Communication method and apparatus for feeding back precoding matrix

Abstract

A communication method and apparatus for feeding back a precoding matrix. The method comprises: a first apparatus receiving a first reference signal, which is carried on a first resource, wherein the first reference signal is used for determining a spatial basis; the first apparatus receiving a second reference signal, which is carried on a second resource, wherein the second reference signal and the spatial basis are used for determining a precoding matrix corresponding to the second resource; and the first apparatus sending first information, which is used for indicating the precoding matrix. By means of the method, a first apparatus can determine a spatial basis on the basis of a first reference signal carried on a first resource, and determine, on the basis of the spatial basis, a precoding matrix corresponding to a second resource, thereby improving the precision of the fed-back precoding matrix corresponding to the second resource.

Description

Communication method and apparatus for feeding back precoding matrix

[0001] Cross Reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202411020248.4, filed on July 26, 2024, and entitled "Communication method and apparatus for feeding back precoding matrix", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular to a communication method and apparatus for feeding back precoding matrix. BACKGROUND

[0004] Multiple input multiple output (MIMO) technology, as a key technology in wireless communication, can meet the demand of high-speed transmission. The technology can utilize the resource of spatial dimension to make the signal obtain array gain, multiplexing and diversity gain, and interference cancellation gain in space without increasing the system bandwidth, so as to improve the capacity and spectrum efficiency of the communication system.

[0005] In the MIMO technology, the receiving device can feed back the precoding matrix determined by the receiving device to the sending device according to the received reference signal. How to improve the accuracy of the feedback precoding matrix needs to be further discussed. SUMMARY

[0006] The present application provides a communication method and apparatus to improve the accuracy of the feedback precoding matrix.

[0007] In a first aspect, an embodiment of the present application provides a communication method, which can be applied to a first device. The first device can be a terminal, or a device (for example, a module, a communication module, a circuit or a chip responsible for communication function (for example, a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core), a chip system or a processor) of the terminal, or a logic node, a logic module or software capable of realizing all or part of the terminal function. The method can include: receiving, by the first device, a first reference signal, the first reference signal being carried on a first resource, and the first reference signal being used to determine a spatial basis. Receiving, by the first device, a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial basis being used to determine a precoding matrix corresponding to the second resource. Transmitting, by the first device, first information, the first information being used to indicate the precoding matrix.

[0008] Through the method, the first device can determine the spatial basis according to the first reference signal carried on the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial basis, so as to improve the accuracy of the precoding matrix corresponding to the second resource in the feedback. For example, in the case that the signal quality of the second resource is poor, the first device can not determine the spatial basis according to the reference signal carried on the second resource, but determine the spatial basis according to the first reference signal carried on the first resource, so as to improve the accuracy of the determined spatial basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial basis.

[0009] In a second aspect, an embodiment of the present application provides a communication method, which can be applied to a second device. The second device can be an access network device, or a device (for example, a module, a communication module, a circuit or a chip responsible for communication function (for example, a modem chip, or a SoC chip or a SIP chip containing a modem core), a chip system or a processor) of the access network device, or a logic node, a logic module or software capable of realizing all or part of the access network device function. The method can include: transmitting, by the second device, a first reference signal, the first reference signal being carried on a first resource, and the first reference signal being used to determine a spatial basis. Transmitting, by the second device, a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial basis being used to determine a precoding matrix corresponding to the second resource. Receiving, by the second device, first information, the first information being used to indicate the precoding matrix. Determining, by the second device, the precoding matrix according to the spatial basis and the first information.

[0010] By the method, the spatial domain basis is determined according to the reference signal carried by the first resource, and the second device can determine the precoding matrix corresponding to the second resource according to the spatial domain basis and the first information, so that the accuracy of the precoding matrix corresponding to the second resource in the feedback can be improved. For example, in the case that the signal quality of the second resource is poor, the spatial domain basis can not be determined according to the reference signal carried by the second resource, but determined according to the reference signal carried by the first resource, so that the accuracy of the determined spatial domain basis can be improved, and the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis can be improved.

[0011] Based on the first aspect or the second aspect, in a possible design, the method further includes: the first device sends a third reference signal; and correspondingly, the second device receives the third reference signal. The third reference signal is carried on the first resource. The third reference signal is used to determine the spatial domain basis; and correspondingly, the second device determines the spatial domain basis according to the third reference signal. By the design, the second device can determine the spatial domain basis according to the third reference signal carried by the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so that the accuracy of the determined precoding matrix corresponding to the second resource can be improved. For example, in the case that the signal quality of the second resource is poor, the second device can not determine the spatial domain basis according to the reference signal carried by the second resource, but determine the spatial domain basis according to the third reference signal carried by the first resource, so that the accuracy of the determined spatial domain basis can be improved, and the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis can be improved. In addition, in the design, the second device can determine the spatial domain basis according to the third reference signal, and the first device can not send information indicating the spatial domain basis to the second device, so that the first device can indicate the parameters of the precoding matrix corresponding to the second resource by more bits without increasing the signaling overhead, so that the accuracy of the indication of the precoding matrix can be further improved.

[0012] Based on the first aspect or the second aspect, in a possible design, the method further includes: the first device sends third information; and correspondingly, the second device receives the third information. The third information indicates the spatial domain basis. By the design, the second device can accurately determine the spatial domain basis according to the third information. In addition, in the design, the third information can indicate the spatial domain basis, so that the complexity of the determination of the spatial domain basis by the second device can be reduced.

[0013] Based on the first aspect, in a possible design, the method further includes: the first device determines a first eigenvector according to the first reference signal; and determines the spatial domain basis according to the first eigenvector. By the design, the first device can accurately determine the spatial domain basis.

[0014] Based on the first aspect, in a possible design, the first eigenvector satisfies the following formula:

[0015] Or

[0016] N RB is the maximum resource block (RB) index of the measurement bandwidth; F is a resource domain transformation matrix, F H is the conjugate transpose of F; H k,n [0] is the channel coefficient of the 0th polarization, the first resource, the nth RB; is the conjugate transpose of H k,n [0], H k,n [0] is determined according to the first reference signal; k is the index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the first reference signal; H k,n [1] is the channel coefficient of the 1st polarization, the first resource, the nth RB, is the conjugate transpose of H k,n [1], H k,n [1] is determined according to the first reference signal; V' is the first eigenvector; V' H is the conjugate transpose of V'; Σ is the eigenvalue corresponding to the first eigenvector.

[0017] Through the design, the first device can accurately determine the first eigenvector, thereby accurately determining the spatial domain basis. In the design, the first device can perform dimension reduction processing on the channel coefficient through eigenvalue decomposition (EVD), thereby determining a feature space on two polarizations, and the calculation complexity is relatively low.

[0018] In addition, in the case where the first device determines the first eigenvector according to the following formula, the first device can perform resource domain (or beam domain) noise reduction processing on the channel coefficient according to F, thereby improving the accuracy of the determined spatial domain basis:

[0019] Based on the first aspect, in a possible design, the first eigenvector satisfies the following formula:

[0020] is an inner product operation, V' h is the horizontal direction eigenvector, V' v is the vertical direction eigenvector, V' h and V' v respectively satisfy the following formula:

[0021] Alternatively, V' h and V'v respectively satisfy the following formulas:

[0022] wherein N RB is the maximum resource block RB index of the measurement bandwidth; F is a resource domain transformation matrix, F H is the conjugate transpose of F; H k,n is the v-th row of H k,n [0], v is a positive integer, is the conjugate transpose of H k,n [v,0], H k,n [0] is the channel coefficient of the 0-th polarization, the first resource, the n-th RB; H k,n [0] is determined according to the first reference signal; k is the index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the first reference signal; H k,n is the v-th row of H k,n [1], is the conjugate transpose of H k,n [v,1], H k,n [1] is the channel coefficient of the 1-st polarization, the first resource, the n-th RB; H k,n [1] is determined according to the first reference signal; is the conjugate transpose of V h ; Σ h is the corresponding eigenvalue of V h .

[0023] H k,n [h,0] is the h-th column of H k,n [0], h is a positive integer, is the conjugate transpose of H k,n [h,0]; H k,n [h,1] is the h-th column of H k,n [1], is the conjugate transpose of H k,n [h,1]; is the conjugate transpose of V v ; Σ v is the corresponding eigenvalue of V v .

[0024] Through the design, the first device can accurately determine the first eigenvector, thereby accurately determining the spatial domain basis. In the design, the first device can perform dimension reduction processing on the channel coefficients through EVD, thereby determining the feature space in the horizontal and vertical directions respectively, and performing inner product operation on the feature spaces in the horizontal and vertical directions, thereby accurately determining the first eigenvector.

[0025] In a possible design based on the first aspect or the second aspect, the signal quality of the first reference signal is higher than the signal quality of the second reference signal. With this design, in the case that the signal quality of the first reference signal is higher than the signal quality of the second reference signal, the spatial domain basis can not be determined according to the reference signal carried by the second resource, but determined according to the reference signal carried by the first resource, thereby improving the accuracy of the determined spatial domain basis, and further improving the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0026] In a possible design based on the first aspect or the second aspect, the first reference signal and the second reference signal are channel state information reference signals (CSI-RSs).

[0027] In a possible design based on the second aspect, the method further includes: determining, by the second device, the first eigenvector according to the third reference signal; and determining, by the second device, the spatial domain basis according to the first eigenvector. With this design, the second device can accurately determine the spatial domain basis.

[0028] In a possible design based on the second aspect, the first eigenvector satisfies the following formula:

[0029] or

[0030] N RB is the maximum resource block (RB) index of the measurement bandwidth; F is a resource domain transformation matrix, F H is the conjugate transpose of F; H k,n is the channel coefficient of the 0th polarization, the first resource, and the nth RB; is the conjugate transpose of H k,n [0], H k,n [0] is determined according to the third reference signal; k is the index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the third reference signal; H k,n is the channel coefficient of the 1st polarization, the first resource, and the nth RB, is the conjugate transpose of H k,n [1], H k,n [1] is determined according to the third reference signal; V' is the first eigenvector; V' H is the conjugate transpose of V'; Σ is the eigenvalue corresponding to the first eigenvector.

[0031] Through the design, the second device can accurately determine the first eigenvector, and thus accurately determine the spatial domain basis. In the design, the second device can perform dimension reduction processing on the channel coefficients through EVD, and thus determine one eigenspace on two polarizations, and the calculation complexity is low.

[0032] In addition, in a case where the second device determines the first eigenvector according to the following formula, the second device can perform resource domain (or beam domain) noise reduction processing on the channel coefficients according to F, and thus the accuracy of the determined spatial domain basis can be improved:

[0033] Based on the second aspect, in a possible design, the first eigenvector satisfies the following formula:

[0034] is an inner product operation, V′ h is a horizontal direction eigenvector, V′ v is a vertical direction eigenvector, V′ h and V′ v respectively satisfy the following formula:

[0035] Alternatively, V′ h and V′ v respectively satisfy the following formula:

[0036] wherein N RB is a maximum resource block (RB) index of a measurement bandwidth; F is a resource domain transformation matrix, F H is a conjugate transpose of F; H k,n [v,0] is a v-th row of H k,n [0], v is a positive integer, is a conjugate transpose of H k,n [v,0], H k,n [0] is a channel coefficient of a 0th polarization, a first resource, and an n-th RB; H k,n [0] is determined according to a third reference signal; k is an index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to a maximum RB number occupied by the third reference signal; H k,n [v,1] is a v-th row of H k,n [1], is a conjugate transpose of H k,n [v,1], H k,n [1] is a channel coefficient of a 1st polarization, a first resource, and an n-th RB; H k,n [1] is determined according to the third reference signal; is V′ hThe conjugate transpose of Σ h For V′ h The corresponding eigenvalues;

[0037] H k,n [h,0] is H k,n The h-th column of [0], where h is a positive integer. It is H k,n The conjugate transpose of [h,0]; H k,n [h,1] is H k,n [1] in the h-th column, It is H k,n The conjugate transpose of [h,1]; For V′ v The conjugate transpose of Σ v For V′ v The corresponding eigenvalues.

[0038] Through this design, the second device can accurately determine the first eigenvector, thereby accurately determining the spatial basis. Furthermore, in this design, the second device can perform dimensionality reduction processing on the channel coefficients using EVD, thereby determining the feature spaces in the horizontal and vertical directions respectively, and then performing an inner product operation on the feature spaces in the horizontal and vertical directions to accurately determine the first eigenvector.

[0039] Thirdly, embodiments of this application provide a communication method that can be applied to a first device. The first device may be a terminal, or a device that is part of a terminal (e.g., a module, communication module, circuit or chip responsible for communication functions (such as a modem chip, or a SoC chip or SIP chip containing a modem core), chip system, or processor), or a logical node, logical module, or software capable of implementing all or part of the terminal functions. The method may include: the first device acquiring a spatial basis, which is determined based on a reference signal carried on a first resource; the first device receiving a second reference signal carried on a second resource, the second reference signal and the spatial basis being used to determine a precoding matrix corresponding to the second resource; and the first device sending first information, which is used to indicate the precoding matrix.

[0040] Using this method, the spatial basis is determined based on the reference signal carried on the first resource. The first device can determine the precoding matrix corresponding to the second resource based on the spatial basis, thereby improving the accuracy of the precoding matrix corresponding to the second resource. For example, if the signal quality of the second resource is poor, the spatial basis may be determined based on the reference signal carried on the first resource, rather than the reference signal carried on the second resource, thereby improving the accuracy of the determined spatial basis and, consequently, the accuracy of the precoding matrix corresponding to the second resource determined based on the spatial basis.

[0041] In a fourth aspect, an embodiment of the present application provides a communication method, which can be applied to a second device. The second device can be an access network device, or can be a device (for example, a module, a communication module, a circuit or a chip responsible for communication function (for example, a modem chip, or a SoC chip or a SIP chip containing a modem core), a chip system or a processor) of the access network device, or can be a logic node, a logic module or software capable of implementing all or part of the function of the access network device. The method can include: the second device obtaining a spatial domain basis, the spatial domain basis being determined according to a reference signal carried on a first resource. The second device sends a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource. The second device receives first information, the first information being used to indicate the precoding matrix. The second device determines the precoding matrix according to the spatial domain basis and the first information.

[0042] Through the method, the spatial domain basis is determined according to the reference signal carried on the first resource. The second device can determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the determined precoding matrix corresponding to the second resource. For example, in the case that the signal quality of the second resource is poor, the spatial domain basis can not be determined according to the reference signal carried on the second resource, but can be determined according to the reference signal carried on the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0043] Based on the third aspect or the fourth aspect, in a possible design, the method further includes: the second device sending a first reference signal; and correspondingly, the first device receiving the first reference signal. The first reference signal is carried on the first resource. The first reference signal is used to determine the spatial domain basis; and correspondingly, the first device can obtain the spatial domain basis determined according to the first reference signal. Through the design, the first device can determine the spatial domain basis according to the first reference signal carried on the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the feedback precoding matrix corresponding to the second resource. For example, in the case that the signal quality of the second resource is poor, the first device can not determine the spatial domain basis according to the reference signal carried on the second resource, but can determine the spatial domain basis according to the first reference signal carried on the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0044] In a possible design based on the third aspect or the fourth aspect, the method further includes: the first device sending a third reference signal; and the second device receiving the third reference signal. The third reference signal is carried on the first resource. The third reference signal is used to determine the spatial domain basis; and the second device obtains the spatial domain basis determined according to the third reference signal. With this design, the second device can determine the spatial domain basis according to the third reference signal carried on the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial domain basis, thereby improving the accuracy of the determined precoding matrix corresponding to the second resource. For example, in the case where the signal quality of the second resource is poor, the second device can not determine the spatial domain basis according to the reference signal carried on the second resource, but determine the spatial domain basis according to the third reference signal carried on the first resource, thereby improving the accuracy of the determined spatial domain basis, and further improving the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0045] In a possible design based on the third aspect or the fourth aspect, the method further includes: the second device sending a first reference signal; and the first device receiving the first reference signal. The first reference signal is carried on the first resource. The first reference signal is used to determine the spatial domain basis; and the first device can obtain the spatial domain basis determined according to the first reference signal. The first device sends third information; and the second device receives the third information. The third information is used to indicate the spatial domain basis. With this design, the second device can accurately determine the spatial domain basis according to the third information. In addition, in this design, the third information can indicate the spatial domain basis, thereby reducing the complexity of the second device in determining the spatial domain basis.

[0046] In a possible design based on the third aspect or the fourth aspect, the method further includes: the first device sending a third reference signal; and the second device receiving the third reference signal, the third reference signal being carried on the first resource, and the third reference signal being used to determine the spatial domain basis. The second device sends fourth information; and the first device receives the fourth information, the fourth information being used to indicate the spatial domain basis. With this design, the first device can accurately determine the spatial domain basis according to the fourth information. In addition, in this design, the fourth information can indicate the spatial domain basis, thereby reducing the complexity of the first device in determining the spatial domain basis.

[0047] In a possible design based on the third aspect or the fourth aspect, the spatial domain basis is determined according to the reference signal carried on the first resource, including: the reference signal carried on the first resource is used to determine a first eigenvector, and the first eigenvector is used to determine the spatial domain basis.

[0048] In a possible design based on the third aspect or the fourth aspect, the first eigenvector satisfies the following formula:

[0049] or

[0050] N RB is the maximum resource block RB index of the bandwidth; F is a resource domain transformation matrix, F H is the conjugate transpose of F; H k,n [0] is the channel coefficient of the 0th polarization, the first resource, the nth RB; is the conjugate transpose of H k,n [0], H k,n [0] is determined according to a reference signal carried on the first resource; k is the index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the reference signal carried on the first resource; H k,n [1] is the channel coefficient of the 1st polarization, the first resource, the nth RB, is the conjugate transpose of H k,n [1], H k,n [1] is determined according to the reference signal carried on the first resource; V' is the first eigenvector; V' H is the conjugate transpose of V'; Σ is the eigenvalue corresponding to the first eigenvector.

[0051] In some implementations, the spatial domain basis is determined by the first device according to the reference signal carried on the first resource, for example, the spatial domain basis is determined by the first device according to the first reference signal carried on the first resource. In this way, the first device can accurately determine the first eigenvector, thereby accurately determining the spatial domain basis. Moreover, in this design, the first device can perform dimension reduction processing on the channel coefficient through EVD, thereby determining one eigenspace on the two polarizations, and the computational complexity is relatively low. In addition, in the case where the first eigenvector is determined by the first device according to the following formula, the first device can perform resource domain (or beam domain) noise reduction processing on the channel coefficient according to F, thereby improving the accuracy of the determined spatial domain basis:

[0052] In other implementations, the spatial domain basis is determined by the second device according to the reference signal carried on the first resource, for example, the spatial domain basis is determined by the second device according to the third reference signal carried on the first resource. In this way, the second device can accurately determine the first eigenvector, thereby accurately determining the spatial domain basis. Moreover, in this design, the second device can perform dimension reduction processing on the channel coefficient through EVD, thereby determining one eigenspace on the two polarizations, and the computational complexity is relatively low. In addition, in the case where the first eigenvector is determined by the second device according to the following formula, the second device can perform resource domain (or beam domain) noise reduction processing on the channel coefficient according to F, thereby improving the accuracy of the determined spatial domain basis:

[0053] In a possible design based on the third aspect or the fourth aspect, the first eigenvector satisfies the following formula:

[0054] is an inner product operation, V′ h is a horizontal direction eigenvector, V′ v is a vertical direction eigenvector, V′ h and V′ v respectively satisfy the following formula:

[0055] Alternatively, V′ h and V′ v respectively satisfy the following formula:

[0056] wherein N RB is a maximum resource block RB index of a measurement bandwidth; F is a resource domain transformation matrix, F H is a conjugate transpose of F; H k,n [v,0] is a v-th row of H k,n [0], v is a positive integer, is a conjugate transpose of H k,n [v,0], H k,n [0] is a channel coefficient of a 0th polarization, a first resource and an n-th RB; H k,n [0] is determined according to a reference signal carried by the first resource; k is an index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to a maximum number of RBs occupied by the reference signal carried by the first resource; H k,n [v,1] is a v-th row of H k,n [1], is a conjugate transpose of H k,n [v,1], H k,n [1] is a channel coefficient of a 1st polarization, a first resource and an n-th RB; H k,n [1] is determined according to a reference signal carried by the first resource; is a conjugate transpose of V′ h ; Σ h is a corresponding eigenvalue of V′ h ;

[0057] H k,n [h,0] is a h-th column of H k,n [0], h is a positive integer, is a conjugate transpose of H k,n [h,0]; H k,n [h,1] is a h-th column of H k,n [1], is a conjugate transpose of Hk,n the conjugate transpose of [h, 1]; V' is v the conjugate transpose of [h, 1]; v V' is v the corresponding eigenvalue.

[0058] In some implementations, the spatial domain basis is determined by the first device based on a reference signal carried by the first resource, e.g., the spatial domain basis is determined by the first device based on a first reference signal carried by the first resource. In this way, the first device can accurately determine the first eigenvector, and thus accurately determine the spatial domain basis. Moreover, in this design, the first device can perform dimension reduction processing on the channel coefficients by EVD, to determine the eigenspaces in the horizontal and vertical directions respectively, and perform inner product operation on the eigenspaces in the horizontal and vertical directions, and thus can accurately determine the first eigenvector.

[0059] In some implementations, the spatial domain basis is determined by the second device based on a reference signal carried by the first resource, e.g., the spatial domain basis is determined by the second device based on a third reference signal carried by the first resource. In this way, the second device can accurately determine the first eigenvector, and thus accurately determine the spatial domain basis. Moreover, in this design, the second device can perform dimension reduction processing on the channel coefficients by EVD, to determine the eigenspaces in the horizontal and vertical directions respectively, and perform inner product operation on the eigenspaces in the horizontal and vertical directions, and thus can accurately determine the first eigenvector.

[0060] In a fifth aspect, an embodiment of the present application provides a communication method, which can be applied to a first device. The first device can be a terminal, or a device (e.g., a module, a communication module, a circuit or a chip responsible for communication function (such as a modem chip, or a SoC chip or a SIP chip containing a modem core), a chip system or a processor) of the terminal, or a logic node, a logic module or software capable of realizing all or part of the terminal function. The method can include: the first device sends a third reference signal, the third reference signal is carried on a first resource, and the third reference signal is used to determine a spatial domain basis. The first device receives fourth information, the fourth information is used to indicate the spatial domain basis. The first device receives a second reference signal, the second reference signal is carried on a second resource, and the second reference signal and the spatial domain basis are used to determine a precoding matrix corresponding to the second resource. The first device sends first information, the first information is used to indicate the precoding matrix.

[0061] By the method, the spatial domain basis is determined according to the third reference signal carried on the first resource. The first device can determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the precoding matrix corresponding to the second resource in the feedback. For example, in the case that the signal quality of the second resource is poor, the spatial domain basis can not be determined according to the reference signal carried on the second resource, but determined according to the third reference signal carried on the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0062] In addition, in the method, the spatial domain basis is indicated by the second device to the first device, so as to reduce the complexity of the first device in obtaining the spatial domain basis.

[0063] In a sixth aspect, an embodiment of the present application provides a communication method, which can be applied to a second device. The second device can be an access network device, or can be a device (for example, a module, a communication module, a circuit or a chip responsible for communication function (such as a modem chip, or a SoC chip or a SIP chip containing a modem core), a chip system or a processor) of the access network device, or can be a logic node, a logic module or software capable of realizing all or part of the function of the access network device. The method can include: the second device receives a third reference signal, the third reference signal is carried on a first resource, and the third reference signal is used to determine a spatial domain basis. The second device sends fourth information, the fourth information is used to indicate the spatial domain basis. The second device sends a second reference signal, the second reference signal is carried on a second resource, and the second reference signal and the spatial domain basis are used to determine a precoding matrix corresponding to the second resource. The second device receives first information, the first information is used to indicate the precoding matrix. The second device determines the precoding matrix corresponding to the second resource according to the spatial domain basis and the first information.

[0064] By the method, the spatial domain basis is determined according to the third reference signal carried on the first resource. The second device can determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the precoding matrix corresponding to the second resource in the feedback. For example, in the case that the signal quality of the second resource is poor, the spatial domain basis can not be determined according to the reference signal carried on the second resource, but determined according to the third reference signal carried on the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0065] In addition, in the method, the spatial domain basis is indicated by the second device to the first device, so as to reduce the complexity of the first device in obtaining the spatial domain basis.

[0066] In a possible design based on any one of the first aspect to the sixth aspect, the method further includes: the second device sending second information; and correspondingly, the first device receiving the second information. The second information is used to indicate at least one of the following: the first resource; or the first device determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. With this design, the first device can accurately determine the first resource, and accurately determine whether the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. In addition, in this design, the second information is sent by the second device to the first device, thereby improving the flexibility of the second device in managing the first device.

[0067] In a possible design based on any one of the first aspect to the sixth aspect, the method further includes: the first device sending capability information; and correspondingly, the second device receiving the capability information. The capability information is used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. With this design, the second device can accurately know the capability of the first device, for example, the second device can accurately know whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis, thereby enabling the second device to configure appropriate feedback precoding matrix parameters for the first device, for example, the parameters indicated by the second information.

[0068] In a possible design based on any one of the first aspect to the sixth aspect, the signal quality of the reference signal carried by the first resource is higher than the signal quality of the reference signal carried by the second resource. With this design, in the case that the signal quality of the reference signal carried by the first resource is higher than the signal quality of the reference signal carried by the second resource, the spatial domain basis can not be determined according to the reference signal carried by the second resource, but determined according to the reference signal carried by the first resource, thereby improving the accuracy of the determined spatial domain basis, and further improving the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0069] In a possible design based on any one of the third aspect to the sixth aspect, the second reference signal is a CSI-RS.

[0070] In a seventh aspect, the present disclosure provides a communication apparatus. In some examples, the communication apparatus can be a terminal, or a device (e.g., a module, a communication module, a circuit or a chip responsible for communication function (e.g., a modem chip, or a SoC chip or a SIP chip including a modem core), a chip system, or a processor) of a terminal, or a logic node, a logic module, or software capable of implementing all or part of the terminal functions. The communication apparatus has the functions of implementing the first aspect or the third aspect or the fifth aspect. In some other examples, the communication apparatus can be an access network device, or a device (e.g., a module, a communication module, a circuit or a chip responsible for communication function (e.g., a modem chip, or a SoC chip or a SIP chip including a modem core), a chip system, or a processor) of an access network device, or a logic node, a logic module, or software capable of implementing all or part of the access network device functions. The communication apparatus has the functions of implementing the second aspect or the fourth aspect or the sixth aspect.

[0071] In a possible design, the communication apparatus includes a module or a unit or a means corresponding to the operations in any of the first aspect to the sixth aspect, which can be implemented by software, or by hardware, or by a combination of software and hardware. For example, the communication apparatus includes an interface unit and a processing unit. The interface unit can be configured to transceive signals to implement communication between the communication apparatus and another apparatus, and the processing unit can be configured to perform some internal operations of the communication apparatus. The processing unit and the interface unit can perform the functions corresponding to the operations in any of the first aspect to the sixth aspect.

[0072] In a possible design, the communication apparatus includes a processor. The processor can execute computer programs or instructions, which, when executed, cause the communication apparatus to implement the method in any of the possible designs of any of the first aspect to the sixth aspect.

[0073] In a possible design, the communication apparatus includes a processor and a memory. The memory can store necessary computer programs or instructions for implementing the functions in any of the first aspect to the sixth aspect. The processor can execute the computer programs or instructions stored in the memory, which, when executed, cause the communication apparatus to implement the method in any of the possible designs of any of the first aspect to the sixth aspect.

[0074] In a possible design, the communication apparatus includes a processor and an interface circuit. The processor can be configured to communicate with another apparatus through the interface circuit, and perform the method in any of the possible designs of any of the first aspect to the sixth aspect.

[0075] In an eighth aspect, the present application provides a communication system, which can include a first device and a second device. The first device can perform the communication method provided in the first aspect, and the second device can perform the communication method provided in the second aspect. Alternatively, the first device can perform the communication method provided in the third aspect, and the second device can perform the communication method provided in the fourth aspect. Alternatively, the first device can perform the communication method provided in the fifth aspect, and the second device can perform the communication method provided in the sixth aspect.

[0076] In some possible designs, the first device is a terminal, and the second device is an access network device.

[0077] In a ninth aspect, the present application provides a computer readable storage medium, which stores a computer program or instructions, when the computer program or instructions are executed, the method in any possible design of any one of the first aspect to the sixth aspect is implemented.

[0078] In a tenth aspect, the present application provides a computer program product, which includes computer program code, when the computer program code is run, the method in any possible design of any one of the first aspect to the sixth aspect is implemented.

[0079] In an eleventh aspect, the present application provides a chip, which is used to read a computer program stored in a memory, so as to execute the method in any possible design of any one of the first aspect to the sixth aspect.

[0080] The technical effects that can be achieved by any one of the seventh aspect to the eleventh aspect can be described with reference to the technical effects that can be achieved by any one of the possible designs of the first aspect to the sixth aspect, and the repeated parts will not be discussed. BRIEF DESCRIPTION OF DRAWINGS

[0081] FIGS. 1A and 1B are architecture diagrams of several communication systems provided by embodiments of the present application;

[0082] FIG. 1C is an architecture diagram of an open radio access network (O-RAN or ORAN) device provided by an embodiment of the present application;

[0083] FIGS. 2A to 2C are schematic diagrams of several beamforming manners provided by embodiments of the present application;

[0084] FIG. 3 is a schematic diagram of a method for determining a precoding matrix provided by an embodiment of the present application;

[0085] FIG. 4A is a schematic diagram of a distribution of an antenna port provided by an embodiment of the present application;

[0086] FIG. 4B is a schematic diagram of a discrete Fourier transformation (DFT) beam according to an embodiment of the present application;

[0087] FIG. 5 is a flowchart of a downlink measurement method according to an embodiment of the present application;

[0088] FIG. 6 is a flowchart of an uplink measurement method according to an embodiment of the present application;

[0089] FIGS. 7-9 are flowcharts of several communication methods according to embodiments of the present application;

[0090] FIGS. 10-13 are structural diagrams of several communication apparatuses according to embodiments of the present application. DETAILED DESCRIPTION

[0091] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings. The technical solutions in the embodiments of the present application can be applied to various communication systems, such as a wireless local area network (WLAN), a wireless fidelity (Wi-Fi or WiFi) system, a 4th generation (4G) mobile communication system (such as a long term evolution (LTE) system), a 5th generation (5G) mobile communication system (such as a new radio (NR) system), or a future communication system. The method provided by the embodiments of the present application can be applied to a terrestrial network communication system or a non-terrestrial network (NTN) communication system. The NTN communication system may, for example, be a satellite communication system, or may include a drone, a high altitude platform station (HAPS), and other aerial access network devices, which are not limited in the present application.

[0092] The present application will present various aspects, embodiments or features around a system that can include a plurality of devices, components, modules, etc. It should be understood and appreciated that each system can include additional devices, components, modules, etc., and / or can not include all of the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. In addition, combinations of these solutions can also be used.

[0093] FIG. 1A illustrates a schematic diagram of a communication system provided by embodiments of the present application. As shown in FIG. 1A, the communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 10 can also include an Internet 300.

[0094] The RAN 100 includes at least one RAN node (e.g., 110a and 110b in FIG. 1A, collectively referred to as 110) and at least one terminal (e.g., 120a-120j in FIG. 1A, collectively referred to as 120). The RAN 100 can also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 1A), etc. The terminals 120 are connected to the RAN nodes 110 in a wireless manner. The RAN nodes 110 are connected to the core network 200 in a wireless or wired manner. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 can be different physical devices respectively, or can be the same physical device integrated with the logical functions of the core network and the logical functions of the radio access network.

[0095] The RAN 100 can be a 3rd generation partnership project (3GPP) related cellular system, such as a 4G, 5G mobile communication system, or a future evolution system. The RAN 100 can also be an ORAN, a cloud radio access network (CRAN), or a WiFi system. The RAN 100 can also be a communication system integrating two or more of the above systems.

[0096] The RAN nodes 110, which can also be referred to as RAN entities or access nodes, etc., form part of the communication system to help terminals to access wirelessly. The RAN nodes 110 in the communication system 10 can be nodes of the same type or nodes of different types. In some scenarios, the roles of the RAN nodes 110 and the terminals 120 are relative, e.g., the network element 120i in FIG. 1A can be a helicopter or a drone, which can be configured as a mobile base station. For a terminal 120j accessing the RAN 100 through the network element 120i, the network element 120i is a base station; but for the base station 110a, the network element 120i is a terminal. The RAN nodes 110 and the terminals 120 are sometimes referred to as communication apparatuses, e.g., the network elements 110a and 110b in FIG. 1A can be understood as communication apparatuses with base station functions, and the network elements 120a-120j can be understood as communication apparatuses with terminal functions.

[0097] The RAN node can also be referred to as an access network device. Hereinafter, the access network device is used as an example for description.

[0098] The access network device can be a device or module with corresponding communication functions located at the network side of the communication system. The access network device usually has a communication module, circuit or chip for performing corresponding communication functions. The access network device also has programs or instructions for performing corresponding communication functions and corresponding programs or instructions.

[0099] In a possible scenario, the access network device can be a base station (BS), an evolved NodeB (eNodeB), a transmission point (TP), an access point (AP), a transmission reception point (TRP), a mobile switching center, a next generation NodeB (gNB), a next generation NodeB in a future communication system, or an access node in a WiFi system, etc. The access network device can be a macro base station (such as 110a in FIG. 1A), a micro base station or an indoor station (such as 110b in FIG. 1A), a relay node or a donor node, a wireless controller in a CRAN scenario, a satellite, a drone, a balloon or an airplane, etc. Optionally, the access network device can also be a server, a wearable device, a vehicle or a vehicle-mounted device, etc. For example, the access network device in vehicle-to-everything (V2X) technology can be a road side unit (RSU). All or part of the functions of the access network device in this application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (such as a cloud platform).

[0100] In another possible scenario, a terminal is assisted by multiple access network devices to implement wireless access, and different access network devices respectively implement part of functions of a base station. For example, an access network device can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and the DU can be separately arranged, or can be included in the same network element, for example, in a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, for example, in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0101] In different systems, the CU (or CU-CP and CU-UP), the DU, or the RU can also have different names, but a person skilled in the art can understand their meanings. For example, in an ORAN system, the CU can also be referred to as an open CU (O-CU), the DU can also be referred to as an open DU (O-DU), the CU-CP can also be referred to as an open CU-CP (O-CU-CP), the CU-UP can also be referred to as an open CU-UP (O-CU-UP), and the RU can also be referred to as an open RU (O-RU). Any of the CU (or CU-CP, CU-UP), the DU, and the RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0102] A terminal can be a device or module with corresponding communication functions and can access the above-mentioned communication system. The terminal can also be referred to as a terminal device, a user equipment (UE), a mobile station, a mobile terminal, a wireless terminal device, a subscriber unit, a subscriber station, a mobile station, a remote station, a user terminal device, a user agent, or a user device, etc. The terminal is usually provided with a communication module, circuit or chip for performing corresponding communication functions. The terminal can also be configured with programs or instructions for performing corresponding communication functions.

[0103] The terminal can be widely used in various scenarios, such as device-to-device (D2D) communication, V2X communication, machine-type communications (MTC), internet of things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, remote medical treatment, smart power grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. The wearable device can also be referred to as a wearable smart device or a smart wearable device, etc., which is a general term for devices that are designed and developed by applying wearable technology to daily wear. The terminal applied to a vehicle can be referred to as a vehicle-mounted terminal device, such as a transport vehicle, a communication module or an on-board unit (OBU) with wireless communication function.

[0104] By way of example, a terminal can include a mobile phone (also referred to as a "cellular" phone), a computer with mobile termination, or a portable, pocket, handheld, computer-embedded mobile device, etc. For example, a terminal can be a device of personal communication service (PCS) phone, a cordless phone, a session initiation protocol phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), etc. A terminal can also include a limited device, such as a device with limited power consumption, or a device with limited storage capability, or a device with limited computing capability, etc. For example, a terminal can be an information sensing device of bar code, radio frequency identification (RFID), sensor, global positioning system (GPS), or laser scanner, etc. Embodiments of the present application do not limit the device form of a terminal.

[0105] In this application, the core network device refers to a device in the core network that provides service support for the terminal. For example, in the case of CN 200 as the core network in the future communication system, or the 5G core network, or the evolved 5G core network, some examples of core network devices are: access and mobility management function (AMF) entity, session management function (SMF) entity, user plane function (UPF) entity, policy control function (PCF) entity, etc., which are not listed one by one here. Among them, the AMF entity can be responsible for access management and mobility management of the terminal; the SMF entity can be responsible for session management, such as session establishment of the user, etc.; the UPF entity can be a functional entity of the user plane, mainly responsible for connecting external networks. For another example, in the case of CN 200 as the 4G core network, some examples of core network devices are: mobile management entity (MME) entity, home subscriber server (HSS) entity, serving gateway (S-GW) entity, policy and charging rules function (PCRF) entity, public data network gateway (PDN gateway, P-GW) entity, etc., which are not listed one by one here. It should be noted that the entity in this application can also be referred to as a network element or a functional entity, for example, the AMF entity can also be referred to as an AMF network element or an AMF functional entity, for another example, the SMF entity can also be referred to as an SMF network element or an SMF functional entity, etc. The above core network devices can work independently, or can be combined together to realize certain control functions, such as: AMF, SMF and PCF can be combined together as a core network device.

[0106] FIG. 1B illustrates an example of an ORAN system architecture according to some embodiments. The ORAN system in the embodiments can include other components than those shown in FIG. 1B. As shown in FIG. 1B, the access network device can communicate with the CN through a backhaul link and communicate with the terminal through an air interface. For example, the BBU in the access network device communicates with the core network through a backhaul link, and the RU in the access network device communicates with at least one terminal through an air interface. The BBU communicates with at least one RU through a front-haul link. The BBU and the RU can be co-located or not co-located. The BBU includes at least one CU and at least one DU, which can communicate through at least one mid-haul link.

[0107] FIG. 1C illustrates an example of a network element function division and protocol layer structure of an ORAN device according to some embodiments.

[0108] In some possible implementations, the CU is a logical node that carries the radio resource control (RRC) layer, the service data adaptation protocol (SDAP) layer, the packet data convergence protocol (PDCP) layer, and other control functions of the access network device. The CU can be connected to a network node such as a core network through some interfaces (e.g., an E2 interface, etc.). Optionally, the CU can have part of the functions of the core network. The CU (e.g., the PDCP layer and higher layers of the CU) is connected to the DU (e.g., the radio link control (RLC) layer and lower layers of the DU) through some interfaces (e.g., an F1 interface, etc.). For example, the F1 interface can provide control plane (C-Plane) and user plane (U-Plane) functions (e.g., interface management, system information management, UE context management, RRC message transmission, etc.). The F1AP is an application protocol of the F1 interface, which defines the signaling procedures of the F1 in some examples. The F1 interface supports the F1 control plane (F1-C) and the F1 user plane (F1-U).

[0109] In some examples, a CU can include a CU-CP and a CU-UP. Wherein the CU-CP is a logical node carrying a control plane part of PDCP (PDCP-C) layer of RRC layer and packet data convergence protocol layer, used to implement the control plane function of the CU. The CU-CP can interact with a network element in the core network for implementing the control plane function. The network element in the core network for implementing the control plane function can be an access and mobility function network element, such as AMF in the 5G system. The CU-UP is a logical node carrying a user plane part of PDCP (PDCP-U) layer of SDAP layer and packet data convergence protocol layer, used to implement the user plane function of the CU. The CU-UP can interact with a network element in the core network for implementing the user plane function. The network element in the core network for implementing the user plane function is, for example, the UPF in the 5G system.

[0110] In some possible implementations, the DU is a logical node carrying an RLC layer, a medium access control (MAC) layer, a higher physical (Higher PHY) layer and other functions. In some examples, the DU can control at least one RU. The DU is connected to the RU through some interfaces (for example, a front-haul interface). In some examples, the Higher PHY layer includes part of physical layer (PHY) processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, and other processing functions.

[0111] The above configuration of the CU and the DU is only an example, and the functions of the CU and / or the DU can be configured as needed. For example, the CU or the DU can be configured to have more functions of protocol layers, or the CU or the DU can be configured to have partial processing functions of protocol layers. For example, part of the functions of the RLC layer and the functions of the protocol layers above the RLC layer are arranged in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are arranged in the DU. For another example, the functions of the CU or the DU can be divided according to the type of service or other system requirements, for example, according to delay. The functions that need to meet the requirement of shorter delay in processing time are arranged in the DU, and the functions that do not need to meet the requirement of shorter delay are arranged in the CU.

[0112] In some possible implementations, the RU is a logical node that hosts lower physical (Lower PHY) layer and radio frequency (RF) processing. In some examples, the RU can be a 3GPP TRP or RRH or other similar functional entity. In some examples, the Low-PHY includes portions of PHY processing such as fast Fourier transformation (FFT), inverse fast Fourier transformation (IFFT), digital beamforming and filtering, and other processing functions. The RU communicates with one or more terminals over a wireless link.

[0113] The DU and the RU can or can not be co-located. The DU and the RU exchange control plane and user plane information over a fronthaul link via a lower-layer split-control, user and synchronization (Lower-Layer Split CUS-Plane, LLS-CUS or LLS-C / U / S) interface. The LLS-CUS can include a lower-layer split-control plane (LLS-C) interface and a lower-layer split-user plane (LLS-U) interface that provide control plane (C-Plane) and user plane (U-Plane), respectively. In some examples, the control plane refers to real-time control between the DU and the RU. The DU and the RU exchange management information over a lower-layer split management (LLS-M) interface of the fronthaul link. The management plane (M-Plane) refers to non-real-time management operations between the DU and the RU.

[0114] The DU and the RU can cooperate to collectively implement the functionality of the PHY layer. One DU can be connected to one or more RUs. The functionalities that the DU and the RU have can be configured in multiple ways according to design. For example, the DU is configured to implement baseband functionality and the RU is configured to implement mid- RF functionality. As another example, the DU is configured to implement high-layer functionality in the PHY layer and the RU is configured to implement low-layer functionality in the PHY layer or to implement the low-layer functionality and RF functionality. The high-layer functionality in the PHY layer can include a portion of the functionality of the PHY layer that is closer to the MAC layer, and the low-layer functionality in the PHY layer can include another portion of the functionality of the PHY layer that is closer to the mid-RF side.

[0115] The communication system and service scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of network architecture and the appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0116] The related terms involved in the embodiments of the present application are explained below. It should be noted that these explanations are for the purpose of making the embodiments of the present application easier to understand, and should not be regarded as a limitation on the scope of protection required by the present application.

[0117] 1、Reference signal (RS):

[0118] Reference signal is also called pilot signal. In a communication system, it is necessary to send and receive data, obtain system synchronization and feedback channel information, and estimate uplink channel or downlink channel. Channel estimation refers to the process of reconstructing or restoring received signals in order to compensate for signal distortion caused by channel fading and noise fading. It determines the time domain and frequency domain changes of the channel by using the reference signals known by the transmitter and the receiver. The above-mentioned reference signals are also called reference signals, which are distributed in one or more resource elements (REs) in the time-frequency two-dimensional space within the orthogonal frequency division multiplexing (OFDM) symbol, and have known amplitude and phase.

[0119] At the physical layer, uplink communication can include transmission of uplink physical channels and uplink signals. Exemplarily, the uplink physical channels can include at least one of a physical random access channel (PRACH), a physical uplink control channel (PUCCH), or a physical uplink shared channel (PUSCH), etc.; the uplink signals can include at least one of a sounding reference signal (SRS), a physical uplink control channel demodulation reference signal (PUCCH-DMRS), a physical uplink shared channel demodulation reference signal (PUSCH-DMRS), a demodulation reference signal (DMRS), a phase tracking reference signal (PTRS), or a positioning RS, etc. Among them, the positioning RS is, for example, an SRS for positioning (SRS for positioning) or a positioning SRS (positioning SRS).

[0120] At the physical layer, the downlink communication can include transmission of downlink physical channels and downlink signals. Exemplarily, the downlink physical channels can include at least one of a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), or a physical downlink shared channel (PDSCH), etc.; and the downlink signals can include at least one of a primary synchronization signal (PSS) / secondary synchronization signal (SSS), a physical downlink control demodulation reference signal (PDCCH-DMRS), a physical downlink shared channel demodulation reference signal (PDSCH-DMRS), a DMRS, a PTRS, a CSI-RS, a cell reference signal (CRS), a tracking reference signal (TRS), or a positioning RS, etc.

[0121] Some reference signals are described as follows.

[0122] SRS, an uplink reference signal sent by a terminal, can be used for at least one of the following: estimating uplink channel quality of different frequency bands; performing uplink beam management, including beam training, beam switching, etc.; and estimating uplink timing. For a time division duplex (TDD) system, the access network device can use the SRS to perform downlink channel estimation and calculate downlink transmission weights according to channel interconnection (or channel interdependence).

[0123] CSI-RS, is a downlink reference signal transmitted by the access network device, which can be used to determine the channel state information (channel state information, CSI). For example, after receiving the CSI-RS, the terminal can perform channel estimation based on the received CSI-RS, such as estimating the CSI of the downlink channel through channel measurement and interference measurement. The terminal can feed back the CSI to the access network device, so that the access network device can manage the communication between the access network device and the terminal according to the CSI. For example, the access network device can perform at least one of the following operations according to the CSI: determine the modulation and coding scheme (modulation and coding scheme, MCS), schedule resources for the terminal, or perform beamforming.

[0124] It should be understood that the reference signals listed above are only examples and should not constitute any limitation on the present application. The present application does not exclude the possibility of defining other reference signals in future protocols to achieve the same or similar functions.

[0125] 2、beam:

[0126] Mobile communication systems (for example, 5G mobile communication systems) can use high frequency communication, that is, use high frequency signals to transmit data. One of the main problems of high frequency communication is that the signal energy decreases sharply with the transmission distance, resulting in a short signal transmission distance. In order to overcome this problem, high frequency communication uses analog beam technology, which concentrates signal energy in a small angular range by weighting the antenna array, forming a signal similar to a light beam (called an analog beam, simply referred to as a beam), thereby increasing the transmission distance. Both the access network device and the terminal can use beams for transmission.

[0127] A beam can be referred to as a spatial domain filter, a spatial filter, a spatial domain parameter, a spatial parameter, a spatial domain setting, a spatial setting, quasi co-location (QCL) information, a QCL assumption, or a QCL indication, and the like in a protocol (e.g., an NR protocol). A beam can also be represented by a transmission configuration indicator state parameter, or by a spatial relation parameter. Among them, the English of the transmission configuration indicator state can be transmission configuration indicator state (TCI-state), transmission configuration indication state (TCI-state), or transmission configuration index state (TCI-state), and the like. Therefore, in this application, the beam can be replaced by the spatial domain filter, the spatial filter, the spatial domain parameter, the spatial parameter, the spatial domain setting, the spatial setting, the QCL information, the QCL assumption, the QCL indication, the TCI-state (e.g., the downlink TCI-state (DL TCI-state), and / or the uplink TCI-state (UL TCI-state)), or the spatial relation, and the like. The above terms are also equivalent to each other. The beam can also be replaced by other terms representing the beam, which is not limited in this application.

[0128] A beam for transmitting a signal can be referred to as a transmission beam (Tx beam), a spatial domain transmission filter, a spatial transmission filter, a spatial domain transmission parameter, a spatial transmission parameter, a spatial domain transmission setting, or a spatial transmission setting.

[0129] A beam for receiving a signal can be referred to as a reception beam (Rx beam), a spatial domain reception filter, a spatial reception filter, a spatial domain reception parameter, a spatial reception parameter, a spatial domain reception setting, or a spatial reception setting.

[0130] A transmission beam can refer to a distribution of signal strength in different directions in space after a signal is transmitted by an antenna, and a reception beam can refer to a distribution of signal strength in different directions in space of a wireless signal received by an antenna.

[0131] In addition, a beam can be a wide beam, or a narrow beam, or another type of beam. The technology for forming a beam can be beamforming technology or other technology. The beamforming technology may, for example, be digital beamforming technology, analog beamforming technology, or hybrid beamforming technology, etc.

[0132] A beam is generally associated with a resource. For example, when performing beam measurement, an access network device measures different beams through different resources, and a terminal feeds back the measured resource quality, so that the access network device knows the quality of the corresponding beam. In data transmission, a beam can also be indicated by its corresponding resource. For example, a beam can be indicated by at least one of the following resources: an SSB resource, a CSI-RS resource, an SRS resource, a DMRS resource, or a PTRS resource, etc. Among them, the SSB resource can be a resource for transmitting an SSB; the CSI-RS resource can be a resource for transmitting a CSI-RS; the SRS resource can be a resource for transmitting an SRS; the DMRS resource can be a resource for transmitting a DMRS; and the PTRS resource can be a resource for transmitting a PTRS. Among them, the full name of SSB in Chinese and English can be a synchronization signal block (synchronization signal block, or SS / PBCH block (SS / PBCH block).

[0133] In some implementations, the access network device can indicate the information of the PDSCH beam of the terminal through a transmission configuration indication field in downlink control information (DCI). The transmission configuration indication can be referred to as transmission configuration indicator (TCI), transmission configuration indication (TCI), transmission configuration index (TCI), etc.

[0134] Optionally, multiple beams with the same or similar communication characteristics can be regarded as one beam. One beam can include one or more antenna ports for transmitting data channels, control channels, and sounding signals, etc. One or more antenna ports forming a beam can also be regarded as an antenna port set.

[0135] 3. Antenna port

[0136] The antenna port can be referred to as a port. The antenna port is a logical concept, and one antenna port is generally associated with one physical antenna. Each antenna port represents a channel model, which can be derived through a reference signal on the antenna port. Therefore, the antenna port is usually associated with a reference signal, and its meaning can be understood as a transceiving interface on the channel experienced by the reference signal. For low frequencies, one antenna port can correspond to one or more antenna elements, and these elements jointly transmit the reference signal, and the receiving end can treat them as a whole and does not need to distinguish these elements. For high-frequency systems, an antenna port can correspond to a beam, and similarly, the receiving end only needs to regard the beam as an interface and does not need to distinguish each element.

[0137] In the protocol, the antenna port is usually represented by antenna port or port, and can also be represented by a resource (such as a CSI-RS resource, an SRS resource, a DMRS resource, a PTRS resource, a CRS resource, a TRS resource, or an SSB resource, etc.) or a resource group. That is, the identifier of the antenna port in the present application can be replaced by the identifier of the above content, such as the identifier of the resource, the identifier of the pilot resource, the identifier of the reference signal resource, etc.

[0138] 4. Beamforming (BF)

[0139] Beamforming is also known as beamforming. Beam refers to the radiation pattern of electromagnetic waves of an antenna system, and beamforming, as the name implies, is the process of forming a beam. In a multi-antenna system, beamforming refers to the process of forming a directional electromagnetic wave radiation pattern by adjusting the amplitude or phase of the signal on the radio frequency link. Since the radio frequency link is divided into digital radio frequency link and analog radio frequency link, beamforming can also be divided into digital beamforming and analog beamforming.

[0140] The signal has been pre-processed before being sent through the physical antenna, and these processes can change the amplitude and / or phase of the signal after being modulated onto the carrier, and the purposes include: eliminating the correlation between channels and channels, ensuring the channel independence between antenna ports, and enabling the sub-flow data mapped to each antenna port to be transmitted in a mutually independent manner on the spatial channel, forming a narrow beam at each antenna port, and the narrower the beam, the lower the correlation between beams. On the digital link, digital beamforming can be achieved through precoding, and the result of precoding is to achieve digital beamforming and spatial multiplexing.

[0141] The following will take the access network device as the base station as an example, and combine the contents shown in FIGS. 2A to 2C to exemplarily describe the beamforming. Generally, in a communication system at a higher frequency band, the base station (and part of the terminal at a frequency band) will usually use a large-scale array antenna (for example, from 500 to 1000 or more antenna units) to counteract the path loss caused by the increase of the frequency band through a higher array gain, and to improve the coverage capability. From the implementation of the base station, the same is a large array, and the array weighting manner (that is, the beamforming manner) used by different frequency bands and different array scales is different. The beamforming manner can include the following three types:

[0142] One way is digital beamforming (DBF). FIG. 2A shows a possible example of a DBF structure. Among them, the DBF technology has one or more digital ports (or digital channels or digital processing channels), each digital port is connected to one or a group of antenna units, and the phase (or amplitude and phase) of the signal is adjusted in the digital domain through each digital port, so that the radiation signal of the signal radiated through the antenna has directionality. On the one hand, the digital domain signal processing has the highest degree of freedom, and can support very complex signal processing methods, so the performance of the DBF architecture is the best under the same array scale. On the other hand, the power consumption and cost of the digital to analog converter (DAC) / analog to digital converter (ADC) are relatively high (especially under large bandwidth conditions). Generally, under the condition of the same array scale, the cost of DBF is the highest.

[0143] Another way is analog beamforming (ABF). FIG. 2B shows a possible example of an ABF structure. The ABF technology has one or more phase shifters, each phase shifter is connected to one or a group of antenna units, by adjusting the phase of each antenna unit corresponding phase shifter, the radiation signal of the signal radiated through the antenna array has directivity. A plurality of antenna units can correspond to a DAC / ADC. In one aspect, the entire array of ABF only corresponds to one DAC / ADC, with low cost and power consumption. On the other hand, the phase shifter setting in the analog domain determines the beam direction after beamforming. Since the signal is directly combined in the analog domain, it cannot be weighted like DBF using digital signal processing. ABF needs to pre-configure the phase shifter setting (i.e., point the analog beam to the target terminal) when transmitting and receiving. This process needs to be completed through beam scanning in the link establishment stage, which brings additional delay. Generally, once the analog beam is blocked or moved, the system link quality will decrease rapidly or even be interrupted. Therefore, the communication reliability of ABF is not as good as that of DBF.

[0144] Another way is hybrid beamforming (HBF). HBF technology is a combination of ABF technology and DBF technology. FIG. 2C shows a possible example of an HBF structure. HBF has one or more digital ports on the one hand, supporting digital beamforming. Each digital port corresponds to an ABF subarray, and each ABF subarray has one or more phase shifters, supporting analog beamforming. FIG. 2C shows an HBF architecture with 3 digital ports, each corresponding to 2 phase shifters. Compared with ABF, the size of the AMF subarray corresponding to each digital port is smaller (4 in FIG. 2C and 6 in FIG. 2B) under the same array size, so the beam is wider, the reliability is better, and the beam scanning overhead is smaller. Generally, the ratio of HBF digital ports and phase shifters varies with different frequencies and system design requirements. For example, the number of digital ports in the high frequency band is small (4-16), and the number of phase shifters corresponding to a single digital port is large (16-32), which is closer to ABF. However, the number of digital ports in the low frequency band is large (32-128), and the number of phase shifters corresponding to a single digital port is small (e.g., 2-10).

[0145] For example, the number of digital ports currently supported by the protocol can be: 2, 4, 8, 12, 16, 24, 32, 48, 64, 96, 128.

[0146] Generally, there are analog beams in ABF and HBF architectures, and when an analog beam is aligned with a communication target, the signal quality will be improved. The direction of the analog beam (determined by the beam weight) needs to be configured before transmission and reception. For a certain terminal, the process of selecting an analog beam by the base station is called beam training or beam scanning. Beam scanning is usually achieved by the base station sending reference signals using different analog beam weights, and the terminal measures the reference signals and feeds back the measurement results to help the base station determine which beam has the best quality.

[0147] 5. Precoding and codebook:

[0148] In a MIMO communication system, the mathematical expression of communication is y = Hx + n. Where y is the received signal, H is the MIMO channel, x is the transmitted signal, and n is the noise. In a communication system with multiple antennas, the signals of multiple transmitting antennas will be superimposed on any receiving antenna, so the method of transmitting signals at the transmitting end will affect the performance of the system, and it is often complex to recover the transmitted signal at the receiving end. In this context, precoding (Precoding) can reduce system overhead and maximize MIMO system capacity on the one hand, and reduce the complexity of implementing channel interference cancellation at the receiver on the other hand. At this time, the mathematical expression is y = HPx + n, and P is the precoding matrix (or vector, or precoder). In order to simplify the implementation complexity, P can be selected from a pre-defined matrix (or vector) set, which is called codebook (Codebook). The above signal transmission method is also called codebook-based transmission method. If the transmitting end can obtain all the information of H, P can be obtained by the transmitting end itself, and this signal transmission method is also called non-codebook transmission method (non-codebook, NCB).

[0149] 6. Precoding matrix indicator (PMI):

[0150] PMI can be used to indicate a precoding matrix. For example, the precoding matrix can be determined by the terminal based on a channel matrix of a frequency domain unit. The channel matrix can be determined by the terminal through channel estimation or based on channel reciprocity. However, it should be understood that the specific method of determining the precoding matrix by the terminal is not limited to the above, and the specific implementation can refer to the protocol. For the sake of brevity, it will not be listed one by one here.

[0151] For example, the precoding matrix can be obtained by singular value decomposition (SVD) of the channel matrix or the covariance matrix of the channel matrix, or can be obtained by EVD of the covariance matrix of the channel matrix. It should be understood that the above-mentioned ways of determining the precoding matrix are only examples and should not constitute any limitation on the present application.

[0152] It should be noted that in the present application, the precoding matrix determined by the access network device based on the feedback of the terminal can be directly used for downlink data transmission; or can be subjected to some beamforming methods, such as zero forcing (ZF), regularized zero-forcing (RZF), minimum mean-squared error (MMSE), maximum signal-to-leakage-and-noise ratio (SLNR), etc., to obtain the final precoding matrix used for downlink data transmission. The present application does not make any limitation on this.

[0153] It can be understood that the precoding matrix determined by the terminal can be understood as a precoding matrix to be fed back. The terminal can indicate the precoding matrix to be fed back through the PMI, so that the access network device recovers the precoding matrix based on the PMI. It can be understood that the precoding matrix recovered by the access network device based on the PMI can be the same as or similar to the above-mentioned precoding matrix to be fed back.

[0154] In the downlink channel measurement, the higher the approximation degree of the precoding matrix determined by the access network device based on the PMI and the precoding matrix determined by the terminal, the more suitable the precoding matrix determined by the access network device for data transmission can be to the channel state, and thus the reception quality of the signal can be improved.

[0155] 7. Precoding matrix:

[0156] The precoding matrix W can be represented as W=W1xW2. W1 is used to describe the wideband long-term characteristics of the channel, can represent a selected wideband beam group, and can be fed back once for a relatively long time. W2 is used to describe the subband instantaneous characteristics of the channel, can be used to select one or more beams from the wideband beam group according to the subband characteristics of the channel, and can realize phase adjustment of the polarization direction by quantizing the phase difference of two polarization directions, and can be fed back once for a relatively short time.

[0157] W1 and W2 will be described below.

[0158] The structure of W1 can be:

[0159] Wherein, B is a matrix composed of L oversampled DFT beams (or called DFT vectors). L represents the number of transmission layers or streams, hereinafter referred to as the number of layers; L is a positive integer. Two diagonal blocks of W1 are respectively for two polarization directions. Here, the DFT beam groups of the two polarization directions are the same, that is, the same DFT beams will be used for the two polarization directions. As can be seen from its structure, the role of W1 is to select a group of DFT beams.

[0160] W2 in the type 1 codebook can be composed of weighted column selection vectors. The DFT beam group selected according to W1 is effective for the entire bandwidth, and due to the frequency selectivity of the channel, the optimal beam corresponding to different subbands can be different. The role of the column selection vector in W2 includes selecting one or more beams for the subband from the L DFT beams. If the same beam is selected for the two polarization directions, the two polarization directions can be phase combined through a phase combining factor to ensure that the signals emitted from the two polarization directions can be superimposed at the same time.

[0161] Optionally, the terminal determines the precoding matrix according to the following three steps: 1. Determine the spatial domain beam set, which is shown in (a) of FIG. 3. The spatial domain beam set can also be referred to as all weight value sets in a codebook; 2. Select a beam group according to W1, and the selected beam group is shown in (b) of FIG. 3; 3. Perform beam selection and phase quantization adjustment according to W2, and the selected beam is shown in (c) of FIG. 3.

[0162] Wherein, the spatial domain beam set can be determined by (N1, N2) and (O1, O2). Wherein, N1 represents the number of logical antenna ports in a certain direction of the same polarization, as shown in FIG. 4A, N1 can refer to the horizontal direction; N2 represents the number of logical antenna ports in another direction of the same polarization, as shown in FIG. 4A, N2 can refer to the vertical direction; O1 represents the DFT oversampling multiple of the direction (horizontal direction) where N1 is located; O2 represents the DFT oversampling multiple of the direction (vertical direction) where N2 is located. The physical meaning corresponding to N1 and N2 is that when beamforming is performed, N1×N2 weight value vectors with horizontal dimension N1 and vertical dimension N2 can be formed, and these weight value vectors are orthogonal to each other, that is, there is no interference between the DFT beams formed by weighting these weight value vectors. The physical meaning of O1 and O2 is that the number of weight value vectors is increased in the horizontal direction and the vertical direction through DFT oversampling, so more weight value vectors can be generated. The values of O1 and O2 also determine the beam density in the horizontal direction and the vertical direction when the antenna form is certain (that is, N1 and N2 are determined). The larger the values of O1 and O2 are, the smaller the step of the beam when beam scanning is performed, and the higher the accuracy is, but the cost is that the weight value vectors are no longer orthogonal, that is, there is interference between the beams.

[0163] Taking the CSI-RS port number as 16 as an example, the combination form of (N1, N2) can include (4, 2) and (8, 1) two cases. Taking N1 as 4, N2 as 2, O1 as 4, and O2 as 4 as an example, each dot in FIG. 4B corresponds to one DFT beam. Among them, the weight vectors corresponding to the black dots are mutually orthogonal, that is, the DFT beams corresponding to the black dots do not interfere with each other; and the weight vectors corresponding to the black dots and the shaded dots are no longer orthogonal, that is, there is a certain interference between the DFT beams corresponding to the black dots and the DFT beams corresponding to the shaded dots.

[0164] As shown in FIG. 4B, according to the position of each dot in the horizontal direction and the vertical direction, the oversampling DFT beam index can be determined. l represents the DFT beam index in the horizontal direction, and m represents the DFT beam index in the vertical direction, for example, (l, m) = (0, 0) is used to indicate the DFT beam corresponding to the dot marked with "1" in the spatial beam in FIG. 4B.

[0165] W1 is formed by DFT matrix oversampling, that is, the DFT matrix obtains the beamforming weight value with the required precision in space in an oversampling manner. The weight vectors of the lth beam and the mth beam corresponding to the horizontal direction and the vertical direction satisfy the following formula:

[0166] wherein v l is the weight vector in the horizontal direction, and the length of the vector is N1. How many weight vectors are contained in the horizontal direction is determined by the number of values of l, that is, l also represents the weight selected in the horizontal direction. u m is the weight vector in the vertical direction, and the length of the vector is N2. How many vectors are contained in the vertical direction is determined by the number of values of m, that is, m also represents the weight selected in the vertical direction.

[0167] After confirming the weight group in the horizontal direction and the vertical direction, the selected weight group is also determined. The result expressed by the kronecker product of v l and u m is only the weight result on one group of polarized antennas, and there is usually a certain phase deviation on the other group of polarized antennas, which is determined by W2. Therefore, the final expression result of W1 is in the form of the latter sub-block diagonal matrix in the kronecker product of v l and u m . The weight vector v l,m of the (l, m)th beam satisfies the following formula:

[0168] 8. Knowing the channel state:

[0169] The key technology of beamforming is to obtain the channel state, i.e., the channel matrix, between the transmitting device and the receiving device, which can be used to determine the precoding matrix, so as to realize digital beamforming and improve the system capacity.

[0170] Taking a TDD system as an example, the access network device can obtain the channel state in two ways: way one, measuring the channel state according to the CSI-RS, for example, the terminal measures the CSI-RS according to the indication of the access network device to obtain the CSI and sends the CSI to the access network device; way two, measuring the channel state according to the SRS, for example, the access network device can determine the uplink channel state according to the SRS, and due to the channel reciprocity, the channel state can be used for downlink communication.

[0171] The way one and the way two will be described below respectively.

[0172] Way one:

[0173] The way one can also be referred to as a downlink measurement method. As shown in FIG. 5, the downlink measurement method can include the following steps.

[0174] S501: The access network device sends measurement configuration information to the terminal.

[0175] The measurement configuration information can also be referred to as reference signal and channel information reporting configuration information. The measurement configuration information can be carried in the RRC signaling sent by the access network device to the terminal.

[0176] Optionally, the measurement configuration information includes resource configuration information and reporting configuration information. The resource configuration information is the information related to the measurement resource, which can be used to configure the measurement resource. In the protocol, the measurement resource can be configured through a three-level structure, which is resource configuration (resourceConfig or resourceSetting), resource set (resourceSet) and resource (resource) respectively. For example, the access network device can configure one or more resource configurations for the terminal, each resource configuration includes one or more resource sets, and each resource set can include one or more resources. Each resource configuration / resource set / resource includes an index of itself. In addition, each resource configuration / resource set / resource also includes other parameters, such as the period of the resource, the signal type corresponding to the resource, etc. The reporting configuration information refers to the information related to the reporting of the measurement result, which can be configured through the reporting configuration (ReportConfig) in the protocol. The access network device can configure one or more reporting configurations for the terminal, each reporting configuration includes the reporting index, the reporting time and period, the reporting format and other information related to the reporting. In addition, the reporting configuration also includes the index of the resource configuration, which is used to indicate that the reporting result is measured through which or which measurement resource.

[0177] Optionally, the measurement configuration information can further include codebook configuration information. The fields n1 and n2 in the codebook configuration information are respectively used to indicate N1 and N2. The specific content of N1 and N2 can refer to the description of N1 and N2 in the explanation of “precoding matrix”, which will not be repeated here.

[0178] S502: The access network device sends one or more downlink signals to the terminal.

[0179] The one or more downlink signals can be one or more downlink reference signals (e.g., CSI-RS, SSB, or TRS), so that the terminal can measure the one or more downlink signals and determine the quality of each resource (i.e., the quality of the beam corresponding to the resource).

[0180] Optionally, the access network device can send the one or more downlink signals on the resources configured by the resource configuration information.

[0181] S503: The terminal measures the one or more downlink signals to obtain CSI.

[0182] For example, the terminal measures the channel and obtains the CSI based on only the codebooks allowed by the codebook subset restriction configuration information.

[0183] Optionally, the CSI is information used to characterize the channel state, and can include at least one of the following: CSI-RS resource indicator (CRI), channel quality indicator (CQI), PMI, rank indicator (RI), layer indicator (LI), reference signal received power (RSRP), signal-to-interference-plus-noise ratio (SINR), etc. Some information in the CSI will be described below.

[0184] (1) CRI, used to indicate which CSI-RS resource the terminal device reports the CSI according to. For example, the CSI-RS resource set used for channel measurement contains 4 CSI-RS resources, if the value of CRI is 00, it means that the reported CSI is obtained according to the first CSI-RS resource in the CSI-RS resource set; if the value of CRI is 01, it means that the reported CSI is obtained according to the second CSI-RS resource in the CSI-RS resource set.

[0185] (2) RI, used to indicate the rank obtained by the terminal device for channel measurement.

[0186] S504: The terminal sends the CSI to the access network device.

[0187] Optionally, the CSI can be carried in a CSI report.

[0188] Method two:

[0189] Method two can also be called an uplink measurement method. As shown in FIG. 6, the uplink measurement method can include:

[0190] S601: The access network device sends uplink signal resource configuration information to the terminal.

[0191] The uplink signal resource configuration information can also be called reference signal configuration information and / or channel information reporting configuration information. The uplink signal resource configuration information can be carried in the RRC signaling sent by the access network device to the terminal.

[0192] The uplink signal resource configuration information is measurement resource related information, which can be configured through a two-level structure in the protocol, and the two-level structure can include: resource set (resourceSet) and resource (resource). For example, the access network device can configure one or more resource sets for the terminal. Each resource set can include one or more resources. Each resource is associated with (or corresponds to or related to) a beam. Each resource set / resource includes its own index. In addition, each resource set / resource also includes other parameters, such as the period of the resource, the signal type corresponding to the resource, etc.

[0193] For ease of understanding, an example of SRS resource configuration information is given below.

[0194] The explanations of some parameters in this example are as follows:

[0195] SRS-ResourceSet is an SRS resource set.

[0196] srs-ResourceSetId is the index of SRS resource set.

[0197] srs-ResourceIdList is the list of SRS resource index, which is used to indicate the SRS resources included in the SRS resource set.

[0198] resourceType in srs-ResourceIdList is used to indicate the type of SRS resource set, for example, aperiodic, semi-static, or periodic.

[0199] usage is used to indicate the usage of SRS resource set, for example: beam management, codebook (or codebook-based uplink transmission), non-codebook (non-codebook-based uplink transmission), or antenna switching.

[0200] srs-ResourceId is the SRS resource index.

[0201] nrofSRS-Ports is the number of ports of SRS resource.

[0202] resourceMapping is the time-frequency resource location corresponding to the SRS resource.

[0203] resourceType in SRS-Resource is used to indicate the type of SRS resource, for example, aperiodic, semi-static, or periodic.

[0204] spatialRelationInfo is the spatial information of SRS resource set, which is used to indicate the transmission spatial parameter of the SRS resource set.

[0205] It should be understood that the examples of the SRS resource configuration information are only illustrative. In actual application, one SRS resource set can include one or more SRS resources, which will not be expanded here.

[0206] S602: The terminal sends one or more uplink signals to the access network device.

[0207] The one or more uplink signals can be one or more uplink reference signals (for example, SRS), so that the access network device can measure the one or more uplink signals and determine the quality of each resource (i.e., the quality of the beam corresponding to the resource).

[0208] Optionally, the terminal can send one or more uplink signals on the resources configured by the uplink signal resource configuration information.

[0209] S603: The access network device measures the uplink signal to obtain channel information. Subsequently, data scheduling, precoding, etc. can be performed based on the channel information.

[0210] 9、In this application, "indicate" or "for indicating" can include explicit indication (or called direct indication) and implicit indication (or called indirect indication). When describing that a certain information is for indicating A, it can include that the information explicitly indicates A or implicitly indicates A, and it does not mean that A must be carried in the information.

[0211] The indication manner involved in the embodiments of the present application should be understood as covering various methods that can make the to-be-indicated party know the to-be-indicated information. The to-be-indicated information can be sent as a whole, or can be sent separately into multiple sub-information, and the sending period and / or sending occasion of the sub-information can be the same or different, which is not limited.

[0212] The "information" in the embodiments of the present application can be explicitly indicated, that is, directly indicated through signaling, or obtained according to the indicated parameters, combined with other rules or combined with other parameters or through derivation. It can also be implicitly indicated, that is, obtained according to rules or relationships, or according to other parameters, or through derivation. It is not limited.

[0213] 10、In this application, the communication between different devices can mean the direct communication between different devices (that is, without the transfer or forwarding of other devices), or can mean the communication between different devices through other devices (that is, the transfer or forwarding of other devices is needed), or can mean that the functional units inside the device communicate with other devices through another functional unit. Exemplarily, "sending information to (a terminal)" can be understood as that the destination of the information is the terminal, which can include directly or indirectly sending information to the terminal. "Receiving information from (a terminal)" can be understood as that the source of the information is the terminal, which can include directly or indirectly receiving information from the terminal. The information can be processed between the source and the destination of the information sending, for example, format conversion, digital-to-analog conversion, amplification, filtering and the like, but the destination can understand the valid information from the source. Similar expressions in this application can be understood similarly, which will not be repeated here.

[0214] 11、In this application, the words "exemplarily", "such as", "for example" and "an example of" are used to represent examples, illustrations or descriptions, and are not used to limit the protection scope of the present application. It should be understood that the examples in the present application can also be implemented in other ways.

[0215] 12、In this application, any two of the programs, instructions and codes can be replaced with each other.

[0216] 13、In this application, "*" and × represent the meaning of multiplication or multiplication.

[0217] 14、In this application, the spatial domain basis can also have other names, such as spatial domain vector, eigenvector or spatial domain beam, as long as it has the same function, it is within the protection scope of this application.

[0218] 15、In this application, the channel coefficient can also have other names, such as channel matrix, as long as it has the same function, it is within the protection scope of this application.

[0219] Currently, the access network device can send downlink reference signals to the terminal through multiple beams. For each beam, the terminal can determine the spatial domain basis according to the reference signal of the beam, and determine and feed back the precoding matrix corresponding to the beam according to the spatial domain basis. There may be a beam with poor performance in the multiple beams, and the accuracy of the precoding matrix determined and fed back by the terminal according to the reference signal on the beam with poor performance is low. How to improve the accuracy of the feedback precoding matrix needs further research.

[0220] Embodiments of the present application provide a communication method. FIG. 7 is a flowchart of the communication method provided by the embodiments of the present application. In FIG. 7, the first device and the second device are taken as an example of the execution subject of the interaction to illustrate the method. Among them, the first device can be a terminal or a device (such as a module, circuit, chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), chip system or processor) in the terminal, or a logic node, logic module or software for realizing all or part of the terminal function. The second device can be an access network device or a device (such as a module, circuit, chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), chip system or processor) in the access network device, or a logic node, logic module or software for realizing all or part of the access network device function.

[0221] As shown in FIG. 7, the method comprises:

[0222] S701: The second device sends a first reference signal; correspondingly, the first device receives the first reference signal.

[0223] Among them, the first reference signal can be carried on the first resource. The first reference signal can be used to determine the spatial domain basis; correspondingly, the first device can determine the spatial domain basis according to the first reference signal.

[0224] The first reference signal can be a traditional reference signal, for example, the first reference signal can be a CSI-RS, in the subsequent standard evolution process, the name of the traditional reference signal can change or remain unchanged, all of which are within the protection scope of this application; or the first reference signal can be an evolution of the traditional reference signal, the name of the evolved reference signal can change or remain unchanged, all of which are within the protection scope of this application; or the first reference signal can be a new reference signal or a future defined reference signal.

[0225] Due to the correspondence between the resource and the beam, the first resource can be understood as (or can be replaced by) the first beam in S701. Optionally, the first beam can be the transmitting beam of the second device and / or the receiving beam of the first device.

[0226] The first resource can have other names, such as a reference resource, a benchmark resource, etc., as long as it has the same function, which is within the protection scope of the present application. The first beam can have other names, such as a reference beam, a benchmark beam, etc., as long as it has the same function, which is within the protection scope of the present application.

[0227] As mentioned above, the first device can determine the spatial basis according to the first reference signal, and the determination manner can be various, such as manner a1 or manner a2:

[0228] Manner a1:

[0229] Manner a1 includes steps A1 to A2:

[0230] Step A1: The first device can determine the first eigenvector according to the first reference signal; or in other words, the first eigenvector is determined according to the first reference signal.

[0231] The first device can determine the first eigenvector according to one of formula (4) and formula (5) and the first reference signal; or in other words, the first eigenvector can satisfy formula (4) or formula (5):

[0232] Wherein, N RB is the maximum RB index of the first bandwidth, and the first bandwidth can have various possible implementation manners, such as the first bandwidth being the measurement bandwidth, or the first bandwidth being a preset bandwidth; F is the resource domain transformation matrix (or the beam domain transformation matrix), F H is the conjugate transpose of F; H k,n [0] is the channel coefficient of the 0th polarization, the first resource, and the nth RB; is the conjugate transpose of H k,n [0], H k,n [0] is determined according to the first reference signal; k is the index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum RB number occupied by the first reference signal; H k,n [1] is the channel coefficient of the 1st polarization, the first resource, and the nth RB, is the conjugate transpose of H k,n [1], H k,n [1] is determined according to the first reference signal; V' is the first eigenvector; V' His the conjugate transpose of V'; and ∑ is the eigenvalue corresponding to the first eigenvector. The present application does not limit the way the first device determines H k,n [0] and H k,n [1] in any way, for example, H k,n [0] and H k,n [1] can be determined in a manner specified by a protocol.

[0233] In the present application, the first eigenvectors can include at least one eigenvector, for example, each column in V' can be an eigenvector. Each eigenvector in the at least one eigenvector can correspond to a resource (or a beam). For example, each eigenvector in the at least one eigenvector corresponds to a beam in (a) in FIG. 3. The first eigenvectors can also have other names, for example, a set of eigenvectors, an eigenvector matrix, etc., as long as they have the same function, which are within the protection scope of the present application. Optionally, since the first eigenvectors can include at least one eigenvector, determining the first eigenvectors can also be understood as determining the eigenspace composed of all eigenvectors in the first eigenvectors.

[0234] Optionally, in the case where the first device determines the first eigenvectors according to formula (4) and the first reference signal, the first device can perform resource domain (or beam domain) noise reduction processing on the channel coefficients according to F. Before performing the noise reduction processing, the first device can obtain a noise reduction power difference, so that the first device can perform the resource domain (or beam domain) noise reduction processing on the channel coefficients according to the noise reduction power difference. The noise reduction power difference can be obtained in various ways. For example, the noise reduction power difference can be pre-set, for example, specified by a protocol; or the noise reduction power difference can be determined by the first device, optionally, in this case, the first device can send information indicating the noise reduction power difference to the second device; or the noise reduction power difference can be notified to the first device by another device (for example, the second device or a core network device). In this way, the first device and the second device can obtain the same noise reduction power difference, so that the difference between the spatial domain bases determined by the first device and the second device due to the inconsistent noise reduction effects of the first device and the second device can be avoided or reduced.

[0235] Step A2: The first device determines the spatial domain base according to the first eigenvectors; or in other words, the spatial domain base is determined according to the first eigenvectors.

[0236] Optionally, the first device can determine a channel H1 of the first resource according to the first reference signal, calculate energy of H1 projected onto each eigenvector in the first eigenvectors, and select L eigenvectors with the highest energy as the spatial domain basis; or in other words, the spatial domain basis includes the L eigenvectors. For example, the first device can calculate energy of H1 projected onto each column in V', and select L columns with the highest energy as the spatial domain basis. The present application does not limit the specific process of determining the channel H1 of the first resource according to the first reference signal, which can be determined in a manner specified by a protocol, for example.

[0237] As described above, the first eigenvectors can include at least one eigenvector, and each eigenvector in the at least one eigenvector can correspond to a resource (or in other words, a beam). Therefore, calculating energy of H1 projected onto each eigenvector in the first eigenvectors can be understood as calculating energy of H1 projected onto a beam corresponding to each eigenvector in the first eigenvectors; and selecting L eigenvectors with the highest energy as the spatial domain basis can be understood as selecting L beams with the highest energy using the spatial domain basis, or in other words, the spatial domain basis corresponds to L beams with the highest energy. For example, the first device can calculate energy of H1 projected onto each beam in (a) in FIG. 3, and the 4 beams in (b) in FIG. 3 are the 4 beams with the highest energy, and the spatial domain basis can be used to select the beams in (b) in FIG. 3.

[0238] Through the manner a1, the first device can accurately determine the first eigenvectors according to the formula (4) or the formula (5), so as to accurately determine the spatial domain basis. In the manner a1, the first device can perform dimension reduction processing on the channel coefficients through EVD, so as to determine one eigenspace on two polarizations, and the calculation complexity is relatively low.

[0239] In addition, in the case where the first device determines the first eigenvectors according to the formula (4), the first device can perform resource domain (or beam domain) noise reduction processing on the channel coefficients according to F, so as to further improve the accuracy of the determined spatial domain basis.

[0240] Manner a2:

[0241] The manner a2 includes steps B1 to B2:

[0242] Step B1: The first device determines the first eigenvectors according to the first reference signal; or in other words, the first eigenvectors are determined according to the first reference signal.

[0243] The first device can determine the first eigenvectors according to the formula (6); or in other words, the first eigenvectors can satisfy the following formula (6):

[0244] is an inner product operation; or V′ represents the Kronecker product. h V′ is the feature vector in the horizontal direction. v is the feature vector in the vertical direction.

[0245] In some implementations, the first device can determine V′ according to formula (7) and the first reference signal. h The first device can determine V′ according to formula (8) and the first reference signal. v Or, in other words, V′ h and V′ v The following formulas (7) and (8) can be satisfied respectively:

[0246] Where, N RB Let F be the maximum RB index of the first bandwidth. The first bandwidth can be implemented in several ways, for example, the first bandwidth can be the measurement bandwidth, or the first bandwidth can be a preset bandwidth; F is the resource domain (or beam domain) transformation matrix. H It is the conjugate transpose of F; H k,n [v,0] is H k,n The v-th row of [0], where v is a positive integer. It is H k,n The conjugate transpose of [v,0], H k,n [0] represents the channel coefficient of the 0th polarization, the first resource, and the nth RB; H k,n [0] is determined based on the first reference signal; k is the index of the first resource, k is a non-negative integer, and n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the first reference signal; H k,n [v,1] is H k,n [1] in the vth row, It is H k,n The conjugate transpose of [v,1], H k,n [1] represents the channel coefficients of the first polarization, the first resource, and the nth RB; H k,n [1] is determined based on the first reference signal; For V′ h The conjugate transpose of Σ; h For V′ h The corresponding eigenvalue; H k,n [h,0] is H k,n The h-th column of [0], where h is a positive integer. It is H k,n The conjugate transpose of [h,0]; H k,n [h,1] is H k,n [1] in the h-th column, It is H k,n The conjugate transpose of [h,1]; V' is the conjugate transpose of V; Σ v V' is the conjugate transpose of V; Σ v V' is the conjugate transpose of V; Σ v The corresponding eigenvalues. The present application does not limit the way the first device determines H k,n [0] and H k,n [1] according to the first reference signal, for example, H k,n [0] and H k,n [1] can be determined in a protocol specified manner.

[0247] Optionally, in the case that the first device determines V' h and V' v according to formula (7) and formula (8) respectively, the first device can perform resource domain (or beam domain) noise reduction processing on the rows and / or columns of the channel coefficients according to F. Before performing the noise reduction processing, the first device can obtain the power difference of the noise reduction, so that the rows and / or columns of the channel coefficients can be subjected to the resource domain (or beam domain) noise reduction processing according to the power difference. The way of obtaining the power difference can refer to the description of the way of obtaining the power difference in step A1, and will not be repeated here.

[0248] In this implementation, the first device can perform resource domain (or beam domain) noise reduction processing on the rows and / or columns of the channel coefficients according to F, so as to improve the accuracy of the determined spatial domain basis.

[0249] In other implementations, the first device can determine V' h according to formula (9) and the first reference signal, and the first device can determine V' v according to formula (10) and the first reference signal; or in other words, V' h and V' v may satisfy the following formula (9) and formula (10) respectively:

[0250] The physical meanings of the parameters in formula (9) and formula (10) can refer to the description of the physical meanings of the parameters in formula (7) and formula (8), and will not be repeated here.

[0251] Step B2: The first device determines the spatial domain basis according to the first eigenvector; or in other words, the spatial domain basis is determined according to the first eigenvector.

[0252] The specific content of step B2 can refer to step A2, and will not be repeated here.

[0253] According to the formula (6), the first device can accurately determine the first eigenvector, and thus accurately determine the spatial domain basis. In the mode a2, the first device can perform dimension reduction processing on the channel coefficients by EVD, determine the feature spaces in the horizontal and vertical directions respectively, and perform inner product operation on the feature spaces in the horizontal and vertical directions, so as to accurately determine the first eigenvector. In addition, in this mode, the first device can determine the feature spaces in the horizontal and vertical directions respectively, so as to reduce the complexity of the dimension reduction processing.

[0254] S702: The second device sends a second reference signal; and correspondingly, the first device receives the second reference signal.

[0255] The second reference signal is carried on a second resource. The second reference signal and the spatial domain basis are used to determine a precoding matrix corresponding to the second resource; and correspondingly, the first device can determine the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0256] The second reference signal can be a conventional reference signal, for example, the second reference signal can be a CSI-RS. In the subsequent standard evolution process, the name of the conventional reference signal can change or remain unchanged, which is within the protection scope of the present application. Alternatively, the second reference signal can be an evolution of the conventional reference signal. The name of the evolved reference signal can change or remain unchanged, which is within the protection scope of the present application. Alternatively, the second reference signal can be a new reference signal or a future defined reference signal.

[0257] Since the resource and the beam correspond to each other, the second resource can be understood as (or can be replaced by) the second beam. Optionally, the second beam can be a transmission beam of the second device and / or a reception beam of the first device. The second resource can have other names, for example, a communication resource, as long as it has the same function, which is within the protection scope of the present application. The second beam can have other names, for example, a communication beam, as long as it has the same function, which is within the protection scope of the present application.

[0258] Optionally, the second resource is different from the first resource; or in other words, the second beam is different from the first beam. For example, the first beam and the second beam can be beams pointing in different directions.

[0259] As described above, the first device can determine the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. There can be various ways to determine the precoding matrix, which will be illustrated below.

[0260] For example, the first device can determine the channel H2 of the second resource according to the second reference signal, calculate the energy of H2 projected onto each eigenvector in the spatial domain basis, and select the eigenvector with the highest energy as the precoding matrix corresponding to the second resource. The specific process of determining the channel matrix H2 of the second resource according to the second reference signal is not limited in the present application, for example, it can be determined in a manner specified by the protocol.

[0261] Each eigenvector in the spatial domain basis can correspond to a resource (or beam). Therefore, calculating the energy of H2 projected onto each eigenvector in the spatial domain basis can be understood as calculating the energy of H2 projected onto the beam corresponding to each eigenvector in the spatial domain basis; selecting the eigenvector with the highest energy as the precoding matrix corresponding to the second resource can be understood as the precoding matrix corresponding to the second resource being used to select the beam with the highest energy, or the precoding matrix corresponding to the second resource corresponding to the beam with the highest energy. For example, the first device calculates the energy of H2 projected onto each beam in (b) in FIG. 3, the beam in (c) in FIG. 3 is the beam with the highest energy, and the precoding matrix corresponding to the second resource can be used to select the beam in (c) in FIG. 3.

[0262] Optionally, the signal quality of the first reference signal is higher than the signal quality of the second reference signal. The signal quality of the first reference signal being higher than the signal quality of the second reference signal can be understood as (or can be replaced by) at least one of the following: the signal quality of the reference signal carried by the first resource is higher than the signal quality of the reference signal carried by the second resource; the signal quality of the first beam is higher than the signal quality of the second beam; or the signal quality of the first resource is higher than the signal quality of the second resource. For example, the signal quality can be signal strength. The parameters used to represent or indicate the signal strength can include but are not limited to at least one of the following: RSRP, reference signal received quality (RSRQ), or received signal strength indicator (RSSI).

[0263] The order of S701 and S702 is not limited in the present application.

[0264] S703: The first device transmits the first information; correspondingly, the second device receives the first information.

[0265] The first information can be used to indicate the precoding matrix; or the first information is used to indicate the parameters of the precoding matrix. For example, the first information includes the parameters of the precoding matrix. The parameters of the precoding matrix can be used to determine the precoding matrix; correspondingly, the second device can determine the precoding matrix according to the parameters of the precoding matrix, and the determination manner will be described in S704, which will not be expanded here.

[0266] For example, the first information indicates W2, and W2 can be a parameter of the precoding matrix. The specific content of W2 can refer to the description of W2 in the term explanation part above, and will not be described here.

[0267] Optionally, the first information can be carried in a CSI report message sent by the first device to the second device. For example, the first information is a PMI, and the CSI report message includes a CSI, and the CSI includes the PMI.

[0268] S704: The second device determines the precoding matrix corresponding to the second resource according to the spatial domain basis and the first information.

[0269] For example, the spatial domain basis is W1, the first information indicates W2 corresponding to the second resource, and the second device can determine the precoding matrix W = W1 x W2 corresponding to the second resource.

[0270] Through the method, the first device can determine the spatial domain basis according to the first reference signal carried by the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the feedback precoding matrix corresponding to the second resource. For example, in the case that the signal quality of the second resource is poor, the first device can not determine the spatial domain basis according to the reference signal carried by the second resource, but determine the spatial domain basis according to the first reference signal carried by the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0271] The present application takes the precoding matrix corresponding to the second resource as an example for description, and the precoding matrix corresponding to other resources in addition to the second resource can also be processed in a similar manner, which will not be described here.

[0272] In some possible manners, the method shown in FIG. 7 further includes S705:

[0273] S705: The first device sends a third reference signal; and correspondingly, the second device receives the third reference signal.

[0274] The third reference signal is carried on the first resource. The third reference signal is used to determine the spatial domain basis; and correspondingly, the second device can determine the spatial domain basis according to the third reference signal.

[0275] The third reference signal can be a conventional reference signal, for example, the third reference signal can be an SRS, and the name of the conventional reference signal can change or remain unchanged in the subsequent standard evolution process, which is within the protection scope of the present application; or the third reference signal can be an evolution of the conventional reference signal, and the name of the evolved reference signal can change or remain unchanged, which is within the protection scope of the present application; or the third reference signal can be a new reference signal or a future defined reference signal.

[0276] Due to the correspondence between the resource and the beam, in S705, the first resource can be understood as (or can be replaced by) the third beam. Optionally, the third beam can be a transmitting beam of the first device and / or a receiving beam of the second device. For example, the third beam and the first beam in S701 can be the same beam, or can be beams pointing in the same direction.

[0277] The first resource can have other names, such as reference resource, benchmark resource, etc., as long as it has the same function, which is within the protection scope of the present application. The third beam can have other names, such as reference beam, benchmark beam, etc., as long as it has the same function, which is within the protection scope of the present application.

[0278] As described above, the second device can determine the spatial domain basis according to the third reference signal, and the determination method can be various, for example, method b1 or method b2:

[0279] Method b1:

[0280] Method b1 includes steps C1 to C2:

[0281] Step C1: The second device determines the first eigenvector according to the third reference signal; or in other words, the first eigenvector is determined according to the third reference signal.

[0282] The second device can determine the first eigenvector according to one of the above formulas (4) and (5), and the first reference signal; or in other words, the first eigenvector satisfies the above formula (4) or (5).

[0283] The specific content of step C1 can refer to step A1 above, except that the first device is replaced by the second device, and the first reference signal is replaced by the third reference signal, which will not be repeated.

[0284] Step C2: The second device determines the spatial domain basis according to the first eigenvector; or in other words, the spatial domain basis is determined according to the first eigenvector.

[0285] The specific content of step C2 can refer to step A2, except that the first device is replaced by the second device, and the first reference signal is replaced by the third reference signal, which will not be repeated.

[0286] According to the mode b1, the second device can accurately determine the first eigenvector according to the formula (4) or the formula (5), thereby accurately determining the spatial domain basis. In the mode b1, the second device can perform dimension reduction processing on the channel coefficients by EVD, thereby determining one eigenspace on two polarizations, and the calculation complexity is low.

[0287] In the case that the second device determines the first eigenvector according to the formula (4), the second device can perform resource domain (or beam domain) noise reduction processing on the channel coefficients according to F, thereby improving the accuracy of the determined spatial domain basis.

[0288] The mode b2 includes steps D1 to D2.

[0289] The mode b2 includes steps D1 to D2.

[0290] In step D1, the second device determines the first eigenvector according to the third reference signal; that is, the first eigenvector is determined according to the third reference signal.

[0291] The second device can determine the first eigenvector according to the formula (6) above; that is, the first eigenvector satisfies the formula (6).

[0292] The specific content of step D1 can refer to step B1 above, except that the first device is replaced by the second device, and the first reference signal is replaced by the third reference signal, which will not be described herein again.

[0293] In step D2, the second device determines the spatial domain basis according to the first eigenvector; that is, the spatial domain basis is determined according to the first eigenvector.

[0294] The specific content of step D2 can refer to step A2, except that the first device is replaced by the second device, and the first reference signal is replaced by the third reference signal, which will not be described herein again.

[0295] According to the mode b2, the second device can accurately determine the first eigenvector according to the formula (6), thereby accurately determining the spatial domain basis. In the mode b2, the second device can perform dimension reduction processing on the channel coefficients by EVD, respectively determine the eigenspaces on the horizontal and vertical directions, and perform inner product operation on the eigenspaces on the horizontal and vertical directions, thereby accurately determining the first eigenvector.

[0296] Due to the channel reciprocity, the spatial domain basis determined by the first device in S701 is the same as the spatial domain basis determined by the second device in S705.

[0297] Optionally, S705 can be performed before S704. The present application is not limited to the order of S705 and any one of S701 to S703.

[0298] In this way, the second device can determine the spatial domain basis according to the third reference signal carried by the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the determined precoding matrix corresponding to the second resource. For example, in the case that the signal quality of the second resource is poor, the second device can not determine the spatial domain basis according to the reference signal carried by the second resource, but determine the spatial domain basis according to the third reference signal carried by the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis. In addition, in this way, the second device can determine the spatial domain basis according to the third reference signal, and the first device can not send information indicating the spatial domain basis to the second device, so that the first device can indicate the parameters (for example, W2) of the precoding matrix corresponding to the second resource through more bits without increasing the signaling overhead, so as to further improve the accuracy of the indication of the precoding matrix.

[0299] In some other possible ways, the method shown in FIG. 7 further includes S706:

[0300] S706: The first device sends third information; correspondingly, the second device receives the third information.

[0301] The third information can be used to indicate the spatial domain basis. The present application does not limit the way in which the third information indicates the spatial domain basis.

[0302] The third information can be carried in a conventional message, or the third information can be carried in a new message. For example, the third information can be carried in an RRC message or uplink control information (UCI).

[0303] The third information and the first information can be carried in the same message, or the third information and the first information can be carried in different messages. In some examples, the third information and the first information can be carried in the CSI report message sent by the first device to the second device. For example, the first information and the third information can be PMI, and the CSI report message includes CSI, and the CSI includes the PMI. In some other examples, the first information can be carried in the CSI report message sent by the first device to the second device, and the third information can be carried in the first message sent by the first device to the second device, and the first message is a message different from the CSI report message.

[0304] Optionally, S706 can be after S701 and before S704. The present application does not limit the order of S706 and any one of S702 to S703.

[0305] In this way, the second device can accurately determine the spatial domain basis according to the third information. In addition, in this way, the third information can indicate the spatial domain basis, so that the complexity of the second device in determining the spatial domain basis can be reduced.

[0306] In some possible manners, the method shown in FIG. 7 further includes S707:

[0307] S707: The second device sends the second information; and correspondingly, the first device receives the second information.

[0308] The second information is used to indicate at least one of the following: the first resource; or a precoding matrix corresponding to the second resource determined by the first device according to the second reference signal and the spatial domain basis. This will be described below respectively.

[0309] 1. The first resource:

[0310] In some implementations, the first information can include an identifier or an index of the first resource.

[0311] In some other implementations, the first information can include indication information of a beam corresponding to the first resource, for example, the first beam in S701 and / or the third beam in S705. For example, the first information can include a spatial relation parameter, a TCI-state parameter, or a beam resource corresponding to the beam corresponding to the first resource. For example, the beam resource can be a combination of one or more of the following: an SSB resource, a CSI-RS resource, an SRS resource, a DMRS resource, or a PTRS resource.

[0312] Optionally, the first resource can be a resource with the best signal quality; correspondingly, the second device can determine the resource with the best signal quality as the first resource, and indicate the first resource to the first device through the second information. Alternatively, a beam corresponding to the first resource can be a beam with the best signal quality; correspondingly, the second device can determine a resource corresponding to the beam with the best signal quality as the first resource, and indicate the first resource to the first device through the second information. For example, there are multiple beams between the first device and the second device, and the second device determines a resource corresponding to a beam with the best signal quality in the multiple beams as the first resource, and indicates the first resource to the first device through the second information.

[0313] 2. The first device determines a precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0314] For example, when the first field in the second information has the first value (e.g., 0 or 1), the second information indicates that the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. It should be understood that the second information can also indicate that the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis in other manners, which are not limited.

[0315] Optionally, since the precoding matrix corresponding to the second resource determined according to the second reference signal and the spatial domain basis has high accuracy, the second information used to indicate that the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis can be understood as (or can be replaced by) that the second information is used to indicate that the first device starts (or initiates or performs) high-accuracy CSI (or PMI) measurement.

[0316] Optionally, the second information indicating that the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis can be understood as that the second information indicates a first mode in which the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. The first mode can also have other names, such as a first type, as long as it has the same meaning and is within the protection scope of the present application.

[0317] The second information can be carried in a conventional message, or the second information can be carried in a new message. For example, the second information can be carried in an RRC message, a medium access control-control element (MAC CE), or DCI.

[0318] The second information can have other names, such as measurement indication information or indication information, as long as it has the same function and is within the protection scope of the present application.

[0319] Optionally, S707 can be before S703, and the present application is not limited to the order of S707 and any one of S701 to S702.

[0320] Optionally, the first resource and the precoding matrix corresponding to the second resource determined by the first device according to the second reference signal and the spatial domain basis can be indicated by different information. For example, the second device sends information #1; correspondingly, the first device receives the information #1. The information #1 indicates the first resource, and the specific content of the indication can be referred to S707, except that the second information is replaced by the information #1, which is not described again. The second device sends information #2; correspondingly, the first device receives the information #2. The information #2 indicates that the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis, and the specific content of the indication can be referred to S707, except that the second information is replaced by the information #2, which is not described again.

[0321] In this way, the first device can accurately determine the first resource according to the second information, and accurately determine whether the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. In addition, in this design, the second information is sent by the second device to the first device, so that the flexibility of the second device in managing the first device can be improved.

[0322] In some possible manners, the method shown in FIG. 7 further includes S708:

[0323] S708: The first device sends capability information; and correspondingly, the second device receives the capability information.

[0324] The capability information can be used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. For example, in a case where the capability information takes a second value (for example, 0 or 1), the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis; in a case where the capability information takes a third value (for example, 1 or 0), the first device does not support determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis. The second value and the third value are different.

[0325] Optionally, whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis can be understood as (or can be replaced by) at least one of the following: whether the first device has the capability of determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis; whether the first device supports a first manner in which the first device determines the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis; whether the first device supports enabling (or starting or performing) high-precision CSI (or PMI) measurement; whether the first device has the capability of enabling (or starting or performing) high-precision CSI (or PMI) measurement.

[0326] The capability information can be carried in a conventional message, or the capability information can be carried in a new message. For example, the capability information can be carried in an RRC message or UCI.

[0327] The capability information can have other names, for example, capability indication information or terminal capability indication information, as long as it has the same function, which is within the protection scope of the present application.

[0328] Optionally, S708 can be performed before S707. In a case where the capability information indicates that the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis, the second device can perform S707.

[0329] The application is not limited to the sequence of S708 and any one of S701 to S702.

[0330] In this way, the second device can accurately learn the capability of the first device, for example, the second device can accurately learn whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis, so that the capability of the first device can be configured with appropriate feedback precoding matrix parameters, for example, the parameters indicated by the second information.

[0331] Embodiments of the application provide another communication method. FIG. 8 is a flowchart of a communication method provided by an embodiment of the application. In FIG. 8, the first device and the second device are taken as an example of the execution subject of the interaction to illustrate the method. The specific content of the first device and the second device can be respectively referred to the description of the first device and the second device in the method shown in FIG. 7, and will not be repeated here.

[0332] As shown in FIG. 8, the method comprises:

[0333] S801: The first device acquires a spatial domain basis.

[0334] The spatial domain basis is determined according to a reference signal carried on the first resource. The specific content of the first resource can be referred to the description of the first resource in S701, and will not be repeated here.

[0335] In some implementations, the spatial domain basis is determined by the first device according to the reference signal carried on the first resource, for example, the spatial domain basis is determined by the first device according to the first reference signal carried on the first resource. The specific content can be referred to the description of "the first device can determine the spatial domain basis according to the first reference signal" in S701, and will not be repeated here.

[0336] In other implementations, the spatial domain basis is determined by the second device according to the reference signal carried on the first resource, for example, the spatial domain basis is determined by the second device according to the third reference signal carried on the first resource. The specific content can be referred to the description of "the second device can determine the spatial domain basis according to the third reference signal" in S705, and will not be repeated here.

[0337] The specific content of S801 will be described in the following mode c1 or mode c2, which will not be expanded here.

[0338] S802: The second device sends a second reference signal; correspondingly, the first device receives the second reference signal.

[0339] The second reference signal is carried on a second resource. The second reference signal and the spatial domain basis are used to determine a precoding matrix corresponding to the second resource; correspondingly, the first device can determine the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0340] The specific content of S802 can refer to S702, and details are not described herein again.

[0341] Optionally, the second resource is different from the first resource, or the second beam is different from the first beam. For example, the first beam and the second beam can be beams pointing to different directions.

[0342] Optionally, the signal quality of the reference signal carried by the first resource is higher than the signal quality of the reference signal carried by the second resource. The specific content can refer to the description of “the signal quality of the reference signal carried by the first resource is higher than the signal quality of the reference signal carried by the second resource” in S702, and details are not described herein again.

[0343] The order of S801 and S802 is not limited in the application.

[0344] S803: The first device sends the first information; and correspondingly, the second device receives the first information.

[0345] The first information is used to indicate a precoding matrix, or the first information is used to indicate a parameter of the precoding matrix. The parameter of the precoding matrix can be used to determine the precoding matrix; correspondingly, the second device can determine the precoding matrix according to the parameter of the precoding matrix.

[0346] The specific content of S803 can refer to S703, and details are not described herein again.

[0347] S804: The second device acquires a spatial domain basis.

[0348] The spatial domain basis is determined according to the reference signal carried on the first resource. The specific content can refer to the description of “the spatial domain basis is determined according to the reference signal carried on the first resource” in S801, and details are not described herein again.

[0349] The specific content of S804 will be described in the following mode d1 or mode d2, which is not expanded herein.

[0350] The order of S804 and any one of S802 to S803 is not limited in the application.

[0351] S804 and S801 can occur at the same time, or S804 can occur before S801, or S804 can occur after S801.

[0352] S805: The second device determines a precoding matrix corresponding to the second resource according to the spatial domain basis and the first information.

[0353] The specific content of S805 can refer to S704, and details are not described herein again.

[0354] Through the method, the spatial domain basis is determined according to the reference signal carried on the first resource. The first device can determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the precoding matrix corresponding to the second resource in the feedback. For example, in the case that the signal quality of the second resource is poor, the spatial domain basis can not be determined according to the reference signal carried on the second resource, but determined according to the reference signal carried on the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0355] As described above, in S801, the first device can obtain the spatial domain basis, and there are various ways to obtain, for example, way c1 or way c2.

[0356] Way c1:

[0357] Way c1 can include step E1:

[0358] Step E1: the second device sends the first reference signal; correspondingly, the first device receives the first reference signal. Wherein, the first reference signal can be carried on the first resource.

[0359] The specific content of step E1 can refer to S701, and will not be repeated here.

[0360] Correspondingly, S801 can include: the first device can determine the spatial domain basis according to the first reference signal, or in other words, the first device can obtain the spatial domain basis determined according to the first reference signal. The specific content can refer to the description of "the first device can determine the spatial domain basis according to the first reference signal" in S701, and will not be repeated here.

[0361] Optionally, step E1 can be before S801, and the order of step E1 and S802 is not limited in the present application.

[0362] Through this way c1, the first device can determine the spatial domain basis according to the first reference signal carried on the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the precoding matrix corresponding to the second resource in the feedback. For example, in the case that the signal quality of the second resource is poor, the first device can not determine the spatial domain basis according to the reference signal carried on the second resource, but determine the spatial domain basis according to the first reference signal carried on the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0363] Way c2:

[0364] Way c2 can include step F1:

[0365] Step F1: the first device sends a third reference signal; correspondingly, the second device receives the third reference signal. The third reference signal is carried on the first resource. The third reference signal is used to determine the spatial domain basis; correspondingly, the second device can determine the spatial domain basis according to the third reference signal.

[0366] The specific content of step F1 can refer to S705, and will not be described again.

[0367] Correspondingly, S801 can include: the second device can send fourth information; correspondingly, the first device can receive the fourth information. The fourth information is used to indicate the spatial domain basis. The present application does not limit the way in which the fourth information indicates the spatial domain basis.

[0368] The fourth information can be carried in a traditional message, or the fourth information can be carried in a new message. For example, the fourth information can be carried in an RRC message, a MAC CE or a DCI.

[0369] Optionally, step F1 can be before S801, and the present application does not limit the order of step F1 and S802.

[0370] In this way c2, the first device can accurately determine the spatial domain basis according to the fourth information. Moreover, in this design, the fourth information can indicate the spatial domain basis, so as to reduce the complexity of the first device in determining the spatial domain basis.

[0371] As described above, in S804, the second device can obtain the spatial domain basis, and there are various ways to obtain, for example, way d1 or way d2.

[0372] Way d1:

[0373] Way d1 can include step G1:

[0374] Step G1: the first device sends a third reference signal; correspondingly, the second device receives the third reference signal. The third reference signal is carried on the first resource.

[0375] The specific content of step G1 can refer to S705, and will not be described again.

[0376] Correspondingly, S804 can include: the second device can determine the spatial domain basis according to the third reference signal, or in other words, the second device can obtain the spatial domain basis determined according to the third reference signal. The specific content can refer to the description of "the second device can determine the spatial domain basis according to the third reference signal" in S705, and will not be described again.

[0377] Optionally, step G1 can be before S804, and the present application does not limit the order of step G1 and S802.

[0378] Through the manner G1, the second device can determine the spatial domain basis according to the third reference signal carried by the first resource, and determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the determined precoding matrix corresponding to the second resource. For example, in the case that the signal quality of the second resource is poor, the second device can not determine the spatial domain basis according to the reference signal carried by the second resource, but determine the spatial domain basis according to the third reference signal carried by the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0379] Manner d2:

[0380] The manner d2 can include step H1:

[0381] Step H1: The second device sends the first reference signal; correspondingly, the first device receives the first reference signal.

[0382] The first reference signal can be carried on the first resource. The first reference signal can be used to determine the spatial domain basis; correspondingly, the first device can determine the spatial domain basis according to the first reference signal.

[0383] The specific content of step H1 can refer to S701, and will not be described herein again.

[0384] Correspondingly, S804 can include: the first device sends the third information; correspondingly, the second device receives the third information. The third information can be used to indicate the spatial domain basis. The specific content can refer to S706, and will not be described herein again.

[0385] Through the manner d2, the second device can accurately determine the spatial domain basis according to the third information. Moreover, in this design, the third information can indicate the spatial domain basis, so as to reduce the complexity of the second device in determining the spatial domain basis.

[0386] Optionally, any one of the manner c1 and the manner c2 can be combined with the manner d1 or any one of the manner d1.

[0387] In some possible manners, the method shown in FIG. 8 further includes S806:

[0388] S806: The second device sends the second information; correspondingly, the first device receives the second information.

[0389] The second information is used to indicate at least one of the following: the first resource; or, the precoding matrix corresponding to the second resource determined by the first device according to the second reference signal and the spatial domain basis.

[0390] The specific content of S806 can refer to S707, and will not be described herein again.

[0391] Optionally, S806 can be before S803. The application is not limited to the order of S806 and S801-S802.

[0392] In some possible manners, the method shown in FIG. 8 further includes S807:

[0393] S807: The first device sends the capability information; correspondingly, the second device receives the capability information.

[0394] The capability information can be used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0395] The specific content of S807 can be referred to S708, and will not be repeated here.

[0396] Optionally, S807 can be before S806. In the case that the capability information indicates that the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis, the second device can perform S806.

[0397] The application is not limited to the order of S807 and S801-S802.

[0398] The embodiment of the application provides another communication method. FIG. 9 is a flowchart of a communication method provided by the embodiment of the application. FIG. 9 takes the first device and the second device as the execution subject of the interaction for example to illustrate the method. The specific content of the first device and the second device can be respectively referred to the description of the first device and the second device in the method shown in FIG. 7, and will not be repeated here.

[0399] As shown in FIG. 9, the method includes:

[0400] S901: The first device sends a third reference signal; correspondingly, the second device receives the third reference signal.

[0401] The third reference signal is carried on a first resource. The third reference signal is used to determine a spatial domain basis; correspondingly, the second device can determine the spatial domain basis according to the third reference signal.

[0402] The specific content of S901 can be referred to S705, and will not be repeated here.

[0403] S902: The second device can send fourth information; correspondingly, the first device can receive the fourth information.

[0404] The fourth information is used to indicate the spatial domain basis.

[0405] The specific content of S902 can be referred to the description of S801 in the manner c2 in the method shown in FIG. 8, and will not be repeated here.

[0406] S903: The second device transmits the second reference signal; and correspondingly, the first device receives the second reference signal.

[0407] The second reference signal is carried on the second resource. The second reference signal and the spatial domain basis are used to determine the precoding matrix corresponding to the second resource; and correspondingly, the first device can determine the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0408] The specific content of S903 can refer to S702, and will not be described herein again.

[0409] S904: The first device transmits the first information; and correspondingly, the second device receives the first information.

[0410] The first information is used to indicate the precoding matrix; or the first information is used to indicate the parameter of the precoding matrix.

[0411] The specific content of S904 can refer to S703, and will not be described herein again.

[0412] S905: The second device determines the precoding matrix corresponding to the second resource according to the spatial domain basis and the first information.

[0413] The specific content of S905 can refer to S704, and will not be described herein again.

[0414] Through the method, the spatial domain basis is determined according to the third reference signal carried on the first resource. The first device can determine the precoding matrix corresponding to the second resource according to the spatial domain basis, so as to improve the accuracy of the feedback precoding matrix corresponding to the second resource. For example, in the case that the signal quality of the second resource is poor, the spatial domain basis can not be determined according to the reference signal carried on the second resource, but determined according to the third reference signal carried on the first resource, so as to improve the accuracy of the determined spatial domain basis, and further improve the accuracy of the precoding matrix corresponding to the second resource determined according to the spatial domain basis.

[0415] In addition, in the method, the spatial domain basis is indicated by the second device to the first device, so as to reduce the complexity of the first device in obtaining the spatial domain basis.

[0416] In some possible manners, the method shown in FIG. 9 further includes S906:

[0417] S906: The second device transmits the second information; and correspondingly, the first device receives the second information.

[0418] The second information is used to indicate at least one of the following: the first resource; or the precoding matrix corresponding to the second resource determined by the first device according to the second reference signal and the spatial domain basis.

[0419] The details of S906 can refer to S707, and will not be repeated here.

[0420] In some possible manners, the method shown in FIG. 9 further includes S907.

[0421] S907: The first device sends the capability information; and correspondingly, the second device receives the capability information.

[0422] The capability information can be used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0423] The details of S907 can refer to S708, and will not be repeated here.

[0424] The present application also provides a communication device 1000. The structure of the communication device is shown in FIG. 10, which includes a processing unit 1002. Optionally, the communication device further includes an interface unit 1001. The functions of each unit in the communication device 1000 are introduced as follows.

[0425] The interface unit 1001 is configured to input and / or output information. The input information can be replaced by received information, and the output information can be replaced by transmitted information. When the information is output, the interface unit 1001 can output the information to other devices outside the communication device 1000, or output the information to other units in the communication device 1000. In some manners, the interface unit 1001 can be implemented by at least one of a physical interface, a communication module, a communication interface, and an input / output interface. In other manners, the interface unit 1001 can be implemented by an interface circuit, for example, a mobile communication module. The mobile communication module can include one or more of at least one antenna, at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), and the like. The interface unit 1001 is configured to perform the receiving operation and the sending operation in the above method embodiments.

[0426] In the present application, the interface unit 1001 can also have other names, such as a transceiver unit or a communication unit. Optionally, the interface unit 1001 can include a receiving unit and a sending unit, which are configured to input and output information, respectively. The receiving unit is configured to perform the receiving operation in the above method embodiments. The sending unit is configured to perform the sending operation in the above method embodiments.

[0427] The processing unit 1002 can be configured to support the communication apparatus 1000 to perform the processing actions in the above method embodiments. The processing unit 1002 can be implemented by one or more processors. For example, the processor can be a central processing unit (CPU), and also can be other general purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA), microcontroller units (MCU), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general purpose processor can be a microprocessor, or any conventional processor. The processing unit 1002 is configured to perform operations related to processing in the above method embodiments, for example, operations in the above method embodiments other than receiving operations and sending operations.

[0428] In an embodiment, the communication apparatus 1000 is applied to a first device in the embodiments of the present application shown in FIG. 7. The specific functions of the processing unit 1002 in this embodiment are described below.

[0429] The processing unit 1002 is configured to: receive, through the interface unit 1001, a first reference signal, the first reference signal being carried on a first resource, and the first reference signal being used to determine a spatial domain basis; receive, through the interface unit 1001, a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; and send, through the interface unit 1001, first information, the first information being used to indicate the precoding matrix.

[0430] In some possible manners, the processing unit 1002 is further configured to: send, through the interface unit 1001, a third reference signal, the third reference signal being carried on the first resource, and the third reference signal being used to determine the spatial domain basis.

[0431] Optionally, the processing unit 1002 is further configured to: receive, through the interface unit 1001, second information, the second information being used to indicate at least one of the following: the first resource; or the precoding matrix corresponding to the second resource determined by the first device according to the second reference signal and the spatial domain basis.

[0432] Optionally, the processing unit 1002 is further configured to: send, through the interface unit 1001, capability information, the capability information being used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0433] In some implementations, the processing unit 1002 is further configured to determine the first eigenvector according to the first reference signal, and determine the spatial domain basis according to the first eigenvector.

[0434] In another implementation, the communication apparatus 1000 is applied to the second device in the embodiment of the application shown in Fig. 7. The specific functions of the processing unit 1002 in this implementation are described as follows.

[0435] The processing unit 1002 is configured to send, through the interface unit 1001, a first reference signal, the first reference signal being carried on a first resource, the first reference signal being used to determine a spatial domain basis; send, through the interface unit 1001, a second reference signal, the second reference signal being carried on a second resource, the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; receive, through the interface unit 1001, first information, the first information being used to indicate the precoding matrix; and determine the precoding matrix according to the spatial domain basis and the first information.

[0436] In some possible manners, the processing unit 1002 is further configured to receive, through the interface unit 1001, a third reference signal, the third reference signal being carried on the first resource, the third reference signal being used to determine the spatial domain basis.

[0437] Optionally, the processing unit 1002 is further configured to send, through the interface unit 1001, second information, the second information being used to indicate at least one of the following: the first resource; or the first device determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0438] Optionally, the processing unit 1002 is further configured to receive, through the interface unit 1001, capability information, the capability information being used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0439] In some implementations, the processing unit 1002 is further configured to determine the first eigenvector according to the third reference signal, and determine the spatial domain basis according to the first eigenvector.

[0440] In yet another implementation, the communication apparatus 1000 is applied to the first device in the embodiment of the application shown in Fig. 8. The specific functions of the processing unit 1002 in this implementation are described as follows.

[0441] The processing unit 1002 is configured to obtain a spatial domain basis, the spatial domain basis being determined according to a reference signal carried on a first resource; receive, through the interface unit 1001, a second reference signal, the second reference signal being carried on a second resource, the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; and send, through the interface unit 1001, first information, the first information being used to indicate the precoding matrix.

[0442] In some possible implementation manners, the processing unit 1002 is further configured to: receive, through the interface unit 1001, the first reference signal, the first reference signal being carried on the first resource; and obtain the spatial domain basis determined according to the first reference signal.

[0443] Optionally, the processing unit 1002 is further configured to: send, through the interface unit 1001, the third reference signal, the third reference signal being carried on the first resource, and the third reference signal being used to determine the spatial domain basis; or send, through the interface unit 1001, the third information, the third information being used to indicate the spatial domain basis.

[0444] In another possible implementation manner, the processing unit 1002 is further configured to: send, through the interface unit 1001, the third reference signal, the third reference signal being carried on the first resource, and the third reference signal being used to determine the spatial domain basis; and receive, through the interface unit 1001, the fourth information, the fourth information being used to indicate the spatial domain basis.

[0445] Optionally, the processing unit 1002 is further configured to: receive, through the interface unit 1001, the second information, the second information being used to indicate at least one of the following: the first resource; or a pre-coding matrix corresponding to the second resource determined by the first device according to the second reference signal and the spatial domain basis.

[0446] Optionally, the processing unit 1002 is further configured to: send, through the interface unit 1001, the capability information, the capability information being used to indicate whether the first device supports determining the pre-coding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0447] In another embodiment, the communication device 1000 is applied to the second device in the embodiment shown in FIG. 8. The specific functions of the processing unit 1002 in this embodiment will be introduced below.

[0448] The processing unit 1002 is configured to: obtain the spatial domain basis determined according to the reference signal carried on the first resource; send, through the interface unit 1001, the second reference signal, the second reference signal being carried on the second resource, and the second reference signal and the spatial domain basis being used to determine the pre-coding matrix corresponding to the second resource; receive, through the interface unit 1001, the first information, the first information being used to indicate the pre-coding matrix; and determine the pre-coding matrix according to the spatial domain basis and the first information.

[0449] In some possible implementation manners, the processing unit 1002 is further configured to: receive, through the interface unit 1001, the third reference signal, the third reference signal being carried on the first resource; and obtain the spatial domain basis determined according to the third reference signal.

[0450] Optionally, the processing unit 1002 is further configured to: send, through the interface unit 1001, the first reference signal, the first reference signal being carried on the first resource, and the first reference signal being used for determining the spatial domain basis; or send, through the interface unit 1001, the fourth information, the fourth information being used for indicating the spatial domain basis.

[0451] In some possible implementation manners, the processing unit 1002 is further configured to: send, through the interface unit 1001, the first reference signal, the first reference signal being carried on the first resource, and the first reference signal being used for determining the spatial domain basis; and receive, through the interface unit 1001, the third information, the third information being used for indicating the spatial domain basis.

[0452] In some possible implementation manners, the processing unit 1002 is further configured to: send, through the interface unit 1001, the second information, the second information being used for indicating at least one of the following: the first resource; or the first device determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0453] Optionally, the processing unit 1002 is further configured to: receive, through the interface unit 1001, the capability information, the capability information being used for indicating whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0454] In another implementation manner, the communication device 1000 is applied to the first device in the embodiment shown in FIG. 9. The specific functions of the processing unit 1002 in this implementation manner are introduced as follows.

[0455] The processing unit 1002 is configured to: send, through the interface unit 1001, the third reference signal, the third reference signal being carried on the first resource, and the third reference signal being used for determining the spatial domain basis; receive, through the interface unit 1001, the fourth information, the fourth information being used for indicating the spatial domain basis; receive, through the interface unit 1001, the second reference signal, the second reference signal being carried on the second resource, and the second reference signal and the spatial domain basis being used for determining the precoding matrix corresponding to the second resource; and send, through the interface unit 1001, the first information, the first information being used for indicating the precoding matrix.

[0456] Optionally, the processing unit 1002 is further configured to: receive, through the interface unit 1001, the second information, the second information being used for indicating at least one of the following: the first resource; or the first device determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0457] Optionally, the processing unit 1002 is further configured to: send, through the interface unit 1001, the capability information, the capability information being used for indicating whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0458] In yet another implementation, the communication apparatus 1000 is applied to a second device in the embodiment of the application shown in FIG. 9. The specific functions of the processing unit 1002 in this implementation are described as follows.

[0459] The processing unit 1002 is configured to: receive, through the interface unit 1001, a third reference signal, the third reference signal being carried on a first resource, and the third reference signal being used to determine a spatial domain basis; send, through the interface unit 1001, fourth information, the fourth information being used to indicate the spatial domain basis; send, through the interface unit 1001, a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; receive, through the interface unit 1001, first information, the first information being used to indicate the precoding matrix; and determine the precoding matrix corresponding to the second resource according to the spatial domain basis and the first information.

[0460] In some possible implementations, the processing unit 1002 is further configured to: send, through the interface unit 1001, second information, the second information being used to indicate at least one of the following: the first resource; or the precoding matrix corresponding to the second resource determined by the first device according to the second reference signal and the spatial domain basis.

[0461] Optionally, the processing unit 1002 is further configured to: receive, through the interface unit 1001, capability information, the capability information being used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

[0462] In one possible design, when the communication apparatus 1000 is a communication device or a communication module in a communication device, the function of the processing unit 1002 can be implemented by one or more processors. For example, the processor can include a modem chip, or a system on chip (SoC) chip or a SIP chip including a modem core. The function of the interface unit 1001 can be implemented by a transceiver circuit.

[0463] In one possible design, when the communication apparatus 1000 is a circuit or chip responsible for communication functions in a communication device, such as a modem chip or a system on chip (SoC) chip or a SIP chip including a modem core, the function of the processing unit 1002 can be implemented by a circuit system including one or more processors or processor cores in the chip. The function of the interface unit 1001 can be implemented by an interface circuit or a data transceiver circuit on the chip.

[0464] The communication device can be a terminal or an access network device.

[0465] For more detailed description of the processing unit 1002 and the interface unit 1001, refer to the related description in the method embodiments shown in FIGS. 6 and 7, which are not repeated here.

[0466] It should be noted that the division of the modules in the above embodiments of the present application is illustrative, and is only a logical function division. Actual implementation can have another division manner. In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or can be physically separated, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware, or in the form of software functional unit, or in the form of combination of hardware and software. Whether a certain function is realized in the form of hardware or software depends on the specific application and design constraint conditions of the technical solution. The skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0467] For example, the functional units in any of the above devices can be one or more integrated circuits configured to implement the above methods, such as one or more ASICs, one or more CPUs, one or more MCUs, one or more DSPs, or one or more FPGAs, or a combination of at least two of these integrated circuit forms.

[0468] The integrated unit described above, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0469] The present application also provides a communication device 1100. Referring to FIG. 11, the communication device 1100 includes a processor 1102. Optionally, the communication device 1100 further includes an interface circuit 1101 and a memory 1103. The interface circuit 1101, the processor 1102 and the memory 1103 are coupled with each other.

[0470] Optionally, the interface circuit 1101, the processor 1102 and the memory 1103 are coupled to each other through a bus 1104. The bus 1104 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in FIG. 11, but it does not mean that there is only one bus or only one type of bus.

[0471] The interface circuit 1101 is configured to input and / or output information. The input information can be replaced by received information, and the output information can be replaced by transmitted information. When outputting the information, the interface circuit 1101 can output the information to other devices outside the communication apparatus 1100, or output the information to other units in the communication apparatus 1100. For example, the interface circuit 1101 can be implemented by at least one of a physical interface, a communication module, a communication interface, an input / output interface, and a mobile communication module. The mobile communication module can include one or more of at least one antenna, at least one filter, a switch, a power amplifier, an LNA, etc. The interface circuit 1101 is configured to perform the receiving operation and the transmitting operation in the above method embodiments.

[0472] The interface circuit 1101 can be one of a transceiver, a transceiving circuit, a communication circuit, an interface, a communication interface, or an input / output interface (for example, an input / output interface of a chip). The interface circuit 1101 can include an input interface circuit and an output interface circuit, which are configured to input and output information, respectively. The input interface circuit is configured to perform the receiving operation in the above method embodiments. The output interface circuit is configured to perform the transmitting operation in the above method embodiments.

[0473] The transceiver can be configured to communicate with other communication apparatuses. For example, the communication apparatus 1100 is a terminal, and the transceiver can be configured to communicate with an access network device, or communicate with another terminal. For another example, the communication apparatus 1100 is an access network device, and the transceiver can be configured to communicate with a terminal, or communicate with another access network device.

[0474] Optionally, the transceiver can include a receiver and a transmitter. The receiver is configured to perform the receiving operation in the above method embodiments. The transmitter is configured to perform the transmitting operation in the above method embodiments.

[0475] Optionally, the transceiver can be integrated with the processor 1102, or exist independently and be coupled to the processor 1102 through the interface circuit of the communication apparatus 1100, and the embodiments of the present application do not make a specific limitation in this regard.

[0476] The processor 1102 can be configured to support the communication apparatus 1100 to perform the processing actions in the above method embodiments. When the communication apparatus 1100 is configured to implement the above method embodiments, the processor 1102 can also be configured to implement the functions of the processing unit 1002. The processor 1102 can be a CPU, and can also be other general-purpose processors, DSPs, ASICs, FPGAs or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor. The processor 1102 is configured to perform operations related to processing in the above method embodiments, for example, configured to instruct operations in the above method embodiments except for receiving operations and sending operations.

[0477] In an embodiment, the communication apparatus 1100 is applied to the first device in the embodiment of the application shown in FIG. 7. The specific functions of the processor 1102 in this embodiment are introduced as follows.

[0478] The processor 1102 is configured to: receive, through the interface circuit 1101, a first reference signal, the first reference signal being carried on a first resource, the first reference signal being used to determine a spatial domain basis; receive, through the interface circuit 1101, a second reference signal, the second reference signal being carried on a second resource, the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; and send, through the interface circuit 1101, first information, the first information being used to indicate the precoding matrix.

[0479] In another embodiment, the communication apparatus 1100 is applied to the second device in the embodiment of the application shown in FIG. 7. The specific functions of the processor 1102 in this embodiment are introduced as follows.

[0480] The processor 1102 is configured to: send, through the interface circuit 1101, a first reference signal, the first reference signal being carried on a first resource, the first reference signal being used to determine a spatial domain basis; send, through the interface circuit 1101, a second reference signal, the second reference signal being carried on a second resource, the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; receive, through the interface circuit 1101, first information, the first information being used to indicate the precoding matrix; and determine the precoding matrix according to the spatial domain basis and the first information.

[0481] In yet another embodiment, the communication apparatus 1100 is applied to the first device in the embodiment of the application shown in FIG. 8. The specific functions of the processor 1102 in this embodiment are introduced as follows.

[0482] The processor 1102 is configured to: obtain a spatial domain basis, the spatial domain basis being determined according to a reference signal carried on a first resource; receive, through the interface circuit 1101, a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; and send, through the interface circuit 1101, first information, the first information being used to indicate the precoding matrix.

[0483] In another embodiment, the communication apparatus 1100 is applied to the second device in the embodiment shown in FIG. 8. The specific functions of the processor 1102 in this embodiment are described as follows.

[0484] The processor 1102 is configured to: obtain a spatial domain basis, the spatial domain basis being determined according to a reference signal carried on a first resource; receive, through the interface circuit 1101, a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; and send, through the interface circuit 1101, first information, the first information being used to indicate the precoding matrix.

[0485] In another embodiment, the communication apparatus 1100 is applied to the first device in the embodiment shown in FIG. 9. The specific functions of the processor 1102 in this embodiment are described as follows.

[0486] The processor 1102 is configured to: send, through the interface circuit 1101, a third reference signal, the third reference signal being carried on a first resource, and the third reference signal being used to determine a spatial domain basis; receive, through the interface circuit 1101, fourth information, the fourth information being used to indicate the spatial domain basis; receive, through the interface circuit 1101, a second reference signal, the second reference signal being carried on a second resource, and the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; and send, through the interface circuit 1101, first information, the first information being used to indicate the precoding matrix.

[0487] In another embodiment, the communication apparatus 1100 is applied to the second device in the embodiment shown in FIG. 9. The specific functions of the processor 1102 in this embodiment are described as follows.

[0488] The processor 1102 is configured to: receive, through the interface circuit 1101, a third reference signal, the third reference signal being carried on a first resource, the third reference signal being used to determine a spatial domain basis; send, through the interface circuit 1101, fourth information, the fourth information being used to indicate the spatial domain basis; send, through the interface circuit 1101, a second reference signal, the second reference signal being carried on a second resource, the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; receive, through the interface circuit 1101, first information, the first information being used to indicate the precoding matrix; and determine the precoding matrix corresponding to the second resource according to the spatial domain basis and the first information.

[0489] The specific functions of the processor 1102 can refer to the descriptions of the communication method provided by the embodiments and examples of the present application, and the specific function descriptions of the communication device 1000 in the embodiments of the present application shown in FIG. 10, which will not be repeated here.

[0490] The memory 1103 is configured to store program instructions and / or data, etc. Specifically, the program instructions can include program codes including computer operation instructions. The memory 1103 can include RAM, and can also include non-volatile memory such as at least one disk memory. The processor 1102 executes the program instructions stored in the memory 1103 and uses the data stored in the memory 1103 to realize the above functions, thereby realizing the communication method provided by the above embodiments of the present application. The memory 1103 can be integrated with the processor 1102, or can be a memory outside the communication device.

[0491] It is to be understood that the memory 1103 in FIG. 11 of the present application can be a volatile memory or a nonvolatile memory, or can include both volatile and nonvolatile memory. Among them, the nonvolatile memory can be a ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a RAM used as an external cache. By way of example, and not limitation, a number of forms of RAM are available, such as a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous dynamic RAM (SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synchlink DRAM (SLDRAM), and a direct rambus RAM (DR RAM). It should be noted that the memory of the system and method described herein is intended to include, but not be limited to, these and any other suitable types of memory.

[0492] The present application also provides a communication apparatus 1200, which can be a terminal, a processor in the terminal, or a chip. The communication apparatus 1200 can be used to perform the operations performed by the first device in the above method embodiments.

[0493] When the communication apparatus 1200 is a terminal, FIG. 12 shows a structural schematic diagram of a terminal. As shown in FIG. 12, the terminal includes a processor, a memory, and a transceiver. The memory can store computer program codes, and the transceiver includes a transmitter 1231, a receiver 1232, a radio frequency circuit (not shown in the figure), an antenna 1233, and an input / output device (not shown in the figure).

[0494] The processor is mainly used for processing communication protocols and communication data, controlling the terminal, executing software programs, and processing data of software programs, etc.

[0495] The memory is mainly used for storing software programs and data.

[0496] The radio frequency circuit is mainly used for conversion between baseband signals and radio frequency signals, and processing of radio frequency signals.

[0497] The antenna is mainly used for transmitting and receiving radio frequency signals in the form of electromagnetic waves.

[0498] The input and output device can include a touch screen, a display screen, a keyboard, or the like. The input and output device is mainly used for receiving data input by a user and outputting data to the user. It should be noted that some types of terminals can not have an input and output device.

[0499] When data needs to be transmitted, the processor performs baseband processing on the data to be transmitted, and outputs a baseband signal to the radio frequency circuit. Then, the radio frequency circuit performs radio frequency processing on the baseband signal, and transmits a radio frequency signal through the antenna in the form of electromagnetic waves. When data is transmitted to the terminal, the radio frequency circuit receives a radio frequency signal through the antenna. The radio frequency circuit converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data.

[0500] For ease of illustration, only one memory, one processor, and one transceiver are shown in FIG. 12. In actual terminal products, there can be one or more processors and one or more memories. The memory can also be referred to as a storage medium or a storage device, etc. The memory can be independent of the processor or integrated with the processor, and the embodiments of the present application do not limit this.

[0501] In the embodiments of the present application, the antenna and the radio frequency circuit having the transceiving function can be regarded as an interface unit of the terminal, and the processor having the processing function can be regarded as a processing unit of the terminal.

[0502] As shown in FIG. 12, the terminal includes a processor 1210, a memory 1220, and a transceiver 1230. The processor 1210 can also be referred to as a processing board, a processing module, or a processing device, etc. The transceiver 1230 can also be referred to as an interface circuit, a transceiver, or a transceiving device, etc. The processor 1210 is configured to perform the processing operation of the first device side in the method embodiments. The transceiver 1230 is configured to perform the transceiving operation of the first device side in the method embodiments.

[0503] Optionally, the device for realizing the receiving function in the transceiver 1230 is regarded as a receiver, and the device for realizing the transmitting function in the transceiver 1230 is regarded as a transmitter, that is, the transceiver 1230 includes a receiver 1232 and a transmitter 1231. The receiver can also be referred to as a receiver, a receiving module, or a receiving circuit, etc. The transmitter can also be referred to as a transmitter, a transmitting module, or a transmitting circuit, etc. The receiver is configured to perform the receiving operation of the first device side in the method embodiments. The transmitter is configured to perform the transmitting operation of the first device side in the method embodiments.

[0504] It should be understood that FIG. 12 is merely an example and is not limiting, and the terminal can not depend on the structure shown in FIG. 12.

[0505] When the communication apparatus 1200 is a chip, the chip includes a processor, a memory and a transceiver. The transceiver can be an input output circuit or a communication interface. The processor can be an integrated processing module on the chip or a microprocessor or an integrated circuit. The sending operation of the first device in the method embodiments can be understood as the output of the chip, and the receiving operation of the first device in the method embodiments can be understood as the input of the chip.

[0506] The application further provides a communication apparatus 1300, which can be an access network device or a chip. The communication apparatus 1300 can be used to perform the operations performed by the second device in the method embodiments.

[0507] When the communication apparatus 1300 is an access network device, for example, a base station. FIG. 13 shows a structural schematic diagram of an access network device. The access network device includes a 1310 part, a 1320 part and a 1330 part.

[0508] The 1310 part is mainly used for baseband processing, controlling the access network device, etc. The 1310 part is usually the control center of the base station, which can be usually referred to as a processor, and is used to control the access network device to perform the processing operations of the second device side in the method embodiments.

[0509] The 1320 part is mainly used for storing computer program codes and data.

[0510] The 1330 part is mainly used for transceiving radio frequency signals and converting radio frequency signals and baseband signals. The 1330 part can be usually referred to as a transceiving module, a transceiver, a transceiving circuit, an interface circuit or a transceiver, etc. The 1330 part can include an antenna 1333 and a radio frequency circuit (not shown in the figure), wherein the radio frequency circuit is mainly used for radio frequency processing. The 1330 part can be used to perform the transceiving operations of the second device side in the method embodiments.

[0511] Optionally, the devices for realizing the receiving function in the 1330 part can be regarded as a receiver, and the devices for realizing the sending function can be regarded as a transmitter, that is, the 1330 part includes a receiver 1332 and a transmitter 1331. The receiver can also be referred to as a receiving module, a receiver or a receiving circuit, etc. The transmitter can be referred to as a transmitting module, a transmitter or a transmitting circuit, etc. The receiver is used to perform the receiving operations of the second device side in the method embodiments. The transmitter is used to perform the sending operations of the second device side in the method embodiments.

[0512] The 1310 part and the 1320 part can include one or more single boards, and each single board can include one or more processors and one or more memories. The processors are used to read and execute programs in the memories to realize baseband processing functions and control of the access network device. If there are multiple single boards, the single boards can be interconnected to enhance processing capability. As an optional implementation, multiple single boards can also share one or more processors, or multiple single boards can share one or more memories, or multiple single boards can share one or more processors at the same time.

[0513] It should be understood that FIG. 13 is merely an example and is not limiting, and the access network device can not depend on the structure shown in FIG. 13.

[0514] When the communication apparatus 1300 is a chip, the chip includes a transceiver, a memory and a processor. The transceiver can be an input / output circuit, a communication interface; the processor is a processor integrated on the chip, or a microprocessor, or an integrated circuit. The sending operation of the second device in the method embodiments can be understood as the output of the chip, and the receiving operation of the second device in the method embodiments can be understood as the input of the chip.

[0515] Based on the above embodiments, the embodiments of the present application further provide a computer program product including computer executable instructions, when the computer program product is executed, the method provided by the above embodiments is executed.

[0516] Based on the above embodiments, the embodiments of the present application further provide a computer readable storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by a computer to make the computer execute the method provided by the above embodiments.

[0517] The storage medium can be any available medium that can be accessed by a computer. For example, but not limited to: the computer readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage medium or other magnetic storage devices, or any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and can be accessed by a computer.

[0518] Based on the above embodiments, the embodiments of the present application further provide a chip for reading a computer program stored in a memory to realize the method provided by the above embodiments.

[0519] Based on the above embodiments, the embodiments of the present application provide a chip system, which comprises a processor for supporting a computer device to realize the functions related to the devices in the above embodiments. In a possible design, the chip system further comprises a memory for storing necessary programs and data of the computer device. The chip system can be composed of a chip, or can include a chip and other discrete devices.

[0520] In each of the embodiments of the present application, the terms and / or descriptions in different embodiments are consistent and can be referred to each other if there is no special description and logical conflict. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0521] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0522] These computer program instructions can also be stored in a computer readable memory capable of guiding the computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer readable memory produce a product including instruction devices, which implement the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0523] These computer program instructions can also be loaded into a computer or other programmable data processing device, so that a series of operation steps are performed on the computer or other programmable device to produce a computer implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0524] In this application, the terms "system" and "network" can be interchangeably used. "At least one" means one or more, and "multiple" means two or more. "And / or" describes an associated relationship with the associated object, which means that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. "At least one" or similar expressions refer to any combination of these items, including any combination of single or multiple items. In the textual description of the present application, the character " / ", generally indicates that the associated objects before and after are in an "or" relationship.

[0525] It can be understood that various numerical numbers involved in the embodiments of the present application are only for convenient differentiation, and are not used to limit the scope of the embodiments of the present application. The size of the serial number of the above processes does not mean the order of execution, and the execution order of the processes should be determined according to its function and inherent logic.

[0526] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A communication method characterized by comprising: The application is applied to a first device, comprising: receiving a first reference signal, the first reference signal being carried on a first resource, the first reference signal being used to determine a spatial domain basis; receiving a second reference signal, the second reference signal being carried on a second resource, the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; sending first information, the first information being used to indicate the precoding matrix.

2. The method of claim 1, wherein, Further comprising: sending a third reference signal, the third reference signal being carried on the first resource, the third reference signal being used to determine the spatial domain basis.

3. The method of claim 1 or 2, wherein, Further comprising: receiving second information, the second information being used to indicate at least one of: the first resource; or the first device determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

4. The method according to any one of claims 1 to 3, characterized in that, Further comprising: sending capability information, the capability information being used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

5. The method according to any one of claims 1 to 4, characterized in that, Further comprising: determining a first eigenvector according to the first reference signal; determining the spatial domain basis according to the first eigenvector.

6. The method of claim 5, wherein, The first feature vector satisfies the following formula: or N RB N is the maximum resource block RB index for the measurement bandwidth; F is a resource domain transformation matrix, F H is the conjugate transpose of F; H k,n [0] is the 0th polarization, the first resource, the channel coefficient of the nth RB; is H k,n [0] the conjugate transpose of H k,n [0] is determined according to the first reference signal; k is the index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the first reference signal; H k,n [1] is the channel coefficient of the first polarization, the first resource, the nth RB, is H k,n the conjugate transpose of V' [1], H k,n [1] is determined according to the first reference signal; V' is the first eigenvector; V' H is the conjugate transpose of V'; Σ is the eigenvalue corresponding to the first eigenvector; or The first feature vector satisfies the following formula: V' is a horizontal direction eigenvector, V' h V' is a horizontal direction eigenvector, V' v V' is a vertical direction eigenvector, V' h and V' v respectively satisfy the following formulas: or V' h and V' v respectively satisfy the following equations: where N RB is the maximum resource block RB index of the measured bandwidth; F is a resource domain transformation matrix, F H is the conjugate transpose of F; H k,n is the vth row of H k,n [0], v being a positive integer, is H k,n the conjugate transpose of [v, 0], H k,n [0] is the channel coefficient of the 0th polarization, the first resource, the nth RB; H k,n [0] is determined according to the first reference signal; k is the index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the first reference signal; H k，n [v, 1] is H k，n the vth row of [1], is H k,n the conjugate transpose of [v,1], H k,n [1] is the channel coefficient of the first resource, the nth RB, for the first polarization; H k,n [1] is determined from the first reference signal; For V′ h The conjugate transpose of Σ h For V′ h The corresponding eigenvalues; H k,n [h,0] is the hth column of H k,n [0], h being a positive integer, is H k,n the conjugate transpose of [h, 0]; H k,n is H k,n the hth column of [1], is H k,n conjugate transpose of [h, 1]; is the conjugate transpose of V';∑ v is the conjugate transpose of V';∑ v is the conjugate transpose of V';∑ v is the corresponding eigenvalue.

7. A communication method characterized by comprising: The application is applied to a second device, comprising: sending a first reference signal, the first reference signal being carried on a first resource, the first reference signal being used to determine a spatial domain basis; sending a second reference signal, the second reference signal being carried on a second resource, the second reference signal and the spatial domain basis being used to determine a precoding matrix corresponding to the second resource; receiving first information, the first information being used to indicate the precoding matrix; determining the precoding matrix according to the spatial domain basis and the first information.

8. The method of claim 7, wherein, Further comprising: receiving a third reference signal, the third reference signal being carried on the first resource, the third reference signal being used to determine the spatial domain basis.

9. The method of claim 7 or 8, wherein, Further comprising: sending second information, the second information being used to indicate at least one of: the first resource; or the first device determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

10. The method according to any one of claims 7 to 9, characterized in that, Further comprising: receiving capability information, the capability information being used to indicate whether the first device supports determining the precoding matrix corresponding to the second resource according to the second reference signal and the spatial domain basis.

11. The method of claim 8, wherein, Further comprising: determining a first eigenvector according to the third reference signal; determining the spatial domain basis according to the first eigenvector.

12. The method of claim 11, wherein, The first feature vector satisfies the following formula: or N RB is the maximum resource block RB index for the measured bandwidth; F is a resource domain transform matrix, F H is the conjugate transpose of F; H k,n [0] is the channel coefficient for the 0th polarization, the first resource, the nth RB; is H k,n [0] the conjugate transpose of H k,n [0] is determined according to the third reference signal; k is an index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the third reference signal; H k,n [1] is the channel coefficient of the first polarization, the first resource, the nth RB, is H k,n [1] the conjugate transpose of H k,n [1] is determined according to the third reference signal; V' is the first eigenvector; V' H is the conjugate transpose of V'; Σ is the eigenvalue corresponding to the first eigenvector; or The first feature vector satisfies the following formula: V' is an inner product operation, h V' is a horizontal direction eigenvector, v V' is a vertical direction eigenvector, h and V', v respectively satisfy the following formulas: or V' h and V' v respectively satisfy the following equations: where N RB is the maximum resource block RB index of the measurement bandwidth; F is a resource domain transformation matrix, F H is the conjugate transpose of F; H k,n is the vth row of H k,n [0], v being a positive integer, is H k,n the conjugate transpose of [v, 0], H k,n [0] is a channel coefficient of the 0th polarization, the first resource, the nth RB; H k,n [0] is determined according to the third reference signal; k is an index of the first resource, k is a non-negative integer, n is an integer greater than or equal to 0 and less than or equal to the maximum number of RBs occupied by the third reference signal; H k,n [v, 1] is H k,n the vth row of [1], is H k,n the conjugate transpose of [v,1], H k,n [1] is the channel coefficient of the first resource, the nth RB, for the first polarization; H k，n [1] is determined according to the third reference signal; the conjugate transpose of V';∑ h the diagonal matrix of eigenvalues; λ h the conjugate transpose of V';∑ h the corresponding eigenvalues; H k，n [h,0] is the hth column of H k，n [0], h being a positive integer, is H k,n the conjugate transpose of [h, 0]; H k,n is H k,n the hth column of [1], is H k,n conjugate transpose of [h, 1]; For V′ v The conjugate transpose of Σ v For V′ v The corresponding eigenvalues.

13. The method of any one of claims 1 to 12, wherein, The signal quality of the first reference signal is higher than that of the second reference signal.

14. The method of any one of claims 1 to 13, wherein, The first reference signal and the second reference signal are channel state information reference signals (CSI-RS).

15. A communications device, characterized by The application comprises units for performing the method of any of claims 1-14.

16. A communications device, characterized by The application comprises a processor configured to execute computer program or instructions, so that the device performs the method of any of claims 1-14.

17. A computer readable storage medium characterized in that, The computer readable storage medium stores computer program or instructions, when the computer program or instructions are executed, the method of any of claims 1-14 is realized.

18. A computer program product, characterised in that, The computer program product comprises computer program code which, when the computer program code is run, implements the method according to any one of claims 1-14.

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