Communication method and communication apparatus

Abstract

Provided in the present application are a communication method and a communication apparatus. The method may comprise: determining a first basis vector; receiving a first reference signal; and sending first indication information, wherein the first indication information is used for indicating a second basis vector, the second basis vector is determined on the basis of the first basis vector and a measurement result of the first reference signal, and the first basis vector and the second basis vector are used for determining a precoding matrix. In the present application, a network device may preconfigure a first basis vector for a terminal device. In this way, the terminal device may not need to feed back the first basis vector. Taking a spatial-domain basis vector as an example, the terminal device feeds back a basis vector (i.e., a second basis vector) among a plurality of spatial-domain basis vectors other than a first basis vector, which can reduce the feedback overhead.

Description

Communication method and communication apparatus

[0001] This application claims priority to the Chinese Patent Application No. 202411336703.1, filed on September 23, 2024, and entitled "Communication method and communication apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of wireless communication, and more particularly, to a communication method and a communication apparatus. BACKGROUND

[0003] In a communication system, in order to transmit and receive data, obtain system synchronization and feedback channel information, etc., a reference signal is transmitted between a sending end and a receiving end. For example, the sending end transmits a reference signal to the receiving end, and the receiving end receives the reference signal, and then can estimate channel information based on the reference information, and feed back the channel information, such as channel state information (CSI).

[0004] In the prior art, the CSI feedback codebook mainly includes the following types: type I codebook, type II codebook, and enhanced type II (etype II) codebook. The type I codebook uses a feedback mode of feedback codebook index, and the etype II codebook and the type II codebook use a feedback mode of feedback codebook index and quantization coefficient. With the increase of the number of antennas and the bandwidth, the overhead of the above feedback modes will increase exponentially. SUMMARY

[0005] The present application provides a communication method and a communication apparatus, which can reduce the feedback overhead of CSI and improve the accuracy of CSI.

[0006] In a first aspect, a communication method is provided. The method can be applied to a communication apparatus, i.e., the communication apparatus can be a communication device (such as a terminal device), or the communication apparatus can be a component (such as a chip or a chip system or a circuit or a communication module) in a communication device. Hereinafter, a terminal device will be mainly taken as an example for illustration.

[0007] The method can include: determining a first basis vector; receiving a first reference signal; and transmitting first indication information, the first indication information being used to indicate a second basis vector, the second basis vector being determined based on the first basis vector and a measurement result of the first reference signal, the first basis vector and the second basis vector being used to determine a precoding matrix.

[0008] Based on the technical solution, the network device configures the first basis vector for the terminal device or predefines the first basis vector, so that the terminal device and the network device can know the first basis vector in advance. Thus, the number of basis vectors reported by the terminal device is reduced, and the signaling overhead caused by the terminal device feeding back channel information (such as CSI) is reduced. Taking the spatial domain basis vector as an example, according to the existing manner, the terminal device feeds back multiple spatial domain basis vectors when performing CSI feedback. By introducing the first basis vector, which can be preconfigured by the network device to the terminal device, the terminal device can not feed back the first basis vector, that is, the terminal device can feed back the basis vectors other than the first basis vector (that is, the second basis vector) in the multiple spatial domain basis vectors. Thus, the feedback overhead can be reduced. In addition, compared with directly determining the precoding matrix based on the first basis vector (such as the basis vectors of the precoding matrix), determining the precoding matrix by using the first basis vector and the second basis vector reported by the terminal device can improve the accuracy of the CSI.

[0009] With reference to the first aspect, in a possible implementation manner, the method further includes: sending second indication information, the second indication information being used to indicate the weighting coefficients, the weighting coefficients including: weighting coefficients of part or all of the basis vectors in the first basis vector, and / or weighting coefficients of all of the basis vectors in the second basis vector.

[0010] Based on the technical solution, the terminal device can further feed back the weighting coefficients of the first basis vector, such as the weighting coefficients of part or all of the basis vectors in the first basis vector, to the network device, and can further feed back the weighting coefficients of each basis vector in the second basis vector to the network device. In this way, the network device can determine the precoding matrix based on the weighting coefficients fed back by the terminal device, the second basis vector, and the first basis vector determined in advance.

[0011] With reference to the first aspect, in a possible implementation manner, the weighting coefficients include the weighting coefficients of part or all of the basis vectors in the first basis vector, and the weighting coefficients of all of the basis vectors in the second basis vector, the second indication information includes first sub-information and second sub-information, and the sending of the second indication information, the second indication information being used to indicate the weighting coefficients, includes: sending the first sub-information, the first sub-information being used to indicate the weighting coefficients of part or all of the basis vectors in the first basis vector; and sending the second sub-information, the second sub-information being used to indicate the weighting coefficients of all of the basis vectors in the second basis vector, or the second sub-information being used to indicate the weighting coefficients of part or all of the basis vectors in the first basis vector and the weighting coefficients of all of the basis vectors in the second basis vector.

[0012] Based on the technical solution, the terminal device can feed back the weighting coefficients to the network device in stages. For example, in the first stage, the terminal device feeds back the weighting coefficients of the first basis vector to the network device; in the second stage, the terminal device feeds back the weighting coefficients of the second basis vector to the network device, or feeds back the weighting coefficients of the first basis vector and the second basis vector to the network device. In one possible case, in the first stage, the basis vector of the first stage is the first basis vector, and the terminal device feeds back the weighting coefficients of the first basis vector to the network device; in the second stage, the basis vector of the second stage is the first basis vector and the second basis vector, and the terminal device feeds back the weighting coefficients of the second basis vector to the network device, or feeds back the weighting coefficients of the first basis vector and the second basis vector to the network device. In this way, the basis vector of the first stage and the basis vector of the second stage satisfy the nested structure, and based on this structure, when the basis vector needs to be updated, the second basis vector can be fed back, and there is no need to feed back all the basis vectors, which can significantly reduce the indication overhead. In addition, when the weighting coefficients of the basis vector need to be updated, the weighting coefficients of the second basis vector can be sent, and there is no need to feed back the weighting coefficients of all the basis vectors, which can significantly reduce the indication overhead.

[0013] With reference to the first aspect, in a possible implementation, the sending the second sub-information comprises: sending the second sub-information based on request information, the request information being used to request the weighting coefficients of part of the basis vectors or all the basis vectors in the first basis vector, and / or the weighting coefficients of all the basis vectors in the second basis vector; or sending the second sub-information after X time units, the X time units being time units after a time unit of sending the first sub-information, and X being an integer greater than 1 or equal to 1.

[0014] Optionally, the method further comprises: receiving the request information.

[0015] Based on the technical solution, the terminal device can send the weighting coefficients of the basis vector of the second stage based on a request, or can send the weighting coefficients of the basis vector of the second node when a certain condition is met (for example, after X time units).

[0016] With reference to the first aspect, in a possible implementation, in the case where the weighting coefficients include the weighting coefficients of part of the basis vectors in the first basis vector, the method further comprises: sending third indication information, the third indication information being used to indicate the part of the basis vectors.

[0017] Based on the technical solution, when the terminal device feeds back the weighting coefficients of part of the basis vectors in the first basis vector to the network device, the terminal device can indicate the part of the basis vectors to the network device, thereby facilitating the network device to determine the precoding matrix.

[0018] With reference to the first aspect, in a possible implementation manner, the weighting coefficient is determined based on a measurement result of the first reference signal; or the method further includes: receiving a second reference signal, and the weighting coefficient is determined based on a measurement result of the second reference signal.

[0019] Based on the technical solution, the reference signal used by the terminal device to determine the weighting coefficient can be the same as or different from the reference signal used to determine the second basis vector, and the manner is flexible and applicable to various scenarios.

[0020] With reference to the first aspect, in a possible implementation manner, a transmission period of the weighting coefficient is less than or equal to a transmission period of the second basis vector.

[0021] With reference to the first aspect, in a possible implementation manner, before the second indication information is transmitted, the method further includes: receiving fourth indication information, and the fourth indication information is used to indicate that the weighting coefficient is reported.

[0022] Based on the technical solution, the terminal device reports the weighting coefficient after receiving the indication of the network device.

[0023] With reference to the first aspect, in a possible implementation manner, the determining the first basis vector includes: determining the first basis vector based on received fifth indication information, and the fifth indication information is used to indicate the first basis vector.

[0024] With reference to the first aspect, in a possible implementation manner, the first basis vector is determined based on a third reference signal, and / or the first basis vector is determined based on a sensing signal.

[0025] With reference to the first aspect, in a possible implementation manner, a transmission period of the first basis vector is associated with a first value, and the first value is a transmission period of the first reference signal, or the first value is a transmission period of a third reference signal or a sensing signal, the third reference signal is used to measure the first basis vector, and the sensing signal is used to measure the first basis vector.

[0026] Based on the technical solution, the transmission period of the first basis vector can be associated with the transmission period of other signals, for example, the transmission period of the first basis vector is the same as the transmission period of a reference signal or a sensing signal used to determine the first basis vector. In this way, the network device can configure a period when configuring, thereby reducing the signaling overhead caused by the notification period.

[0027] With reference to the first aspect, in a possible implementation manner, the transmission period of the first base vector is associated with a first value, including any one of the following: the transmission period of the first base vector is the first value; or, the transmission period of the first base vector is an integer multiple of the first value; or, the transmission period of the first base vector is a sum of the first value and a second value, the second value being a number greater than 0.

[0028] With reference to the first aspect, in a possible implementation manner, before the first indication information is transmitted, the method further includes: receiving sixth indication information, the sixth indication information being used to indicate that the second base vector is reported; and the transmitting the first indication information includes: in response to the sixth indication information, transmitting the first indication information.

[0029] Based on the above technical solution, the terminal device reports the second base vector again after receiving the indication of the network device.

[0030] With reference to the first aspect, in a possible implementation manner, the method further includes: determining the number of base vectors included in the second base vector.

[0031] Based on the above technical solution, the terminal device can determine the number of base vectors included in the second base vector according to actual conditions.

[0032] With reference to the first aspect, in a possible implementation manner, the first indication information is further used to indicate the number of base vectors included in the second base vector.

[0033] Based on the above technical solution, the network device can indicate the number of base vectors included in the second base vector to the terminal device, so that the terminal device can determine the second base vector based on the number.

[0034] With reference to the first aspect, in a possible implementation manner, the first base vector and the second base vector satisfy at least one of the following: the first base vector is a full-band base vector, and the second base vector is a full-band base vector or a sub-band base vector; or, the first base vector is a sub-band base vector, and the second base vector is a sub-band base vector; the first base vector is a base vector at a terminal device group level or a terminal device level, and the second base vector is a base vector at a terminal device level; and the transmission period of the first base vector is greater than or equal to the transmission period of the second base vector.

[0035] In a possible implementation manner of the first aspect, the second basis vector is determined based on the first basis vector and the measurement result of the first reference signal, including: the second basis vector is determined based on the first basis vector, the measurement result of the first reference signal, and a first condition, the first condition being at least one of: a linear combination of the first basis vector and the second basis vector being a precoding matrix; a vector set composed of the first basis vector and the second basis vector being linearly independent; all basis vectors contained in the first basis vector and the second basis vector being linearly independent; any basis vector in the first basis vector and the second basis vector being linearly independent.

[0036] As an example, one example of linear independence is orthogonality. For example, the vector set composed of the first basis vector and the second basis vector being linearly independent can be that the vector set composed of the first basis vector and the second basis vector is orthogonal. All basis vectors contained in the first basis vector and the second basis vector are orthogonal; any basis vector in the first basis vector and the second basis vector is orthogonal.

[0037] In a possible implementation manner of the first aspect, the second basis vector is determined based on the first basis vector, the measurement result of the first reference signal, and a first condition, including: the second basis vector is determined based on the first basis vector, the measurement result of the first reference signal, and a first condition, and a second condition, wherein the second condition is any one of: an angle or correlation between any two basis vectors in the vector set being greater than or equal to a first threshold; an angle or correlation between a space corresponding to the first basis vector and a space corresponding to the second basis vector being greater than or equal to a second threshold; an angle or correlation between the space corresponding to the first basis vector and any basis vector in the second basis vector being greater than or equal to a third threshold.

[0038] In a second aspect, a communication method is provided. The method can be applied to a communication device, that is, the communication device can be a communication equipment (such as a network equipment), or the communication device can be a component (such as a chip or a chip system or a circuit or a communication module) in the communication equipment.

[0039] The method can include: transmitting a first reference signal; receiving first indication information, the first indication information being used to indicate a second basis vector, the second basis vector being determined based on a first basis vector and a measurement result of the first reference signal, the first basis vector and the second basis vector being used to determine a precoding matrix.

[0040] With reference to the second aspect, in a possible implementation manner, the method further includes: receiving second indication information, the second indication information being used to indicate the weighting coefficients, the weighting coefficients including: weighting coefficients of part of the basis vectors in the first basis vector or all of the basis vectors in the first basis vector, and / or, weighting coefficients of all of the basis vectors in the second basis vector.

[0041] With reference to the second aspect, in a possible implementation manner, the weighting coefficients include the weighting coefficients of part of the basis vectors in the first basis vector or all of the basis vectors in the first basis vector, and the weighting coefficients of all of the basis vectors in the second basis vector, and the second indication information includes first sub-information and second sub-information, the receiving the second indication information being used to indicate the weighting coefficients includes: receiving the first sub-information, the first sub-information being used to indicate the weighting coefficients of part of the basis vectors in the first basis vector or all of the basis vectors in the first basis vector; and receiving the second sub-information, the second sub-information being used to indicate the weighting coefficients of all of the basis vectors in the second basis vector, or the second sub-information being used to indicate the weighting coefficients of part of the basis vectors in the first basis vector or all of the basis vectors in the first basis vector and the weighting coefficients of all of the basis vectors in the second basis vector.

[0042] With reference to the second aspect, in a possible implementation manner, before the receiving the second sub-information, the method further includes: sending request information, the request information being used to request the weighting coefficients of part of the basis vectors in the first basis vector or all of the basis vectors in the first basis vector, and / or, the weighting coefficients of all of the basis vectors in the second basis vector; or the receiving the second sub-information includes: receiving the second sub-information after X time units, the X time units being time units after time units of receiving the first sub-information, X being an integer greater than 1 or equal to 1.

[0043] With reference to the second aspect, in a possible implementation manner, in a case where the weighting coefficients include the weighting coefficients of part of the basis vectors in the first basis vector, the method further includes: receiving third indication information, the third indication information being used to indicate the part of the basis vectors.

[0044] With reference to the second aspect, in a possible implementation manner, the weighting coefficients are determined based on measurement results of the first reference signal; or the method further includes: receiving a second reference signal, the weighting coefficients being determined based on measurement results of the second reference signal.

[0045] With reference to the second aspect, in a possible implementation manner, a sending period of the weighting coefficients is less than or equal to a sending period of the second basis vector.

[0046] With reference to the second aspect, in a possible implementation manner, before receiving the second indication information, the method further includes: sending fourth indication information, the fourth indication information being used for indicating reporting the weighting coefficient.

[0047] With reference to the second aspect, in a possible implementation manner, the method further includes: determining a precoding matrix based on the weighting coefficient, the first basis vector and the second basis vector.

[0048] With reference to the second aspect, in a possible implementation manner, the method further includes: sending fifth indication information, the fifth indication information being used for indicating the first basis vector.

[0049] With reference to the second aspect, in a possible implementation manner, the first basis vector is determined based on a third reference signal, and / or the first basis vector is determined based on a sensing signal.

[0050] With reference to the second aspect, in a possible implementation manner, a sending period of the first basis vector is associated with a first value; the first value is a sending period of the first reference signal, or the first value is a sending period of a third reference signal or a sensing signal, the third reference signal being used for measuring the first basis vector, and the sensing signal being used for measuring the first basis vector.

[0051] With reference to the second aspect, in a possible implementation manner, before receiving the first indication information, the method further includes: sending sixth indication information, the sixth indication information being used for indicating reporting the second basis vector.

[0052] With reference to the second aspect, in a possible implementation manner, the first basis vector and the second basis vector satisfy at least one of the following: the first basis vector is a full-band basis vector, and the second basis vector is a full-band basis vector or a sub-band basis vector; or the first basis vector is a sub-band basis vector, and the second basis vector is a sub-band basis vector; the first basis vector is a terminal device group level or terminal device level basis vector, and the second basis vector is a terminal device level basis vector; or a sending period of the first basis vector is greater than or equal to a sending period of the second basis vector.

[0053] With reference to the second aspect, in a possible implementation manner, the second basis vector is determined based on the first basis vector and the measurement result of the first reference signal, including: the second basis vector is determined based on the first basis vector, the measurement result of the first reference signal, and a first condition, the first condition being at least one of: a linear combination of the first basis vector and the second basis vector being a precoding matrix; a vector set composed of the first basis vector and the second basis vector being linearly independent; all basis vectors contained in the first basis vector and the second basis vector being linearly independent; any basis vector in the first basis vector and the second basis vector being linearly independent.

[0054] With reference to the second aspect, in a possible implementation manner, the second basis vector is determined based on the first basis vector, the measurement result of the first reference signal, and a first condition, including: the second basis vector is determined based on the first basis vector, the measurement result of the first reference signal, and the first condition, and a second condition, wherein the second condition is any one of: an angle or correlation between any two basis vectors in the vector set being greater than or equal to a first threshold; an angle or correlation between a space corresponding to the first basis vector and a space corresponding to the second basis vector being greater than or equal to a second threshold; an angle or correlation between the space corresponding to the first basis vector and any basis vector in the second basis vector being greater than or equal to a third threshold.

[0055] The third aspect provides a communication method. The method can be applied to a communication device, that is, the communication device can be a communication equipment (such as a terminal equipment), or the communication device can be a component (such as a chip or a chip system or a circuit or a communication module) in the communication equipment.

[0056] The method can include: receiving a second reference signal; determining a first basis vector and a second basis vector, the first basis vector and the second basis vector being used to determine a precoding matrix, the second basis vector being an offset vector of the first basis vector; and sending second indication information, the second indication information being used to indicate a weighting coefficient, the weighting coefficient being determined based on a measurement result of the second reference signal, the weighting coefficient including: a weighting coefficient of part or all basis vectors in the first basis vector, and / or a weighting coefficient of all basis vectors in the second basis vector.

[0057] With reference to the third aspect, in a possible implementation manner, the second indication information includes first sub-information and second sub-information, and the sending the second indication information used for indicating the weighting coefficients includes: sending the first sub-information used for indicating the weighting coefficients of the partial or all base vectors in the first base vectors; and sending the second sub-information used for indicating the weighting coefficients of all base vectors in the second base vectors, or the second sub-information used for indicating the weighting coefficients of the partial or all base vectors in the first base vectors and the weighting coefficients of all base vectors in the second base vectors.

[0058] With reference to the third aspect, in a possible implementation manner, the sending the second sub-information includes: sending the second sub-information based on request information, the request information being used for requesting the weighting coefficients of the partial or all base vectors in the first base vectors and / or the weighting coefficients of all base vectors in the second base vectors; or sending the second sub-information after X time units, the X time units being time units after time units of sending the first sub-information, and X being an integer greater than 1 or equal to 1.

[0059] With reference to the third aspect, in a possible implementation manner, in a case where the weighting coefficients include the weighting coefficients of the partial base vectors in the first base vectors, the method further includes: sending third indication information used for indicating the partial base vectors.

[0060] With reference to the third aspect, in a possible implementation manner, a sending period of the weighting coefficients is less than or equal to a sending period of the second base vectors.

[0061] With reference to the third aspect, in a possible implementation manner, before the sending the second indication information, the method further includes: receiving fourth indication information used for indicating reporting the weighting coefficients.

[0062] With reference to the third aspect, in a possible implementation manner, the determining the first base vectors includes: receiving fifth indication information used for indicating the first base vectors.

[0063] With reference to the third aspect, in a possible implementation manner, the first base vectors are determined based on third reference signals, and / or the first base vectors are determined based on sensing signals.

[0064] In a possible implementation manner of the third aspect, the first base vector is transmitted in a transmission period associated with a first value; the first value is a transmission period of the first reference signal, or the first value is a transmission period of a third reference signal or a sensing signal, the third reference signal is used for measuring the first base vector, and the sensing signal is used for measuring the first base vector.

[0065] In a possible implementation manner of the third aspect, the second base vector is determined by receiving seventh indication information, the seventh indication information being used for indicating the second base vector.

[0066] In a possible implementation manner of the third aspect, the first base vector and the second base vector satisfy at least one of the following conditions: the first base vector is a full-band base vector, and the second base vector is a full-band base vector or a sub-band base vector; or the first base vector is a sub-band base vector, and the second base vector is a sub-band base vector; the first base vector is a terminal device group level base vector, and the second base vector is a terminal device group level base vector or a terminal device level base vector; or the first base vector is a terminal device level base vector, and the second base vector is a terminal device level base vector; and a transmission period of the first base vector is greater than or equal to a transmission period of the second base vector.

[0067] A fourth aspect provides a communication method. The method can be applied to a communication device, which can be a communication apparatus (such as a network device), or the communication device can be a component (such as a chip or a chip system or a circuit or a communication module) in a communication apparatus.

[0068] The method can include: transmitting a second reference signal; and receiving second indication information, the second indication information being used for indicating a weighting coefficient, the weighting coefficient being determined based on a measurement result of the second reference signal, the weighting coefficient including a weighting coefficient of a part or all base vectors in a first base vector and / or a weighting coefficient of all base vectors in a second base vector, the first base vector and the second base vector being used for determining a precoding matrix, and the second base vector being an offset vector of the first base vector.

[0069] With reference to the fourth aspect, in a possible implementation manner, the second indication information includes first sub-information and second sub-information, the receiving the second indication information, the second indication information being used for indicating the weighting coefficients, includes: receiving the first sub-information, the first sub-information being used for indicating the weighting coefficients of the partial or all base vectors in the first base vector; and receiving the second sub-information, the second sub-information being used for indicating the weighting coefficients of all base vectors in the second base vector, or the second sub-information being used for indicating the weighting coefficients of the partial or all base vectors in the first base vector and the weighting coefficients of all base vectors in the second base vector.

[0070] With reference to the fourth aspect, in a possible implementation manner, the sending the second sub-information includes: before the receiving the second sub-information, the method further includes: sending request information, the request information being used for requesting the weighting coefficients of the partial or all base vectors in the first base vector, and / or the weighting coefficients of all base vectors in the second base vector; or the receiving the second sub-information includes: after X time units, the receiving the second sub-information, the X time units being time units after the time units of receiving the first sub-information, and X being an integer greater than 1 or equal to 1.

[0071] With reference to the fourth aspect, in a possible implementation manner, in a case where the weighting coefficients include the weighting coefficients of the partial base vectors in the first base vector, the method further includes: receiving third indication information, the third indication information being used for indicating the partial base vectors.

[0072] With reference to the fourth aspect, in a possible implementation manner, a sending period of the weighting coefficients is less than or equal to a sending period of the second base vector.

[0073] With reference to the fourth aspect, in a possible implementation manner, before the receiving the second indication information, the method further includes: sending fourth indication information, the fourth indication information being used for indicating reporting the weighting coefficients.

[0074] With reference to the fourth aspect, in a possible implementation manner, the method further includes: sending fifth indication information, the fifth indication information being used for indicating the first base vector.

[0075] With reference to the fourth aspect, in a possible implementation manner, the first base vector is determined based on a third reference signal, and / or the first base vector is determined based on a sensing signal.

[0076] With reference to the fourth aspect, in a possible implementation manner, the sending period of the first base vector is associated with a first value; and the first value is a sending period of the first reference signal, or the first value is a sending period of a third reference signal or a sensing signal, the third reference signal is used for measuring the first base vector, and the sensing signal is used for measuring the first base vector.

[0077] With reference to the fourth aspect, in a possible implementation manner, the method further includes: sending seventh indication information, the seventh indication information being used for indicating the second base vector.

[0078] With reference to the fourth aspect, in a possible implementation manner, the first base vector and the second base vector satisfy at least one of the following: the first base vector is a full-band base vector, and the second base vector is a full-band base vector or a sub-band base vector; or the first base vector is a sub-band base vector, and the second base vector is a sub-band base vector; the first base vector is a base vector at a terminal device group level, and the second base vector is a base vector at a terminal device group level or a terminal device level; or the first base vector is a base vector at a terminal device level, and the second base vector is a base vector at a terminal device level; and a sending period of the first base vector is greater than or equal to a sending period of the second base vector.

[0079] With reference to the first aspect to the fourth aspect, in a possible implementation manner, the first base vector and the second base vector are any one of the following: a discrete Fourier transform (DFT) vector, a right singular vector or a left singular vector of a channel matrix corresponding to a precoding matrix or a precoding matrix pair, an oversampling DFT vector, a conjugate transpose vector of a DFT vector, a conjugate transpose vector of an oversampling DFT vector, a steering vector, or an orthogonalized steering vector.

[0080] With reference to the first aspect to the fourth aspect, in a possible implementation manner, the first base vector and the second base vector satisfy any one of the following: the first base vector is a first subset in a vector set, the second base vector is a second subset in the vector set, and an intersection of the first subset and the second subset is an empty set; the first base vector is a first code word in a codebook, the second base vector is a second code word in the codebook, and elements in the first code word and the second code word are different.

[0081] With reference to the first aspect to the fourth aspect, in a possible implementation manner, the first base vector and the second base vector are any one of the following: a frequency domain base vector, a space domain base vector, and a space-frequency base vector.

[0082] The beneficial effects and possible designs of the second aspect to the fourth aspect can be referred to the related description in the first aspect, which will not be repeated here.

[0083] In a fifth aspect, a communication apparatus is provided. The apparatus is configured to perform the method in any one of the first aspect to the fourth aspect and any possible implementation thereof. Specifically, the apparatus can include a unit and / or module configured to perform the method in any one of the first aspect to the fourth aspect and any possible implementation thereof, such as a processing unit and / or a communication unit.

[0084] In an implementation, the apparatus is a communication device, such as a terminal device, or a network device. When the apparatus is a communication device, the communication unit can be a transceiver, or an input / output interface; and the processing unit can be at least one processor. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0085] In another implementation, the apparatus is a chip, chip system or circuit, or a communication module for a communication device, such as a terminal device, or a network device. When the apparatus is a chip, chip system or circuit for a communication device, the communication unit can be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin or related circuitry, etc. on the chip, chip system or circuit; and the processing unit can be at least one processor, a processing circuit or a logic circuit, etc.

[0086] In a sixth aspect, a communication apparatus is provided. The apparatus includes at least one processor configured to cause the apparatus to perform the method in any one of the first aspect to the fourth aspect and any possible implementation thereof.

[0087] Optionally, the at least one processor is configured to execute computer program or instructions to perform the method in any one of the first aspect to the fourth aspect and any possible implementation thereof.

[0088] Optionally, the apparatus further includes a memory configured to store the computer program or instructions.

[0089] Optionally, the at least one processor is coupled to the memory configured to store the computer program or instructions. The memory can be external to the apparatus.

[0090] Optionally, the apparatus further includes a communication interface through which the processor reads the instructions on the memory. It can be understood that the communication interface is coupled to the processor and can be used to input the computer program or instructions to the processor, or output information in the processor.

[0091] For the operations involved in sending and acquiring / receiving, if no special description is given, or if it does not contradict the actual role or internal logic in the relevant description, it can be understood as output, input, etc. operation, or as sending and receiving operation by radio frequency circuit and antenna, which is not limited in the present application.

[0092] In an implementation manner, the apparatus is a communication device (e.g., a terminal device, or a network device).

[0093] In another implementation manner, the apparatus is a chip, a chip system or a circuit or a communication module for a communication device (e.g., a terminal device, or a network device). Optionally, the chip is 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.

[0094] In a seventh aspect, a computer readable storage medium is provided, the computer readable medium storing a computer program (e.g., program code) or instructions thereon, which, when run on a communication apparatus, causes the communication apparatus to perform the method in any one of the first aspect to the fourth aspect and any possible implementation manner thereof.

[0095] In an eighth aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the method in any one of the first aspect to the fourth aspect and any possible implementation manner thereof.

[0096] In a ninth aspect, a communication system is provided, including a first communication apparatus and a second communication apparatus. The first communication apparatus is configured to perform the method provided in any one of the implementation manners of the first aspect, and the second communication apparatus is configured to perform the method provided in any one of the implementation manners of the second aspect; or the first communication apparatus is configured to perform the method provided in any one of the implementation manners of the third aspect, and the second communication apparatus is configured to perform the method provided in any one of the implementation manners of the fourth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0097] FIG. 1 is a schematic diagram of a wireless communication system suitable for embodiments of the present application.

[0098] FIG. 2 is a schematic diagram of an ORAN system suitable for embodiments of the present application.

[0099] FIG. 3 is a schematic diagram of an access network device suitable for embodiments of the present application.

[0100] FIG. 4 is a schematic diagram of a space-frequency matrix.

[0101] FIG. 5 is a schematic diagram of a communication method 500 according to an embodiment of the present application.

[0102] FIGs. 6-9 are schematic diagrams of a first basis vector and a second basis vector according to an embodiment of the present application.

[0103] FIGs. 10-11 are schematic diagrams of a second basis vector and a coefficient A according to an embodiment of the present application.

[0104] FIG. 12 is a schematic diagram of a two-stage feedback weighting coefficient according to an embodiment of the present application.

[0105] FIGs. 13-15 are schematic diagrams of determining a precoding matrix according to an embodiment of the present application.

[0106] FIG. 16 is a schematic diagram of a communication method 1600 according to an embodiment of the present application.

[0107] FIG. 17 is a schematic diagram of a communication method 1700 according to an embodiment of the present application.

[0108] FIG. 18 is a schematic diagram of a communication method 1800 according to an embodiment of the present application.

[0109] FIG. 19 is a schematic diagram of a communication method 1900 according to an embodiment of the present application.

[0110] FIG. 20 is a schematic diagram of a communication method 2000 according to an embodiment of the present application.

[0111] FIG. 21 is a schematic diagram of a communication method 2100 according to an embodiment of the present application.

[0112] FIG. 22 is a schematic diagram of a communication apparatus 2200 according to an embodiment of the present application.

[0113] FIG. 23 is a schematic diagram of another communication apparatus 2300 according to an embodiment of the present application.

[0114] FIG. 24 is a schematic diagram of a chip system 2400 according to an embodiment of the present application. DETAILED DESCRIPTION

[0115] The technical solutions in the present application will be described below with reference to the drawings.

[0116] Before introducing the solutions in the present application, the following points are explained.

[0117] (1) In this application, "indication" can include direct indication, indirect indication, explicit indication, implicit indication, etc. When describing that certain indication information is used to indicate A, it can be understood that the indication information carries A, carries an identifier of A, carries B having an association relationship with A, carries an identifier of B having an association relationship with A, etc. In other words, if the receiving side of certain indication information can determine A according to the indication information, it can be described that the indication information is used to indicate A, and the specific determination is not limited. When it is understood that the indication information carries A, "indication" or "used to indicate" can be replaced by "include", at this time, similar to the expression "send / receive indication information, the indication information is used to indicate A", it can be replaced by "send / receive A".

[0118] In this application, the information indicated by the indication information is called to-be-indicated information. In the specific implementation process, there are many ways to indicate the to-be-indicated information, for example, but not limited to, the to-be-indicated information can be directly indicated, such as the to-be-indicated information itself or an index of the to-be-indicated information. The to-be-indicated information can also be indirectly indicated by indicating other information, where the other information has an association relationship with the to-be-indicated information. The to-be-indicated information can also be indicated only by a part of the to-be-indicated information, and the other part of the to-be-indicated information is known or agreed in advance. For example, the indication of a specific information can also be realized by means of the arrangement order of each information agreed in advance (for example, the protocol stipulates), thereby reducing the indication overhead to a certain extent. In addition, 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 time of these sub-information can be the same or different.

[0119] (2) In this application, the expression " / " is used to represent that the objects before and after the association are in an "or" relationship; for example, A / B can represent A or B. The expression "and / or" is used to represent that the objects before and after the association can be in an "and" association relationship or an "or" association relationship; for example, A and / or B can represent the following cases: A exists alone, B exists alone, A and B exist together, where A and B can be single or multiple. "At least one of the following" or similar expressions are used to represent any combination of the listed items; for example, at least one of A, B and (or) C can represent the following cases: A exists alone, B exists alone, C exists alone, A and B exist together, B and C exist together, A and C exist together, A, B and C exist together, where A, B and C can be single or multiple.

[0120] (3) In this application, "send" and "receive" indicate the direction of signal transmission. For example, "send information to XX" can be understood as the destination of the information being XX, which may include direct transmission via the air interface or indirect transmission by other units or modules via the air interface. "Receive information from YY" can be understood as the source of the information being YY, which may include direct reception from YY via the air interface or indirect reception from YY by other units or modules via the air interface. "Send" can also be understood as the "output" of the chip interface, and "receive" can also be understood as the "input" of the chip interface. In other words, sending and receiving can occur between devices, such as between network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via a bus, wiring, or interface.

[0121] (4) In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0122] (5) In this application, "first," "second," and "#1," "#2," and "#A" are merely for descriptive convenience and are used to distinguish objects, and are not intended to limit the scope of the embodiments of this application. They are not used to describe the order or sequence of features. It should be understood that such described objects can be interchanged where appropriate in order to describe solutions other than those in the embodiments of this application.

[0123] (6) In this application, "predefined" can mean a standard protocol predefined, or it can mean a pre-agreed or pre-negotiated agreement between devices. Here, "protocol" can refer to a standard protocol in the field of communications, for example, it may include fourth-generation (4G) protocols. th Generation 4G network, fifth generation (5G) network th This application does not limit the scope to network protocols such as 5G (generation, 5G), New Radio (NR), 5.5G, and related protocols applied in future communication networks.

[0124] (7) In this application, the words "example", "such as", and the like are used as an example, illustration, or instance. Any embodiment or designations described as "example" in this application should not be construed as preferable or advantageous over other embodiments or designations. Rather, the word "example" is used to present a concept in a specific manner. In this application, "of", "corresponding", and "corresponding" are sometimes mixed. It should be pointed out that when there is no emphasis on the difference, the meaning expressed is consistent.

[0125] (8) In this application, the transformation of the matrix is mentioned several times. For the convenience of understanding, the unified description is as follows. The superscript T represents the transpose, such as A T represents the transpose of matrix (or vector) A; the superscript * represents the conjugate, such as A * represents the conjugate of matrix (or vector) A; the superscript H represents the conjugate transpose, such as A H represents the conjugate transpose of matrix (or vector) A. In the following, in order to simplify, the description of the same or similar cases is omitted.

[0126] (9) In this application, "report" and "feedback" can be mixed. It should be pointed out that when there is no emphasis on the difference, the meaning expressed is consistent.

[0127] First, introduce the communication system applicable to this application.

[0128] The technical solutions provided in the present application can be applied to various communication systems, for example, a 5th generation (5G) or new radio (NR) system, a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD) system, and the like. The technical solutions provided in the present application can also be applied to future communication networks. The technical solutions provided in the present application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and internet of things (IoT) communication systems. The technical solutions provided in the present application can also be applied to non-terrestrial network (NTN) systems such as inter-satellite communication and satellite communication.

[0129] As an example, a satellite communication system includes a satellite base station and a terminal device. The satellite base station provides communication services for the terminal device. The satellite base station can also communicate with a base station. The satellite can act as a base station or a terminal device. The satellite can refer to a drone, a hot air balloon, a low earth orbit satellite, a medium earth orbit satellite, a high earth orbit satellite, and the like. The satellite can also refer to a non-ground base station or a non-ground device, and the like.

[0130] As an example, V2X communication can include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, and vehicle-to-network (V2N) communication.

[0131] A device in a communication system can send a signal to another device or receive a signal from another device. The signal can include information, signaling, or data, and the like. The device can also be replaced by an entity, a network entity, a communication device, a communication module, a node, a communication node, and the like. The device is described as an example in the embodiments of the present application.

[0132] The terminal device in the embodiments of the present application can be a device or module with corresponding communication functions for accessing the above-mentioned communication system. The terminal device can include various devices with wireless communication functions, which can be used to connect people, things, machines, etc. The terminal device can be widely used in various scenarios, such as cellular communication, D2D, V2X, peer to peer, M2M, MTC, IoT, virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, remote medical treatment, smart power grid, smart furniture, smart office, smart wear, smart transportation, smart city UAV, robot, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery, etc. The terminal device can be a terminal in any of the above scenarios, such as an MTC terminal, an IoT terminal, etc. The terminal device can be a user equipment (UE) of the 3rd generation partnership project (3GPP) standard, a terminal, a fixed device, a mobile station device or a mobile device, a subscriber unit, a handset, a vehicle-mounted device, a wearable device, a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a wireless data card, a personal digital assistant (PDA), a computer, a tablet computer, a notebook computer, a wireless modem, a handset, a laptop computer, a computer with wireless transceiver function, a smart book, a vehicle, a satellite, a global positioning system (GPS) device, a target tracking device, an aircraft (such as a drone, a helicopter, a multi-copter, a quad-copter, or an airplane, etc.), a ship, a remote control device, a smart home device, an industrial device, a transport vehicle with wireless communication function, a communication module, a road side unit (RSU) with terminal function, or a device built-in the above-mentioned device (such as a communication module, a modem or a chip in the above-mentioned device, etc.), or other processing devices connected to the wireless modem.

[0133] It should be understood that in some scenarios, the UE can also be used as a base station. For example, the UE can act as a scheduling entity, which provides sidelink signals between UEs in V2X, D2D or peer to peer scenarios, etc.

[0134] In the embodiments of the present application, the apparatus for implementing the function of the terminal device, i.e., the terminal apparatus, can be a terminal device or an apparatus capable of supporting the terminal device to implement the function, such as a chip system or a chip or a circuit or a communication module (i.e., a communication module performing a communication function), which can be installed in the terminal device. In the embodiments of the present application, the chip system can be composed of a chip or can include a chip and other discrete devices. In addition, program instructions for performing corresponding communication functions can also be configured in the apparatus.

[0135] The network device in the embodiments of the present application can be a device or a module with a corresponding communication function. The network device can be a device for communicating with the terminal device, and the network device can also be referred to as an access network device or a radio access network device, such as a network device, which can be a base station. The network device in the embodiments of the present application can refer to a radio access network (RAN) node (or device) for accessing the terminal device to a wireless network. The base station can broadly cover various names in the following or be replaced by the following names, such as: Node B (NodeB), evolved Node B (eNB), next generation Node B (gNB), relay station, access point, transmitting and receiving point (TRP), transmission point, primary station, secondary station, multiple standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station can be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. The base station can also refer to a communication module, a modem, or a chip for being disposed in the foregoing devices or apparatuses. The base station can also be a mobile switching center and a device assuming a base station function in D2D, V2X, M2M communication, a device assuming a base station function in a future communication system, etc. The base station can support networks of the same or different access technologies. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the network device.

[0136] A base station can be fixed, or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, with one or more cells moving according to the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0137] In some deployments, the network device mentioned in embodiments of the present application can be a device including a CU, or a DU, or a device including a CU and a DU, or a control plane CU node (central unit-control plane (CU-CP)) and a user plane CU node (central unit-user plane (CU-UP)), and a DU node.

[0138] In some deployments, a plurality of RAN nodes cooperate to assist a terminal device to implement wireless access, and different RAN nodes respectively implement part of the functions of a base station. For example, a RAN node can be a CU, a DU, a CU-CP, a CU-UP, or a radio unit (RU), etc. The CU and the DU can be separately arranged, or can also be included in the same network element, such as a BBU. The RU can be included in a radio frequency device or a radio frequency unit, such as an RRU, an AAU, or an RRH.

[0139] In different systems, the CU (or CU-CP and CU-UP), DU, or RU can also have different names, but those skilled in the art can understand their meanings. For example, the wireless access network can also be an open radio access network (O-RAN or ORAN) architecture, in which 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), DU, and RU in the present application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0140] In an embodiment of the present application, the apparatus for implementing the function of the network device can be a network device, or can be an apparatus capable of supporting the network device to implement the function, such as a chip system or a chip or a circuit or a communication module (i.e., a communication module performing a communication function), which can be installed in the network device. In an embodiment of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices. In addition, program instructions for performing corresponding communication functions can also be configured in the apparatus. In an embodiment of the present application, only the apparatus for implementing the function of the network device is taken as an example of the network device, and the scheme of the embodiment of the present application is not limited.

[0141] The network device and the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water surface; and can also be deployed on airplanes, balloons and satellites in the air. The scenario in which the network device and the terminal device are located is not limited in the embodiment of the present application.

[0142] Referring to FIG. 1, as an example, FIG. 1 is a schematic diagram of a wireless communication system suitable for an embodiment of the present application. As shown in FIG. 1, the wireless communication system includes a radio access network 100. The radio access network 100 can be a future or higher version radio access network, or a conventional (for example, 5G, 4G, 3G or 2G) radio access network. One or more terminal devices (120a-120j, collectively referred to as 120) can be connected to each other or connected to one or more network devices (110a, 110b, collectively referred to as 110) in the radio access network 100. The network elements in the wireless communication system are connected through an interface (such as NG, Xn), or connected through an air interface.

[0143] In the communication between the network device and the terminal device, the network device can manage one or more cells, and each cell can include at least one terminal device. The cell can be understood as an area within the coverage range of the wireless signal of the network device.

[0144] FIG. 1 is only a schematic diagram, and the wireless communication system can also include other devices, such as core network devices, wireless relay devices and / or wireless backhaul devices, etc., which are not shown in FIG. 1.

[0145] Referring to FIG. 2, as an example, FIG. 2 is a schematic diagram of an ORAN system suitable for an embodiment of the present application. The ORAN system includes a core network, an access network device and a UE. As an example, the ORAN system can also include other components in addition to the components shown in FIG. 2, which are not limited in the present application.

[0146] The access network device can communicate with a core network (CN) through a backhaul. The access network device can communicate with a UE through an air interface. Specifically, a BBU in the access network device communicates with the core network through the backhaul. An RU in the access network device communicates with at least one UE through the air interface. The BBU communicates with at least one RU through a fronthaul, and the BBU and the RU can be co-located or not. The BBU includes at least one CU and at least one DU, and the CU and the DU can communicate through at least one midhaul. The BBU includes at least one CU and at least one DU, and the CU and the DU can communicate through at least one midhaul.

[0147] Referring to FIG. 3, as an example, FIG. 3 is a schematic diagram of an access network device suitable for embodiments of the present application.

[0148] Optionally, the access network device includes a CU. The CU is a logical node that carries the radio resource control (RRC), service data adaptation protocol (SDAP) layer, packet data convergence protocol (PDCP) layer, and other control functions of the access network device. The CU can be connected to network nodes such as core networks through some interfaces. For example, the E2 interface. The CU can have part of the functions of the core network. The CU (e.g., the PDCP layer and / or 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. For example, the F1 interface. Optionally, 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.). F1AP is the application protocol of the F1 interface, which defines the signaling procedures of F1 in some examples. The F1 interface supports control plane F1-C and user plane F1-U.

[0149] As an example, the CU includes a CU-CP and a CU-UP. Among them, the CU-CP is a logical node carrying the 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 an access and mobility management (AMF) in a 5G system. The AMF network element is used to be responsible for the mobility management in the mobile network, such as location update of the terminal device, registration network of the terminal device, handover of the terminal device, etc. The CU-UP is a logical node carrying the 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, for example, a user plane function (UPF) in a 5G system, is used to be responsible for the forwarding and receiving of data in the terminal device. The above configuration of the CU and the DU is only an example, and in actual application, the CU and the DU can also be configured to have functions according to needs. 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 service type or other system requirements, for example, according to the delay, the functions that need to meet the delay requirement are arranged in the DU, and the functions that do not need to meet the delay requirement are arranged in the CU.

[0150] Optionally, the access network device includes a DU. As shown in FIG. 3, 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, which can be a front interface. In some examples, the Higher PHY layer includes part of the PHY layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.

[0151] Optionally, the access network device includes a RU. As shown in FIG. 3, the RU is a logical node that carries lower physical layer (Lower PHY) and radio frequency (RF) processing. In some examples, the RU can be a 3GPP transmission reception point (TRP) or a remote radio head (RRH) or other similar functional entity. In some examples, the Low-PHY includes portions of PHY processing such as fast fourier transform (FFT), inverse fast fourier transformation (IFFT), digital beamforming and filtering, and other processing functions. The RU communicates with one or more UEs over a wireless link.

[0152] The DU and the RU can be co-located or not co-located. The DU and the RU exchange control plane information and user plane information via a lower-layer split-CUS-plane (LLS-CUS) interface over a fronthaul link. The LLS-CUS can include a lower-layer split control (LLS-C) interface and a lower-layer split user (LLS-U) interface that provide control plane (C-Plane) and user plane (U-Plane), respectively. In some examples, the control plane (C-Plane) refers to real-time control between the DU and the RU. The DU and the RU exchange management information via a lower-layer split-M (LLS-M) interface of the fronthaul link, and the management plane (M-Plane) refers to non-real-time management operations between the DU and the RU.

[0153] 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 functionality of the DU and the RU 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 intermediate RF functionality. For 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 intermediate RF side.

[0154] FIGS. 1-3 are illustrative examples, and embodiments of the present application are not limited thereto.

[0155] For the convenience of understanding the embodiments of the present application, the terms involved in the present application are briefly explained.

[0156] 1. Multi-input multi-output (MIMO) technology: using the resource of spatial dimension, the signal can obtain array gain, multiplexing and diversity gain, and interference cancellation gain in space without increasing the system bandwidth, which can multiply the capacity and spectrum efficiency of the communication system. For example, in the LTE system, the MIMO system can support up to 8 layers of transmission at the transmitting end and the receiving end using multiple antennas.

[0157] 2. Channel estimation and channel information: channel estimation refers to the process of reconstructing or recovering the received signal in order to compensate for the signal distortion caused by channel fading and noise fading. It mainly uses the reference signal (RS) known by the transmitting end and the receiving end to track the time domain and frequency domain changes of the channel. Channel information refers to information that can reflect the characteristics and quality of the channel.

[0158] Among them, the reference signal refers to a physical signal carrying a sequence sent for a specific function. Specifically, the reference signal is a physical signal generated by mapping a specific sequence to the corresponding resource according to the pre-designed resource mapping method. The reference signal can also be called pilot, reference sequence, reference signal, etc. In the present application, the reference signal involved as an example can be any of the following: channel state information reference signal (CSI-RS), sounding reference signal (SRS), demodulation reference signal (DMRS), phase tracking reference signal (PT-RS), cell reference signal (CRS), etc. Among them, the DMRS can be used for demodulation of the physical downlink shared channel (PDSCH) or the physical uplink shared channel (PUSCH). 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.

[0159] As an example, the channel information is at least one of: channel state information (CSI), channel time variation information, or channel frequency offset information, etc. Hereinafter, the channel information is taken as an example of CSI, and it can be understood that information reflecting channel characteristics and channel quality is applicable to the embodiments of the present application.

[0160] As an example, the network side obtains the downlink CSI by means of uplink feedback of the terminal device. Specifically, the network side sends a downlink reference signal to the terminal device, and the terminal device receives the downlink reference signal. Since the terminal device knows the transmission information of the downlink reference signal, the terminal device can estimate (or measure) the downlink channel experienced by the downlink reference signal based on the received downlink reference signal, and then the terminal device can generate the CSI based on the measurement of the downlink channel matrix, and feed back the CSI to the network side.

[0161] As an example, the CSI includes at least one of: channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), CSI-RS resource indicator (CRI), layer indicator (LI), reference signal receiving power (RSRP), or signal to interference plus noise ratio (SINR), etc. The signal to interference plus noise ratio can also be referred to as signal to noise and interference ratio. Among them, the PMI can be used to indicate the precoding matrix.

[0162] 3. Precoding matrix: the sending end processes the to-be-sent signal by means of a precoding matrix matched with the channel resource in the case of knowing the channel state, so that the to-be-sent signal after precoding is adapted to the channel, thereby reducing the complexity of eliminating the influence between channels by the receiving end. As an example, the precoding matrix can be a precoding matrix determined based on a frequency band or a port channel matrix. As an example, the channel matrix can be determined by a channel estimation method. The vector in the precoding matrix can be referred to as a precoding vector.

[0163] 4. Frequency domain vector: or frequency domain basis vector.

[0164] The frequency domain vector can be a vector with a length of N f N f is an integer greater than 1 or equal to 1. As an example, Nf The number of frequency domain units can be represented.

[0165] The frequency domain unit can be used to represent different frequency domain resource granularity. One frequency domain unit can be one resource block (RB), one subcarrier, one resource block group (RBG), one predefined subband, one precoding resource block group (PRG), one bandwidth part (BWP), one resource element (RE) (also referred to as resource unit or resource particle), one carrier, one serving cell.

[0166] Based on a set of weighting coefficients, weighting one or more frequency domain vectors can be used to obtain a precoding vector or a precoding matrix, or a channel matrix corresponding to the precoding vector or the precoding matrix.

[0167] As an example, the frequency domain vector is a discrete Fourier transform (DFT) vector or a conjugate transpose vector of the DFT vector; or, the frequency domain vector is an oversampled DFT vector or a conjugate transpose vector of the oversampled DFT vector.

[0168] The terminal device can feed back the indication information of the selected one or more frequency domain vectors to the network device through the PMI.

[0169] 5. Spatial domain vector: also referred to as spatial domain basis vector or beam vector or angle vector.

[0170] The spatial domain vector can be a vector with a length of N T , N T being an integer greater than 1 or equal to 1. As an example, N T may represent the number of transmit antenna ports.

[0171] Based on a set of weighting coefficients, weighting one or more spatial domain vectors can be used to obtain a precoding vector or a precoding matrix, or a channel matrix corresponding to the precoding vector or the precoding matrix.

[0172] As an example, the spatial domain vector is a DFT vector or a conjugate transpose vector of the DFT vector; or, the spatial domain vector is an oversampled DFT vector or a conjugate transpose vector of the oversampled DFT vector.

[0173] The terminal device can feed back the indication information of the selected one or more spatial domain vectors to the network device through the PMI.

[0174] 6, Space-frequency vector: or space-frequency domain basis vector (or space-frequency vector pair, or angle-delay pair).

[0175] As an example, a space-frequency vector is a vector of length N T x N f , N T x N f is an integer greater than 1 or equal to 1. As an example, N T represents the number of transmit antenna ports, N f represents the number of frequency domain units.

[0176] One possible case is that a space-frequency vector can be a Kronecker product of a port selection vector and a frequency domain vector. For example, a space-frequency vector is denoted as b, a port selection vector is denoted as e, and a frequency domain vector is denoted as u, then represents the Kronecker product operation. A port selection vector can be a spatial domain vector.

[0177] Another possible case is that a space-frequency vector is a left singular vector or a right singular vector, etc.

[0178] Weighting one or more space-frequency vectors based on a set of weighting coefficients can be used to obtain a precoding vector or a precoding matrix corresponding to a channel matrix. The terminal device can feed back the indication information of the selected one or more space-frequency vectors to the network device through a PMI.

[0179] 7, Time unit: or time domain unit, represents the granularity of resources in the time domain. A time unit can be a symbol, or an orthogonal frequency division multiplexing (OFDM) symbol, or a mini-slot, or a slot, or a partial slot, or a subframe, or a radio frame, etc. Among them, a slot can be composed of 6, 7, 12 or 14 symbols; a mini-slot can include at least one symbol (for example, 2 symbols or 7 symbols or 14 symbols, or any number of symbols less than or equal to 14 symbols); the duration of a subframe in the time domain can be 1 millisecond (ms). It should be understood that the above-mentioned time unit sizes are only for the convenience of understanding the scheme of the present application and do not limit the protection scope of the present application. It can be understood that the above-mentioned time unit sizes can be other values, and the present application is not limited.

[0180] In the prior art, the CSI feedback codebook mainly includes the following types: type I codebook, type II codebook, and enhanced type II (etype II) codebook. The type I codebook uses a feedback mode of feedback codebook index, and the etype II codebook and the type II codebook use a feedback mode of feedback codebook index and quantized coefficients. Taking the etype II as an example, the etype II is a data stream level feedback PMI, and uses the feedback mode of codebook index and quantized coefficients.

[0181] For example, it is assumed that the precoding matrix is a space-frequency matrix W, which can be approximately represented by a space-domain basis matrix, a frequency-domain basis matrix, and a weighting coefficient.

[0182] Referring to FIG. 4, as an example, FIG. 4 is a schematic diagram of a space-frequency matrix. As shown in FIG. 4, the space-frequency matrix W is composed of precoding vectors of N F frequency-domain units. The precoding vector contains N T weight values for weighting N T antenna ports, and the dimension of the precoding vector is N T × 1. The dimension of the space-frequency matrix W is N T × N F , the space-domain basis matrix is composed of L space-domain basis vectors, the length of the space-domain basis vector is N T , and the dimension of the space-domain basis matrix is N T × L. The dimension of the weighting coefficient is L × M, the frequency-domain basis matrix is composed of M frequency-domain basis vectors, the length of the frequency-domain basis vector is N F , and the dimension of the frequency-domain basis vector is M × N F . As an example, N T represents the number of transmitting antenna ports, N T is an integer greater than 1 or equal to 1; N F represents the number of frequency-domain units, N F is an integer greater than 1 or equal to 1; L represents the number of space-domain basis vectors, L is an integer greater than 1 or equal to 1; and M represents the number of frequency-domain basis vectors, M is an integer greater than 1 or equal to 1.

[0183] According to the existing mode, the content of channel information (such as CSI) feedback includes the space-domain basis vector index contained in the space-domain basis matrix, the space-domain basis vector index contained in the space-domain basis matrix, and the weighting coefficient.

[0184] However, with the increase of the number of antennas and bandwidth, the above feedback mode, i.e., the feedback mode of the feedback codebook index and the quantized coefficient, will increase the overhead exponentially. Specifically, 1) with the increase of the number of antennas, because the existing codebook is a given DFT codebook, the set size of the codebook will increase exponentially, even if the number of feedback base vectors is unchanged, the feedback bit size of the index will also increase exponentially. 2) In order to ensure the PMI accuracy, with the increase of the number of antennas, the spatial domain base vector required in the spatial domain will also increase, thereby increasing the CSI feedback overhead. 3) In order to ensure the PMI accuracy, with the increase of the bandwidth, the frequency domain base vector required in the frequency domain will also increase, thereby increasing the CSI feedback overhead.

[0185] Therefore, the present application proposes a scheme, by designing feedback based on reference channel base vectors, to reduce the CSI feedback overhead and improve the CSI feedback accuracy when the number of antennas and bandwidth increases.

[0186] The method provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments provided by the present application can be applied to the scenario shown in the above-mentioned figures, without limitation. In addition, the terms involved below can refer to the previous explanation, which will not be repeated hereinafter. In the following method embodiments, the terminal device and the network device are taken as examples for illustration. The terminal device can also be replaced by a component of the terminal device, such as a chip or a chip system or a circuit or a communication module. The network device can also be replaced by a component of the network device, such as a chip or a chip system or a circuit or a communication module. In addition, the steps described below as executed by a single execution subject can also be divided into execution by multiple execution subjects, which can be logically and / or physically separated.

[0187] Referring to FIG. 5, as an example, FIG. 5 is a schematic diagram of a communication method 500 provided by an embodiment of the present application. The method 500 shown in FIG. 5 can include the following steps.

[0188] 510, the terminal device determines a first base vector.

[0189] The first base vector includes one or more base vectors (or vectors, or channel base vectors). For example, the first base vector is a matrix including one or more base vectors. The first base vector can also be referred to as a reference channel base vector or a reference base vector, and the naming does not limit the protection scope of the embodiments of the present application.

[0190] Optionally, the terminal device determining the first base vector comprises: the terminal device determining the first base vector based on an indication of the network device, in other words, the network device configuring the first base vector for the terminal device. Specifically, the method 500 further comprises: the network device sending indication information #1 (an example of the fifth indication information) to the terminal device, the indication information #1 being used to indicate the first base vector; and correspondingly, the terminal device receiving the indication information #1. The terminal device can determine the first base vector based on the indication information #1.

[0191] In a possible implementation, the indication information #1 directly indicates the first base vector. For example, the indication information #1 indicates elements included in each base vector of the first base vector.

[0192] In another possible implementation, the indication information #1 indirectly indicates the first base vector. For example, a plurality of first base vectors are predefined or preconfigured, and the plurality of first base vectors correspond to different indexes; the network device indicates an index of the first base vector through the indication information #1, and the terminal device determines the corresponding first base vector based on the index.

[0193] As an example, the indication information #1 can be carried in at least one of the following signaling: radio resource control (RRC), media access control (MAC) (such as media access control-control element (MAC CE)), or downlink control information (DCI).

[0194] Regarding the manner in which the terminal device determines the first base vector, the above is an example description, and embodiments of the present application are not limited thereto. In other words, as long as the manner in which the terminal device and the network device align the first base vector in advance is applicable to the embodiments of the present application. For example, the first base vector can be predefined or pre-agreed. For another example, a plurality of first base vectors are predefined, and the network device and the terminal device can select one of them as the first base vector based on a preset condition, wherein the preset condition can be predefined or configured by the network device, which is not limited herein. For another example, the terminal device and the network device can each determine (or generate) the first base vector based on a preset manner, wherein the preset manner can be predefined or configured by the network device, which is not limited herein.

[0195] 520, the terminal device receives a reference signal #1 (an example of a first reference signal).

[0196] The reference signal #1 is a downlink reference signal, such as a CSI-RS.

[0197] 530, the terminal device sends indication information #2 (an example of the first indication information), which is used to indicate the second basis vector. Correspondingly, the network device receives the indication information #2.

[0198] The second basis vector is determined based on the first basis vector and the measurement result of the reference signal #1. The first basis vector and the second basis vector can be used to determine a precoding matrix. Details will be described later.

[0199] As an example, the indication information #2 can be carried in uplink control information (UCI), that is, the terminal device sends UCI to the network device, and the UCI is used to indicate the second basis vector.

[0200] As an example, the terminal device sends the indication information #2 based on the indication of the network device (an example of the sixth indication information). Specifically, the network device sends indication information to the terminal device, and the indication information is used to indicate the reporting of the second basis vector; in response to the indication information, the terminal device sends the indication information #2. The indication information can be carried in any of the following signaling: RRC, or MAC CE, or DCI, etc.

[0201] The second basis vector includes one or more basis vectors (or vectors, or channel basis vectors). For example, the second basis vector is a matrix that includes one or more basis vectors. As an example, the second basis vector can be understood as a bias vector (or a supplementary vector) of the first basis vector. The naming of the second basis vector does not limit the protection scope of the embodiments of the present application.

[0202] The first basis vector and the second basis vector will be introduced from different angles in combination with several cases.

[0203] First, the relationship between the first basis vector and the second basis vector will be introduced.

[0204] The first possible case is that the first basis vector and the second basis vector can be one or more of the following: spatial domain basis vector, frequency domain basis vector, and space-frequency basis vector.

[0205] For example, the first basis vector and the second basis vector are spatial domain basis vectors. For ease of description, in the embodiments of the present application, if the first basis vector and the second basis vector are spatial domain basis vectors, the matrix composed of the first basis vector and the second basis vector can be referred to as a spatial domain basis matrix, in other words, the spatial domain basis matrix represents the matrix composed of the first basis vector and the second basis vector. Specifically, it is assumed that the spatial domain basis matrix includes M spatial domain basis vectors, the first basis vector is M1 spatial domain basis vectors in the M spatial domain basis vectors, the second basis vector is M2 spatial domain basis vectors in the M spatial domain basis vectors except the M1 spatial domain basis vectors, M1 and M2 are integers greater than 1 or equal to 1 and less than M, and M1+M2=M.

[0206] For example, the first basis vector and the second basis vector are spatial domain basis vectors. For ease of description, in the embodiments of the present application, if the first basis vector and the second basis vector are spatial domain basis vectors, the matrix composed of the first basis vector and the second basis vector can be referred to as a spatial domain basis matrix, in other words, the spatial domain basis matrix represents the matrix composed of the first basis vector and the second basis vector. Specifically, it is assumed that the spatial domain basis matrix includes M spatial domain basis vectors, the first basis vector is M1 spatial domain basis vectors in the M spatial domain basis vectors, the second basis vector is M2 spatial domain basis vectors in the M spatial domain basis vectors except the M1 spatial domain basis vectors, M1 and M2 are integers greater than 1 or equal to 1 and less than M, and M1+M2=M.

[0207] For example, the first basis vector and the second basis vector are spatial domain basis vectors. For ease of description, in the embodiments of the present application, if the first basis vector and the second basis vector are spatial domain basis vectors, the matrix composed of the first basis vector and the second basis vector can be referred to as a spatial domain basis matrix, in other words, the spatial domain basis matrix represents the matrix composed of the first basis vector and the second basis vector. Specifically, it is assumed that the spatial domain basis matrix includes M spatial domain basis vectors, the first basis vector is M1 spatial domain basis vectors in the M spatial domain basis vectors, the second basis vector is M2 spatial domain basis vectors in the M spatial domain basis vectors except the M1 spatial domain basis vectors, M1 and M2 are integers greater than 1 or equal to 1 and less than M, and M1+M2=M.

[0208] The second possible case, taking the first basis vector as an example, the first basis vector can be any of the following: a DFT vector, a conjugate transpose vector of the DFT vector, an oversampling DFT vector, a conjugate transpose vector of the oversampling DFT vector, a right singular vector of W, a left singular vector of W, a steering vector, and a steering vector after orthogonalization processing. The second basis vector can also be any of the above.

[0209] Wherein, W represents a precoding matrix or a channel matrix corresponding to the precoding matrix.

[0210] The steering vector or array steering vector can be used to represent the spatial phase difference caused by the spatial interval between antenna ports in the same wave direction. The steering vector can be used to calculate the array response under different angles of arrival / angles of departure, and each steering vector can represent a specific angle of arrival or angle of departure, and each element can represent an array element in the array. The steering vectors corresponding to different arrangements of the antenna array can be different.

[0211] For example, the first basis vector can be a steering vector in the direction of signal propagation, or the first basis vector can be a steering vector in the direction of a beam or a beam cluster (e.g., a departure direction determined based on an AOD and / or a ZOD), and the like.

[0212] In a third possible case, a vector set is predefined or preconfigured, the first basis vector and the second basis vector are two subsets of the vector set, and the intersection of the two subsets is an empty set.

[0213] In a fourth possible case, a codebook is predefined or preconfigured, the first basis vector and the second basis vector are two code words in the codebook, in other words, the first basis vector and the second basis vector correspond to code words with different indices in the codebook.

[0214] The above describes the possible relationship between the first basis vector and the second basis vector in the first possible case to the fourth possible case. The possible attributes of the first basis vector and the second basis vector are described below.

[0215] In a fifth possible case, the first basis vector is terminal device group specific (UE group specific) or radio frequency map (RF map) grid specific (RF map grid specific), and the second basis vector is terminal device specific (UE specific). The RF map, which can also be referred to as a radio frequency map, is a map used to display the coverage range and signal strength distribution of a wireless signal, and can reflect the parameter values of various position points in a wireless network. Common RF maps include a channel gain map, a received signal strength map, a power spectral density map, a channel multiple path component (MPC) map, and the like.

[0216] Referring to FIG. 6, as an example, FIG. 6 is a schematic diagram of the first basis vector and the second basis vector provided by the embodiments of the present application. As shown in FIG. 6, it is assumed that the terminal device includes: UE0, UE1, UE2, and UE3, wherein UE0 and UE1 form a group, and UE2 and UE3 form a group. The first basis vector can be UE group specific. Specifically, for UE0 and UE1, the same first basis vector (for example, referred to as first basis vector 0) can be used, in other words, the first basis vector configured by the network device for UE0 and UE1 is the first basis vector 0; for UE2 and UE3, the same first basis vector (for example, referred to as first basis vector 1) can be used, in other words, the first basis vector configured by the network device for UE2 and UE3 is the first basis vector 2. The second basis vector can be UE specific. Specifically, the second basis vector corresponding to UE0 is the second basis vector 0, the second basis vector corresponding to UE1 is the second basis vector 1, the second basis vector corresponding to UE2 is the second basis vector 2, and the second basis vector corresponding to UE3 is the second basis vector 3.

[0217] The above case is an example for illustration, and is not limited thereto. For example, the first basis vector and the second basis vector can both be UE specific; or the first basis vector and the second basis vector can both be UE group specific; or the first basis vector and the second basis vector can both be RF map grid specific.

[0218] The sixth possible case is that the update period of the first basis vector is greater than the update period of the second basis vector; in other words, the first basis vector is long-term and stable, and the second basis vector is instantaneous.

[0219] Referring to FIG. 7, as an example, FIG. 7 is a schematic diagram of the first basis vector and the second basis vector provided by the embodiments of the present application. As shown in FIG. 7, the update period of the first basis vector is greater than the update period of the second basis vector. Specifically, at t1, the second basis vector is the second basis vector 1; at t2, the first basis vector does not change, and the second basis vector is updated to the second basis vector 2.

[0220] The seventh possible case is that the first basis vector is full-band or sub-band common, and the second basis vector is sub-band.

[0221] Referring to FIG. 8, as an example, FIG. 8 is a schematic diagram of the first basis vector and the second basis vector provided by the embodiments of the present application. As shown in FIG. 8, in subband (SB) 1 and SB2, the first basis vector is the same, and the second basis vector is different. Specifically, in SB1, the second basis vector is the second basis vector 1; in SB2, the second basis vector is the second basis vector 2.

[0222] The above is an example and is not limited thereto. For example, the first basis vector and the second basis vector can both be full-band.

[0223] In an eighth possible case, the first basis vector is configured (i.e., configured by the network device) or predefined, and the second basis vector is dynamically determined, such as being fed back by the terminal device to the network device based on a result of channel measurement.

[0224] It can be understood that the above is merely for describing the first basis vector and the second basis vector from different aspects, and does not limit that the above cases can only be used alone and cannot be used in combination. In other words, the above cases can be used in combination.

[0225] Optionally, the method 500 further includes step 540: determining, by the network device, a basis vector of a precoding matrix (or a basis vector of a PMI, or a precoding basis vector, or a precoding basis matrix) based on the first basis vector and the second basis vector.

[0226] For example, the first basis vector and the second basis vector are spatial domain basis vectors, and the network device can determine a spatial domain basis vector of a precoding matrix (or a spatial domain basis matrix) based on the first basis vector and the second basis vector. As an example, the spatial domain basis vector of the precoding matrix includes the first basis vector and the second basis vector.

[0227] For another example, the first basis vector and the second basis vector are frequency domain basis vectors, and the network device can determine a frequency domain basis vector of a precoding matrix (or a frequency domain basis matrix) based on the first basis vector and the second basis vector. As an example, the frequency domain basis vector of the precoding matrix includes the first basis vector and the second basis vector.

[0228] For another example, the first basis vector and the second basis vector are space-frequency basis vectors, and the network device can determine a space-frequency basis vector of a precoding matrix (or a space-frequency basis matrix) based on the first basis vector and the second basis vector. As an example, the space-frequency basis vector of a channel matrix corresponding to the precoding matrix includes the first basis vector and the second basis vector.

[0229] Further optionally, the network device determines the basis vector of the precoding matrix based on the first basis vector and the second basis vector, including at least the following two implementation manners. The network device directly determines the basis vector of the precoding matrix based on the first basis vector and the second basis vector; or the network device determines the basis vector of a channel matrix corresponding to the precoding matrix based on the first basis vector and the second basis vector. Details of the above implementation manners are described below.

[0230] In order to facilitate description and understanding, the schemes of the embodiments of the present application are introduced from multiple aspects. It can be understood that the schemes of different aspects can be combined, referred to, and cited to each other, and details are not described below.

[0231] First, introduce the first base vector related scheme in combination with aspect 1.

[0232] / / Aspect 1, first base vector

[0233] In a possible implementation, the first base vector is determined based on at least one of the following: a sensing signal, a reference signal #2 (i.e., an example of a third reference signal).

[0234] For example, the network device determines the first base vector based on the sensing signal. For example, the network device senses the multipath information (such as the angle, delay, power, polarization, Doppler, etc. of the multipath) of the channel related to the environment, and then determines the first base vector based on the multipath information; then, the network device indicates the first base vector to the terminal device. Optionally, if the network device determines the first base vector based on the sensing signal, the period of the first base vector can be associated with the period of the sensing signal, such as the period of the first base vector being the same as the period of the sensing signal. Wherein the angle can include at least one of the following: horizontal dimension angle of arrival (AOA), horizontal dimension angle of departure (AOD), vertical dimension angle of arrival (ZOA), and vertical dimension angle of departure (ZOD). AOA and ZOA respectively refer to the horizontal and vertical dimensions of the angle of arrival of the signal arriving at the receiving antenna via the wireless channel, and AOD and ZOD respectively refer to the horizontal and vertical dimensions of the angle of departure of the signal transmitted by the transmitting antenna.

[0235] The period of the first basis vector, or the transmission period of the first basis vector (or the reception period of the first basis vector), indicates the value (or size) of the period in which the network device indicates the first basis vector to the terminal device. Similarly, the period of the second basis vector, or the transmission period of the second basis vector (or the reception period of the second basis vector), indicates the value (or size) of the period in which the terminal device transmits (or feeds back, or reports) the second basis vector to the network device. Similarly, the period of the coefficient A, or the transmission period of the coefficient A (or the reception period of the coefficient A), indicates the value (or size) of the period in which the terminal device transmits (or feeds back, or reports) the coefficient A to the network device. Similarly, the period of the reference signal, or the transmission period of the reference signal (or the reception period of the reference signal), indicates the value (or size) of the period in which the network device transmits the reference signal (i.e., the downlink reference signal) to the terminal device, or the value (or size) of the period in which the terminal device transmits the reference signal (i.e., the uplink reference signal) to the network device. The following will not be described in detail. For ease of description, the following will be described in terms of the period of the first basis vector, the period of the second basis vector, and the period of the coefficient A.

[0236] For another example, the network device determines the first basis vector based on the reference signal 2 (e.g., the uplink reference signal). For example, the network device receives the uplink reference signal (e.g., the SRS) from the terminal device, performs channel measurement based on the uplink reference signal to obtain uplink channel information, determines the downlink channel information based on the uplink-downlink channel reciprocity, and determines the first basis vector.

[0237] The above is an example, and the embodiments of the present application are not limited thereto. For example, the network device can also determine the first basis vector based on historical channel data, and then indicates the first basis vector to the terminal device.

[0238] Optionally, the first basis vector is periodic, semi-persistent, or aperiodic. The following describes several possible cases.

[0239] In a first possible case, the first basis vector is periodic. In this case, the network device can periodically indicate the first basis vector to the terminal device.

[0240] Optionally, the period of the first basis vector (denoted as T1) is associated with the first value (denoted as T).

[0241] Wherein, T can be a period of the reference signal #1; or, T can be a period of the reference signal #2; or, T can be a period of the sensing signal. Wherein, the reference signal #2 represents a reference signal used by the network device to determine the first base vector, that is, the network device determines the first base vector based on the reference signal #2. The sensing signal represents a sensing signal used by the network device to determine the first base vector, that is, the network device determines the first base vector based on the sensing signal.

[0242] In a possible implementation, T1 = f(T). Wherein, f() represents a function. For example, T1 = T; for another example, T1 = a*T, a is an integer greater than 1; for another example, T1 = T+β, β is a number greater than 0.

[0243] The above is an example for illustration, and the embodiments of the present application are not limited thereto. For example, T1 and T have an association relationship, and the association relationship exists in the form of a table. T1 associated with T can be determined by T and table lookup.

[0244] Optionally, the method 500 further includes that the network device indicates the period of the first base vector to the terminal device through signaling (such as RRC, or MAC CE, or DCI, etc.).

[0245] In a possible implementation, the network device directly indicates the period of the first base vector.

[0246] In another possible implementation, the network device indirectly indicates the period of the first base vector. For example, the network device indicates T to the terminal device, and the terminal device determines T1 based on the association between T1 and T.

[0247] In a second possible case, the first base vector is semi-static. In this case, the network device semi-statically indicates the first base vector to the terminal device, that is, after the network device configures the information of the semi-static first base vector, the network device will not immediately send the first base vector. The network device will first send an activation signaling to notify the terminal device. After the activation signaling takes effect, the network device will periodically send the first base vector.

[0248] In a third possible case, the first base vector is aperiodic. In this case, the network device aperiodically (or dynamically) indicates the first base vector to the terminal device.

[0249] The above introduces the related scheme of the first base vector in combination with aspect 1, and the following introduces the related scheme of the second base vector in combination with aspect 2.

[0250] / / Aspect 2, second base vector

[0251] As described above, one or more base vectors can be included in the second base vector. As to the number of base vectors included in the second base vector, it can be determined by the terminal device itself, or can be indicated by the network device (e.g., through RRC signaling), or can be predefined, and no limitation is made in this regard.

[0252] Optionally, the second base vector is periodic, or semi-static, or aperiodic. Reference can be made to the foregoing description of the first base vector, and no further description is made herein. Hereinafter, mainly the periodic relationship between the first base vector and the second base vector is described in the case that the second base vector is periodic.

[0253] In one possible implementation, the period of the second base vector is less than or equal to the period of the first base vector.

[0254] Referring to FIG. 9, which is a schematic diagram of the first base vector and the second base vector provided by the embodiments of the present application, as an example. It is assumed that the period of the first base vector is T#1, the period of the second base vector is T#2, and the reference signal #1 is CSI-RS. The period of the second base vector is the same as the period of the CSI-RS, that is, the terminal device feeds back the second base vector to the network device once every time it receives the CSI-RS.

[0255] As shown in (a) of FIG. 9, T#1 is equal to T#2. Specifically, the network device periodically sends the first base vector and the CSI-RS to the terminal device, and the periods are the same. The terminal device determines the second base vector based on the received CSI-RS and the first base vector, and feeds back the second base vector to the network device. The network device can send the first base vector and the CSI-RS to the terminal device at the same time, or can send the first base vector first and then send the CSI-RS, or can send the CSI-RS first and then send the first base vector, and no limitation is made in this regard.

[0256] As shown in (b) of FIG. 9, T#1 is greater than T#2. Specifically, the network device periodically sends the first base vector to the terminal device, and the period is T#1; the network device periodically sends the CSI-RS to the terminal device, and the period is T#2, wherein T#1 is greater than T#2; after receiving the CSI-RS, the terminal device determines the second base vector based on the received CSI-RS and the first base vector, and feeds back the second base vector to the network device.

[0257] Optionally, the second base vector is determined based on the first base vector and the measurement result of the reference signal #1, including that the second base vector is determined based on the first base vector, the measurement result of the reference signal #1, and the first condition. Specifically, the terminal device performs channel measurement based on the reference signal #1, and determines the second base vector based on the result of the channel measurement, the first base vector, and the first condition.

[0258] The first condition can be predefined, indicated by the network device, or preconfigured, and is not limited in this regard.

[0259] As an example, the first condition is that a linear combination of the first basis vector and the second basis vector is a precoding matrix (or approximately a precoding matrix), and / or the vector set composed of the first basis vector and the second basis vector is linearly independent. The linear independence may, for example, be orthogonality, i.e., the vector set composed of the first basis vector and the second basis vector is orthogonal. Several examples are described below.

[0260] Example 1: The first condition is that a linear combination of the first basis vector and the second basis vector is a precoding matrix (or approximately a precoding matrix). Specifically, the terminal device performs channel measurement based on the received reference signal #1 to obtain a plurality of basis vectors; and the terminal device selects, from the plurality of basis vectors, a basis vector that can form a linear combination of the first basis vector as a precoding matrix (or approximately a precoding matrix) as the second basis vector.

[0261] Example 2: The first condition is that the vector set composed of the first basis vector and the second basis vector is linearly independent. Specifically, the terminal device performs channel measurement based on the received reference signal #1 to obtain a plurality of basis vectors; and the terminal device selects, from the plurality of basis vectors, a basis vector that forms a linearly independent vector set with the first basis vector as the second basis vector.

[0262] The above examples are mainly described by taking the linear combination of the first basis vector and the second basis vector as a precoding matrix as an example, and are not limited in this regard. For example, the linear combination of the first basis vector and the second basis vector can also be a channel matrix corresponding to the precoding matrix.

[0263] Further optionally, the terminal device determines the second basis vector in combination with a second condition. For example, the terminal device determines a plurality of basis vectors based on the first basis vector, the measurement result of the reference signal #1, and the first condition, and then determines the second basis vector from the plurality of basis vectors based on the second condition. The second condition can be predefined, indicated by the network device, or preconfigured, and is not limited in this regard.

[0264] As an example, the second condition includes at least one of the following: an angle or correlation between any two basis vectors in the vector set composed of the first basis vector and the second basis vector is greater than or equal to a first threshold value; an angle or correlation between the space corresponding to the first basis vector and the space corresponding to the second basis vector is greater than or equal to a second threshold value; an angle or correlation between the space corresponding to the first basis vector and any basis vector in the second basis vector is greater than or equal to a third threshold value.

[0265] For example, the second condition is that the angle or correlation between any two basis vectors in the vector set composed of the first basis vector and the second basis vector is greater than or equal to a first threshold. Specifically, the terminal device performs channel measurement based on the received reference signal #1 to obtain a plurality of basis vectors; the terminal device selects, from the plurality of basis vectors, basis vectors that are linearly independent of the vector set composed of the first basis vector (for example, referred to as basis vectors #A); and the terminal device selects, from the basis vectors #A, basis vectors that can be partial or all basis vectors as the second basis vectors, and the angle or correlation between any two basis vectors in the vector set composed of the first basis vector and the second basis vector is greater than or equal to the first threshold.

[0266] For another example, the second condition is that the angle or correlation between the space corresponding to the first basis vector and the space corresponding to the second basis vector is greater than or equal to a second threshold. Specifically, the terminal device performs channel measurement based on the received reference signal #1 to obtain a plurality of basis vectors; the terminal device selects, from the plurality of basis vectors, basis vectors that are linearly independent of the vector set composed of the first basis vector (for example, referred to as basis vectors #A); and the terminal device selects, from the basis vectors #A, basis vectors that can be partial or all basis vectors as the second basis vectors, and the angle or correlation between the space corresponding to any one of the second basis vectors and the space corresponding to any one of the first basis vectors is greater than or equal to the second threshold.

[0267] For another example, the second condition is that the angle or correlation between the space corresponding to the first basis vector and the space corresponding to any one of the second basis vectors is greater than or equal to a third threshold. Specifically, the terminal device performs channel measurement based on the received reference signal #1 to obtain a plurality of basis vectors; the terminal device selects, from the plurality of basis vectors, basis vectors that are linearly independent of the vector set composed of the first basis vector (for example, referred to as basis vectors #A); and the terminal device selects, from the basis vectors #A, basis vectors that can be partial or all basis vectors as the second basis vectors, and the angle or correlation between the space corresponding to any one of the second basis vectors and the space corresponding to any one of the first basis vectors is greater than or equal to the third threshold.

[0268] The above various thresholds (for example, the first threshold, the second threshold, and the third threshold) can be predefined, indicated by the network device, or preconfigured, and are not limited in this regard.

[0269] Example 3: The first condition is that the linear combination of the first basis vector and the second basis vector is a precoding matrix (or approximately a precoding matrix), and the vector set composed of the first basis vector and the second basis vector is linearly independent. For this, reference can be made to the above two examples, which will not be described here.

[0270] The above introduces the related scheme of the second basis vector in combination with aspect 2. The following introduces the related scheme of the weighting coefficient in combination with aspect 3.

[0271] / / Aspect 3, weighting coefficient

[0272] Further optionally, the method 500 further includes: the terminal device sending, to the network device, indication information #3 (i.e., an example of the second indication information) used for indicating the coefficient #A (i.e., an example of the weighting coefficient).

[0273] As an example, the coefficient #A includes a weighting coefficient of the first basis vector and a weighting coefficient of the second basis vector. One basis vector can correspond to one weighting coefficient (or a group of weighting coefficients). Taking one basis vector as an example, the weighting coefficient of the basis vector indicates the weight value of the basis vector in the basis vectors of the precoding matrix. As an example, the precoding matrix can be obtained by weighting the first basis vector by using the weighting coefficient of the first basis vector and weighting the second basis vector by using the weighting coefficient of the second basis vector. As another example, the channel matrix corresponding to the precoding matrix can be obtained by weighting the first basis vector by using the weighting coefficient of the first basis vector and weighting the second basis vector by using the weighting coefficient of the second basis vector.

[0274] When the terminal device indicates the weighting coefficients of the first basis vector and the second basis vector, the terminal device can indicate the weighting coefficients, or can indicate quantized values of the weighting coefficients, or can indicate indexes of the quantized values of the weighting coefficients, and the like, which are not limited herein.

[0275] In one possible implementation, the coefficient #A includes a weighting coefficient of part of the basis vectors in the first basis vector and weighting coefficients of all the basis vectors in the second basis vector.

[0276] Specifically, assuming that the first basis vector determined by the terminal device in the step 510 includes N basis vectors, the terminal device can select to report the weighting coefficients of part of the basis vectors (e.g., N1 basis vectors, N1 is an integer greater than 1 or equal to 1 and less than N) in the N basis vectors and the weighting coefficients of all the basis vectors in the second basis vector (or the weighting coefficients of each basis vector in the second basis vector).

[0277] In this case, optionally, the method 500 further includes: the terminal device sending, to the network device, indication information #4 (i.e., an example of the third indication information) used for indicating the N1 basis vectors. For example, the indication information #4 can indicate indexes of the N1 basis vectors; as another example, the indication information #4 can indicate elements included in each basis vector in the N1 basis vectors.

[0278] In another possible implementation, the coefficient #A includes weighting coefficients of all the basis vectors in the first basis vector and weighting coefficients of all the basis vectors in the second basis vector.

[0279] Specifically, assuming that the first base vectors determined by the terminal device in step 510 include N base vectors, the terminal device can directly report the weighting coefficients of the N base vectors and the weighting coefficients (or the weighting coefficients of each base vector in the second base vectors) of all base vectors in the second base vectors.

[0280] The above implementation manners are examples and are not limited thereto. For example, in some cases, such as when the network device indicates to the terminal device that the number of base vectors contained in the second base vectors is W, the terminal device can also report the weighting coefficients of part of the W base vectors and indicate the part of the base vectors to the network device. In addition, in the following embodiments, unless otherwise specified, the "weighting coefficients of the first base vectors" can represent the weighting coefficients of part of the base vectors in the first base vectors, or can also represent the weighting coefficients of all base vectors in the first base vectors. The "weighting coefficients of the second base vectors" can represent the weighting coefficients of part of the base vectors in the second base vectors, or can also represent the weighting coefficients of all base vectors in the second base vectors.

[0281] The terminal device determines the coefficient #A in at least two ways.

[0282] In one possible implementation manner, the terminal device determines the coefficient #A based on the reference signal #1. Specifically, after receiving the reference signal #1, the terminal device can perform channel measurement and determine the second base vectors according to the result of the channel measurement, and determine the weighting coefficients of the first base vectors and the weighting coefficients of the second base vectors according to the result of the channel measurement.

[0283] In another possible implementation manner, the terminal device determines the coefficient #A based on the reference signal #3 (i.e., an example of the second reference signal). Based on this, the method 500 can further include that the network device sends the reference signal #3 to the terminal device, and the terminal device determines the coefficient #A based on the reference signal #3. The reference signal #3 can be a downlink reference signal, such as a CSI-RS.

[0284] The terminal device sends the indication information #3 in at least the following cases.

[0285] In a first possible case, the terminal device periodically feeds back the coefficient #A.

[0286] Assuming that the second base vectors are also periodic, the second base vectors and the coefficient #A can be optionally the same or different in period.

[0287] In one possible implementation manner, the second base vectors and the coefficient #A are the same in period. In this manner, the terminal device can determine the coefficient #A based on the reference signal #1.

[0288] Referring to FIG. 10, as an example, FIG. 10 is a schematic diagram of the second basis vector and the coefficient A, according to an embodiment of the present application. As shown in FIG. 10, it is assumed that the period of the first basis vector is T 1, the period of the second basis vector is T 2, the period of the coefficient A is T 3, and the reference signal 1 is a CSI-RS. Wherein, T 2 and T 3 are the same. Specifically, the network device periodically sends the CSI-RS to the terminal device, and the terminal device determines the second basis vector based on the received CSI-RS and the first basis vector, and feeds back the second basis vector to the network device; in addition, the terminal device determines the coefficient A based on the received CSI-RS, and feeds back the coefficient A to the network device.

[0289] It is assumed that the first basis vector is periodic, as an example, the period of the first basis vector is greater than or equal to the period of the second basis vector, and / or the period of the first basis vector is greater than or equal to the period of the coefficient A. As shown in FIG. 10, as an example, T 1>T 2=T 3.

[0290] Another possible implementation, the periods of the second basis vector and the coefficient A are different. As an example, the period of the second basis vector is greater than the period of the coefficient A. In this way, the terminal device can determine the coefficient A based on the reference signal 3.

[0291] The second basis vector is measured based on the reference signal 1, so the period of the second basis vector can be the same as the period of the reference signal 1; similarly, the coefficient A is measured based on the reference signal 3, so the period of the coefficient A can be the same as the period of the reference signal 3; the period of the second basis vector and the period of the coefficient A are different, which also means that the periods of the reference signal 3 and the reference signal 1 are different. As an example, the period of the reference signal 1 can be greater than the period of the reference signal 3.

[0292] Wherein, the configuration information of the reference signal 3 and the reference signal 1 is the same or different. As an example, the configuration information of the reference signal includes at least one of the following: time domain resource configuration, frequency domain resource configuration, code group configuration, density, frequency domain bandwidth, etc.

[0293] Wherein, the reference signal 3 and the reference signal 1 can belong to the same reference signal resource, such as a CSI-RS resource (CSI-RS resource) or a CSI-RS resource set (CSI-RS resource set); or the reference signal 3 and the reference signal 1 belong to different reference signal resources.

[0294] Referring to FIG. 11, as an example, FIG. 11 is another schematic diagram of the second basis vector and the coefficient #A provided by the embodiments of the present application. As shown in FIG. 11, the period of the first basis vector is T#1, the period of the second basis vector is T#2, the period of the coefficient #A is T#3, the reference signal #1 is CSI-RS #1, and the reference signal #3 is CSI-RS #2. Wherein, T#2 is greater than T#3. Specifically, the network device periodically sends the CSI-RS #1 to the terminal device, and the terminal device determines the second basis vector based on the received CSI-RS #1 and the first basis vector, and feeds back the second basis vector to the network device; in addition, the network device can periodically send the CSI-RS #2 to the terminal device, and the terminal device determines the coefficient #A based on the received CSI-RS #2, and feeds back the coefficient #A to the network device. Wherein, the period of the CSI-RS #1 is greater than the period of the CSI-RS #2. Assuming that the first basis vector is periodic, as an example, the period of the first basis vector is greater than or equal to the period of the second basis vector, and / or the period of the first basis vector is greater than or equal to the period of the coefficient #A. As shown in FIG. 11, as an example, T#1>T#2>T#3.

[0295] The second possible case is that the terminal device feeds back the coefficient #A non-periodically or semi-statically.

[0296] A possible implementation is that the terminal device actively feeds back the coefficient #A to the network device, that is, after measuring the coefficient #A, the terminal device sends the indication information #3 to the network device to indicate the coefficient #A.

[0297] Another possible implementation is that the terminal device feeds back the coefficient #A to the network device based on the indication (or request) of the network device. Optionally, the method 500 further includes: the network device sends the indication information #5 (an example of the fourth indication information) to the terminal device, the indication information #5 being used to indicate the reporting of the coefficient #A; and in response to the indication information #5, the terminal device sends the indication information #3 to the network device, the indication information #3 being used to indicate the coefficient #A.

[0298] Further optionally, when the terminal device feeds back the coefficient #A, the terminal device can feed back in stages (or in time periods).

[0299] As an example, the terminal device feeds back the coefficient #A in two stages. The two stages include a stage 1 and a stage 2.

[0300] In a possible implementation, in stage 1, the terminal device feeds back the weighting coefficient of the first base vector; and in stage 2, the terminal device feeds back the weighting coefficient of the first base vector and the weighting coefficient of the second base vector. That is, the indication information #3 includes first sub-information and second sub-information, the terminal device first sends the first sub-information, and the first sub-information is used to indicate the weighting coefficient of the first base vector; and then the terminal device sends the second sub-information, and the second sub-information is used to indicate the weighting coefficient of the first base vector and the weighting coefficient of the second base vector.

[0301] For example, the terminal device can first send the first sub-information to the network device, that is, the terminal device first feeds back the weighting coefficient of the first base vector; and then, after receiving the request of the network device, the terminal device sends the second sub-information to the network device, that is, feeds back the weighting coefficient of the first base vector and the weighting coefficient of the second base vector. For another example, the terminal device first sends the first sub-information to the network device, that is, the terminal device first feeds back the weighting coefficient of the first base vector; and then, in a case where it is determined to feed back the weighting coefficient of the second base vector to the network device (for example, the terminal device determines that the communication environment is poor, or the terminal device moves, or after X time units, etc.), the terminal device sends the second sub-information to the network device, that is, feeds back the weighting coefficient of the first base vector and the weighting coefficient of the second base vector. Wherein, the X time units are time units after the time unit of sending the first sub-information, for example, assuming that the terminal device sends the first sub-information in time unit #1, the terminal device can send the second sub-information in time unit #2, wherein the time unit #2 is located after the time unit #1, and the time unit #2 and the time unit #1 are separated by X time units, and X is an integer greater than 1 or equal to 1. Based on this, in the case where the communication environment is poor or the terminal device moves, etc., considering that the precoding matrix determined based on the first base vector can be inaccurate, the first stage can be switched to the second stage, and the base vector of the second stage is the first base vector and the second base vector, so that the precoding matrix or the channel matrix corresponding to the precoding matrix can be determined based on the first base vector and the second base vector together, and the accuracy of the precoding matrix can be improved.

[0302] In another possible implementation, in stage 1, the terminal device feeds back the weighting coefficient of the first base vector; and in stage 2, the terminal device feeds back the weighting coefficient of the second base vector. That is, the indication information #3 includes first sub-information and second sub-information, the terminal device first sends the first sub-information, and the first sub-information is used to indicate the weighting coefficient of the first base vector; and then the terminal device sends the second sub-information, and the second sub-information is used to indicate the weighting coefficient of the second base vector.

[0303] For example, the terminal device can first send the first sub-information to the network device, i.e., the terminal device first feeds back the weighting coefficient of the first basis vector; then, after receiving the request of the network device, the terminal device sends the second sub-information to the network device, i.e., feeds back the weighting coefficient of the second basis vector. For another example, the terminal device first sends the first sub-information to the network device, i.e., the terminal device first feeds back the weighting coefficient of the first basis vector; in the case of judging to feed back the weighting coefficient of the second basis vector to the network device (for example, the terminal device judges that the communication environment is deteriorated, or the terminal device moves, or after X time units, etc.), the terminal device sends the second sub-information to the network device, i.e., feeds back the weighting coefficient of the second basis vector.

[0304] Referring to FIG. 12, as an example, FIG. 12 is a schematic diagram of two-stage feedback of weighting coefficients provided by the embodiments of the present application. As shown in FIG. 12, in stage 1, the basis vector of the precoding matrix of stage 1 is the first basis vector, and the terminal device can feed back the weighting coefficient of the first basis vector to the network device; in stage 2, the basis vector of stage 2 is the first basis vector and the second basis vector, and the terminal device feeds back the weighting coefficient of the second basis vector to the network device, or feeds back the weighting coefficients of the first basis vector and the second basis vector to the network device. Based on this, the basis vector of stage 1 (the first basis vector) and the basis vector of stage 2 (the second basis vector and the first basis vector) satisfy the nested structure, based on this structure, when the basis vector needs to be updated, the second basis vector can be fed back, and there is no need to issue all the basis vectors, which can significantly reduce the indication overhead.

[0305] If the terminal device indicates the coefficient #A to the network device, in step 540, the network device determines the basis vector of the precoding matrix based on the first basis vector and the second basis vector, which includes that the network device determines the precoding matrix (or determines the PMI) based on the first basis vector, the second basis vector, and the coefficient #A. In addition, further optionally, the network device can also send data based on the determined precoding matrix, such as precoding processing of the data, and sending the precoding processed data.

[0306] Before starting to introduce the implementation manners, the meanings of the parameters mentioned below are uniformly explained. As an example, L represents the number of spatial domain basis vectors, L is an integer greater than 1 or equal to 1; M represents the number of frequency domain basis vectors, M is an integer greater than 1 or equal to 1; N F represents the number of frequency domain units, N F is an integer greater than 1 or equal to 1; N T represents the number of transmit antenna ports, N T is an integer greater than 1 or equal to 1; N R represents the number of receive antenna ports, N R is an integer greater than 1 or equal to 1. The meanings of the parameters are not described below.

[0307] In a first possible implementation, the network device directly determines the precoding matrix based on the first basis vector, the second basis vector, and the coefficient #A.

[0308] Referring to FIG. 13, as an example, FIG. 13 is a schematic diagram of determining a precoding matrix according to an embodiment of the present application. As shown in FIG. 13, taking the first basis vector and the second basis vector as the spatial domain basis vectors as an example, the first basis vector and the second basis vector can be different column vectors in a spatial domain basis matrix, and the spatial domain basis matrix has a dimension of N T *L; then the spatial domain basis matrix and the coefficient #A (i.e., the weighting coefficient of the first basis vector and the weighting coefficient of the second basis vector) are multiplied to obtain a precoding matrix P (i.e., the spatial frequency matrix is the precoding matrix). The coefficient #A has a dimension of L F *N T *N F .

[0309] Taking N T *L as an example, it can represent that the spatial domain basis matrix has N T rows and L columns; or it can represent that the spatial domain basis matrix has N T columns and L rows, which is not limited. Similarly, other similar implementations are not described herein.

[0310] In a second possible implementation, the network device directly determines channel information (such as a channel matrix H) based on the first basis vector, the second basis vector, and the coefficient #A, and then determines the precoding matrix based on the channel information. Taking the channel information as the channel matrix as an example, since the precoding matrix can be determined based on the channel matrix, the first basis vector and the second basis vector can be understood as the basis vectors of the precoding matrix; or the first basis vector and the second basis vector can also be understood as the basis vectors of the channel matrix corresponding to the precoding matrix. Similarly, the coefficient #A can be understood as the coefficient #A of the precoding matrix; or the coefficient #A can also be understood as the coefficient #A of the channel matrix corresponding to the precoding matrix.

[0311] Referring to FIG. 14, as an example, FIG. 14 is a schematic diagram of determining a precoding matrix according to an embodiment of the present application. As shown in FIG. 14, taking the first basis vector and the second basis vector as the spatial frequency basis vectors as an example, the first basis vector and the second basis vector can be different column vectors in a spatial frequency basis matrix, and the spatial frequency basis matrix has a dimension of (N T *N F )×L; then the spatial frequency basis matrix and the coefficient #A (i.e., the weighting coefficient of the first basis vector and the weighting coefficient of the second basis vector) are multiplied to obtain a channel matrix H, wherein the coefficient #A has a dimension of L R *N T *N F .R ; then the network device can determine a precoding matrix P based on the channel matrix H, where the precoding matrix P is composed of right singular vectors of the channel matrix H.

[0312] The above describes two implementation manners, and embodiments of the present application are not limited thereto. The specific manner of determining the precoding matrix or the channel matrix corresponding to the precoding matrix will be described below in combination with FIG. 15.

[0313] First, the first possible implementation manner will be taken as an example, and several cases will be described in detail.

[0314] In case 1, the first basis vector and the second basis vector are spatial domain basis vectors, and the network device determines a spatial domain matrix based on the first basis vector, the second basis vector, and the coefficient A. In this case, the precoding matrix is a spatial domain matrix or a spatial frequency matrix, for example. The spatial domain matrix can be determined based on a spatial domain basis matrix and a weighting coefficient, for example.

[0315] Referring to FIG. 15, which is a schematic diagram of determining a precoding matrix provided by an embodiment of the present application, for example, in the case where the precoding matrix is a spatial frequency matrix, as shown in (a) of FIG. 15, the first basis vector and the second basis vector can be different column vectors of a spatial domain basis matrix, and when the network device determines the precoding matrix (or determines the PMI, or determines the spatial frequency matrix), the network device can first determine a spatial domain basis matrix (or spatial domain basis vectors) composed of the first basis vector and the second basis vector, where the spatial domain basis matrix has a dimension of N T ×L. F Then, the spatial domain basis matrix and the coefficient A are multiplied to obtain the precoding matrix, where the coefficient A has a dimension of L T ×N F , and the precoding matrix has a dimension of N . For example, each stream corresponds to a spatial frequency matrix. The stream can also be referred to as a layer, which refers to a parallel data stream of a multi-antenna system. Details are not described herein.

[0316] In case 2, the first basis vector and the second basis vector are frequency domain basis vectors, and the network device determines a frequency domain matrix based on the first basis vector, the second basis vector, and the coefficient A. In this case, the precoding matrix is a frequency domain matrix or a spatial frequency matrix, for example. The frequency domain matrix can be determined based on a frequency domain basis matrix and a weighting coefficient, for example.

[0317] For example, in the case where the precoding matrix is a spatial frequency matrix, as shown in (b) of FIG. 15, the first basis vector and the second basis vector can be different row vectors of a frequency domain basis matrix, and when the network device determines the precoding matrix (or determines the PMI, or determines the spatial frequency matrix), the network device can first determine a frequency domain basis matrix (or frequency domain basis vectors) composed of the first basis vector and the second basis vector, where the frequency domain basis matrix has a dimension of M ×N.F ; then, the frequency domain basis matrix and the coefficient #A are multiplied to obtain the precoding matrix. The dimension of the coefficient #A is N T x M, and the dimension of the precoding matrix is N T x N F . As an example, each stream corresponds to a spatial frequency matrix.

[0318] Case 3, the first basis vector and the second basis vector include spatial domain basis vectors and frequency domain basis vectors, and the network device determines a spatial frequency matrix based on the first basis vector, the second basis vector, and the coefficient #A. In this case, as an example, the precoding matrix is a spatial frequency matrix. As an example, the spatial frequency matrix can be determined by the spatial domain basis matrix and / or the frequency domain basis matrix, and the weighting coefficient.

[0319] Taking the spatial frequency matrix as an example, as shown in (d) of FIG. 15, the first basis vector and the second basis vector include different column vectors of the spatial domain basis matrix and different row vectors of the frequency domain basis matrix. When the network device determines the precoding matrix (or determines the PMI, or determines the spatial frequency matrix), the network device can determine a spatial domain basis matrix composed of the first part of the basis vectors in the first basis vector and the first part of the basis vectors in the second basis vector, and the dimension of the spatial domain basis matrix is N T x L; and determine a frequency domain basis matrix composed of the second part of the basis vectors in the first basis vector and the second part of the basis vectors in the second basis vector, and the dimension of the frequency domain basis matrix is M F x N T . As an example, each stream corresponds to a spatial frequency matrix. F

[0320] Next, taking the second possible implementation as an example, the several cases are described in detail.

[0321] Case 1, the first basis vector and the second basis vector are spatial domain basis vectors, and the network device determines a channel matrix H corresponding to the precoding matrix based on the first basis vector, the second basis vector, and the coefficient #A. In this case, as an example, the channel matrix corresponding to the precoding matrix is a spatial domain matrix or a spatial frequency matrix. As an example, the channel matrix H corresponding to the precoding matrix can be determined by the spatial domain basis matrix and the weighting coefficient.

[0322] ​As an example, the channel matrix corresponding to the precoding matrix is a spatial-frequency matrix, as shown in (a') of FIG. 15. The network device determines the channel matrix corresponding to the precoding matrix (or determines the spatial-frequency matrix) as follows. First, the network device determines a spatial basis matrix, which is composed of a first basis vector and a second basis vector. For example, the first basis vector and the second basis vector can be different column vectors of the spatial basis matrix, and the spatial basis matrix has a dimension of N T × L. Then, the network device performs multiplication between the spatial basis matrix and a coefficient #A to obtain the channel matrix H corresponding to the precoding matrix. The coefficient #A has a dimension of L F × N, and the channel matrix corresponding to the precoding matrix has a dimension of N T × N F . As an example, each antenna port (such as a receiving antenna port) corresponds to a spatial-frequency matrix.

[0323] In a second case, the first basis vector and the second basis vector are frequency basis vectors. The network device determines the channel matrix H corresponding to the precoding matrix based on the first basis vector, the second basis vector, and the coefficient #A. In this case, as an example, the channel matrix corresponding to the precoding matrix is a frequency matrix or a spatial-frequency matrix. As an example, the channel matrix H corresponding to the precoding matrix can be determined based on a frequency basis matrix and a weighting coefficient.

[0324] As an example, the channel matrix corresponding to the precoding matrix is a spatial-frequency matrix, as shown in (b') of FIG. 15. The network device determines the channel matrix corresponding to the precoding matrix (or determines the spatial-frequency matrix) as follows. First, the network device determines a frequency basis matrix, which is composed of a first basis vector and a second basis vector. For example, the first basis vector and the second basis vector can be different row vectors of the frequency basis matrix, and the frequency basis matrix has a dimension of M F × N. Then, the network device performs multiplication between the frequency basis matrix and a coefficient #A to obtain the channel matrix H corresponding to the precoding matrix. The coefficient #A has a dimension of N T × M, and the channel matrix corresponding to the precoding matrix has a dimension of N T × N F . As an example, each antenna port (such as a receiving antenna port) corresponds to a spatial-frequency matrix.

[0325] In a third case, the first basis vector and the second basis vector are spatial-frequency basis vectors. The network device determines the channel matrix H corresponding to the precoding matrix based on the first basis vector, the second basis vector, and the coefficient #A. In this case, as an example, the channel matrix corresponding to the precoding matrix is a spatial-frequency matrix. As an example, the channel matrix H corresponding to the precoding matrix can be determined based on a spatial-frequency basis matrix and a weighting coefficient.

[0326] As shown in (c) of FIG. 15, when determining the channel matrix corresponding to the precoding matrix (or determining the spatial-frequency matrix), the network device can first determine a spatial-frequency base matrix, which is composed of the first base vector and the second base vector. For example, the first base vector and the second base vector can be different column vectors of the spatial base matrix, and the spatial-frequency base matrix has a dimension of (N T *N F )×L. Then, the spatial-frequency base matrix and the coefficient #A are multiplied to obtain the channel matrix H corresponding to the precoding matrix. The coefficient #A has a dimension of L×N R , and the channel matrix H corresponding to the precoding matrix has a dimension of (N T *N F )×N R .

[0327] In a case 4, the first base vector and the second base vector include a spatial base vector and a frequency base vector. The network device determines the channel matrix H corresponding to the precoding matrix based on the first base vector, the second base vector, and the coefficient #A. In this case, as an example, the channel matrix H corresponding to the precoding matrix is a spatial-frequency matrix. As an example, the channel matrix H corresponding to the precoding matrix can be determined by the spatial base matrix and / or the frequency base matrix, and the weighting coefficient.

[0328] As shown in (d') of FIG. 15, when determining the channel matrix corresponding to the precoding matrix (or determining the spatial-frequency matrix), the network device can determine a spatial base matrix, which is composed of the first part of the first base vector and the first part of the second base vector. For example, the first part of the first base vector and the first part of the second base vector can be different column vectors of the spatial base matrix, and the spatial base matrix has a dimension of N T ×L. The network device also determines a frequency base matrix, which is composed of the second part of the first base vector and the second part of the second base vector. For example, the first part of the first base vector and the first part of the second base vector can be different row vectors of the frequency base matrix, and the frequency base matrix has a dimension of M×N F . Then, the spatial base matrix, the frequency base matrix, and the coefficient #A are multiplied to obtain the channel matrix H corresponding to the precoding matrix. The coefficient #A has a dimension of L×M, and the channel matrix H corresponding to the precoding matrix has a dimension of N T ×N F . As an example, each antenna port (such as a receiving antenna port) corresponds to a spatial-frequency matrix.

[0329] The above describes several possible cases, and embodiments of the present application are not limited thereto.

[0330] The above mainly takes the terminal device reporting the second base vector as the main point, and introduces the scheme of the embodiments of the present application, which is not limited to this. The network device can also configure the second base vector for the terminal device, which will be described in detail in combination with method 1600. The following is not described in detail, and the related description in method 500 can be referred to, which will not be described hereinafter.

[0331] Referring to FIG. 16, as an example, FIG. 16 is a schematic diagram of a communication method 1600 provided by the embodiments of the present application. The method 1600 shown in FIG. 16 can include the following steps.

[0332] 1610, the terminal device receives a reference signal #4 (i.e. an example of a second reference signal).

[0333] Among them, the reference signal #4 is a downlink reference signal, such as CSI-RS.

[0334] 1620, the terminal device determines a first base vector and a second base vector.

[0335] Among them, the first base vector and the second base vector are used to determine the precoding matrix. For details, please refer to the related description in method 500.

[0336] Among them, the second base vector can be understood as a bias vector (or called a supplementary vector, or called a change amount) of the first base vector. The first base vector and the second base vector are linearly independent, such as orthogonal.

[0337] As an example, the second base vector is determined based on the first base vector. For example, a vector set is predefined or preconfigured, the first base vector and the second base vector are two subsets in the vector set, and the intersection of the two subsets is empty. For another example, a codebook is predefined or preconfigured, the first base vector and the second base vector are two code words in the codebook, in other words, the first base vector and the second base vector correspond to code words with different indexes in the codebook.

[0338] There is no strict order between step 1610 and step 1620, for example, step 1610 and step 1620 can be executed at the same time; or step 1610 can be executed first, and then step 1620 can be executed; or step 1620 can be executed first, and then step 1610 can be executed.

[0339] 1630, the terminal device sends indication information #3, which indicates the coefficient #A.

[0340] Among them, the coefficient #A includes the weighting coefficient of the first base vector (such as the weighting coefficient of part or all base vectors in the first base vector) and the weighting coefficient of the second base vector (such as the weighting coefficient of part or all base vectors in the second base vector).

[0341] Optionally, the method 1600 further includes step 1640: determining, by the network device, the precoding matrix based on the coefficient #A, the first basis vector, and the second basis vector.

[0342] For the first basis vector, the second basis vector, the coefficient #A, the terminal device determining the first basis vector, and the network device determining the precoding matrix, refer to the related description in the method 500. The difference is that, in the method 500, the second basis vector is terminal device level; in the method 1600, the second basis vector can be terminal device level, or can also be terminal device group level. For example, in the method 1600, the first basis vector is terminal device group level, and the second basis vector is terminal device group level or terminal device level basis vector; for another example, the first basis vector is terminal device level basis vector, and the second basis vector is terminal device level basis vector. In addition, in the method 500, the second basis vector is fed back by the terminal device to the network device; in the method 1600, the second basis vector can be fed back by the terminal device to the network device, or can be indicated by the network device to the terminal device.

[0343] Here, mainly introduce the scheme of the terminal device determining the second basis vector. As an example, the terminal device determining the second basis vector can include at least the following implementation manners.

[0344] One possible implementation manner is that the second basis vector is determined by the terminal device itself.

[0345] For example, the terminal device receives a reference signal (such as CSI-RS), and determines the second basis vector based on the measurement result of the reference signal and the first basis vector. For this, refer to the method 500, which is not limited here.

[0346] Another possible implementation manner is that the second basis vector is configured by the network device.

[0347] For example, the network device determines the second basis vector based on the sensing signal. For example, the network device senses the multipath information (such as the angle, time delay, power, polarization, Doppler, etc. of the multipath) of the channel related to the environment, and then determines the second basis vector based on the multipath information; then, the network device indicates the second basis vector to the terminal device. Wherein, the angle can include at least one of the following: AOA, AOD, ZOA, ZOD.

[0348] Another example is that the second basis vector can be a steering vector in the direction of signal propagation; or the second basis vector can be a steering vector in the direction (such as the departure direction, which is determined based on AOD and / or ZOD) of the path or path cluster, which is not limited here.

[0349] In another example, the network device determines the second basis vector based on an uplink reference signal (e.g., SRS). For example, the network device receives the uplink reference signal from the terminal device, performs channel measurement based on the uplink reference signal to obtain uplink channel information, and determines downlink channel information based on uplink-downlink channel reciprocity, and then determines the second basis vector. Optionally, if the network device determines the second basis vector based on the uplink reference signal, the period of the second basis vector can be associated with the period of the uplink reference signal, e.g., the period of the second basis vector is the same as the period of the uplink reference signal.

[0350] In another example, the network device determines the second basis vector based on feedback from the terminal device. For example, the network device sends a downlink reference signal to the terminal device; the terminal device receives the downlink reference signal, performs channel measurement based on the downlink reference signal, determines the second basis vector (referred to as the second basis vector 1 for distinction), and feeds back the second basis vector 1 to the network device; the network device determines the second basis vector (referred to as the second basis vector 2 for distinction) based on the second basis vector 1 fed back by the terminal device, and indicates the second basis vector 2 to the terminal device. The second basis vector 2 can be part of the second basis vector 1, or the second basis vector 2 can be the same as the second basis vector 1. Optionally, if the network device determines the second basis vector based on the feedback from the terminal device, the period of the second basis vector can be associated with the period of the downlink reference signal, e.g., the period of the second basis vector is the same as the period of the downlink reference signal.

[0351] As described above, the first basis vector, the second basis vector, and the coefficient A can be periodic, or semi-static, or non-periodic. In the case where the first basis vector, the second basis vector, and the coefficient A can all be periodic, it is assumed that the period of the first basis vector is T1, the period of the second basis vector is T2 (e.g., the terminal device sends the second basis vector with a period, or the network device indicates the period of the second basis vector to the terminal device), and the period of the coefficient A is T3. As an example, T1, T2, and T3 satisfy any one of the following: T1=T2>T3; or, T1>T2>T3; or, T1>T2=T3.

[0352] The above is an example for illustration, and embodiments of the present application are not limited thereto. For example, the network device can also determine the second basis vector based on historical channel data; then, the network device indicates the second basis vector to the terminal device.

[0353] For ease of understanding, the following describes a specific process suitable for embodiments of the present application, taking CSI-RS as an example. It can be understood that the process described below is only an example for illustration, and embodiments of the present application are not limited thereto. The content not described in detail below can be referred to the description in the foregoing method, and will not be described here.

[0354] Referring to FIG. 17, as an example, FIG. 17 is a schematic diagram of a communication method 1700 provided by the embodiments of the present application. The method 1700 can be used in the method 500 described above. The method 1700 shown in FIG. 17 can include the following steps.

[0355] 1710, the network device indicates the first basis vector to the terminal device.

[0356] That is, in step 1710, the network device sends indication information #1 to the terminal device, where the indication information #1 is used to indicate the first basis vector. Specifically, the network device configures the first basis vector for the terminal device, and the terminal device can determine the first basis vector based on the indication of the network device. For this, please refer to the related description in the method 500.

[0357] Optionally, before 1710, the method 1700 further includes: the network device determines the first basis vector. For example, the network device determines the first basis vector based on a sensing signal or an uplink reference signal, etc.

[0358] 1720, the network device sends a CSI-RS (i.e., an example of the first reference signal) to the terminal device.

[0359] 1730, the terminal device determines a second basis vector based on the CSI-RS and the first basis vector.

[0360] Specifically, the terminal device performs channel measurement based on the CSI-RS, and determines the second basis vector based on the measurement result (i.e., the channel measurement result) of the CSI-RS and the first basis vector. For this, please refer to the related description in the method 500 described above.

[0361] 1740, the terminal device indicates the second basis vector to the network device.

[0362] That is, in step 1740, the terminal device sends indication information #2 to the network device, where the indication information #2 is used to indicate the second basis vector. For this, please refer to the related description in the method 500.

[0363] 1750, the network device determines a basis vector of a precoding matrix (or referred to as a precoding basis vector, or referred to as a basis vector of a PMI) based on the first basis vector and the second basis vector.

[0364] For this, please refer to the related description in the method 500 described above.

[0365] Based on the above technical solution, the network device configures the first basis vector for the terminal device, and the number of basis vectors reported by the terminal device is reduced, thereby reducing the signaling overhead caused by the terminal device feeding back the CSI. Taking the basis vectors of the PMI as the spatial domain basis vectors as an example, according to the existing mode, when the terminal device feeds back the CSI, L spatial domain basis vectors (L is an integer greater than 1) are fed back. By introducing the first basis vector, the first basis vector can be obtained in advance through historical channel data or sensing, and the network device pre-configures the first basis vector to the terminal device. In this way, the terminal device can not feed back the first basis vector, that is, the terminal device can feed back the basis vectors (i.e., the second basis vectors) other than the first basis vectors in the L spatial domain basis vectors. In this way, the feedback overhead can be reduced. In addition, compared with directly determining the basis vectors of the PMI based on the first basis vector, determining the basis vectors of the PMI based on the first basis vector and the second basis vectors reported by the terminal device can improve the accuracy of the CSI.

[0366] Referring to FIG. 18, FIG. 18 is a schematic diagram of a communication method 1800 provided by the embodiments of the present application, as an example. The method 1800 can be used in the method 500 described above, and can also be used in the method 1600 described above. The method 1800 can be used in the scenario in which the terminal device determines the second basis vector by itself. The method 1800 shown in FIG. 18 can include the following steps.

[0367] 1810, the network device indicates the first basis vector to the terminal device.

[0368] 1820, the network device sends the CSI-RS to the terminal device.

[0369] 1830, the terminal device determines the second basis vector and the coefficient #A based on the CSI-RS.

[0370] The coefficient #A includes the weighting coefficients of the first basis vector (i.e., the weighting coefficients of all basis vectors in the first basis vector) and the weighting coefficients of the second basis vector (i.e., the weighting coefficients of all basis vectors in the second basis vector). Specifically, the terminal device performs channel measurement based on the CSI-RS, determines the second basis vector based on the first basis vector based on the result of the channel measurement; and determines the weighting coefficients of the first basis vector and the weighting coefficients of the second basis vector based on the result of the channel measurement.

[0371] 1840, the terminal device indicates the second basis vector to the network device.

[0372] 1850, the terminal device indicates the coefficient #A to the network device.

[0373] That is, the terminal device sends the indication information #3 to the network device, and the indication information #3 is used to indicate the coefficient #A. For this, reference can be made to the related description in the method 500.

[0374] There is no strict sequence between step 1840 and step 1850, for example, step 1840 and step 1850 can be executed simultaneously, such as carried in the same signaling; or step 1840 can be executed first, and then step 1850 is executed; or step 1850 can be executed first, and then step 1840 is executed.

[0375] 1860, the network device determines the precoding matrix based on the first basis vector, the second basis vector, and the coefficient #A.

[0376] The method 1800 can refer to the related description in the method 1700, which will not be repeated here.

[0377] Based on the above technical solution, by configuring the first basis vector for the terminal device by the network device, the number of basis vectors reported by the terminal device will be reduced, reducing the signaling overhead caused by the terminal device feeding back the CSI. In addition, compared with directly determining the basis vector of the PMI based on the first basis vector, using the first basis vector and the second basis vector reported by the terminal device to determine the basis vector of the PMI can improve the accuracy of the CSI. In addition, the terminal device also feeds back the weighting coefficient of the first basis vector and the second basis vector, so that the network device can determine the precoding information (such as the precoding matrix) of the terminal device based on the feedback of the terminal device.

[0378] Referring to FIG. 19, as an example, FIG. 19 is a schematic diagram of a communication method 1900 provided by an embodiment of the present application. The method 1900 can be used in the method 1600 described above. The method 1900 can be used in the scenario where the network device configures the second basis vector for the terminal device. The method 1900 shown in FIG. 19 can include the following steps.

[0379] 1910, the network device indicates the first basis vector to the terminal device.

[0380] 1920, the network device indicates the second basis vector to the terminal device.

[0381] There is no strict sequence between step 1910 and step 1920, for example, step 1910 and step 1920 can be executed simultaneously, such as carried in the same signaling; or step 1910 can be executed first, and then step 1920 is executed; or step 1920 can be executed first, and then step 1910 is executed.

[0382] 1930, the network device sends the CSI-RS to the terminal device.

[0383] There is no strict sequence between steps 1910-1930, for example, steps 1910-1930 can be executed simultaneously, such as being carried in the same signaling; or steps 1910 and 1920 can be executed first, and then step 1930; or step 1930 can be executed first, and then steps 1910 and 1920.

[0384] 1940, the terminal device determines the coefficient #A based on the CSI-RS, the first base vector, and the second base vector.

[0385] The coefficient #A includes the weighting coefficients of the first base vector (i.e., the weighting coefficients of all base vectors in the first base vector) and the weighting coefficients of the second base vector (i.e., the weighting coefficients of all base vectors in the second base vector). Specifically, the terminal device performs channel measurement based on the CSI-RS, and determines the weighting coefficients of the first base vector and the weighting coefficients of the second base vector based on the result of the channel measurement.

[0386] 1950, the terminal device indicates the coefficient #A to the network device.

[0387] 1960, the network device determines the precoding matrix based on the first base vector, the second base vector, and the coefficient #A.

[0388] The method 1900 is similar to the method 1800, except that in the method 1800, the network device configures the first base vector for the terminal device, and the terminal device determines the second base vector based on the first base vector and the CSI-RS; in the method 1900, the network device configures the first base vector and the second base vector for the terminal device.

[0389] Based on the above technical solutions, by configuring the first base vector and the second base vector for the terminal device, the terminal device can not need to feed back the base vector, i.e., the terminal device can feed back the weighting coefficients of the first base vector and the second base vector, which can greatly reduce the feedback overhead of the CSI.

[0390] Referring to FIG. 20, as an example, FIG. 20 is a schematic diagram of a communication method 2000 provided by an embodiment of the present application. The method 2000 can be used in the above method 500, and can also be used in the above method 1600. The method 2000 can be used in the scenario where the terminal device determines the second base vector by itself, and the terminal device feeds back the weighting coefficients of part of the base vectors in the first base vector. The method 2000 shown in FIG. 20 can include the following steps.

[0391] 2010, the network device indicates the first base vector to the terminal device.

[0392] 2020, the network device sends the CSI-RS to the terminal device.

[0393] 2030, the terminal device determines the second basis vector based on the CSI-RS and the first basis vector.

[0394] 2040, the terminal device indicates the second basis vector to the network device.

[0395] 2050, the terminal device indicates part of the basis vectors in the first basis vector to the network device.

[0396] For distinction, the part of the basis vectors is referred to as the first basis vector A.

[0397] In one possible implementation, the terminal device indicates an index of the first basis vector A to the network device.

[0398] In another possible implementation, the terminal device indicates elements included in each basis vector in the first basis vector A to the network device.

[0399] 2060, the terminal device indicates the coefficient #A to the network device.

[0400] The coefficient #A includes a weighting coefficient of the part of the basis vectors in the first basis vector (i.e., a weighting coefficient of the first basis vector A in the first basis vector) and a weighting coefficient of each basis vector in the second basis vector.

[0401] Specifically, the terminal device performs channel measurement based on the CSI-RS, determines the weighting coefficient of the first basis vector A and the weighting coefficient of all the basis vectors in the second basis vector based on a result of the channel measurement, and indicates the weighting coefficient of the first basis vector A and the weighting coefficient of all the basis vectors in the second basis vector to the network device.

[0402] 2070, the network device determines the precoding matrix based on the part of the basis vectors in the first basis vector (i.e., the first basis vector A), the second basis vector, and the coefficient #A.

[0403] The method 2000 is similar to the method 1800, except that in the method 1800, the terminal device feeds back the weighting coefficient of each basis vector in the first basis vector and the weighting coefficient of each basis vector in the second basis vector to the network device; in the method 2000, the terminal device feeds back the weighting coefficient of the part of the basis vectors in the first basis vector (i.e., the first basis vector A) and the weighting coefficient of each basis vector in the second basis vector to the network device, and indicates the part of the basis vectors to the network device. The related description in the method 1800 can be referred to for the part not described in detail in the method 2000.

[0404] Based on the technical scheme, the network device configures the first basis vector for the terminal device, the number of basis vectors reported by the terminal device is reduced, and signaling overhead caused by the terminal device feeding back CSI is reduced. In addition, compared with directly determining the basis vector of the PMI based on the first basis vector, the first basis vector and the second basis vector reported by the terminal device are used to determine the basis vector of the PMI, which can improve the accuracy of the CSI. In addition, the terminal device further feeds back the weighting coefficients of the partial basis vectors in the first basis vector and the second basis vector, so that the weighting coefficients can be used not only for the network device to determine the precoding information (such as a precoding matrix) of the terminal device, but also to reduce the overhead caused by the terminal device feeding back the weighting coefficients.

[0405] Referring to FIG. 21, as an example, FIG. 21 is a schematic diagram of a communication method 2100 provided by an embodiment of the present application. The method 2100 can be used in the method 1600 described above. The method 2100 can be used in a scenario in which the network device configures the second basis vector for the terminal device, and the terminal device feeds back the weighting coefficients of the partial basis vectors in the first basis vector. The method 2100 shown in FIG. 21 can include the following steps.

[0406] 2110, the network device indicates the first basis vector to the terminal device.

[0407] 2120, the network device indicates the second basis vector to the terminal device.

[0408] 2130, the network device sends a CSI-RS to the terminal device.

[0409] 2140, the terminal device determines a coefficient #A based on the CSI-RS, the second basis vector (i.e., all basis vectors in the second basis vector), and the partial basis vectors in the first basis vector (i.e., the first basis vector A).

[0410] 2150, the terminal device indicates the partial basis vectors in the first basis vector (i.e., the first basis vector A) to the network device.

[0411] 2160, the terminal device indicates the coefficient #A to the network device.

[0412] The coefficient #A includes the weighting coefficients of the partial basis vectors in the first basis vector (i.e., the weighting coefficients of the first basis vector A in the first basis vector) and the weighting coefficients of each basis vector in the second basis vector.

[0413] 2170, the network device determines a precoding matrix based on the partial basis vectors in the first basis vector (i.e., the first basis vector A), the second basis vector (i.e., all basis vectors in the second basis vector), and the coefficient #A.

[0414] There is no strict sequence between the above steps. For example, step 2110 and step 2120 can be executed simultaneously or sequentially. For another example, step 2160 and step 2170 can be executed simultaneously or sequentially.

[0415] The method 2100 is similar to the method 1900, except that in the method 1900, the terminal device feeds back the weighting coefficients of each basis vector in the first basis vector and the weighting coefficients of each basis vector in the second basis vector to the network device; in the method 2100, the terminal device feeds back the weighting coefficients of part of the basis vectors (i.e., the first basis vector A) in the first basis vector and the weighting coefficients of each basis vector in the second basis vector to the network device, and indicates the part of the basis vectors to the network device.

[0416] Based on the above technical solution, by configuring the first basis vector and the second basis vector for the terminal device by the network device, the terminal device can not need to feed back the basis vectors, i.e., the terminal device feeds back the weighting coefficients of part of the basis vectors in the first basis vector and the second basis vector, which can greatly reduce the feedback overhead of the CSI.

[0417] In the above, the method provided by the embodiments of the present application is described in detail in combination with FIGS. 5 to 21. In the following, the apparatus provided by the embodiments of the present application is described in detail in combination with FIGS. 22 to 24. It should be understood that the description of the apparatus embodiments corresponds to the description of the method embodiments, and therefore, the content not described in detail can be referred to the method embodiments described above, which will not be described here for brevity.

[0418] Referring to FIG. 22, as an example, FIG. 22 is a schematic diagram of a communication apparatus 2200 provided by the embodiments of the present application. The communication apparatus 2200 includes a transceiver unit 2210 and a processing unit 2220. The transceiver unit 2210 can be used to implement the corresponding communication function. The transceiver unit 2210 can also be referred to as a communication interface or a communication unit. The processing unit 2220 can be used for processing, such as determining a precoding matrix, etc.

[0419] Optionally, the apparatus 2200 further includes a storage unit, which can be used to store instructions and / or data. The processing unit 2220 can read the instructions and / or data in the storage unit, so that the apparatus implements the foregoing method embodiments.

[0420] In a first possible design of the apparatus 2200, the apparatus 2200 can be a terminal device in the foregoing embodiments, and can implement the steps or procedures performed by the terminal device in the foregoing method embodiments. In this case, the transceiver 2210 can be configured to perform the operations related to the transceiving (e.g., operations of transmitting and / or receiving data or messages) of the terminal device in the foregoing method embodiments, and the processing unit 2220 can be configured to perform the operations related to the processing (or operations other than the transceiving) of the terminal device in the foregoing method embodiments.

[0421] In a possible implementation, the processing unit 2220 is configured to determine the first basis vectors, the transceiver 2210 is configured to receive the first reference signal, and the transceiver 2210 is further configured to transmit the first indication information, where the first indication information is used to indicate the second basis vectors, and the second basis vectors are determined based on the first basis vectors and the measurement result of the first reference signal, and the first basis vectors and the second basis vectors are used to determine the precoding matrix.

[0422] Optionally, the transceiver 2210 is further configured to transmit the second indication information, where the second indication information is used to indicate the weighting coefficients, and the weighting coefficients include the weighting coefficients of the part or all of the basis vectors in the first basis vectors and / or the weighting coefficients of all the basis vectors in the second basis vectors.

[0423] Optionally, the weighting coefficients include the weighting coefficients of the part or all of the basis vectors in the first basis vectors and the weighting coefficients of all the basis vectors in the second basis vectors, the second indication information includes first sub-information and second sub-information, and the transceiver 2210 is further configured to transmit the second indication information, where the second indication information is used to indicate the weighting coefficients, including that the transceiver 2210 is further configured to transmit the first sub-information, where the first sub-information is used to indicate the weighting coefficients of the part or all of the basis vectors in the first basis vectors; and transmit the second sub-information, where the second sub-information is used to indicate the weighting coefficients of all the basis vectors in the second basis vectors, or the second sub-information is used to indicate the weighting coefficients of the part or all of the basis vectors in the first basis vectors and the weighting coefficients of all the basis vectors in the second basis vectors.

[0424] Optionally, in the case where the weighting coefficients include the weighting coefficients of the part of the basis vectors in the first basis vectors, the transceiver 2210 is further configured to transmit the third indication information, where the third indication information is used to indicate the part of the basis vectors.

[0425] Optionally, the transceiver 2210 is further configured to receive the second reference signal, and the weighting coefficients are determined based on the measurement result of the second reference signal.

[0426] Optionally, the transceiver 2210 is further configured to receive the fourth indication information, where the fourth indication information is used to indicate the reporting of the weighting coefficients.

[0427] Optionally, the transceiver 2210 is further configured to receive fifth indication information, the fifth indication information being used to indicate the first base vector. Optionally, the processing unit 2220 is configured to determine the first base vector according to the fifth indication information.

[0428] Optionally, the transceiver 2210 is further configured to receive sixth indication information, the sixth indication information being used to indicate the reporting of the second base vector.

[0429] In another possible implementation, the transceiver 2210 is configured to receive a second reference signal; the processing unit 2220 is configured to determine a first base vector and a second base vector, the first base vector and the second base vector being used to determine a precoding matrix, the second base vector being a bias vector of the first base vector; the transceiver 2210 is further configured to send second indication information, the second indication information being used to indicate a weighting coefficient, the weighting coefficient being determined based on a measurement result of the second reference signal, the weighting coefficient including: a weighting coefficient of part of base vectors or all base vectors in the first base vector, and / or a weighting coefficient of all base vectors in the second base vector.

[0430] Optionally, the second indication information includes first sub-information and second sub-information, the transceiver 2210 is further configured to send the second indication information, the second indication information being used to indicate the weighting coefficient, including: the transceiver 2210 is further configured to send the first sub-information, the first sub-information being used to indicate the weighting coefficient of part of base vectors or all base vectors in the first base vector; and send the second sub-information, the second sub-information being used to indicate the weighting coefficient of all base vectors in the second base vector, or the second sub-information being used to indicate the weighting coefficient of part of base vectors or all base vectors in the first base vector and the weighting coefficient of all base vectors in the second base vector.

[0431] Optionally, in the case where the weighting coefficient includes the weighting coefficient of part of base vectors in the first base vector, the transceiver 2210 is further configured to send third indication information, the third indication information being used to indicate the part of base vectors.

[0432] Optionally, the transceiver 2210 is further configured to receive fourth indication information, the fourth indication information being used to indicate the reporting of the weighting coefficient.

[0433] Optionally, the transceiver 2210 is further configured to receive fifth indication information, the fifth indication information being used to indicate the first base vector.

[0434] Optionally, the transceiver 2210 is further configured to receive seventh indication information, the seventh indication information being used to indicate the second base vector.

[0435] In a second possible design, the apparatus 2200 can be a network device in the preceding embodiments, and the apparatus 2200 can implement the steps or procedures performed by the network device in the preceding method embodiments. In this case, the transceiver 2210 can be configured to perform the operations related to transceiving (e.g., operations of transmitting and / or receiving data or messages) of the network device in the preceding method embodiments, and the processor 2220 can be configured to perform the operations related to processing or operations other than transceiving (e.g., operations other than transmitting and / or receiving data or messages) of the network device in the preceding method embodiments.

[0436] In a possible implementation, the transceiver 2210 is configured to transmit a first reference signal, and the transceiver 2210 is further configured to receive first indication information, where the first indication information is used to indicate a second basis vector, and the second basis vector is determined based on a first basis vector and a measurement result of the first reference signal, and the first basis vector and the second basis vector are used to determine a precoding matrix.

[0437] Optionally, the transceiver 2210 is further configured to receive second indication information, where the second indication information is used to indicate a weighting coefficient, and the weighting coefficient includes: a weighting coefficient of part of basis vectors or all of the basis vectors in the first basis vector, and / or a weighting coefficient of all of the basis vectors in the second basis vector.

[0438] Optionally, the weighting coefficient includes the weighting coefficient of part of the basis vectors or all of the basis vectors in the first basis vector, and the weighting coefficient of all of the basis vectors in the second basis vector, and the second indication information includes first sub-information and second sub-information. The transceiver 2210 is further configured to receive the second indication information, where the second indication information is used to indicate the weighting coefficient, including: the transceiver 2210 is further configured to receive the first sub-information, where the first sub-information is used to indicate the weighting coefficient of part of the basis vectors or all of the basis vectors in the first basis vector; and the transceiver 2210 is further configured to receive the second sub-information, where the second sub-information is used to indicate the weighting coefficient of all of the basis vectors in the second basis vector, or the second sub-information is used to indicate the weighting coefficient of part of the basis vectors or all of the basis vectors in the first basis vector and the weighting coefficient of all of the basis vectors in the second basis vector.

[0439] Optionally, the transceiver 2210 is further configured to transmit request information, where the request information is used to request the weighting coefficient of part of the basis vectors or all of the basis vectors in the first basis vector, and / or the weighting coefficient of all of the basis vectors in the second basis vector.

[0440] Optionally, in a case where the weighting coefficient includes the weighting coefficient of part of the basis vectors in the first basis vector, the transceiver 2210 is further configured to receive third indication information, where the third indication information is used to indicate the part of the basis vectors.

[0441] Optionally, the transceiver 2210 is further configured to receive a second reference signal, and the weighting coefficient is determined based on a measurement result of the second reference signal.

[0442] Optionally, the transceiver 2210 is further configured to send fourth indication information, where the fourth indication information is used to indicate the reported weighting coefficients.

[0443] Optionally, the processing unit 2220 is further configured to determine the precoding matrix based on the weighting coefficients, the first basis vectors, and the second basis vectors.

[0444] Optionally, the transceiver 2210 is further configured to send fifth indication information, where the fifth indication information is used to indicate the first basis vectors.

[0445] Optionally, the transceiver 2210 is further configured to send sixth indication information, where the sixth indication information is used to indicate the reported second basis vectors.

[0446] In another possible implementation, the transceiver 2210 is further configured to send a second reference signal; and the transceiver 2210 is further configured to receive second indication information, where the second indication information is used to indicate the weighting coefficients, the weighting coefficients are determined based on measurement results of the second reference signal, and the weighting coefficients include weighting coefficients of part or all of the first basis vectors and / or weighting coefficients of all of the second basis vectors, the first basis vectors and the second basis vectors are used to determine a precoding matrix, and the second basis vectors are offset vectors of the first basis vectors.

[0447] Optionally, the second indication information includes first sub-information and second sub-information, and the transceiver 2210 is further configured to receive the second indication information, including: the transceiver 2210 is further configured to receive the first sub-information, where the first sub-information is used to indicate the weighting coefficients of part or all of the first basis vectors; and the transceiver 2210 is further configured to receive the second sub-information, where the second sub-information is used to indicate the weighting coefficients of all of the second basis vectors, or the second sub-information is used to indicate the weighting coefficients of part or all of the first basis vectors and the weighting coefficients of all of the second basis vectors.

[0448] Optionally, the transceiver 2210 is further configured to send request information, where the request information is used to request the weighting coefficients of part or all of the first basis vectors and / or the weighting coefficients of all of the second basis vectors.

[0449] Optionally, in a case where the weighting coefficients include the weighting coefficients of part of the first basis vectors, the transceiver 2210 is further configured to receive third indication information, where the third indication information is used to indicate the part of the basis vectors.

[0450] Optionally, the transceiver 2210 is further configured to send fourth indication information, where the fourth indication information is used to indicate the reported weighting coefficients.

[0451] Optionally, the transceiver 2210 is further configured to send fifth indication information, where the fifth indication information is used to indicate the first basis vector.

[0452] Optionally, the transceiver 2210 is further configured to send seventh indication information, where the seventh indication information is used to indicate the second basis vector.

[0453] It should be understood that the specific process in which each unit performs the corresponding steps described above has been described in detail in the method embodiments described above, and for the sake of brevity, it will not be repeated here.

[0454] It should also be understood that the apparatus 2200 herein is embodied in the form of functional units. The term "unit" herein can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (for example, a shared processor, a dedicated processor, or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combination of logic circuitry and / or other suitable components that support the described functions. In an alternative example, those skilled in the art can understand that the apparatus 2200 can be embodied as the communication device in the above embodiments, and can be used to execute the processes and / or steps corresponding to the communication device in each of the method embodiments described above. To avoid repetition, it will not be repeated here.

[0455] The apparatus 2200 of each of the above schemes has the function of implementing the corresponding steps performed by the communication device (such as a terminal device, and such as a network device) in the above methods. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions; for example, the transceiver unit can be replaced by a transceiver (for example, the sending unit in the transceiver unit can be replaced by a transmitter, and the receiving unit in the transceiver unit can be replaced by a receiver), and other units, such as the processing unit, can be replaced by a processor, which respectively performs the transceiving operations and related processing operations in each of the method embodiments.

[0456] In addition, the transceiver unit 2210 described above can also be a transceiver circuit (for example, it can include a receiving circuit and a sending circuit), and the processing unit can be a processing circuit.

[0457] It should be noted that the apparatus in FIG. 22 can be a communication device (such as a terminal device, and such as a network device) in the above embodiments, or a chip or a chip system, for example, a system on chip (SoC). Wherein, the transceiver unit can be an input / output circuit, a communication interface; the processing unit is a processor or microprocessor or integrated circuit integrated on the chip. It is not limited here.

[0458] Referring to FIG. 23, as an example, FIG. 23 is a schematic diagram of another communication apparatus 2300 provided by the embodiments of the present application. The apparatus 2300 includes a processor 2310, and the processor 2310 is coupled to a memory 2320. The memory 2320 is configured to store computer programs or instructions and / or data. The processor 2310 is configured to execute the computer programs or instructions stored in the memory 2320, or read the data stored in the memory 2320, to perform the methods in the above method embodiments.

[0459] Optionally, the processor 2310 is one or more.

[0460] Optionally, the memory 2320 is one or more.

[0461] Optionally, the memory 2320 is integrated with the processor 2310, or is separately arranged.

[0462] Optionally, as shown in FIG. 23, the apparatus 2300 further includes a transceiver 2330 configured to receive and / or send signals. For example, the processor 2310 is configured to control the transceiver 2330 to receive and / or send signals.

[0463] As an example, the processor 2310 can have the functions of the processing unit 2220 shown in FIG. 22, the memory 2320 can have the functions of a storage unit, and the transceiver 2330 can have the functions of the transceiving unit 2210 shown in FIG. 22.

[0464] As an example, the apparatus 2300 is configured to implement the operations performed by the communication apparatus (such as a terminal device, or a network device) in the above method embodiments.

[0465] For example, the processor 2310 is configured to execute the computer programs or instructions stored in the memory 2320, to implement the related operations of the communication apparatus in the above method embodiments.

[0466] It should be understood that the processor mentioned in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), ASIC, field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0467] It should also be appreciated that the memory referenced in the embodiments described herein can be volatile memory and / or non-volatile memory. Among others, the non-volatile memory can be read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM), or flash memory. The volatile memory can be random access memory (RAM). For example, the RAM can be used as an external cache. By way of example, and not limitation, RAM includes forms of: static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0468] It should be noted that when the processor is a general processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated in the processor.

[0469] It should also be noted that the memory described herein is intended to include, but not be limited to, these and any other suitable type of memory.

[0470] Referring to FIG. 24, as an example, FIG. 24 is a schematic diagram of a chip system 2400 provided by an embodiment of the present application. The chip system 2400 (or also can be referred to as a processing system) includes a logic circuit 2410 and an input / output interface 2420.

[0471] The logic circuit 2410 can be a processing circuit in the chip system 2400. The logic circuit 2410 can be coupled with a storage unit, and invoke instructions in the storage unit, so that the chip system 2400 can implement the methods and functions of the embodiments of the present application. The input / output interface 2420 can be an input / output circuit in the chip system 2400, and output processed information of the chip system 2400, or input data or signaling information to be processed into the chip system 2400.

[0472] As an option, the chip system 2400 is configured to implement operations performed by a communication apparatus (e.g., a terminal device, or a network device) in the above method embodiments.

[0473] For example, the logic circuit 2410 is configured to implement processing-related operations performed by a communication apparatus (e.g., a terminal device, or a network device) in the above method embodiments; and the input / output interface 2420 is configured to implement sending and / or receiving-related operations performed by a communication apparatus (e.g., a terminal device, or a network device) in the above method embodiments.

[0474] The embodiments of the present application further provide a computer readable storage medium, having stored thereon a computer program or instructions for implementing the method performed by a communication apparatus (e.g., a terminal device, or a network device) in the above method embodiments. For example, the computer program or instructions, when executed by a communication apparatus, enable the communication apparatus (e.g., a terminal device, or a network device) to perform the above method (e.g., the method 500, the method 1600, the method 1700, the method 1800, the method 1900, the method 2000, or the method 2100).

[0475] The embodiments of the present application further provide a computer program product, containing instructions, which, when executed by a computer, implement the method performed by a communication apparatus (e.g., a terminal device, or a network device) in the above method embodiments. For example, the computer program or instructions, when executed by a communication apparatus, enable the communication apparatus (e.g., a terminal device, or a network device) to perform the above method (e.g., the method 500, the method 1600, the method 1700, the method 1800, the method 1900, the method 2000, or the method 2100).

[0476] The embodiments of the present application further provide a communication system, which comprises the terminal device and / or the network device in the above embodiments. For example, the system comprises the terminal device and the network device in the embodiment of FIG. 5. For another example, the system comprises the terminal device and the network device in the embodiment of FIG. 16. For another example, the system comprises the terminal device and the network device in the embodiment of FIG. 17. For another example, the system comprises the terminal device and the network device in the embodiment of FIG. 18. For another example, the system comprises the terminal device and the network device in the embodiment of FIG. 19. For another example, the system comprises the terminal device and the network device in the embodiment of FIG. 20. For another example, the system comprises the terminal device and the network device in the embodiment of FIG. 21.

[0477] The explanations and beneficial effects of the related contents in any of the above provided devices can refer to the corresponding method embodiments provided above, and will not be repeated here.

[0478] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented by other means. For example, the apparatus embodiments described above are only illustrative, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0479] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable apparatus. For example, the computer can be a personal computer, a server, a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transferred from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media sets. The available media can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD), etc. For example, the foregoing available media includes but is not limited to: a variety of media that can store program codes such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0480] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method characterized by comprising: The method comprises: determining a first basis vector; receiving a first reference signal; sending first indication information, the first indication information being used for indicating a second basis vector, the second basis vector being determined based on the first basis vector and a measurement result of the first reference signal, the first basis vector and the second basis vector being used for determining a precoding matrix.

2. The method of claim 1, wherein, The method further comprises: sending second indication information, the second indication information being used for indicating a weighting coefficient, the weighting coefficient comprising: a weighting coefficient of part of basis vectors or all of the basis vectors in the first basis vector, and / or, a weighting coefficient of all of the basis vectors in the second basis vector.

3. The method according to claim 2, wherein the weighting coefficient is determined based on the measurement result of the first reference signal; or the method further comprises: receiving a second reference signal, the weighting coefficient being determined based on a measurement result of the second reference signal.

4. A communication method characterized by comprising: The method comprises: receiving a second reference signal; determining a first basis vector and a second basis vector, the first basis vector and the second basis vector being used for determining a precoding matrix, the second basis vector being an offset vector of the first basis vector; sending second indication information, the second indication information being used for indicating a weighting coefficient, the weighting coefficient being determined based on a measurement result of the second reference signal, the weighting coefficient comprising: a weighting coefficient of part of basis vectors or all of the basis vectors in the first basis vector, and / or, a weighting coefficient of all of the basis vectors in the second basis vector.

5. The method according to any one of claims 2 to 4, characterized in that, The weighting coefficient comprises a weighting coefficient of part of basis vectors or all of the basis vectors in the first basis vector, and a weighting coefficient of all of the basis vectors in the second basis vector, the second indication information comprising first sub-information and second sub-information, the sending of the second indication information, the second indication information being used for indicating a weighting coefficient, comprises: sending the first sub-information, the first sub-information being used for indicating a weighting coefficient of part of basis vectors or all of the basis vectors in the first basis vector; and sending the second sub-information, the second sub-information being used for indicating a weighting coefficient of all of the basis vectors in the second basis vector, or, the second sub-information being used for indicating a weighting coefficient of part of basis vectors or all of the basis vectors in the first basis vector and a weighting coefficient of all of the basis vectors in the second basis vector.

6. The method of claim 5, wherein, The sending of the second sub-information comprises: sending the second sub-information based on request information, the request information being used for requesting a weighting coefficient of part of basis vectors or all of the basis vectors in the first basis vector, and / or, a weighting coefficient of all of the basis vectors in the second basis vector; or sending the second sub-information after X time units, the X time units being time units after time units of sending the first sub-information, X being an integer greater than 1 or equal to 1.

7. The method according to any one of claims 2 to 6, characterized in that, In a case where the weighting coefficient comprises a weighting coefficient of part of basis vectors in the first basis vector, the method further comprises: sending third indication information, the third indication information being used for indicating the part of basis vectors.

8. The method according to any one of claims 2 to 7, characterized in that, Before the sending of the second indication information, the method further comprises: receive fourth indication information, the fourth indication information being used for indicating reporting the weighting coefficients.

9. The method according to any one of claims 1 to 8, characterized in that, The determining the first base vector comprises: The first base vector is determined based on received fifth indication information, the fifth indication information being used for indicating the first base vector.

10. The method according to any one of claims 1 to 9, characterized in that, The transmission period of the first base vector is associated with a first value. The first value is a transmission period of the first reference signal, or the first value is a transmission period of a third reference signal or a sensing signal, the third reference signal being used for measuring the first base vector, and the sensing signal being used for measuring the first base vector.

11. The method according to any one of claims 1 or 2 or 3 or 5 to 10, characterized in that, Before the transmitting the first indication information, the method further comprises: receive sixth indication information, the sixth indication information being used for indicating reporting the second base vector; The transmitting the first indication information comprises: In response to the sixth indication information, the first indication information is transmitted.

12. A communication method, comprising: comprise: transmitting a first reference signal; receive first indication information, the first indication information being used for indicating a second base vector, the second base vector being determined based on a first base vector and a measurement result of the first reference signal, the first base vector and the second base vector being used for determining a precoding matrix.

13. The method of claim 12, wherein, The method further comprises: receive second indication information, the second indication information being used for indicating weighting coefficients, the weighting coefficients comprising: weighting coefficients of part of base vectors or all base vectors in the first base vector, and / or weighting coefficients of all base vectors in the second base vector.

14. A communication method, comprising: comprise: transmitting a second reference signal; receive second indication information, the second indication information being used for indicating weighting coefficients, the weighting coefficients being determined based on a measurement result of the second reference signal, the weighting coefficients comprising: weighting coefficients of part of base vectors or all base vectors in the first base vector, and / or weighting coefficients of all base vectors in the second base vector, the first base vector and the second base vector being used for determining a precoding matrix, and the second base vector being a bias vector of the first base vector.

15. The method according to claim 13 or 14, characterized in that, The weighting coefficients comprise: weighting coefficients of part of base vectors or all base vectors in the first base vector, and weighting coefficients of all base vectors in the second base vector, the second indication information comprising first sub-information and second sub-information, the receiving the second indication information, the second indication information being used for indicating the weighting coefficients, comprising: receive the first sub-information, the first sub-information being used for indicating the weighting coefficients of part of base vectors or all base vectors in the first base vector; and receive the second sub-information, the second sub-information being used for indicating the weighting coefficients of all base vectors in the second base vector, or the second sub-information being used for indicating the weighting coefficients of part of base vectors or all base vectors in the first base vector and the weighting coefficients of all base vectors in the second base vector.

16. The method of claim 15, wherein before receiving the second sub-information, the method further comprises: transmitting request information, the request information being used for requesting the weighting coefficients of part of base vectors or all base vectors in the first base vector, and / or the weighting coefficients of all base vectors in the second base vector; or The receiving the second sub-information comprises: receiving the second sub-information after X time units, the X time units being time units after time units of receiving the first sub-information, and X being an integer greater than 1 or equal to 1.

17. The method according to any one of claims 13 to 16, characterized in that, In a case where the weighting coefficient comprises a weighting coefficient of a partial basis vector in the first basis vector, the method further comprises: receiving third indication information, the third indication information being used for indicating the partial basis vector.

18. The method according to any one of claims 13 to 17, characterized in that, Before receiving the second indication information, the method further comprises: sending fourth indication information, the fourth indication information being used for indicating reporting the weighting coefficient.

19. The method according to any one of claims 12 to 18, characterized in that, The method further comprises: sending fifth indication information, the fifth indication information being used for indicating the first basis vector.

20. The method of any one of claims 12-19, wherein, A sending period of the first basis vector is associated with a first numerical value; The first numerical value is a sending period of the first reference signal, or the first numerical value is a sending period of a third reference signal or a sensing signal, the third reference signal being used for measuring the first basis vector, and the sensing signal being used for measuring the first basis vector.

21. The method according to any one of claims 12 or 13 or 14 or 16 to 20, characterized in that, Before receiving the first indication information, the method further comprises: sending sixth indication information, the sixth indication information being used for indicating reporting the second basis vector.

22. The method of any one of claims 1 to 21, wherein, The first basis vector and the second basis vector satisfy at least one of the following: The first basis vector is a full-band basis vector, and the second basis vector is a full-band basis vector or a sub-band basis vector; or the first basis vector is a sub-band basis vector, and the second basis vector is a sub-band basis vector. The first basis vector is a basis vector at a terminal device group level or a terminal device level, and the second basis vector is a basis vector at a terminal device level. The sending period of the first basis vector is greater than or equal to the sending period of the second basis vector.

23. The method of any one of claims 1 to 22, wherein, The first basis vector and the second basis vector are any one of the following: a discrete Fourier transform (DFT) vector, a right singular vector or a left singular vector of a channel matrix corresponding to a precoding matrix or a precoding matrix, an oversampling DFT vector, a conjugate transpose vector of a DFT vector, a conjugate transpose vector of an oversampling DFT vector, a steering vector, or an orthogonalized steering vector.

24. The method of any one of claims 1 to 23, wherein, The first basis vector and the second basis vector satisfy any one of the following: The first basis vector is a first subset in a vector set, the second basis vector is a second subset in the vector set, and the intersection of the first subset and the second subset is an empty set. The first basis vector is a first code word in a codebook, the second basis vector is a second code word in the codebook, and elements in the first code word and the second code word are different.

25. The method of any one of claims 1 to 24, wherein, The second basis vector is determined based on the first basis vector and a measurement result of the first reference signal, comprising: The second basis vector is determined based on the first basis vector, a measurement result of the first reference signal, and a first condition, the first condition being at least one of the following: A linear combination of the first basis vector and the second basis vector is a precoding matrix. A vector set composed of the first basis vector and the second basis vector is linearly independent. All basis vectors contained in the first basis vectors and the second basis vectors are linearly independent; Any basis vector in the first basis vectors and any basis vector in the second basis vectors are linearly independent.

26. The method of any one of claims 1 to 25, wherein, The first basis vectors and the second basis vectors are any one of: frequency domain basis vectors, spatial domain basis vectors, space-frequency basis vectors.

27. A communications device, characterized by The apparatus comprises a module or unit for performing the method of any one of claims 1 to 26.

28. A communications device, characterized by The apparatus comprises a processor configured to cause the apparatus to perform the method of any one of claims 1 to 26.

29. The apparatus of claim 28, wherein, The apparatus further comprises a memory and / or a communication interface, The memory is coupled to the processor and configured to store computer programs or instructions; The communication interface is coupled to the processor and configured to input and / or output information.

30. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer programs or instructions, which, when executed on the apparatus, cause the apparatus to perform the method of any one of claims 1 to 26.

31. A computer program product, characterised in that, The computer program product comprises computer programs or instructions, which, when executed on the apparatus, cause the apparatus to perform the method of any one of claims 1 to 26.

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