CN108322244B

CN108322244B - Precoding matrix indication feedback method, receiving end and transmitting end

Info

Publication number: CN108322244B
Application number: CN201810281011.XA
Authority: CN
Inventors: 张雷鸣; 吴强; 刘江华; 王建国
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2013-03-08
Filing date: 2013-05-17
Publication date: 2021-08-31
Anticipated expiration: 2033-05-17
Also published as: CN108599819B; CN108322244A; CN104303442B; CN108322243A; CN108599819A; CN108322243B; CN104303442A

Abstract

The invention provides a feedback method, a receiving end and a transmitting end of precoding matrix indication, wherein the method comprises the following steps: the receiving end selects a precoding matrix W from a codebook based on a reference signal, wherein,

theta is described₁And said theta₂Respectively representing the phase difference of the weighted values of the transmission signals of the same transmission layer of the adjacent two antennas in the first antenna group and the second antenna group at the transmitting end

A phase difference representing a transmission signal weight value of the first antenna group and the second antenna group for the same transmission layer and

m is a positive integer, n is a non-negative integer less than M, and θ of at least one precoding matrix in the codebook₁And theta₂Different, the first antenna group and the second antenna group belong to the same multi-antenna system; and the receiving end sends Precoding Matrix Indicator (PMI) to the transmitting end. Therefore, weak correlation of the antenna can be ensured, and precoding precision is effectively improved, so that performance loss is reduced, and system throughput is improved.

Description

Precoding matrix indication feedback method, receiving end and transmitting end

Technical Field

The embodiment of the invention relates to the field of wireless communication, in particular to a feedback method of precoding matrix indication, a receiving end and a transmitting end.

Background

Through a transmission precoding technology and a reception combining technology, a Multiple Input Multiple Output (MIMO) wireless communication system can obtain diversity and array gain. A system utilizing precoding can be represented as

Where y is the received signal vector, H is the channel matrix,

is the precoding matrix, s is the transmitted symbol vector, and n is the measurement noise.

Optimal precoding typically requires that the transmitter has complete knowledge of the Channel State Information (CSI). A common method is that a User Equipment (UE) quantizes an instantaneous CSI and reports the CSI to a Base Station, where the UE includes a Mobile Station (MS), a Relay (Relay), a Mobile phone (Mobile Telephone), a Mobile phone (handset), a portable device (portable Equipment), and the like, and the Base Station includes a Node B (nodeb), a Base Station (BS), an Access Point (Access Point), a Transmission Point (TP), an Evolved Node B (Evolved Node B, eNB), or a Relay (Relay). CSI information reported by an existing Long Term Evolution (LTE) system includes Rank Indicator (RI), Precoding Matrix Indicator (PMI), Channel Quality Indicator (CQI) information, and the like, where the RI and the PMI indicate the number of transmission layers and a Precoding Matrix to be used, respectively. The set of used precoding matrices is generally referred to as a codebook, where each precoding matrix is a codeword in the codebook.

The codebook design used in the existing LTE system is based on the characteristic of strong correlation between antennas. However, as the distance between two antennas having the same polarization direction increases, the correlation between the antennas gradually decreases, and the phase differences of the antenna elements in the codebook based on the strong correlation characteristic between the antennas are kept uniform. Therefore, the existing codebook design cannot be well matched when applied to a scene with a large antenna configuration interval, which causes the precoding precision reduction of the base station according to the PMI information fed back by the UE, thereby causing a large performance loss and reducing the throughput of the system.

Disclosure of Invention

The embodiment of the invention provides a feedback method of precoding matrix indication, a receiving end and a transmitting end, which can improve precoding precision, thereby reducing performance loss and improving system throughput.

In a first aspect, a method for feeding back a precoding matrix indicator is provided, and the method includes: the receiving end selects a precoding matrix W from a codebook based on a reference signal, wherein the precoding matrix W is

Matrix X₁Is according to theta₁Determined, matrix X₂Is according to theta₂And

determined, said theta₁The phase difference represents the weighted value of the transmission signal of the same transmission layer of two adjacent antennas in the first antenna group of the transmitting terminal₂A phase difference representing a weighted value of transmission signals of two adjacent antennas in the second antenna group at the transmitting end for the same transmission layer

A phase difference representing a transmit signal weight value for the same transmission layer for the first and second antenna groups and

m is a positive integer, n is a non-negative integer less than M, and θ of at least one precoding matrix in the codebook₁And theta₂Different, the first antenna group and the second antenna group belong to the same multi-antenna system; and the receiving end sends Precoding Matrix Indicator (PMI) to the transmitting end so that the transmitting end can determine the W according to the PMI.

With reference to the first aspect, in an implementation manner of the first aspect, the receiving end determines a rank indication based on the reference signal, where the rank indication corresponds to a useful number of transmission layers; the receiving end selects a precoding matrix W from a codebook based on a reference signal, and the method comprises the following steps: the receiving end selects the W corresponding to the rank indication from a codebook based on the reference signal.

With reference to the first aspect and any one of the above-described implementations thereof, in another implementation of the first aspect,

when the rank indication is 1, the

Or

When the rank indication is 2, the

Wherein both the α and β are constants.

With reference to the first aspect and any one of the foregoing implementation manners of the first aspect, in another implementation manner of the first aspect, before the receiving end selects a precoding matrix W from a codebook based on a reference signal, the method further includes: the receiving end receives the reference signal sent by the transmitting end; wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

In a second aspect, a method for receiving a precoding matrix indicator is provided, the method comprising: a transmitting end receives a precoding matrix indicator PMI sent by a receiving end; the transmitting terminal determines a precoding matrix W selected by the receiving terminal from a codebook based on a reference signal according to the precoding matrix indicator PMI, wherein the precoding matrix W is selected by the receiving terminal from the codebook based on the reference signal

m is a positive integer, n is a non-negative integer less than M, and θ of at least one precoding matrix in the codebook₁And theta₂Different, the first antenna group and the second antenna group belong to the same multi-antenna system.

With reference to the second aspect, in an implementation manner of the second aspect, the W corresponds to a rank indication, and the rank indication corresponds to a useful number of transmission layers.

With reference to the second aspect and any one of the above-described implementations thereof, in another implementation of the second aspect,

when the rank indication is 1, the

When the rank indication is 2, the

Wherein both the α and β are constants.

With reference to the second aspect and any one of the foregoing implementation manners of the second aspect, in another implementation manner of the second aspect, before the receiving, by the transmitting end, a precoding matrix indicator PMI sent by a receiving end, the method further includes: the transmitting end sends the reference signal to the receiving end so that the receiving end can select a precoding matrix W from a codebook based on the reference signal; wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

In a third aspect, a receiving end is provided, which includes: a selection unit for selecting a precoding matrix W from a codebook based on a reference signal, wherein the precoding matrix W is selected

Indicating that the first antenna group and the second antenna group are for the same transmission layerA phase difference of the weighted values of the transmitted signals and

m is a positive integer, n is a non-negative integer less than M, and θ of at least one precoding matrix in the codebook₁And theta₂Different, the first antenna group and the second antenna group belong to the same multi-antenna system; a sending unit, configured to send a precoding matrix indicator PMI to the transmitting end, so that the transmitting end determines the W according to the PMI.

With reference to the third aspect, in an implementation manner of the third aspect, the receiving end further includes a determining unit, configured to determine a rank indication based on the reference signal, where the rank indication corresponds to a useful number of transmission layers; the selection unit is specifically configured to: selecting a precoding matrix W corresponding to the rank indication determined by the determining unit from a codebook based on a reference signal.

With reference to the third aspect and any one of the foregoing implementation manners of the third aspect, in another implementation manner of the third aspect,

when the rank indication determined by the determining unit is 1,

selected by the selection unit

Or

When the rank indication determined by the determining unit is 2,

selected by the selection unit

Wherein both the α and β are constants.

With reference to the third aspect and any one of the foregoing implementation manners of the third aspect, in another implementation manner of the third aspect, the receiving end further includes a receiving unit, where the receiving unit is configured to receive the reference signal sent by the transmitting end; wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

In a fourth aspect, a transmitting terminal is provided, which includes: a receiving unit, configured to receive a precoding matrix indicator PMI sent by a receiving end; a determining unit, configured to determine a precoding matrix W selected by the receiving end from a codebook based on a reference signal according to the precoding matrix indicator PMI received by the receiving unit, wherein the precoding matrix W is

With reference to the fourth aspect, in an implementation manner of the fourth aspect, the W corresponds to a rank indication, and the rank indication corresponds to a useful number of transmission layers.

In combination with the fourth aspect and any one of the above implementations of the fourth aspect, in another implementation of the fourth aspect,

when the rank indication is 1, the

When the rank indication is 2, the

Wherein both the α and β are constants.

With reference to the fourth aspect and any one of the foregoing implementation manners of the fourth aspect, in another implementation manner of the fourth aspect, the transmitting end further includes a sending unit: the sending unit is configured to send the reference signal to the receiving end, so that the receiving end selects a precoding matrix W from a codebook based on the reference signal; wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

In a fifth aspect, a receiving end is provided, which includes: a processor configured to select a precoding matrix W from a codebook based on a reference signal, wherein the precoding matrix W is selected

Phase representing a transmit signal weight value for the same transmission layer for the first and second antenna groupsIs poor in

M is a positive integer, n is a non-negative integer less than M, and θ of at least one precoding matrix in the codebook₁And theta₂Different, the first antenna group and the second antenna group belong to the same multi-antenna system; a transmitter, configured to send a precoding matrix indicator PMI to the transmitting end, so that the transmitting end determines the W selected by the processor according to the PMI.

With reference to the fifth aspect, in an implementation manner of the fifth aspect, the processor is further configured to: determining a rank indication based on the reference signal, the rank indication corresponding to a useful number of transmission layers; the processor is specifically configured to: selecting the W corresponding to the determined rank indication from a codebook based on a reference signal.

With reference to the fifth aspect and any one of the above-described implementations thereof, in another implementation of the fifth aspect,

the processor selects when the processor determined rank indication is 1

Or

The processor selects when the processor determined rank indication is 2

Wherein both the α and β are constants.

With reference to the fifth aspect and any one of the foregoing implementation manners of the fifth aspect, in another implementation manner of the fifth aspect, the receiving end further includes a receiver, where the receiver is configured to receive the reference signal sent by the transmitting end; wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

In a sixth aspect, there is provided a transmitting terminal comprising: the receiver is used for receiving the precoding matrix indicator PMI sent by the receiving end; a processor for determining a precoding matrix W selected by the receiving end from a codebook based on a reference signal according to the precoding matrix indicator PMI received by the receiver, wherein the precoding matrix W is obtained by the receiving end

With reference to the sixth aspect, in one implementation form of the sixth aspect, the W corresponds to a rank indication, and the rank indication corresponds to a useful number of transmission layers.

With reference to the sixth aspect and any one of the above implementation manners of the sixth aspect, in another implementation manner of the sixth aspect,

when the rank indication is 1, the

When the rank indication is 2, the

Wherein both the α and β are constants.

With reference to the sixth aspect and any one of the foregoing implementation manners of the sixth aspect, in another implementation manner of the sixth aspect, the transmitting end further includes a transmitter, where the transmitter is configured to transmit the reference signal to the receiving end, so that the receiving end selects a precoding matrix W from a codebook based on the reference signal; wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

Based on the above scheme, the user equipment selects a precoding matrix W from a codebook based on a reference signal, wherein,

respectively through theta₁And theta₂A phase difference between two adjacent antennas in the first antenna group and a phase difference between two adjacent antennas in the second antenna group are indicated. Therefore, the base station performs precoding based on the precoding matrix selected from the codebook structure fed back by the user equipment, so that the precoding precision is effectively improved, the performance loss is reduced, and the throughput of the system is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of a method for feeding back a precoding matrix indicator according to an embodiment of the present invention.

Fig. 2 is a flowchart of a method of receiving a precoding matrix indication according to another embodiment of the present invention.

Fig. 3 is a block diagram of a receiving end according to an embodiment of the present invention.

Fig. 4 is a block diagram of a transmitting end according to an embodiment of the present invention.

FIG. 5 is a block diagram of an apparatus of one embodiment of the invention.

Fig. 6 is a block diagram of a receiving end according to another embodiment of the present invention.

Fig. 7 is a block diagram of a transmitting end according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

It should be understood that the solution of the present invention can be applied to various communication systems, such as: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (LTE) System, an Advanced Long Term Evolution (LTE-a) System, a Universal Mobile Telecommunications System (UMTS), and the like.

It should also be understood that, in the embodiment of the present invention, the User Equipment (UE) includes, but is not limited to, a Mobile Station (MS), a Relay (Relay), a Mobile Terminal (Mobile Terminal), a Mobile phone (Mobile Telephone), a handset (handset), a portable device (portable Equipment), and the like, and the User Equipment may communicate with one or more core networks via a Radio Access Network (RAN), for example, the User Equipment may be a Mobile phone (or referred to as a "cellular" phone), a computer with a wireless communication function, and the User Equipment may also be a portable, pocket, handheld, computer-included, or vehicle-mounted Mobile device.

In this embodiment of the present invention, the Base Station may be a Base Transceiver Station (BTS) in GSM or CDMA, a Base Station (NodeB, NB) in WCDMA, an evolved Node B (eNB or e-NodeB) in LTE, or a relay, and the present invention is not limited thereto.

Fig. 1 is a flowchart of a method for feeding back a precoding matrix indicator according to an embodiment of the present invention. The method is performed by the receiving end.

101. The receiving end selects a precoding matrix W from a codebook based on a reference signal, wherein,

determined, theta₁A phase difference theta representing a weighted value of transmission signals of two adjacent antennas in the first antenna group of the transmitting terminal for the same transmission layer₂A phase difference indicating a transmission signal weight value of the same transmission layer for two adjacent antennas in the second antenna group at the transmitting end,

a phase difference representing a weight value of a transmission signal transmitted by the first antenna group and the second antenna group for the same transmission layer

102. And the receiving end sends a Precoding Matrix Indicator (PMI) to the transmitting end so that the transmitting end can acquire a precoding matrix W according to the PMI.

The multi-antenna system refers to a system in which a transmitting end (e.g., a base station) and a receiving end (e.g., a UE) communicate through multiple antennas. Compared with a single-antenna system, the multiple antennas at the transmitting end and the receiving end can form spatial diversity gain or multiplexing gain, and the transmission reliability and the system capacity can be effectively improved. The diversity gain and the multiplexing gain in the multi-antenna system can be generally obtained by a precoding method at a transmitting end and a receiving and combining algorithm at a receiving end. For example, in the LTE system, 4 antennas are used at the transmitting end, and 2 antennas are used at the receiving end.

In addition, the multi-antenna system of the embodiment of the present invention may also be applied to a scenario of multi-point joint transmission, where multi-point joint transmission refers to joint transmission of signals performed by multiple transmitting terminals for the same user, for example, a transmitting terminal a has 2 antennas, a transmitting terminal B also has 2 antennas, and two transmitting terminals perform joint transmission for a receiving terminal at the same time. The signal received by the receiving end can be regarded as a signal transmitted by a 4-antenna base station.

Based on the above scheme, the receiving end selects a precoding matrix W from the codebook based on the reference signal, wherein,

θ₁and theta₂And respectively representing the phase difference of the signal weighted values transmitted by the adjacent two antennas in the first antenna group and the second antenna group aiming at the same transmission layer. Therefore, the transmitting end performs precoding based on the precoding matrix selected from the codebook structure fed back by the receiving end, so that the precoding precision is effectively improved, the performance loss is reduced, and the throughput of the system is improved.

For convenience of description, the transmitting end and the receiving end in the following embodiments will be described by taking a base station as an example, and the receiving end will be described by taking a UE as an example.

It should be noted that the embodiment of the present invention does not limit the type of the reference signal in 101. For example, the CSI may be a Channel State Information Reference Signal (CSI RS), a Demodulation Reference Signal (DM RS), or a Cell-specific Reference Signal (CRS), and the CSI may further include a Channel Quality Indicator (CQI). It should be further noted that the UE may obtain the Resource configuration of the reference signal and obtain the reference signal in the corresponding Resource or subframe by receiving a base station notification (e.g., Radio Resource Control (RRC) signaling or Downlink Control Information (DCI)) or based on the cell identifier ID.

Alternatively, in step 101, the receiving end may obtain a channel estimation value based on the reference signal, calculate channel capacity or throughput or chordal distance based on the channel estimation value, and select a precoding matrix from the codebook according to a criterion predefined by the receiving end, such as a criterion for maximizing channel capacity or throughput or a chordal distance minimization criterion.

Further, the receiving end may also determine a rank indication RI based on the reference signal, the rank indication RI corresponding to the number of useful transmission layers. For example, the UE may obtain the RI based on the port number of the reference signal and the unique value of the allowed RI corresponding to the codebook subset restriction; or the UE acquires a channel estimation value based on the reference signal, and calculates measurement values such as channel capacity or throughput for each allowed rank indication RI value and corresponding precoding matrix based on the channel estimation value; a rank indication RI that optimizes the metric value is selected as the determined rank indication RI. In step 101, the receiving end may select a precoding matrix W corresponding to the rank indication from a codebook based on a reference signal. Specifically, a codebook subset corresponding to the rank indication may be determined from the codebook, and then the precoding matrix W may be selected from the codebook subset, or the precoding matrix W may be directly determined through the rank indication.

Optionally, the codebook subset may be predefined, or the receiving end reports the codebook to the transmitting end, and the transmitting end determines the codebook subset and notifies the receiving end; or the codebook subset may be determined and reported by the receiving end, e.g., the codebook subset restriction may be signaled to the UE by the base station through higher layer signaling, such as RRC signaling. Optionally, in step 102, the UE may send a precoding matrix indicator PMI to the base station through a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH). It should be understood that the embodiments of the present invention are not limited thereto.

In addition, the precoding matrix indicator PMI and the rank indicator RI may be transmitted in the same subframe or different subframes.

It should be understood that matrix X₁May also be according to θ₁And other factors (e.g. amplitude), i.e. X₁Is at least according to theta₁Determining; similarly, matrix X₂Is at least according to theta₂And

it is to be understood that the invention is not limited thereto.

Optionally, as an embodiment, in step 101, the precoding matrix W corresponds to a rank indication, and the rank indication corresponds to a useful number of transmission layers. When the rank indication is greater than or equal to 2, θ₁And theta₂A phase difference of weighted values of transmission signals of two adjacent antennas in the first antenna group and the second antenna group for any one of the plurality of transmission layers may be represented, respectively.

Specifically, in a 4-antenna scenario, when the rank indication is 1, the precoding matrix may be:

alternatively, when the rank indication is 2, the precoding matrix may be:

both alpha and beta are constants and, optionally,

and

the above example is merely exemplary and is not intended to limit the scope of the present invention, and the codebook in the present invention may also be a codebook with a rank indication of other values, and for convenience of description, the codebook with a rank indication of 1 and the codebook with a rank indication of 2 are used as examples in the present invention, and it should be understood that the present invention is not limited thereto.

It should be understood that the codebook is represented in a single codebook structure, and may be represented in a dual codebook structure, which is not limited in the present invention.

Preferably, the embodiment of the present invention is described by taking a 4-antenna scenario as an example, where the 4 antennas are divided into two antenna groups, and each group includes two antennas. It should be understood that the embodiment of the present invention is not limited to this, for example, the embodiment of the present invention may also be applied to a scenario with 8 antennas.

In the 8-antenna scenario, in particular, each of the two antenna groups may include 4 antennas,

when the rank indication is 1, the precoding matrix may be:

alternatively, when the rank indication is 2, the precoding matrix may be:

for convenience of description, the following example will be described with a 4-antenna scenario as an example.

Optionally, in an implementation, taking rank indications as 1 and 2 as an example, when the rank indication is 1, the precoding matrix:

when the rank indication is 2, the precoding matrix:

wherein the content of the first and second substances,

y1 and Y2 are independent P × 1-dimensional column selection vectors, and N is 2^kK is a non-negative integer, m is a non-negative integer less than N, and P is a positive integer less than N. I.e., N is a power of 2 and can take the value 0, 2, 4, 8 … …, etc., m is equal to {0,1, L, N-1}, and P is equal to {0,1, L, N-1 }.

For example, k is 4, i.e., N is 16, m ∈ {0,1, L, N-1} {0,1, L,15}, P is 4, Y1 and Y2 may each be one of the following vectors:

and

namely:

y1 and Y2 may be the same or different.

Suppose that

Namely, it is

Is the first column of matrix X in equation (5), assuming

Namely, it is

Is the second column of the matrix X in the formula (5).

Optionally, in step 102, the receiving end may send a first precoding matrix indicator PMI to the transmitting end₁And a second precoding matrix indication PMI₂I.e. precoding matrix indication PMI comprises PMI₁And PMI₂. Further, the PMIs are transmitted at the same or different time periods₁And PMI₂. Wherein, PMI₁For indicating W₁，PMI₂For indicating W₂ ¹Or W₂ ². In other words, PMI₁And PMI₂May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes).

Alternatively, W₁For a matrix representing the channel characteristics of the wideband, W₂ ¹And W₂ ²Are all matrices representing the channel characteristics of the sub-bands, or W₁For a matrix representing the long-term channel characteristics, W₂ ¹And W₂ ²Are matrices representing short-term channel characteristics. W₂The numbers in the middle superscript represent the rank values. Accordingly, the receiving end may transmit the PMI to the transmitting end at a longer time interval₁Transmitting PMI to a transmitting end at a short time interval₂。

Of course, the receiving end may directly indicate the selected precoding matrix W through one PMI, for example, the codebook has 256 precoding matrices in total, when the PMI sent by the receiving end is 0, the 1 st precoding matrix of the 256 precoding matrices is indicated to the transmitting end, and when the PMI sent by the receiving end is 1, the 2 nd precoding matrix … … of the 256 precoding matrices is indicated to the transmitting end, that is, values of the PMI 0 to 255 respectively correspond to corresponding precoding matrices of the 256 precoding matrices. It should be understood that, in the embodiment of the present invention, a manner of indicating the precoding matrix by the receiving end is not limited.

Optionally, the receiving end may send the precoding matrix indicator PMI to the transmitting end through a physical control channel or a physical shared channel. For example, the UE may transmit the precoding matrix indicator PMI to the base station through a physical uplink control channel or a physical uplink shared channel. It should be understood that the embodiments of the present invention are not limited thereto.

Therefore, according to the embodiment of the invention, the column selection vectors Y1 and Y2 respectively and independently select one column vector in the matrix X, so that the weak correlation of the codebook corresponding to the antenna with larger distance is ensured.

Alternatively, in another implementation, θ₁And theta₂Can be respectively taken as follows:

wherein N is 2^kK is a non-negative integer, a is a positive integer that divides N (e.g., N-16, a-2), M is a positive integer less than N, i is a positive integer less than N₁Is a non-negative integer less than (N/A-1), i₂And i₃Are all positive integers and i₂And i₃Are independent of each other and can be used for,

is a rounded-down operation sign. I.e., N is a power of 2 and can take the values 0, 2, 4, 8 … …, etc., P ∈ {0,1, L, N-1}, i₁∈{0,1,L,N/A-1}。

Optionally, in step 102, the receiving end may send a third precoding matrix indicator PMI to the transmitting end₃And a fourth precoding matrix indication PMI₄I.e. precoding matrix indication PMI comprises PMI₃And PMI₄. Further, the PMIs are transmitted at the same or different time periods₃And PMI₄. Wherein, PMI₃For indicating i₁，PMI₄For indicating i₂And i₃. In particular, PMI₄May be i₂And i₃The joint encoded value of (1). The transmitting end can pass PMI₄Value of and i₂And i₃Determining the corresponding relationship of i₂And i₃. For example, the transmitting end may preset PMI₄And i₂Correspondence relationship, by PMI₄Is determined by the value of₂Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₃(ii) a Similarly, the transmitting end may preset PMI₄And i₃Correspondence relationship, by PMI₄Is determined by the value of₃Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₂。

In other words, PMI₃And PMI₄May have different time domain or frequency domain granularity. Of course, the receiving end may directly indicate the selected precoding matrix W through one PMI. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

It should be understood that, in the embodiment of the present invention, a manner of indicating the precoding matrix by the receiving end is not limited.

Optionally, the receiving end may send the precoding matrix indicator PMI to the transmitting end through a physical control channel or a physical shared channel. It should be understood that the embodiments of the present invention are not limited thereto.

Therefore, the embodiment of the invention can pass through i according to the current channel characteristics₂And i₃Each independently selecting theta₁And theta₂And weak correlation of the codebook corresponding to the antenna with larger distance is ensured.

Alternatively, in another implementation, θ₁And theta₂The values can also be taken as follows:

wherein N is 2^kK is a non-negative integer, A is a positive integer capable of dividing N, P is a positive integer less than N, i₁Is a non-negative integer less than (N/A-1), i₄Is a positive integer less than (PM-1) (e.g., P-4, M-4, i₄<15)，

Mod is the sign of the rounding-down operation. I.e., N is a power of 2 and can take the values 0, 2, 4, 8 … …, etc., P ∈ {0,1, L, N-1}, i₁∈{0,1,L,N/A-1}。

Optionally, in step 102, the receiving end may send a fifth precoding matrix indication PMI to the transmitting end₅And sixth precoding matrix indication PMI₆I.e. precoding matrix indication PMI comprises PMI₅And PMI₆. Further, the PMIs are transmitted at the same or different time periods₅And PMI₆. Wherein, PMI₅For indicating i₁，PMI₆For indicating i₄. In other words, PMI₅And PMI₆May have different time domain or frequency domain granularity. Of course, the receiving end may directly indicate the selected precoding matrix W through one PMI. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Therefore, the embodiment of the invention can pass through i according to the current channel characteristics₄Determining theta₁And theta₂Theta in the selected precoding matrix₁And theta₂The same or different, and the weak correlation of the codebook corresponding to the antenna with larger distance is ensured.

θ₂＝θ₁+Δθ (11)

wherein N is 2^kK is a non-negative integer, m is a non-negative integer less than N, Δ θ ═ 2 π t, and t is less than 1 in absolute terms, e.g., t is 1/8, -1/16, -1/32, 0, 1/32, 1/16, or 1/8, etc.

In step 101, the receiving end may determine θ₁And selection of delta theta (e.g., current channel characteristics) selects the precoding matrix W from the codebook.

Similarly, in step 102, the receiving end may send two precoding matrix indications to the transmitting end, respectively indicating θ₁And Δ θ. Further, the two precoding matrix indicators may also be transmitted at the same or different time periods, in other words, the two precoding matrix indicators may have different time domain or frequency domain granularity. Of course, the receiving end may directly indicate the selected precoding matrix W through one PMI. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Therefore, the embodiment of the invention can pass theta according to the current channel characteristics₁And theta₂The phase deviation delta theta between the antennas can be regulated within a limited variation range, so that the weak correlation of the codebook corresponding to the antenna with larger distance is ensured.

Optionally, in another implementation, taking rank indications as 1 and 2 as an example, when the rank indication is 1, the precoding matrix:

alternatively, the first and second electrodes may be,

wherein the content of the first and second substances,

n₁,n₂,L,n_Pare integers which may be continuous or discontinuous, Y, Y₁' and Y₂' both are P × 1-dimensional column selection vectors, and N is 2^kK is a non-negative integer, m1 is a non-negative integer less than N, and P is a positive integer less than N. I.e., N is a power of 2 and can take the values 0, 2, 4, 8 … …, etc., m1 ∈ {0,1, L, N-1}, P ∈ {0,1, L, N-1 }. For example, k is 4, i.e., N is 16, m1 ∈ {0,1, L, N-1} {0,1, L,15}, α is a constant, and θ' is a real number.

Optionally, P-4, Y, Y₁' and Y₂' may be one of the following vectors, respectively:

and

namely:

optionally, in step 102, the receiving end may send a seventh precoding matrix indicator PMI to the transmitting end₇And eighth precoding matrix indication PMI₈I.e. precoding matrix indication PMI comprises PMI₇And PMI₈. Further, the PMIs are transmitted at the same or different time periods₇And PMI₈. Wherein, PMI₇For indicating W₃，PMI₈For indicating W₄ ¹. In other words, PMI₇And PMI₈May have the same or different time domain or frequency domain granularity (or be based on different subframe periods or sub-bands)Size).

Alternatively, W₃For a matrix representing the channel characteristics of the wideband, W₄ ¹Is a matrix representing the channel characteristics of the sub-bands, or W₃For a matrix representing the long-term channel characteristics, W₄ ¹Is a matrix representing the short-term channel characteristics. Accordingly, the receiving end may transmit the PMI to the transmitting end at a longer time interval₇Transmitting PMI to a transmitting end at a short time interval₈。

When the rank indication is 2, the precoding matrix:

wherein the content of the first and second substances,

n₁,n₂,L,n_Pare integers, and can be continuous or discontinuous, Y₃And Y₄Are all P × 1-dimensional column selection vectors, N ═ 2^kK is a non-negative integer, m1 is a non-negative integer less than N, and P is a positive integer less than N. I.e., N is a power of 2 and can take the values 0, 2, 4, 8 … …, etc., m1 ∈ {0,1, L, N-1}, P ∈ {0,1, L, N-1 }. For example, k is 4, i.e., N is 16, m1 ∈ {0,1, L, N-1} {0,1, L,15}, β is a constant, and θ' is a real number.

Alternatively, when the rank indication is 2, the precoding matrix may also be:

in the above formula (16), θ₁Specifically, the phase difference θ between the two adjacent antennas in the first antenna group at the transmitting end and the transmitting signal weight value of the first transmission layer in the two transmission layers is represented₂Specifically represents the phase difference theta of the weighted values of the signals transmitted by two adjacent antennas in the second antenna group at the transmitting end for the first transmission layer in the two transmission layers₃A phase difference representing a weight value of two adjacent antennas in the first antenna group of the transmitting end for transmitting a signal for the second of the two transmission layers, and theta₄A phase difference representing a transmission signal weight value of two adjacent antennas in the second antenna group at the transmitting end for the second of the two transmission layers. D, Y in the above formula (16)₃，Y₄And

so that two columns in any one precoding matrix in the codebook set are orthogonal to each other.

Wherein, when the rank is 2, Y₃And Y₄Which may be the same or different, are not limited in this respect by the embodiments of the invention.

It should be noted that θ may take any real number, and the value of θ 'in the embodiment of the present invention is not limited, for example, the value of θ' may be 0 or an integer multiple of 2 pi, for example,

θ' may be a positive number and not an integer multiple of 2 π, or may be a negative number and not an integer multiple of 2 π. For example,

or

l is a positive integer and is not an integer multiple of N.

Optionally, P ═ 4, Y₃And Y₄May each be one of the following vectors:

and

namely:

optionally, in step 102, the receiving end may send a ninth precoding matrix indicator PMI to the transmitting end₉And a tenth precoding matrix indication PMI₁₀I.e. precoding matrix indication PMI comprises PMI₉And PMI₁₀. Further, the PMIs are transmitted at the same or different time periods₉And PMI₁₀. Wherein, PMI₉For indicating W₃，PMI₁₀For indicating W₄ ². In other words, PMI₉And PMI₁₀May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes).

Alternatively, W₃For a matrix representing the channel characteristics of the wideband, W₄ ²Are all matrices representing the channel characteristics of the sub-bands, or W₃For a matrix representing the long-term channel characteristics, W₄ ²Is a matrix representing the short-term channel characteristics. Accordingly, the receiving end may transmit the PMI to the transmitting end at a longer time interval₉Transmitting PMI to a transmitting end at a short time interval₁₀。

Of course, the receiving end may directly indicate the selected precoding matrix W through one PMI. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Therefore, through the selection of theta' in the embodiment of the invention, the weak correlation of the codebook corresponding to the antenna with larger distance is ensured.

It should be noted that other equivalent ways of representing the above codebook (or precoding matrix) by other matrices fall within the scope of the present invention. For example, a precoding matrix obtained by row or column permutation on the precoding matrix W in the embodiment of the present invention also falls into the scope of the present invention, for example, different antenna numbers will correspondingly cause row permutation on the precoding matrix.

Fig. 2 is a flowchart of a precoding method according to another embodiment of the present invention. The method of fig. 2 is performed by the transmitting end and corresponds to the method of fig. 1, and thus a description overlapping with the embodiment of fig. 1 will be appropriately omitted.

A transmitting end receives a precoding matrix indicator PMI sent by a receiving end.

202, the transmitting end determines a precoding matrix W selected by the receiving end from the codebook based on the reference signal according to the precoding matrix indicator PMI, wherein,

Based on the scheme, the transmitting end receives the precoding matrix indicator PMI sent by the receiving end and indicates the precoding matrix indicator PMI according to the precoding matrixThe PMI determines that the receiving end selects a precoding matrix W from a codebook based on a reference signal, wherein,

Optionally, the reference signal in step 202 may be a CSI RS, a DM RS, or a CRS, and the CSI may further include a channel quality indicator CQI. It should be further noted that the UE may obtain the resource configuration of the reference signal and obtain the reference signal in the corresponding resource or subframe by receiving a notification (e.g., RRC signaling or DCI) from the base station or based on the cell identification ID.

Optionally, in step 201, the transmitting end may receive the precoding matrix indicator PMI sent by the receiving end through a physical control channel or a physical shared channel. For example, the base station may receive the precoding matrix indication PMI transmitted by the UE through the PUCCH or the PUSCH. It should be understood that the embodiments of the present invention are not limited thereto.

Preferably, the embodiment of the present invention applies a 4-antenna scenario, where 4 antennas are divided into two antenna groups, and each group includes two antennas. It should be understood that the embodiment of the present invention is not limited to this, for example, the embodiment of the present invention may also be applied to an 8-antenna scenario, and the precoding matrix form in the 8-antenna scenario may refer to the above description, which is not described herein again. For convenience of description, the following example will be described with a 4-antenna scenario as an example.

It should be understood that matrix X₁May also be according to θ₁And other factors such as amplitude, i.e. X₁Is at least according to theta₁Determining; similarly, matrix X₂Is at least according to theta₂And

it is to be understood that the invention is not limited thereto.

Optionally, as an embodiment, the precoding matrix W corresponds to a rank indication, and the rank indication corresponds to a useful number of transmission layers, and the rank indication may be determined by a receiving end, for a specific example, refer to the foregoing, and details are not described here again. Specifically, in a 4-antenna scenario, the precoding matrix with rank indication of 1 may be equation (1) above; alternatively, the precoding matrix with rank indication 2 may be the above equation (2).

Optionally, in an implementation manner, in step 202, taking rank indications as 1 and 2 as examples, when the rank indication is 1, the precoding matrix determined by the transmitting end may be equation (3) above; alternatively, when the rank indication is 2, the precoding matrix determined by the transmitting end may be equation (4) above.

and

namely:

y1 and Y2 may be the same or different.

Suppose that

Namely, it is

For the first column of the matrix X in the above equation (5), assume

Namely, it is

Is the second column of the matrix X in the above formula (5).

Optionally, in step 201, the transmitting end receives a first precoding matrix indicator PMI sent by the receiving end₁And a second precoding matrix indication PMI₂Precoding matrix indicator PMI including PMI₁And PMI₂. Further, the PMI sent by the receiving end is received in the same or different time periods₁And PMI₂. In other words, PMI₁And PMI₂May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes). In step 202, the transmitting end transmits according to the PMI₁Determining the W selected by a receiving end from a codebook based on a reference signal₁And according to PMI₂Determining W selected by UE from codebook₂ ¹Or W₂ ²The transmitting end can be according to W₁And W₂ ¹Determining a precoding matrix W, or from W₁And W₂ ²A precoding matrix W is determined.

Alternatively, W₁For a matrix representing the channel characteristics of the wideband, W₂ ¹And W₂ ²Are all matrices representing the channel characteristics of the sub-bands, W₂The numbers of the middle superscript represent the rank values; or W₁For a matrix representing the long-term channel characteristics, W₂ ¹And W₂ ²Are matrices representing short-term channel characteristics. Accordingly, the transmitting end can receive the PMI transmitted by the receiving end at a longer time interval₁Receiving PMI transmitted from a receiving end at a shorter time interval₂。

Certainly, the transmitting end may directly determine the selected precoding matrix W through one PMI sent by the receiving end, for example, the codebook has 256 precoding matrices, when the transmitting end receives that the PMI sent by the receiving end is 0, the transmitting end determines that the receiving end selects the 1 st precoding matrix in the 256 precoding matrices in the codebook, and when the transmitting end receives that the PMI sent by the receiving end is 1, the transmitting end determines that the receiving end selects the 2 nd precoding matrix in the 256 precoding matrices in the codebook, … …, that is, values of the PMI 0 to 255 respectively correspond to corresponding precoding matrices in the 256 precoding matrices. It should be understood that the embodiment of the present invention does not limit the way in which the UE indicates the precoding matrix.

Optionally, the transmitting end may receive the precoding matrix indicator PMI sent by the receiving end through a physical control channel or a physical shared channel. It should be understood that the embodiments of the present invention are not limited thereto.

Alternatively, in another implementation, θ₁And theta₂Can respectively take values of

And

Optionally, in step 201, the transmitting end receives a third precoding matrix indicator PMI sent by the receiving end₃And a fourth precoding matrix indication PMI₄Further, the PMI sent by the receiving end is received in the same or different time periods₃And PMI₄. In step 202, the transmitting end transmits according to the PMI₃Determining i₁According to PMI₄Determining i₂And i₃. In particular, PMI₄May be i₂And i₃The joint encoded value of (1). The transmitting end can pass PMI₄Value of and i₂And i₃Determining the corresponding relationship of i₂And i₃. For example, the transmitting end may preset PMI₄And i₂Correspondence relationship, by PMI₄Is determined by the value of₂Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₃(ii) a Similarly, the transmitting end may preset PMI₄And i₃Correspondence relationship, by PMI₄Is determined by the value of₃Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₂。

In other words, PMI₃And PMI₄May have different time domain or frequency domain granularity. Of course, the transmitting end can directly determine the selected precoding matrix W through one PMI sent by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Alternatively, in another implementation, θ₁And theta₂Can also take the values respectively as

And

Optionally, in step 201, the transmitting end receives a fifth precoding matrix indicator PMI sent by the receiving end₅And sixth precoding matrix indication PMI₆Further, the PMI sent by the receiving end is received in the same or different time periods₅And PMI₆. In step 202, according to PMI₅Determining i₁According to PMI₆Determining i₄. In other words, PMI₅And PMI₆May have different time domain or frequency domain granularity. Of course, the transmitting end can directly determine the selected precoding matrix W through one PMI sent by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

And theta₂＝θ₁+ Δ θ. Wherein N is 2^kK is a non-negative integer, m is a non-negative integer less than N, V θ is 2 π t, and t is less than 1 in absolute terms, e.g., t is 1/8, -1/16, -1/32, 0, 1/32, 1/16, 1/8, or the like.

Similarly, in step 201, the transmitting end may receive two precoding matrix indicators sent by the receiving end, where the two precoding matrix indicators respectively indicate θ₁And Δ θ. Further, the two precoding matrix indicators sent by the receiving end may also be received in the same or different time periods, in other words, the two precoding matrix indicators may have different time domain or frequency domain granularities. The transmitting end can pass through theta₁Determining a precoding matrix W according to the sum delta theta; of course, the transmitting end can directly determine the precoding matrix W selected by the receiving end through one PMI sent by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Optionally, in an implementation manner, in step 202, when the rank indication is 1, the precoding matrix determined by the transmitting end may be the above equation (12) or (13).

Similarly, in step 201, the transmitting end may receive two precoding matrix indicators sent by the receiving end, and the seventh precoding matrix indicator PMI₇And eighth precoding matrix indication PMI₈The two precoding matrix indicators respectively indicate PMI₇And PMI₈Further, the two precoding matrix indicators sent by the receiving end may also be received in the same or different time periods, in other words, the two precoding matrix indicators may have different time domain or frequency domain granularities. In step 202, the transmitting end transmits according to the PMI₇Determining W selected by a receiving end from a codebook based on a reference signal₃And according to PMI₈Determining W selected by UE from codebook₄ ¹The transmitting end can be according to W₃And W₄ ¹A precoding matrix W is determined.

When the rank indication is 2, the precoding matrix determined by the transmitting end may be the above equation (14) or (16).

Similarly, in step 201, the transmitting end may receive two precoding matrix indicators sent by the receiving end, and the ninth precoding matrix indicator PMI₉And a tenth precoding matrix indication PMI₁₀The two precoding matrix indicators respectively indicate PMI₉And PMI₁₀Further, the two precoding matrix indicators sent by the receiving end may also be received in the same or different time periods, in other words, the two precoding matrix indicators may have different time domain or frequency domain granularities. In a step 202, the process is executed,transmitting end according to PMI₉Determining W selected by a receiving end from a codebook based on a reference signal₃And according to PMI₁₀Determining W selected by UE from codebook₄ ²The transmitting end can be according to W₃And W₄ ²A precoding matrix W is determined.

Of course, the transmitting end can directly determine the precoding matrix W selected by the receiving end through one PMI sent by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Fig. 3 is a block diagram of a receiving end according to an embodiment of the present invention. The receiving end 300 includes a selection unit 301 and a transmission unit 302.

A selecting unit 301 for selecting a precoding matrix W from a codebook based on a reference signal, wherein,

determined, theta₁Representing two adjacent days in the first antenna group of the transmitting terminalPhase difference, theta, of line for transmitting signal weighted values for the same transmission layer₂A phase difference indicating a transmission signal weight value of the same transmission layer for two adjacent antennas in the second antenna group at the transmitting end,

A sending unit 302, configured to send a precoding matrix indicator PMI to the transmitting end, so that the transmitting end determines the precoding matrix W selected by the selecting unit 301 according to the PMI.

The multi-antenna system is a system in which a transmitting end and a receiving end communicate with each other through a plurality of antennas. Compared with a single-antenna system, the multiple antennas at the transmitting end and the receiving end can form spatial diversity gain or multiplexing gain, and the transmission reliability and the system capacity can be effectively improved. The diversity gain and the multiplexing gain in the multi-antenna system can be generally obtained by a precoding method at a transmitting end and a receiving and combining algorithm at a receiving end. For example, in the LTE system, 4 antennas are used at the transmitting end, and 2 antennas are used at the receiving end.

The transmitting end can be a base station, and correspondingly, the receiving end can be UE; or the transmitting end may be a UE and correspondingly the receiving end may be a base station. It is to be understood that the embodiments of the present invention are not limited thereto.

The receiving end 300 may implement each step related to the receiving end in the method of fig. 1 to fig. 2, and is not described in detail for avoiding repetition.

Optionally, as an embodiment, the receiving end 300 may further include a determining unit 303, where the determining unit 303 is configured to determine a rank indication based on the reference signal, where the rank indication corresponds to the useful number of transmission layers. The selecting unit 301 is specifically configured to: based on the reference signal, a precoding matrix W corresponding to the rank indication determined by the determining unit 303 is selected from the codebook.

Specifically, when the rank indication determined by determining section 303 is 1, the precoding matrix selected by selecting section 301 may be equation (1) above; alternatively, when the rank indication determined by determining section 303 is 2, the precoding matrix selected by selecting section 301 may be equation (2) above.

Alternatively, in an implementation manner, taking rank indications as 1 and 2 as an example, when the rank indication determined by the determining unit 303 is 1, the precoding matrix selected by the selecting unit 301 may be the above equation (3); alternatively, when the rank indication determined by determining section 303 is 2, the precoding matrix selected by selecting section 301 may be equation (4) above. For specific examples, reference may be made to the above description, which is not repeated herein.

Alternatively, W₁For a matrix representing the channel characteristics of the wideband, W₂ ¹And W₂ ²Are all matrices representing the channel characteristics of the sub-bands, W₂The numbers of the middle superscript represent the rank values; or W₁For a matrix representing the long-term channel characteristics, W₂ ¹And W₂ ²Are matrices representing short-term channel characteristics.

Optionally, the precoding matrix indicator PMI transmitted by the transmitting unit 302 may include a first precoding matrix indicator PMI₁And a second precoding matrix indication PMI₂，PMI₁For indicating W₁，PMI₂For indicating W₂ ¹Or W₂ ². Accordingly, the transmitting end may receive the PMI transmitted by the transmitting unit 302 at a longer time interval₁Receiving the PMI transmitted by the transmitting unit 302 at a shorter time interval₂。

Optionally, in another implementation manner, when the rank indication determined by the determining unit 303 is 1, the precoding matrix selected by the selecting unit 301 may be the above equation (12) or (13), and for a specific example, reference may be made to the above equation, and details are not described here again.

Alternatively, W₃For a matrix representing the channel characteristics of the wideband, W₄ ¹Is a matrix representing the channel characteristics of the sub-bands, or W₃For a matrix representing the long-term channel characteristics, W₄ ¹To indicate short-term channelsA matrix of characteristics.

Optionally, the precoding matrix indicator PMI transmitted by the transmitting unit 302 may include a seventh precoding matrix indicator PMI₇And eighth precoding matrix indication PMI₈，PMI₇For indicating W₃，PMI₈For indicating W₄ ¹. In other words, PMI₇And PMI₈May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes). Accordingly, the transmitting end may receive the PMI transmitted by the transmitting unit 302 at a longer time interval₇Receiving the PMI transmitted by the transmitting unit 302 at a shorter time interval₈。

Optionally, in another implementation manner, when the rank indication determined by the determining unit 303 is 2, the precoding matrix selected by the selecting unit 301 may be the above equation (14) or (16), and for a specific example, reference may be made to the above equation, and details are not described here again.

Alternatively, W₃For a matrix representing the channel characteristics of the wideband, W₄ ²Are all matrices representing the channel characteristics of the sub-bands, or W₃For a matrix representing the long-term channel characteristics, W₄ ²Is a matrix representing the short-term channel characteristics.

Optionally, the precoding matrix indicator PMI transmitted by the transmitting unit 302 may include a ninth precoding matrix indicator PMI₉And a tenth precoding matrix indication PMI₁₀，PMI₉For indicating W₃，PMI₁₀For indicating W₄ ². Accordingly, the transmitting end may receive the PMI transmitted by the transmitting unit 302 at a longer time interval₉Receiving the PMI transmitted by the transmitting unit 302 at a shorter time interval₁₀。

And

Optionally, the precoding matrix indicator PMI transmitted by the transmitting unit 302 may include a third precoding matrix indicator PMI₃And a fourth precoding matrix indication PMI₄，PMI₃For indicating i₁，PMI₄For indicating i₂And i₃In particular, PMI₄May be i₂And i₃The joint encoded value of (1). The transmitting end can pass PMI₄Value of and i₂And i₃Determining the corresponding relationship of i₂And i₃. For example, the transmitting end may preset PMI₄And i₂Correspondence relationship, by PMI₄Is determined by the value of₂Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₃(ii) a Similarly, the transmitting end may preset PMI₄And i₃Correspondence relationship, by PMI₄Is determined by the value of₃Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₂。

And

Optionally, the precoding matrix indicator PMI transmitted by the transmitting unit 302 may include a fifth precoding matrix indicator PMI₅And sixth precoding matrix indication PMI₆The PMI₅For indicating i₁，PMI₆For indicating i₄。

Optionally, as another embodiment, the selecting unit 301 may further be configured to: and performing row permutation or column permutation on the precoding matrix W according to the number of the antenna.

Optionally, as another embodiment, the receiving end 300 may further include a receiving unit 304, where the receiving unit 304 is configured to receive the reference signal sent by the transmitting end. The determining unit 303 is specifically configured to determine a rank indication based on the reference signal received by the receiving unit 304; alternatively, selecting section 301 is specifically configured to select precoding matrix W from the codebook based on the reference signal received by receiving section 304. Wherein the reference signal comprises at least one of: CSI RS, DM RS, CRS, or the like.

Fig. 4 is a block diagram of a transmitting end according to an embodiment of the present invention. The transmitting end 400 of fig. 4 comprises a receiving unit 401 and a determining unit 402.

A receiving unit 401, configured to receive a precoding matrix indicator PMI sent by a receiving end.

A determining unit 402 for determining a precoding matrix W selected by the receiving end from the codebook based on the reference signal according to the precoding matrix indicator PMI received by the receiving unit 401,

Based on the above scheme, the transmitting end receives the precoding matrix indicator PMI sent by the receiving end, determines that the receiving end selects the precoding matrix W from the codebook based on the reference signal according to the precoding matrix indicator PMI, wherein,

The transmitting end 400 may implement various steps related to the transmitting end in the method of fig. 1 to 2, and in order to avoid repetition, the steps are not described in detail.

Optionally, as an embodiment, the precoding matrix W corresponds to a rank indication, and the rank indication corresponds to a useful number of transmission layers.

Specifically, the codebook having the rank indication of 1 may be the above equation (1); alternatively, the codebook having the rank indication of 2 may be the above equation (2).

The codebook of the present invention may also be a codebook with a rank indication of other values, and for convenience of description, a codebook with a rank indication of 1 and a codebook with a rank indication of 2 are used as examples in the present invention, and it should be understood that the present invention is not limited thereto.

Alternatively, in an implementation manner, taking rank indications as 1 and 2 as examples, when the rank indication is 1, the precoding matrix determined by the determining unit 402 may be equation (3) above; alternatively, when the rank indication is 2, the precoding matrix determined by determining section 402 may be equation (4) above. For specific examples, reference may be made to the above description, which is not repeated herein.

Optionally, the precoding matrix indicator PMI that the receiving unit 401 may specifically use for receiving may include a first precoding matrix indicator PMI₁And a second precoding matrix indication PMI₂. Optionally, PMI₁And PMI₂May have the same or different time domain or frequency domain granularity (or based on different subframe periods or subband sizes), the receiving unit 401 may be specifically configured to receive the PMI sent by the receiving end at longer time intervals₁Receiving PMI transmitted from a receiving end at a shorter time interval₂. The determining unit 402 may be specifically configured to: according to PMI₁Determining W selected by a receiving end from a codebook based on a reference signal₁And according to PMI₂Determining W selected from codebook by receiving end₂ ¹Or W₂ ². Correspondingly, the determining unit 402 may be further specifically configured to: according to W₁And W₂ ¹Determining a precoding matrix W, or from W₁And W₂ ²A precoding matrix W is determined.

Of course, the determining unit 402 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiving end and transmitted by the receiving end, where, for example, the codebook has 256 precoding matrices, when the receiving unit 401 receives that the PMI transmitted by the receiving end is 0, the determining unit 402 determines that the receiving end selects the 1 st precoding matrix of the 256 precoding matrices of the codebook, and when the receiving unit 401 receives that the PMI transmitted by the receiving end is 1, the determining unit 402 determines that the receiving end selects the 2 nd precoding matrix of the 256 precoding matrices of the codebook, … …, that is, values of 0 to 255 of the PMI respectively correspond to corresponding precoding matrices of the 256 precoding matrices. It should be understood that the embodiment of the present invention does not limit the way in which the UE indicates the precoding matrix.

Alternatively, the receiving unit 401 of the transmitting end 400 may receive the precoding matrix indicator PMI sent by the receiving end through a physical control channel or a physical shared channel. It should be understood that the embodiments of the present invention are not limited thereto.

Alternatively, in another implementation, when the rank indication is 1, the precoding matrix determined by the determining unit 402 may be the above equation (12) or (13). For specific examples, reference may be made to the above description, which is not repeated herein.

Optionally, the precoding matrix indicator PMI that the receiving unit 401 may specifically use for receiving may include a seventh precoding matrix indicator PMI₇And eighth precoding matrix indication PMI₈. Optionally, PMI₇And PMI₈May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes). The receiving unit 401 may be specifically configured to receive the PMI sent by the receiving end at a longer time interval₇Receiving PMI transmitted from a receiving end at a shorter time interval₈. The determining unit 402 may be specifically configured to: according to PMI₇Determining W selected by a receiving end from a codebook based on a reference signal₁Root of Chinese angelicaAccording to PMI₈Determining W selected from codebook by receiving end₄ ¹. Correspondingly, the determining unit 402 may be further specifically configured to: according to W₁And W₄ ¹A precoding matrix W is determined.

Alternatively, W₃For a matrix representing the channel characteristics of the wideband, W₄ ¹Is a matrix representing the channel characteristics of the sub-bands, or W₃For a matrix representing the long-term channel characteristics, W₄ ¹Is a matrix representing the short-term channel characteristics.

Alternatively, in another implementation, when the rank indication is 2, the precoding matrix determined by the determining unit 402 may be the above equation (14) or (16). For specific examples, reference may be made to the above description, which is not repeated herein.

Optionally, the precoding matrix indicator PMI that the receiving unit 401 may specifically use for receiving may include a ninth precoding matrix indicator PMI₉And a tenth precoding matrix indication PMI₁₀. The receiving unit 401 may be specifically configured to receive the PMI sent by the receiving end at a longer time interval₉Receiving PMI transmitted from a receiving end at a shorter time interval₁₀. The determining unit 402 may be specifically configured to: according to PMI₉Determining W selected by a receiving end from a codebook based on a reference signal₁And according to PMI₁₀Determining W selected from codebook by receiving end₄ ². Correspondingly, the determining unit 402 may be further specifically configured to: according to W₁And W₄ ²A precoding matrix W is determined.

And

Optionally, the receiving unit 401 may be specifically configured to receive a third precoding matrix indicator PMI sent by the receiving end₃And a fourth precoding matrix indication PMI₄Further, the PMI sent by the receiving end is received in the same or different time periods₃And PMI₄. The determining unit 402 may specifically be configured to determine the PMI according to₃Determining i₁According to PMI₄Determining i₂And i₃. In particular, PMI₄May be i₂And i₃Of joint coding value, PMI₄＝P·i₂+i₃. The determining unit 402 may specifically be configured to pass PMI₄Value of and i₂And i₃Determining the corresponding relationship of i₂And i₃。

In other words, PMI₃And PMI₄May have different time domain or frequency domain granularity. Of course, the determining unit 402 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiving unit 401 and transmitted by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

And

Optionally, the receiving unit 401 may be specifically configured to receive a fifth precoding matrix indicator PMI sent by the receiving end₅And sixth precoding matrix indication PMI₆Further, the PMI sent by the receiving end is received in the same or different time periods₅And PMI₆. The determining unit 402 may specifically be configured to determine the PMI according to₅Determining i₁According to PMI₆Determining i₄. In other words, PMI₅And PMI₆May have different time domain or frequency domain granularity. Of course, the determining unit 402 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiving unit 401 and transmitted by the receiving end. Detailed description of the preferred embodimentThe above embodiments can be referred to, and are not described herein again.

Similarly, the receiving unit 401 may be specifically configured to receive two precoding matrix indicators sent by the receiving end, where the two precoding matrix indicators respectively indicate θ₁And Δ θ. Further, the two precoding matrix indicators sent by the receiving end may also be received in the same or different time periods, in other words, the two precoding matrix indicators may have different time domain or frequency domain granularities. The determination unit 402 may be specifically adapted to pass theta₁And Δ θ determines the precoding matrix W. Of course, the determining unit 402 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiving unit 401 and transmitted by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Optionally, as another embodiment, the determining unit 402 may further be configured to: and performing row permutation or column permutation on the precoding matrix W according to the number of the antenna.

Optionally, as another embodiment, the transmitting end 400 may further include a sending unit 403, where the sending unit 403 is configured to send a reference signal to the receiving end, so that the receiving end selects a precoding matrix W from a codebook based on the reference signal. Wherein the reference signal comprises at least one of: CSI RS, DM RS, CRS, or the like.

The embodiment of the invention further provides an embodiment of a device for realizing the steps and the method in the embodiment of the method. Fig. 5 shows an embodiment of a device, in which the device 500 comprises a processor 501, a memory 502, a transmitter 503 and a receiver 504. Processor 501 controls the operation of device 500, and processor 501 may also be referred to as a CPU (Central Processing Unit). Memory 502 may include both read-only memory and random-access memory, and provides instructions and data to processor 501. A portion of the memory 502 may also include non-volatile row random access memory (NVRAM). The processor 501, the memory 502, the transmitter 503 and the receiver 504 are coupled together by a bus system 55, wherein the bus system 510 comprises a power bus, a control bus and a status signal bus in addition to a data bus. For clarity of illustration, however, the various buses are designated in the figure as the bus system 510.

The method disclosed in the above embodiments of the present invention can be applied to the apparatus 500 described above. The processor 501 may be an integrated circuit chip having signal processing capability. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 501.

Further, fig. 6 is a block diagram of a receiving end according to another embodiment of the present invention. The receiving end 600 includes a processor 601 and a transmitter 602.

A processor 601 for selecting a precoding matrix W from a codebook based on a reference signal, wherein,

M is a positive integer, n is a non-negative integer less than M, and θ of at least one precoding matrix in the codebook₁And theta₂Not identical, the first antenna set and the second dayThe wire groups belong to the same multi-antenna system.

A transmitter 602, configured to send a precoding matrix indicator PMI to the transmitting end, so that the transmitting end determines the precoding matrix W selected by the processor 601 according to the PMI.

The receiving end 600 may implement the steps related to the receiving end in the methods of fig. 1 to fig. 2, and will not be described in detail for avoiding repetition.

Optionally, as an embodiment, the processor 601 may be further configured to determine a rank indication based on the reference signal, the rank indication corresponding to a useful number of transmission layers. The processor 601 is specifically configured to: based on the reference signal, a precoding matrix W corresponding to the rank indication is selected from the codebook.

Specifically, when the rank indication determined by processor 601 is 1, the precoding matrix selected by processor 601 may be equation (1) above; alternatively, when the rank indication determined by processor 601 is 2, the precoding matrix selected by processor 601 may be equation (2) above.

Alternatively, in an implementation, taking rank indications as 1 and 2 as an example, when the rank indication determined by the processor 601 is 1, the precoding matrix selected by the processor 601 may be the above equation (3); alternatively, when the rank indication determined by processor 601 is 2, the precoding matrix selected by processor 601 may be equation (4) above. For specific examples, reference may be made to the above description, which is not repeated herein.

Alternatively, W₁For a matrix representing the channel characteristics of the wideband, W₂ ¹And W₂ ²Are all matrices representing the channel characteristics of the sub-bands, W₂The numbers of the middle superscript represent the rank values; or W₁For a matrix representing the long-term channel characteristics, W₂ ¹And W₂ ²Are all matrices representing short-term channel characteristics. Accordingly, the transmitting end can receive the PMI transmitted by the receiving end at a longer time interval₁Receiving PMI transmitted from a receiving end at a shorter time interval₂。

Optionally, the precoding matrix indication PMI transmitted by the transmitter 602 may include a first precoding matrix indication PMI₁And a second precoding matrix indication PMI₂，PMI₁For indicating W₁，PMI₂For indicating W₂ ¹Or W₂ ²。

Optionally, in another implementation manner, when the rank indication determined by the processor 601 is 1, the precoding matrix selected by the processor 601 may be the above equation (12) or equation (13), and a specific example may refer to the above equation, which is not described herein again.

Optionally, the precoding matrix indication PMI transmitted by the transmitter 602 may include a seventh precoding matrix indication PMI₇And eighth precoding matrix indication PMI₈，PMI₇For indicating W₃，PMI₈For indicating W₄ ¹. In other words, PMI₇And PMI₈May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes). Accordingly, the transmitting end may receive the PMI transmitted from the transmitter 602 at a longer time interval₇Receiving the PMI transmitted by the transmitter 602 at a shorter time interval₈。

Optionally, in another implementation manner, when the rank indication determined by the processor 601 is 2, the precoding matrix selected by the processor 601 may be the above equation (14) or equation (16), and a specific example may refer to the above equation, which is not described herein again.

Optionally, the precoding matrix indication PMI transmitted by the transmitter 602 may include a ninth precoding matrix indication PMI₉And a tenth precoding matrix indication PMI₁₀，PMI₉For indicating W₃，PMI₁₀For indicating W₄ ². Accordingly, the transmitting end may receive the PMI transmitted from the transmitter 602 at a longer time interval₉Receiving the PMI transmitted by the transmitter 602 at a shorter time interval₁₀。

And

Optionally, the precoding matrix indication PMI transmitted by the transmitter 602 may include a third precoding matrix indication PMI₃And a fourth precoding matrix indication PMI₄，PMI₃For indicating i₁，PMI₄For indicating i₂And i₃In particular, PMI₄May be i₂And i₃The joint encoded value of (1). The transmitting end can pass PMI₄Value of and i₂And i₃Determining the corresponding relationship of i₂And i₃. For example, the transmitting end may preset PMI₄And i₂Correspondence relationship, by PMI₄Is determined by the value of₂Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₃(ii) a Similarly, the transmitting end may preset PMI₄And i₃Correspondence relationship, by PMI₄Is determined by the value of₃Then according to the relational expression PMI₄＝P·i₂+i₃Determining i₂。

And

Mod is the sign of the rounding-down operation. I.e., N is a power of 2 and can take the values 0, 2, 4,8 … …, etc., P ∈ {0,1, L, N-1}, i₁∈{0,1,L,N/A-1}。

Optionally, the precoding matrix indication PMI transmitted by the transmitter 602 may include a fifth precoding matrix indication PMI₅And sixth precoding matrix indication PMI₆The PMI₅For indicating i₁，PMI₆For indicating i₄。

Optionally, as another embodiment, the processor 601 may further be configured to: and performing row permutation or column permutation on the precoding matrix W according to the number of the antenna.

Optionally, as another embodiment, the receiving end 600 may further include a receiver 603, where the receiver 603 is configured to receive the reference signal sent by the transmitting end. The processor 602 is specifically configured to determine a rank indication based on a reference signal received by the receiver 603; alternatively, processor 6021 is specifically configured to select precoding matrix W from the codebook based on the reference signal received by receiver 603. Wherein the reference signal comprises at least one of: CSI RS, DM RS, CRS, or the like.

Fig. 7 is a block diagram of a transmitting end according to another embodiment of the present invention. The transmitting end 700 of fig. 7 includes a receiver 701 and a processor 702.

A receiver 701, configured to receive a precoding matrix indicator PMI sent by a receiving end.

A processor 702 configured to determine a precoding matrix W selected by the receiving end from the codebook based on the reference signal according to the precoding matrix indicator PMI received by the receiver 701, wherein,

The transmitting end 700 may implement various steps related to the transmitting end in the methods of fig. 1 to 2, and in order to avoid repetition, the steps are not described in detail.

Alternatively, in an implementation, taking rank indications as 1 and 2 as examples, when the rank indication is 1, the precoding matrix determined by the processor 702 may be equation (3) above; alternatively, when the rank indication is 2, the precoding matrix determined by processor 702 may be equation (4) above. For specific examples, reference may be made to the above description, which is not repeated herein.

Optionally, the precoding matrix indication PMI that the receiver 701 may specifically use for reception may include a first precoding matrix indication PMI₁And a second precoding matrix indication PMI₂. Optionally, PMI₁And PMI₂May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes), receiver701 may be specifically used for receiving the PMI transmitted by the receiving end at a longer time interval₁Receiving PMI transmitted from a receiving end at a shorter time interval₂. The processor 702 may be specifically configured to: according to PMI₁Determining W selected by a receiving end from a codebook based on a reference signal₁And according to PMI₂Determining W selected from codebook by receiving end₂ ¹Or W₂ ². Accordingly, the processor 702 may be further specifically configured to: according to W₁And W₂ ¹Determining a precoding matrix W, or from W₁And W₂ ²A precoding matrix W is determined.

Of course, the processor 702 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiver 701 and transmitted by the receiving end, for example, the codebook has 256 precoding matrices, when the receiver 701 receives that the PMI transmitted by the receiving end is 0, the processor 702 determines that the receiving end selects the 1 st precoding matrix in the 256 precoding matrices in the codebook, and when the receiver 701 receives that the PMI transmitted by the receiving end is 1, the processor 702 determines that the receiving end selects the 2 nd precoding matrix in the 256 precoding matrices in the codebook, … …, that is, values of 0 to 255 of the PMI respectively correspond to corresponding precoding matrices in the 256 precoding matrices. It should be understood that the embodiment of the present invention does not limit the way in which the UE indicates the precoding matrix.

Alternatively, the receiver 701 of the transmitting end 700 may receive the precoding matrix indicator PMI sent by the receiving end through a physical control channel or a physical shared channel. It should be understood that the embodiments of the present invention are not limited thereto.

Alternatively, in another implementation, when the rank indication is 1, the precoding matrix determined by the processor 702 may be the above equation (12) or (13). For specific examples, reference may be made to the above description, which is not repeated herein.

Optionally, the precoding matrix indication PMI that the receiver 701 may specifically use for reception may include a seventh precoding matrix indication PMI₇And eighth precoding matrix indication PMI₈. Optionally, PMI₇And PMI₈May have the same or different time domain or frequency domain granularity (or based on different subframe periods or sub-band sizes). The receiver 701 may be specifically configured to receive the PMI transmitted by the receiving end at a longer time interval₇Receiving PMI transmitted from a receiving end at a shorter time interval₈. The processor 702 may be specifically configured to: according to PMI₇Determining W selected by a receiving end from a codebook based on a reference signal₁And according to PMI₈Determining W selected from codebook by receiving end₄ ¹. Accordingly, the processor 702 may be further specifically configured to: according to W₁And W₄ ¹A precoding matrix W is determined.

Alternatively, in another implementation, when the rank indication is 2, the precoding matrix determined by the processor 702 may be the above equation (14) or (16). For specific examples, reference may be made to the above description, which is not repeated herein.

Optionally, the precoding matrix indication PMI that the receiver 701 may specifically use for reception may include a ninth precoding matrix indication PMI₉And a tenth precoding matrix indication PMI₁₀. The receiver 701 mayPMI transmitted by receiving end in specific use for receiving longer time interval₉Receiving PMI transmitted from a receiving end at a shorter time interval₁₀. The processor 702 may be specifically configured to: according to PMI₉Determining W selected by a receiving end from a codebook based on a reference signal₁And according to PMI₁₀Determining W selected from codebook by receiving end₄ ². Accordingly, the processor 702 may be further specifically configured to: according to W₁And W₄ ²A precoding matrix W is determined.

And

Optionally, the receiver 701 may be specifically configured to receive a third precoding matrix indicator PMI sent by the receiving end₃And a fourth precoding matrix fingerPMI₄Further, the PMI sent by the receiving end is received in the same or different time periods₃And PMI₄. The processor 702 may be specifically configured to operate according to PMI₃Determining i₁According to PMI₄Determining i₂And i₃. In particular, PMI₄May be i₂And i₃Of joint coding value, PMI₄＝P·i₂+i₃. The processor 702 may be specifically configured for passing PMIs₄Value of and i₂And i₃Determining the corresponding relationship of i₂And i₃。

In other words, PMI₃And PMI₄May have different time domain or frequency domain granularity. Of course, the processor 702 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiver 701 and transmitted by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

And

Optionally, the receiver 701 may be specifically configured to receive a fifth precoding matrix indicator PMI sent by the receiving end₅And sixth precoding matrix indication PMI₆Further, the PMI sent by the receiving end is received in the same or different time periods₅And PMI₆. The processor 702 may be specifically configured to operate according to PMI₅Determining i₁According to PMI₆Determining i₄. In other words, PMI₅And PMI₆May have different time domain or frequency domain granularity. Of course, the processor 702 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiver 701 and transmitted by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Similarly, the receiver 701 may be specifically configured to receive two precoding matrix indicators sent by the receiving end, where the two precoding matrix indicators respectively indicate θ₁And Δ θ. Further, the two precoding matrix indicators sent by the receiving end may also be received in the same or different time periods, in other words, the two precoding matrix indicators may have different time domain or frequency domain granularities. The processor 702 may be specifically configured to pass theta₁And Δ θ determines the precoding matrix W. Of course, the processor 702 may be specifically configured to directly determine the selected precoding matrix W through one PMI received by the receiver 701 and transmitted by the receiving end. For specific implementation, reference may be made to the above embodiments, which are not described herein again.

Optionally, as another embodiment, the processor 702 may further be configured to: and performing row permutation or column permutation on the precoding matrix W according to the number of the antenna.

Optionally, as another embodiment, the transmitting end 700 may further include a transmitter 703, where the transmitter 703 is configured to transmit a reference signal to the receiving end, so that the receiving end selects the precoding matrix W from the codebook based on the reference signal. Wherein the reference signal comprises at least one of: CSI RS, DM RS, CRS, or the like.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for feeding back a precoding matrix indicator, comprising:

the receiving end selects a precoding matrix W from a codebook based on a reference signal, wherein the precoding matrix W is

determined, said theta₁The phase difference represents the weighted value of the transmission signal of the same transmission layer of two adjacent antennas in the first antenna group of the transmitting terminal₂A phase difference representing a weighted value of transmission signals of two adjacent antennas in the second antenna group of the transmitting end for the same transmission layer

m is a positive integer, n is a non-negative integer less than M, and θ of at least one precoding matrix in the codebook₁And theta₂Different, the first antenna group and the second antenna group belong to the same multi-antenna system;

the receiving end sends Precoding Matrix Indicator (PMI) to the transmitting end;

the receiving end is a base station and the transmitting end is user equipment, or the transmitting end is a base station and the receiving end is user equipment.

2. The method of claim 1, wherein the method further comprises:

the receiving end determines a rank indication based on the reference signal, wherein the rank indication corresponds to a useful transmission layer number;

the receiving end selects a precoding matrix W from a codebook based on the reference signal, and the selecting comprises the following steps:

the receiving end selects the W corresponding to the rank indication from a codebook based on the reference signal.

3. The method of claim 2,

when the rank indication is 1, the

Or

When the rank indication is 2, the

Wherein both the α and β are constants.

4. The method of any of claims 1 to 3, wherein before the receiving end selects a precoding matrix W from a codebook based on a reference signal, the method further comprises:

the receiving end receives the reference signal from the transmitting end, wherein the reference signal comprises at least one of the following: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

5. A receiving end, comprising:

a selection unit for selecting a precoding matrix W from a codebook based on a reference signal, wherein the precoding matrix W is selected

determined, said theta₁The phase difference represents the weighted value of the transmission signal of the same transmission layer of two adjacent antennas in the first antenna group of the transmitting terminal₂Indicating that two adjacent antennas in the second antenna group of the transmitting end transmit signals and add signals for the same transmission layerPhase difference of the weights, said

a sending unit, configured to send a precoding matrix indicator PMI to the transmitting end;

6. The receiving end according to claim 5, wherein the receiving end further comprises a determining unit,

the determining unit is configured to determine a rank indication based on the reference signal, wherein the rank indication corresponds to a useful number of transmission layers;

the selection unit is specifically configured to: selecting a precoding matrix W corresponding to the rank indication determined by the determining unit from a codebook based on the reference signal.

7. The receiving end of claim 6,

when the rank indication determined by the determining unit is 1,

selected by the selection unit

Or

When the rank indication determined by the determining unit is 2,

selected by the selection unit

Wherein both the α and β are constants.

8. The receiving end according to any of claims 5 to 7,

the receiving end further comprises a receiving unit,

the receiving unit is configured to receive the reference signal from the transmitting end, where the reference signal includes at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

9. A receiving end, comprising:

a processor configured to select a precoding matrix W from a codebook based on a reference signal, wherein the precoding matrix W is selected

m is a positive integer, n is less than MNegative integer, theta of at least one precoding matrix in the codebook₁And theta₂Different, the first antenna group and the second antenna group belong to the same multi-antenna system;

a transmitter, configured to transmit a precoding matrix indicator PMI to the transmitting end;

10. The receiving end of claim 9,

the processor is further configured to: determining a rank indication based on the reference signal, the rank indication corresponding to a useful number of transmission layers;

the processor is specifically configured to: selecting the W corresponding to the determined rank indication from a codebook based on the reference signal.

11. The receiving end of claim 10,

the processor selects when the processor determined rank indication is 1

The above-mentioned

Or

The processor selects when the processor determined rank indication is 2

The above-mentioned

Wherein both the α and β are constants.

12. The receiving end according to any of claims 9 to 11, wherein the receiving end further comprises a receiver,

the receiver is configured to receive the reference signal from the transmitting end, where the reference signal includes at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

13. An integrated circuit chip, wherein the integrated circuit chip comprises an integrated circuit configured to:

selecting a precoding matrix W from a codebook based on a reference signal, wherein the precoding matrix W is selected

sending a Precoding Matrix Indicator (PMI) to the transmitting terminal;

the transmitting terminal is user equipment or a base station.

14. The integrated circuit chip of claim 13, wherein the integrated circuit is further to:

determining a rank indication based on the reference signal, the rank indication corresponding to a useful number of transmission layers;

selecting a precoding matrix W corresponding to the determined rank indication from a codebook based on the reference signal.

15. The integrated circuit chip of claim 14,

when the rank indication is 1, the rank indication is set to 1,

the above-mentioned

Or

When the rank indication is 2, the rank indication is,

the above-mentioned

Wherein both the α and β are constants.

16. The integrated circuit chip of any of claims 13 to 15, wherein the integrated circuit is further to: receiving the reference signal from the transmitting end, wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).

17. A computer-readable storage medium having stored thereon a computer program or instructions which, when executed, perform the steps of:

sending a Precoding Matrix Indicator (PMI) to the transmitting terminal;

the transmitting terminal is user equipment or a base station.

18. The computer-readable storage medium of claim 17, wherein the computer program or instructions, when executed, further perform the steps of:

19. The computer-readable storage medium of claim 18,

when the rank indication is 1, the rank indication is set to 1,

the above-mentioned

Or

When the rank indication is 2, the rank indication is,

the above-mentioned

Wherein both the α and β are constants.

20. A computer-readable storage medium according to any one of claims 17 to 19, wherein the computer program or instructions, when executed, further performs the steps of: receiving the reference signal from the transmitting end, wherein the reference signal comprises at least one of: channel state information reference signal (CSI RS), demodulation reference signal (DM RS) and cell specific reference signal (CRS).