure One . Figure 4 The terminal device in the middle can be Figure 1 Any terminal device in the context of network equipment can refer to any component within that terminal device (such as a processor, chip, or chip system). Network equipment can be... Figure 1 Any access network device, or a component within an access network device (such as a processor, chip, or chip system). For example... Figure 4 As shown, the communication method includes the following steps:

[0240] S401, the terminal device obtains the main precoding vector and candidate precoding vector of the i-th spatial layer.

[0241] The number of spatial layers is RI. In this embodiment, i ranges from 1 to F, where F equals RI, and i and RI are both positive integers. For example, if RI is 3, there are 3 spatial layers. i ranges from 1 to 3, meaning that for each of these 3 spatial layers, the terminal device obtains the master precoding vector and candidate precoding vector for each spatial layer. The specific implementation of the terminal device obtaining RI can be found in existing technologies and will not be elaborated here.

[0242] The master precoding vector is the optimal precoding vector determined based on the spatial basis vector set allowed by CBSR.

[0243] CBSR can restrict (N1·N2) / (X1·X2) spatial basis vector groups. For details, please refer to the relevant introduction in S201 above, which will not be repeated here.

[0244] The aforementioned optimal precoding vector can be understood as the precoding vector with the highest reference signal received power (RSRP) among all precoding vectors (denoted as P precoding vectors, where P is a positive integer) corresponding to the i-th spatial layer, determined based on the spatial basis vector set allowed by CBSR. In this embodiment, before the terminal device obtains the master precoding vector of the i-th spatial layer, the above method may further include: the terminal device obtaining P precoding vectors determined based on the spatial basis vector set allowed by CBSR; the terminal device obtaining the master precoding vector of the i-th spatial layer may specifically include: determining the master precoding vector based on the channel response matrix H and the P precoding vectors, wherein the master precoding vector is the precoding vector with the highest RSRP among the P precoding vectors.

[0245] The terminal device can obtain P precoding vectors by: constructing a first set of spatial basis vectors allowed by CBSR, that is, the first set includes the spatial basis vectors allowed by CBSR; for each spatial basis vector set in the first set, the terminal device can select L different spatial basis vectors from the spatial basis vector set, and perform a linear combination of the amplitude and phase of the L spatial basis vectors to obtain a precoding vector generated based on the L spatial basis vectors, thereby obtaining P precoding vectors; L is a positive integer, and the value of L is related to N1 and N2.

[0246] After acquiring P precoding vectors, the terminal device can calculate the RSRP of each precoding vector based on the channel response matrix H, and select the precoding vector with the highest RSRP as the master precoding vector. The formula for calculating the RSRP of each precoding vector based on the channel response matrix H is as follows: ;in, Let x be the row vector formed by the elements of the i-th row in the channel response matrix H, where x ranges from 1 to P. Let x be the x-th precoding vector among the P precoding vectors corresponding to the i-th spatial layer, where x is a positive integer.

[0247] It is understood that in this embodiment, P precoding vectors are used to obtain the main precoding vector corresponding to each spatial layer. The difference lies in that when calculating the RSRP of the P precoding vectors corresponding to different spatial layers, row vectors composed of elements from different rows of the channel response matrix H are used. For example, when calculating the RSRP of the P precoding vectors corresponding to the first spatial layer, row vectors composed of elements from the first row of the channel response matrix H are used; when calculating the RSRP of the P precoding vectors corresponding to the second spatial layer, row vectors composed of elements from the second row of the channel response matrix H are used. The i-th row element of the channel response matrix H can characterize the channel response from all transmit antennas to the i-th receive antenna (or the i-th receive radio frequency (RF) chain connected to all transmit antennas).

[0248] The candidate precoding vector is the optimal precoding vector determined based on the spatial basis vector set prohibited by CBSR. This optimal precoding vector can be understood as the precoding vector with the highest RSRP among all precoding vectors (denoted as Q precoding vectors, where Q is a positive integer) corresponding to the i-th spatial layer determined based on the spatial basis vector set prohibited by CBSR. In this embodiment, before the terminal device obtains the candidate precoding vector for the i-th spatial layer, the above method may further include: the terminal device obtaining the Q precoding vectors determined based on the spatial basis vector set prohibited by CBSR; specifically, obtaining the candidate precoding vector for the i-th spatial layer may include: determining the candidate precoding vector based on the channel response matrix H and the Q precoding vectors, wherein the candidate precoding vector is the precoding vector with the highest RSRP among the Q precoding vectors.

[0249] The terminal device can obtain Q precoding vectors by: constructing a second set of spatial basis vectors prohibited by CBSR, i.e., the second set includes spatial basis vectors prohibited by CBSR; for each spatial basis vector group in the second set, the terminal device can select L different spatial basis vectors from the spatial basis vector group, and perform a linear combination of the amplitude and phase of the L spatial basis vectors to obtain a precoding vector generated based on the L spatial basis vectors, thereby obtaining Q precoding vectors; L is a positive integer, and the value of L is related to N1 and N2.

[0250] After acquiring Q precoding vectors, the terminal device can calculate the RSRP of each of the Q precoding vectors based on the channel response matrix H, and select the precoding vector with the highest RSRP as a candidate precoding vector. The formula for calculating the RSRP of each precoding vector based on the channel response matrix H is as follows: ;in, Let be the row vector formed by the elements of the i-th row in the channel response matrix H. For details, please refer to the relevant introduction above; y takes values ​​from 1 to Q. Let y be the y-th precoding vector among the Q precoding vectors corresponding to the i-th spatial layer, where y is a positive integer.

[0251] It is understood that in this embodiment, Q precoding vectors are used to obtain the candidate precoding vectors corresponding to different spatial layers. The difference lies in that, when calculating the RSRP of the Q precoding vectors corresponding to different spatial layers, row vectors composed of elements from different rows of the channel response matrix H are used. Furthermore, the specific implementation of obtaining candidate precoding vectors for different spatial layers is similar to the specific implementation of obtaining master precoding vectors for different spatial layers described above. The difference is that Q precoding vectors are used when obtaining candidate precoding vectors, while P precoding vectors are used when obtaining master precoding vectors. The Q and P precoding vectors are different; the similarities can be understood by referring to each other, and will not be elaborated further here.

[0252] In this embodiment, after determining the RI, the terminal device can determine a primary precoding vector and a candidate precoding vector for each spatial layer. The primary and candidate precoding vectors corresponding to different spatial layers can each be constructed using different L spatial basis vectors. These L spatial basis vectors can come from the same set of spatial basis vectors, or they can come from sets of spatial basis vectors allowed or prohibited by the CBSR. Furthermore, the aforementioned P and Q precoding vectors are all column vectors, meaning that the primary and candidate precoding vectors for the i-th layer are both column vectors.

[0253] S402, the terminal device sends a PMI set to the network device. Correspondingly, the network device receives the PMI set from the terminal device.

[0254] The PMI set includes a main PMI for indicating the main precoding vector of the i-th spatial layer, and, in the case that the candidate precoding vector is superior to the main precoding vector, the PMI set also includes candidate PMIs for indicating the candidate precoding vector of the i-th spatial layer.

[0255] Specifically, the difference between the RSRP of the candidate precoding vector of the i-th spatial layer and the RSRP of the main precoding vector of the i-th spatial layer can be greater than a preset threshold.

[0256] The methods for obtaining the RSRP corresponding to the candidate precoding vector and the RSRP corresponding to the main precoding vector can be found in the relevant introduction in S401 above, and will not be repeated here.

[0257] The preset threshold can be determined by the terminal device itself. For example, the terminal device can set the preset threshold to 3 dB. For instance, when the environment fluctuates greatly or there is significant interference, the terminal device can set the preset threshold to a larger value to avoid frequently sending candidate PMIs; or, the terminal device can set the preset threshold to a larger value in high-density scenarios with multiple users; or, the terminal device can set the preset threshold to a smaller value in single-user scenarios or low-density scenarios with few users.

[0258] The difference between the RSRP of the candidate precoding vector of the i-th spatial layer and the RSRP of the main precoding vector can be expressed as: >K; where, Let be the difference between the RSRP of the candidate precoding vector for the i-th spatial layer and the RSRP of the main precoding vector. The RSRP corresponding to the candidate precoding vector, i.e. , Let i be the candidate precoding vector for the i-th spatial layer. The RSRP corresponding to the main precoding vector, i.e. , Let K be the main precoding vector of the i-th spatial layer, and K be the preset threshold.

[0259] In this embodiment, after obtaining the primary precoding vector and candidate precoding vector of the i-th spatial layer, the terminal device can compare the primary precoding vector and the candidate precoding vector to determine whether the candidate precoding vector is superior to the primary precoding vector. For example, it can determine whether the difference between the RSRP corresponding to the candidate precoding vector and the RSRP corresponding to the primary precoding vector is greater than a preset threshold. If the candidate precoding vector of the i-th spatial layer is superior to the primary precoding vector, the terminal device reports a candidate PMI to the network device to indicate the candidate precoding vector, so as to indicate the fine beam direction with good channel quality for CBSR mismasking to the network device through the candidate PMI.

[0260] The primary PMI is related to the first spatial basis vector set used by the primary precoding vector, which belongs to the spatial basis vector sets allowed by the CBSR. Upon receiving the primary PMI, the network device can determine the spatial basis vector set used by the primary precoding vector based on the relationship between the primary PMI and the first spatial basis vector set, and can also determine whether the primary coding vector is a precoding vector generated based on a spatial basis vector set allowed by the CBSR. Thus, the network device does not need to fully decode the primary PMI before determining whether the precoding vector indicated by the primary PMI is within the CBSR-allowed range, thereby reducing the computational overhead incurred by the network device in verifying whether the precoding matrix indicated by the primary PMI is within the CBSR-allowed range.

[0261] The main PMI can include the first-level PMI and the second-level PMI.

[0262] The first-level PMI of the primary PMI can be used to indicate the first spatial basis vector group. The first-level PMI of the primary PMI can be the index of the first spatial basis vector group within all spatial basis vector groups partitioned based on the CBSR; in this case, this index can be determined by... Each bit indicates the number of spatial basis vector groups defined by the CBSR, where G is the total number of spatial basis vector groups. The first-level PMI of the primary PMI can also be the index of the first spatial basis vector group within the spatial basis vector groups allowed by the CBSR; in this case, the index can be determined by... Each bit is used for indication, and N is the number of spatial basis vector groups allowed in CBSR.

[0263] The second-level PMI of the main PMI is used to indicate the linear combination of the magnitude and phase of the L spatial basis vectors and the L spatial basis vectors in the first spatial basis vector group. L is less than or equal to the number of spatial basis vectors included in the spatial basis vector group, and L is a positive integer. The value of L can be found in the relevant introduction in S201 above, and will not be repeated here.

[0264] In this embodiment, after determining the master precoding vector of the i-th spatial layer, the terminal device can determine the first-level PMI and the second-level PMI of the master PMI based on the master precoding vector. For example, the master precoding vector of the i-th spatial layer can be: ;in, The main precoding vector, Select a matrix for broadband beams. For specific beam combining and vectors. It corresponds to the first-level PMI of the main PMI; and It can represent the first spatial basis vector set, or in other words, It can be a matrix based on the first spatial basis vector group. It has a corresponding relationship with the secondary PMI of the main PMI; and It can characterize the linear combination of the magnitude and phase of the L spatial basis vectors in the first spatial basis vector set, or in other words, It can be a vector used to characterize the L spatial basis vectors in the first spatial basis vector set and the linear combination of the magnitude and phase of these L spatial basis vectors. The terminal device determines... After that, the composition can be determined. of and and based on Determine the primary PMI level PMI, and the PMI based on... Determine the secondary PMI of the main PMI.

[0265] It is understood that the setting method of the first level PMII and the second level PMI of the main PMI in the embodiments of this application is the same as that described above. Figure 2 The configuration of the first PMII and the second-level PMI in the illustrated embodiment is similar, except that the primary PMI in this embodiment is determined for a single spatial layer. Figure 2 The main PMI in the illustrated embodiment is determined for the entire spatial layer (i.e., at least one spatial layer). Similarities can be understood by referring to each other, and will not be repeated here.

[0266] The candidate PMI is related to the second spatial basis vector used by the candidate precoding vector. This second spatial basis vector set belongs to the spatial basis vector set prohibited by the CBSR. After receiving the candidate PMI, the network device can determine the spatial basis vector set used by the candidate precoding vector based on the relationship between the candidate PMI and the first spatial basis vector set. Furthermore, it can determine whether the candidate coding vector is a precoding vector generated based on a spatial basis vector set prohibited by the CBSR. Thus, the network device does not need to fully decode the candidate PMI before determining whether the precoding vector indicated by the candidate PMI is within the CBSR-prohibited range, thereby reducing the computational overhead of decoding the candidate PMI.

[0267] Candidate PMIs can include first-level PMIs and second-level PMIs. The first-level PMI of a candidate PMI can be used to indicate a second spatial basis vector group, and the second-level PMI of a candidate PMI can be used to indicate the L spatial basis vectors in the second spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors.

[0268] It is understandable that setting the first-level PMI and the second-level PMI in the candidate PMI is similar to setting the first-level PMI and the second-level PMI in the main PMI. The difference is that the main PMI is determined based on the spatial basis vector group allowed by CBSR (such as the first spatial basis vector group), while the candidate PMI is determined based on the spatial basis vector group prohibited by CBSR (such as the second spatial basis vector group). The similarities can be understood by referring to the relevant introduction above, and will not be repeated here.

[0269] S403, the network device determines the precoding matrix for communicating with terminal devices based on the PMI set.

[0270] After receiving a set of PMIs, the network device can determine the primary precoding vector corresponding to the i-th spatial layer based on the primary PMI corresponding to the i-th spatial layer in the PMI set. Furthermore, if the PMI set also includes candidate PMIs corresponding to the i-th spatial layer, the network device can determine the candidate precoding vector corresponding to the spatial layer based on those candidate PMIs. For example, the network device can determine the primary precoding vector based on the first-level PMI of the primary PMI. Determined based on the secondary PMI of the main PMI. Based on and ,Sure This refers to the primary precoding vector. The specific implementation of network devices determining candidate precoding vectors based on candidate PMIs is similar to that of determining primary precoding vectors based on primary PMIs. For further understanding, please refer to the relevant content mentioned above, and it will not be repeated here.

[0271] After determining the primary precoding vector and candidate precoding vectors corresponding to the i-th spatial layer, the network device can determine the precoding vector used for each spatial layer—either the candidate precoding vector or the primary precoding vector—based on the primary and candidate precoding vectors for each spatial layer in the PMI set and the actual situation (such as the service carried by the terminal device, channel quality, system policies, etc.). After determining the precoding vectors used for each spatial layer, the network device can combine the precoding vectors used by each spatial layer into a precoding matrix according to the order of the spatial layers. For example, the precoding vector used by the i-th spatial layer can be used as the i-th column vector of the combined precoding matrix, and this precoding matrix can be used to communicate with the terminal device.

[0272] In summary, in this embodiment, the terminal device determines the primary precoding vector and candidate precoding vector for the i-th spatial layer based on the spatial basis vector set prohibited by CBSR. If the candidate precoding vector for the i-th spatial layer is superior to the primary precoding vector, the terminal device reports a candidate PMI (Precoding Indicator Minute) to the network device to indicate the candidate precoding vector. This enables the network device to determine the precoding matrix for communication with the terminal device based on the candidate PMI. This avoids missing better fine beam directions, thereby balancing signaling overhead and system performance. Furthermore, reporting candidate PMIs according to spatial layers allows the network side to determine a more efficient precoding matrix for communication with the terminal device based on the PMI set.

[0273] Furthermore, if the candidate precoding vector of the i-th spatial layer is not superior to the master precoding vector, the terminal device only sends the master PMI indicating the master precoding vector of the i-th spatial layer to the network device. That is, the PMI set does not include the candidate PMI indicating the candidate precoding vector of the i-th spatial layer.

[0274] The statement that a candidate precoding vector is not superior to the master precoding vector can specifically include: the equivalent channel performance corresponding to the master precoding vector is superior to the equivalent channel performance corresponding to the candidate precoding vector; or, the equivalent channel performance corresponding to the master precoding vector is equal to the equivalent channel performance corresponding to the candidate precoding vector. This performance indicator can be found in the aforementioned descriptions and will not be repeated here. Furthermore, the statement that a candidate precoding vector is not superior to the master precoding vector can indicate that there is no fine beam direction with better channel quality for the CBSR shielding direction corresponding to the i-th spatial layer.

[0275] If the candidate precoding vector of the i-th spatial layer is not better than the master precoding vector, the terminal device only sends the master PMI corresponding to the i-th spatial layer to the network device, which can avoid resource waste.

[0276] Optionally, in conjunction with the above embodiments, the number of spatial basis vector groups prohibited by CBSR is M, and the number of spatial basis vector groups allowed by CBSR is N, where M and N are both positive integers. The sum of M and N is (N1·N2) / (X1·X2), where N1 is the number of antenna ports of the network device in the horizontal direction, N2 is the number of antenna ports of the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors in the horizontal direction of the spatial basis vector group, X1 is a positive integer less than or equal to N1, and N1 is divisible by X1; X2 is the number of consecutive spatial basis vectors in the vertical direction of the spatial basis vector group, X2 is a positive integer less than or equal to N2, and N2 is divisible by X2. For details, please refer to the foregoing. Figure 2 The relevant descriptions in the illustrated embodiments will not be repeated here.

[0277] Optionally, in conjunction with the above embodiments, before the terminal device obtains the primary precoding vector and candidate precoding vector of the i-th spatial layer, the method may further include: the network device sending first information to the terminal device, and correspondingly, the terminal device receiving the first information from the network device, wherein the first information indicates whether to report the candidate precoding vector of the i-th spatial layer; the terminal device obtaining the candidate precoding vector may specifically include: the terminal device obtaining the candidate precoding vector of the i-th spatial layer when the value of the first information is a first value; the network device receiving the PMI set from the terminal device may specifically include: the network device receiving the PMI set when the value of the first information is a first value.

[0278] The aforementioned first information can be carried in an existing message or in a newly defined message. For example, the first information can be carried in a DCI.

[0279] Furthermore, if the value of the first information is the second value, the first information indicates that only the main precoding vector used to indicate the i-th spatial layer is reported.

[0280] It is understood that the specific implementation of the network device in this application embodiment instructing the terminal device whether to report the candidate precoding vector of the i-th spatial layer through the first information is different from... Figure 2 The implementation of the network device in the illustrated embodiment indicating whether the terminal device should report the candidate precoding matrix via the first information is similar, except that the first information in this embodiment indicates the candidate precoding vector. Figure 2 The first information in the illustrated embodiment indicates the candidate precoding matrix. Similarities can be understood by referring to the foregoing related descriptions, such as... Figure 2 In the illustrated embodiment, "candidate precoding matrix" is replaced with "candidate precoding vector" for understanding purposes, and will not be elaborated further here.

[0281] Optionally, in conjunction with the above embodiments, the PMI set is carried in the CSI report. This improves resource utilization. It is understood that the CSI report can refer to the aforementioned... Figure 2 The relevant descriptions in the illustrated embodiments will not be repeated here.

[0282] In one possible implementation, the first part of the CSI report includes an indicator bitmap indicating whether the candidate PMI of the i-th spatial layer (corresponding) is included in the second part of the CSI report; if the indicator bitmap indicates that the second part of the CSI report includes the candidate PMI of the i-th spatial layer, the candidate PMI of the i-th spatial layer and the main PMI are included in the second part of the CSI report.

[0283] For example, the terminal device can set an indicator bitmap of length F in the first part of the CSI report. Each bit in the indicator bitmap can indicate which spatial layer candidate PMIs are included in the second part of the CSI report; or, each bit in the indicator bitmap can indicate which spatial layers in the second part of the CSI report use the encoded field for candidate PMIs. For example, if the i-th bit of the indicator bitmap is 1, it can indicate that the second part of the CSI report includes the PMI of the i-th spatial layer, or it can indicate that the i-th spatial layer in the second part of the CSI report uses the encoded field for candidate PMIs; if the i-th bit of the indicator bitmap is 0, it can indicate that the second part of the CSI report does not include the PMI of the i-th spatial layer, or it can indicate that the i-th spatial layer in the second part of the CSI report does not use the encoded field for candidate PMIs. The indicator bitmap can be named SoftPMI_indication_Bitmap or other names, without limitation.

[0284] The second part of the CSI report includes a set of PMIs, namely the primary PMI and candidate PMIs for the i-th spatial layer. When the primary PMI and candidate PMI include first-level and second-level PMIs, as shown in Table 3 below, the second part of the CSI report can include the first-level PMI of the primary PMI (PMI_Leveli_1 in Table 3 below) and the second-level PMI (PMI_Leveli_2 in Table 3 below), as well as the first-level PMI (SoftPMI_Leveli_1 in Table 3 below) and the second-level PMI (SoftPMI_Leveli_2 in Table 3 below) of the candidate PMIs. Table 3 shows the PMI fields for the i-th spatial layer in the second part of the CSI report.

[0285] Table 3

[0286]

[0287] In this embodiment, after receiving a CSI report, the network device can determine which spatial layer candidate PMIs are included in the second part of the CSI report based on the indicator bitmap in the first part of the CSI report, thereby determining the candidate PMIs corresponding to these spatial layers based on the second part of the CSI report. By setting the indicator bitmap in the first part of the CSI report and setting the candidate PMIs of the i-th spatial layer in the second part of the CSI report, the transmission of the candidate PMIs of the i-th spatial layer can be realized based on the existing structure of the CSI report, thereby reducing the difficulty of transmitting candidate PMIs through the CSI report.

[0288] In another possible implementation, the first part of the CSI report includes a decoding indicator symbol, which can be used to indicate the byte length of the second part of the CSI report; and the second part of the CSI report includes F candidate indicator symbols, the i-th candidate indicator symbol of the F candidate indicator symbols being used to indicate whether there is a candidate PMI in the i-th spatial layer, or the i-th candidate indicator symbol of the F candidate indicator symbols being used to indicate whether there is a candidate precoding vector superior to the main precoding vector in the CBSR prohibited direction of the i-th spatial layer.

[0289] The decoding indicator symbol can be referenced from the above. Figure 2The relevant descriptions in the illustrated embodiments will not be repeated here. Candidate indicator symbols can use different bits to indicate whether a candidate PMI exists in its corresponding spatial layer, or whether a candidate precoding vector superior to the main precoding vector exists in the CBSR-forbidden direction of its corresponding spatial layer. For example, when the i-th candidate indicator symbol is 0 (or 1), it indicates that a candidate PMI does not exist in the i-th spatial layer, or that a candidate precoding vector superior to the main precoding vector does not exist in the i-th spatial layer in the CBSR-forbidden direction; when the i-th candidate indicator symbol is 1 (or 0), it indicates that a candidate PMI exists in the i-th spatial layer, or that a candidate precoding vector superior to the main precoding vector exists in the i-th spatial layer in the CBSR-forbidden direction. The candidate indicator symbol can be SoftPMI_Flag_i or other names, without limitation.

[0290] For example, as shown in Table 4 below, the second part of the CSI report may include candidate indicator symbols (SoftPMI_Flag_i in Table 4 below), which may be located after the primary PMI of the i-th spatial layer (PMI_Leveli_1 and PMI_Leveli_2 in Table 4 below). Furthermore, when the candidate PMI of the i-th spatial layer includes a first-level PMI (SoftPMI_Leveli_1 in Table 4 below) and a second-level PMI (SoftPMI_Leveli_2 in Table 4 below), the first and second PMIs may be set after the candidate indicator symbols. Table 4 shows the PMI field for the i-th spatial layer in the second part of the CSI report.

[0291] Table 4

[0292]

[0293] In this embodiment, after receiving a CSI report, the network device can first determine the byte length for decoding the second part of the CSI report based on the decoding indicator symbols in the first part of the CSI report. After decoding the content of the second part of the CSI report according to the byte length, it can determine which spatial layer candidate PMIs are included in the second part of the CSI report based on the candidate indicator symbols in the second part of the CSI report, thereby determining the candidate PMIs corresponding to these spatial layers based on the second part of the CSI report. By setting decoding indicator symbols in the first part of the CSI report and candidate indicator symbols in the second part of the CSI report, the transmission of the candidate PMI of the i-th spatial layer can be realized based on the existing structure of the CSI report, thereby reducing the difficulty of transmitting candidate PMIs through the CSI report.

[0294] Optionally, in conjunction with the above embodiments, the method may further include: when the network device receives candidate PMIs of the i-th spatial layer from the terminal device multiple times in a row, updating the CBSR, wherein the updated CBSR allows the use of the second spatial basis vector group; and sending the updated CBSR to the terminal device.

[0295] In this embodiment, when a terminal device sends candidate PMIs for the i-th spatial layer to a network device multiple times consecutively, it can indicate that the beam direction corresponding to the candidate PMI is the optimal beam direction for the i-th spatial layer measured by the terminal device. In this case, the network device can set the spatial basis vector group corresponding to the beam direction as an allowed spatial basis vector group in the CBSR. This improves the flexibility and accuracy of network scheduling.

[0296] Understandable. Figure 4 The illustrated embodiments and Figure 2 The embodiments shown are similar, except that: Figure 4 The illustrated embodiment determines the primary precoding vector and candidate precoding vector for each spatial layer, and reports the primary PMI and candidate PMI for each spatial layer to the network device. Figure 2 The embodiment shown selects the same L spatial basis vectors for each spatial layer, determines the master precoding matrix and candidate precoding matrix based on the entire spatial layer, and reports the master PMI and candidate PMI corresponding to the entire spatial layer to the network device. The similarities can be referred to for mutual understanding, and will not be repeated here.

[0297] Figure 5 Flowchart of the communication method provided in the embodiments of this application Figure Four This method is applicable to Figure 1 The communication system shown mainly involves communication between terminal devices and network devices. In this scenario, the network device instructs the terminal to report candidate PMIs. If the candidate precoding vector of the i-th spatial layer is better than the main precoding vector, the terminal device reports the main PMI and candidate PMI corresponding to the i-th spatial layer to the network device. Based on the main PMI and the candidate PMI, the network device determines the precoding matrix used for communication with the terminal.

[0298] S501, the network device sends an RRC message to the terminal device. Correspondingly, the terminal device receives the RRC message from the network device.

[0299] RRC messages can be used to update the configuration parameters of terminal devices. Furthermore, RRC messages can include a CBSR bitmap and CSI configuration information. For a detailed implementation of S501, please refer to the aforementioned introduction to S301; it will not be repeated here.

[0300] S502, the network device sends a DCI to the terminal device. Correspondingly, the terminal device receives the DCI from the network device.

[0301] The DCI carries first information, which takes the value of a first value. The first information can be referred to in the preceding text. Figure 4 The relevant descriptions in the illustrated embodiments will not be repeated here.

[0302] S503, the network device sends CSI-RS to the terminal device. Correspondingly, the terminal device receives the CSI-RS from the network device.

[0303] The specific implementation of S503 can be found in existing technologies, and will not be elaborated here.

[0304] S504, the terminal device obtains the master precoding vector and candidate precoding vector of each spatial layer based on CSI-RS.

[0305] The terminal device measures the CSI-RS to obtain the channel response matrix H and RI. For details, please refer to the relevant introduction in S304 above, which will not be repeated here.

[0306] The RI measured by the terminal device is 3, indicating that there are 3 spatial layers. The terminal device acquires the master precoding vector and candidate precoding vector for each of the 3 spatial layers, obtaining the master precoding vector #a1 and candidate precoding vector #a2 for the first spatial layer, the master precoding vector #b1 and candidate precoding vector #b2 for the second spatial layer, and the master precoding vector #c1 and candidate precoding vector #c2 for the third spatial layer. It can be understood that the specific implementation of the terminal device acquiring the master precoding vector and candidate precoding vector for each spatial layer can be referred to the relevant description in S401 above, and will not be repeated here.

[0307] S505, the terminal device determines whether to report the candidate PMI corresponding to the spatial layer based on the master precoding vector and candidate precoding vector of each spatial layer.

[0308] That is, the terminal device can compare the relationship between the master precoding vector and the candidate precoding vector of each spatial layer, and based on this relationship, determine whether to report the candidate PMI corresponding to that spatial layer.

[0309] Specifically, the terminal device compares the primary precoding vector #a1 and the candidate precoding vector #a2, and determines that the primary precoding vector #a1 is superior to the candidate precoding vector #a2. In this case, the terminal device does not report the candidate PMI corresponding to the first spatial layer. The terminal device compares the primary precoding vector #b1 and the candidate precoding vector #b2, and determines that the candidate precoding vector #b2 is superior to the primary precoding vector #b1. In this case, the terminal device reports the candidate PMI corresponding to the second spatial layer. The terminal device compares the primary precoding vector #c1 and the candidate precoding vector #c2, and determines that the candidate precoding vector #c2 is superior to the primary precoding vector #c1. In this case, the terminal device reports the candidate PMI corresponding to the third spatial layer.

[0310] S506, the terminal device sends a CSI report to the network device. Correspondingly, the network device receives the CSI report from the terminal device.

[0311] The first part of the CSI report includes an indicator bitmap, and the second part includes a PMI set, as detailed above. Figure 2 The relevant descriptions in the illustrated embodiments will not be repeated here.

[0312] The aforementioned PMI set includes the main PMI corresponding to the first spatial layer, the main PMI and candidate PMI corresponding to the second spatial layer, and the main PMI and candidate PMI corresponding to the third spatial layer.

[0313] It is understood that in the embodiments of this application, the primary PMI corresponding to the spatial layer is the primary PMI used to indicate the primary precoding vector of the spatial layer, and the candidate PMI corresponding to the spatial layer is the candidate PMI used to indicate the candidate precoding vector of the spatial layer.

[0314] S507, network devices determine the precoding matrix for communication with terminal devices based on the PMI set.

[0315] The specific implementation of S507 can be found in the aforementioned introduction to S403, and will not be repeated here.

[0316] It is understandable that the specific implementations of S501-S507 can be referred to the aforementioned... Figure 4 The relevant descriptions of the embodiments shown will not be repeated here.

[0317] Figure 6 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application. Figure One .like Figure 6As shown, the communication device 600 may include a communication module 620. The communication module 620 can implement corresponding communication functions, which can be internal communication functions of the communication device 600 or communication functions between the communication device 600 and other devices. Optionally, the communication module 620 may also be referred to as a communication interface or transceiver module. Optionally, the communication device 600 further includes a processing module 610. The processing module 610 can implement corresponding processing functions.

[0318] Optionally, the communication device 600 further includes a storage module, which can be used to store instructions and / or data; the processing module 610 can read the instructions and / or data in the storage module so that the communication device 600 can implement the aforementioned method embodiments.

[0319] In one possible design, the communication device 600 may correspond to the method embodiment described above (i.e. Figures 2-5 The communication device 600 can be used to execute the steps or processes performed by the terminal device in any of the above method embodiments. (The terminal device is described in the method embodiments above.)

[0320] For example, the processing module 610 is used to obtain a candidate precoding matrix, which is the optimal precoding matrix determined based on the spatial basis vector set prohibited by CBSR.

[0321] The communication module 620 is used to send a candidate PMI to the network device to indicate the candidate precoding matrix when the candidate precoding matrix is ​​better than the main precoding matrix. The main precoding matrix is ​​the optimal precoding matrix determined based on the spatial basis vector set allowed by the CBSR.

[0322] The above are merely examples; for detailed steps or procedures, please refer to the descriptions in the foregoing embodiments.

[0323] In one possible design, the communication device 600 may correspond to the method embodiment described above (i.e. Figures 2-5 The communication device 600 can be used to execute the steps or processes performed by the network device in any of the above method embodiments. (The network device is described in the method embodiments above.)

[0324] For example, the communication module 620 is used to receive a candidate PMI from a terminal device for indicating a candidate precoding matrix, the candidate precoding matrix being the optimal precoding matrix determined based on a set of spatial basis vectors prohibited by the CBSR, the candidate precoding matrix being superior to the master precoding matrix, the master precoding matrix being the optimal precoding matrix determined based on a set of spatial basis vectors allowed by the CBSR.

[0325] The processing module 610 is used to determine a precoding matrix for communicating with the terminal device based on the candidate PMI.

[0326] The above are merely examples; for detailed steps or procedures, please refer to the descriptions in the foregoing embodiments.

[0327] Figure 7 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application. Figure Two .like Figure 7 As shown, the communication device 700 can be a terminal device or a network device to implement the above method (i.e. Figures 2-5 The method described herein includes circuits, chips, chip systems, or processors. The communication device 700 can be used to implement the methods described in the above method embodiments; for details, please refer to the descriptions in the above method embodiments.

[0328] like Figure 7 As shown, the communication device 700 may include one or more processors 710, which may also be referred to as processing units or processing modules, and can implement certain control functions. The processor 710 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, while the central processing unit can be used to control the communication device 700 (e.g., a base station, baseband chip, user, user chip), execute software programs, and process data from the software programs.

[0329] In an alternative design, the processor 710 may also store instructions and / or data that can be executed by the processor 710 to cause the communication device 700 to perform the methods described in the above method embodiments.

[0330] In another alternative design, the communication device 700 may include a communication interface 720 for implementing receiving and transmitting functions. For example, the communication interface 720 may be a transceiver circuit, interface, interface circuit, or transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0331] Optionally, the communication device 700 may include one or more memories 730, which may store instructions that can be executed on the processor 710, causing the communication device 700 to perform the methods described in the above method embodiments. Optionally, the memories 730 may also store data. Optionally, the processor 710 may also store instructions and / or data. The processor 710 and the memories 730 may be provided separately or integrated together.

[0332] It should be understood that, in one possible design, the steps in the method embodiments provided in this application can be implemented by integrated logic circuits in the processor's hardware or by instructions in software form. The steps of the methods disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0333] In one implementation, the communication device 700 may correspond to the terminal device in the above method embodiments and may be used to execute the various steps and / or processes executed by the terminal device in the above method embodiments. The processor 710 may be used to execute instructions stored in the memory 730, and when the processor 710 executes the instructions stored in the memory, the processor 710 is used to execute the various steps and / or processes of the above method embodiments corresponding to the terminal device.

[0334] In another implementation, the communication device 700 may correspond to the network device in the above method embodiments and may be used to execute the various steps and / or processes executed by the network device in the above method embodiments. The processor 710 may be used to execute instructions stored in the memory 730, and when the processor 710 executes the instructions stored in the memory, the processor 710 is used to execute the various steps and / or processes of the above method embodiments corresponding to the network device.

[0335] It should be understood that the aforementioned processing device can be one or more chips. For example, the processing device can be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0336] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0337] According to the method provided in the embodiments of this application, this application also provides a chip system, which includes one or more processors for calling and executing instructions stored in memory, thereby causing the method described in the embodiments of this application to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0338] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0339] According to the method provided in the embodiments of this application, this application also provides a communication system, which includes the aforementioned network device and terminal device. Optionally, the communication system may further include other devices that communicate with the terminal device and / or network device.

[0340] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: a computer program or instructions, which, when the computer program is run, causes the various steps or processes executed by the network device or terminal device in any of the foregoing method embodiments to be executed.

[0341] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing a program or instructions. When the computer program or instructions are executed, they cause the computer to perform the various steps or processes performed by the network device or terminal device in any of the foregoing method embodiments.

[0342] The computer-readable storage medium may be the aforementioned volatile memory or non-volatile memory, or it may include both volatile memory and non-volatile memory.

[0343] In the embodiments of this application, the terms and English abbreviations are exemplary examples given for ease of description and should not be construed as limiting the application in any way. This application does not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0344] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When these computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated.

[0345] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0346] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0347] In summary, the above description is merely a preferred embodiment of the technical solution of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A communication method, characterized in that, The method includes: Obtain a candidate precoding matrix, which is the optimal precoding matrix determined based on a subset of the codebook that restricts the use of spatial basis vectors prohibited by CBSR. If the candidate precoding matrix is ​​superior to the master precoding matrix, a candidate PMI indicating the candidate precoding matrix is ​​sent to the network device. The master precoding matrix is ​​the optimal precoding matrix determined based on the spatial basis vector set allowed by the CBSR.

2. The method according to claim 1, characterized in that, The number of spatial basis vector groups prohibited by the CBSR is M, and the number of spatial basis vector groups allowed by the CBSR is N, where M and N are both positive integers. The sum of M and N is (N1·N2) / (X1·X2), where N1 is the number of antenna ports of the network device in the horizontal direction, N2 is the number of antenna ports of the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors of the spatial basis vector group in the horizontal direction, X1 is a positive integer less than or equal to N1, and N1 is divisible by X1, and X2 is the number of consecutive spatial basis vectors of the spatial basis vector group in the vertical direction, X2 is a positive integer less than or equal to N2, and N2 is divisible by X2.

3. The method according to claim 1, characterized in that, Prior to obtaining the candidate precoding matrix, the method further includes: Receive first information from the network device, the first information indicating whether to report the candidate precoding matrix; The process of obtaining the candidate precoding matrix includes: If the value of the first information is the first value, the candidate precoding matrix is ​​obtained.

4. The method according to claim 3, characterized in that, When the value of the first information is the second value, the first information indicates that only the master precoding matrix is ​​reported.

5. The method according to claim 3 or 4, characterized in that, The first information is carried in the downlink control information (DCI).

6. The method according to claim 1, characterized in that, The candidate PMI is related to the first spatial basis vector group used by the candidate precoding matrix, which belongs to the spatial basis vector group prohibited by the CBSR.

7. The method according to claim 6, characterized in that, The candidate PMI includes a first-level PMI and a second-level PMI. The first-level PMI of the candidate PMI is used to indicate the first spatial basis vector group. The second-level PMI of the candidate PMI is used to indicate the L spatial basis vectors in the first spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. L is less than or equal to the number of spatial basis vectors included in the first spatial basis vector group, and L is a positive integer.

8. The method according to claim 1, characterized in that, The candidate PMI is carried in the Channel State Information (CSI) report.

9. The method according to claim 8, characterized in that, The first part of the CSI report includes an indicator symbol for indicating that the candidate PMI is included in the second part of the CSI report.

10. The method according to claim 1, characterized in that, The process of obtaining the candidate precoding matrix includes: Obtain a first set, which includes the spatial basis vector set prohibited by the CBSR, or the first set includes a precoding matrix determined based on the spatial basis vector set prohibited by the CBSR; Based on the first set, the candidate precoding matrix is ​​obtained.

11. The method according to claim 1, characterized in that, The method further includes: The network device is sent a primary PMI indicating the primary precoding matrix, the primary PMI being related to a second spatial basis vector set used by the primary precoding matrix, the second spatial basis vector set being a spatial basis vector set allowed by the CBSR.

12. The method according to claim 11, characterized in that, The main PMI includes a first-level PMI and a second-level PMI. The first-level PMI of the main PMI is used to indicate the second spatial basis vector group. The second-level PMI of the main PMI is used to indicate the L spatial basis vectors in the second spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. L is less than or equal to the number of spatial basis vectors included in the second spatial basis vector group, and L is a positive integer.

13. A communication method, characterized in that, The method includes: Receive a candidate PMI from a terminal device for indicating a candidate precoding matrix, the candidate precoding matrix being the optimal precoding matrix determined based on a subset of codebooks restricting the use of spatial basis vectors prohibited by the CBSR, the candidate precoding matrix being superior to the master precoding matrix, the master precoding matrix being the optimal precoding matrix determined based on the set of spatial basis vectors allowed by the CBSR; Based on the candidate PMI, a precoding matrix for communicating with the terminal device is determined.

14. The method according to claim 13, characterized in that, The number of spatial basis vector groups prohibited by the CBSR is M, and the number of spatial basis vector groups allowed by the CBSR is N, where M and N are both positive integers. The sum of M and N is (N1·N2) / (X1·X2), where N1 is the number of antenna ports of the network device in the horizontal direction, N2 is the number of antenna ports of the network device in the vertical direction, X1 is the number of consecutive spatial basis vectors of the spatial basis vector group in the horizontal direction, X1 is a positive integer less than or equal to N1, and N1 is divisible by X1, and X2 is the number of consecutive spatial basis vectors of the spatial basis vector group in the vertical direction, X2 is a positive integer less than or equal to N2, and N2 is divisible by X2.

15. The method according to claim 13, characterized in that, Before receiving the candidate PMI from the terminal device, which indicates the candidate precoding matrix, the method further includes: Send first information to the terminal device, the first information indicating whether to report the candidate precoding matrix; Receiving the candidate PMI from the terminal device, which indicates the candidate precoding matrix, includes: If the value of the first information is a first value, the candidate PMI is received.

16. The method according to claim 15, characterized in that, The first information is carried in the downlink control information (DCI).

17. The method according to claim 13, characterized in that, The candidate PMI is related to the first spatial basis vector group used by the candidate precoding matrix, which belongs to the spatial basis vector group prohibited by the CBSR.

18. The method according to claim 17, characterized in that, The candidate PMI includes a first-level PMI and a second-level PMI. The first-level PMI of the candidate PMI is used to indicate the first spatial basis vector group. The second-level PMI of the candidate PMI is used to indicate the L spatial basis vectors in the first spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. L is less than or equal to the number of spatial basis vectors included in the first spatial basis vector group, and L is a positive integer.

19. The method according to claim 13, characterized in that, The candidate PMI is carried in the Channel State Information (CSI) report.

20. The method according to claim 19, characterized in that, The first part of the CSI report includes an indicator symbol for indicating that the candidate PMI is included in the second part of the CSI report.

21. The method according to claim 13, characterized in that, The method further includes: The terminal device receives a primary PMI (Primary Precoding Matrix) indicating the primary precoding matrix, the primary PMI being related to a second spatial basis vector set used by the primary precoding matrix, the second spatial basis vector set being a spatial basis vector set allowed by the CBSR (Centralized Precoding Matrix).

22. The method according to claim 21, characterized in that, The main PMI includes a first-level PMI and a second-level PMI. The first-level PMI of the main PMI is used to indicate the second spatial basis vector group. The second-level PMI of the main PMI is used to indicate the L spatial basis vectors in the second spatial basis vector group and the linear combination of the magnitude and phase of the L spatial basis vectors. L is less than or equal to the number of spatial basis vectors included in the second spatial basis vector group, and L is a positive integer.

23. The method according to claim 17, characterized in that, The method further includes: If the candidate PMI is received multiple times consecutively from the terminal device, the CBSR is updated, and the updated CBSR allows the use of the first spatial basis vector set. The updated CBSR is sent to the terminal device.

24. A communication method, characterized in that, The method includes: Obtain the main precoding vector and candidate precoding vector of the i-th spatial layer. The main precoding vector is the optimal precoding vector determined based on the spatial basis vector set allowed by the CBSR according to the codebook subset. The candidate precoding vector is the optimal precoding vector determined based on the spatial basis vector set prohibited by the CBSR. i ranges from 1 to F, where the value of F is equal to the value of the rank indicator RI, and i is a positive integer. A set of precoding matrix indication (PMI) is sent to the network device. The set of PMI includes a main PMI for indicating the main precoding vector of the i-th spatial layer, and if the candidate precoding vector is superior to the main precoding vector, the set of PMI also includes candidate PMIs for indicating the candidate precoding vector of the i-th spatial layer.

25. A communication method, characterized in that, The method includes: The system receives a set of precoding matrix indications (PMIs) from a terminal device. The PMI set includes a main PMI indicating the main precoding vector of the i-th spatial layer, and, if the candidate precoding vector of the i-th spatial layer is better than the main precoding vector, the PMI set also includes candidate PMIs indicating the candidate precoding vector of the i-th spatial layer. The main precoding vector is the optimal precoding vector determined based on the spatial basis vector set allowed by the CBSR (Central Codebook Restriction). The candidate precoding vector is the optimal precoding vector determined based on the spatial basis vector set prohibited by the CBSR. i ranges from 1 to F, where F is equal to the value of the rank indication RI, and i is a positive integer. Based on the PMI set, a precoding matrix for communicating with the terminal device is determined.

26. A communication device, characterized in that, The apparatus includes a module for performing the method as described in any one of claims 1 to 25.

27. A communication device, characterized in that, The device includes at least one processor coupled to a memory storing a program or instructions, the processor executing the program or instructions to cause the device to perform the method as described in any one of claims 1 to 25.

28. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed, they cause the computer to perform the method as described in any one of claims 1 to 25.

29. A chip system, characterized in that, The chip system includes one or more processors, which are configured to retrieve and execute instructions stored in memory, such that the method as described in any one of claims 1 to 25 is performed.

30. A computer program product, characterized in that, The computer program product includes a computer program or instructions that, when executed by a communication device, cause the method of any one of claims 1 to 25 to be performed.

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