WO2018094709A1 - Method, device, and system for determining precoding matrix - Google Patents

Abstract

The present application relates to the field of mobile communications, and particularly relates to a multi-antenna technique in a radio communication system. If a terminal apparatus feeds back a precoding matrix indicator on a physical uplink shared channel, a precoding matrix set corresponding to the precoding matrix indicator comprises precoding matrices for two sets of dual polarization antennae having the same beam direction, and precoding matrices for two sets of dual polarization antennae having different beam directions. If the terminal apparatus feeds back a precoding matrix indicator on a physical uplink control channel, a precoding matrix set corresponding to the precoding matrix indicator only comprises precoding matrices for two sets of dual polarization antennae having the same beam direction. The solution provided in the present application enables a balance between performance and a feedback cost.

Description

Method, device and system for determining precoding matrix Technical field

The present application relates to the field of mobile communications, and more particularly to multi-antenna technology in wireless communication systems.

Background technique

Active Antenna System (AAS) is a popular antenna form in the communications industry. Compared to the Passive Antenna System, in the case of the same antenna element, AAS can Provide better performance.

For passive antennas, all antenna elements in one polarization direction of one column in Figure 1 have only one PA (Power Amplifier, amplifier) connected to them. For AAS, all antenna elements in one column of one polarization direction have multiple PAs connected to them. At most each antenna array is connected to a PA. Thus, in the antenna diagram shown in Figure 1, the passive antenna system can form four antenna ports, as shown in Figure 2a.

In an active antenna system, more antenna ports can be formed due to the multiple columns of PAs. When data is transmitted, it is more flexible to perform weighting (precoding) between the antennas, and in the case of the same number of antenna elements, better performance can be obtained. AAS can easily form 3D-MIMO (Three dimensional MIMO, MIMO, Multiple Input Multiple Output, Multiple Input Multiple Output). The 3D-MIMO antenna port is not only placed in the horizontal direction, but also forms the antenna port in the vertical direction to form a 2D antenna array. Figure 2b shows a schematic diagram of a 2D antenna array composed of antenna ports in 3D-MIMO. In Figure 2b, 4H2V represents 4 horizontal antenna ports, 2 vertical antenna ports, and a total of 8 antenna ports; 8H2V represents 8 horizontal antenna ports, 2 vertical antenna ports, and a total of 16 antenna ports. 3D-MIMO can form a beam in the vertical direction and is suitable for 3D user distribution scenarios.

By transmitting beamforming (BF)/precoding and reception combining, MIMO wireless systems can obtain diversity and array gain. In a MIMO system, a typical system that utilizes BF or precoding can usually be expressed as

y=HWs+n (1)

Where y is the received signal vector, H is the channel matrix, W is the precoding matrix, s is the transmitted symbol vector, and n is the measurement noise. Optimal precoding typically requires the transmitter to fully know channel state information (CSI). A commonly used method is that the terminal device (or the MS is hereinafter referred to as a terminal device) quantizes the instantaneous CSI and feeds it back to the NodeB (hereinafter, the BS is referred to as a NodeB). The CSI information fed back by the existing LTE R8 system includes a rank indication (RI), a precoding matrix indication (PMI), and channel quality indication (CQI) information, etc., wherein the RI and the PMI indicate the number of layers used and the precoding matrix, respectively.

The precoding matrix indicates that feedback may be performed on a Physical Uplink Shared Channel (PUSCH) or may be fed back on a Physical Uplink Control Channel (PUCCH). The number of bits indicated by the precoding matrix of the physical uplink shared channel feedback may be greater than the number of bits fed back by the physical uplink control channel. Therefore, for the feedback indicated by the PUSCH and PUCCH precoding matrix, different precoding matrix sets are needed to achieve a balance between system performance and terminal device feedback overhead.

Summary of the invention

The present application describes methods, apparatus, and systems for determining precoding matrices to achieve a balance between system performance and terminal device feedback overhead.

In a first aspect, a method of determining a precoding matrix, the method comprising:

Receiving, by the base station, a rank fed back by the terminal device and a precoding matrix indication;

The base is received when the base station receives the precoding matrix indication from a physical uplink shared channel Standing in a first precoding matrix set corresponding to the rank, determining a first precoding matrix according to the precoding matrix indication; and

When the base station receives the precoding matrix indication from the physical uplink control channel, the base station determines the second precoding according to the precoding matrix indication in the second precoding matrix set corresponding to the rank. a matrix, the second precoding matrix set being a true subset of the first precoding matrix set;

Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B. Since the base station receives the PMI on the PUSCH, the precoding can be obtained with greater degree of freedom; the PMI is received on the PUCCH, and the performance of the precoding is optimized in the case of receiving fewer PMI bits. The solution of the present application achieves a balance between system performance and terminal device feedback overhead.

In a second aspect, a method of determining a precoding matrix, the method comprising:

The terminal device determines the rank and the precoding matrix indication; and

Transmitting, by the terminal device, the determined rank and a precoding matrix indication by using a physical uplink shared channel or a physical uplink control channel;

The precoding matrix indication is used to indicate the first precoding corresponding to the precoding matrix in the first precoding matrix set, when the terminal device sends the precoding matrix indication by using a physical uplink shared channel. matrix;

When the terminal device sends the precoding matrix indication by using a physical uplink control channel, the precoding matrix indication is used to indicate a second precoding matrix corresponding to the precoding matrix in the second precoding matrix set, The second precoding matrix set is a true subset of the first precoding matrix set; the first precoding matrix set and the second precoding matrix set correspond to the rank;

Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B. Since the terminal feeds back the PMI on the PUSCH, the precoding obtains a greater degree of freedom; the PMI is fed back on the PUCCH, and the performance of the precoding is optimized with a smaller number of feedback bits. The solution of the present application achieves a balance between system performance and terminal device feedback overhead.

In a third aspect, an embodiment of the present application provides a terminal device, where the terminal device has a function of implementing a behavior of a terminal device in the foregoing method design. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. The modules can be software and/or hardware.

The terminal device includes:

a processing unit, configured to determine a rank and a precoding matrix indication;

a sending unit, configured to send, by the terminal device, the determined rank and a precoding matrix indication by using a physical uplink shared channel or a physical uplink control channel;

The precoding matrix indication is used to indicate the first precoding corresponding to the precoding matrix in the first precoding matrix set, when the terminal device sends the precoding matrix indication by using a physical uplink shared channel. a matrix; when the terminal device sends the precoding matrix indication by using a physical uplink control channel, the precoding matrix indication is used to indicate a first precoding corresponding to the precoding matrix in a second precoding matrix set a matrix, the second precoding matrix set is a true subset of the first precoding matrix set; the first precoding matrix set and the second precoding matrix set correspond to the rank;

Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B. Since the terminal feeds back the PMI on the PUSCH, the precoding obtains a greater degree of freedom; the PMI is fed back on the PUCCH, and the performance of the precoding is optimized with a smaller number of feedback bits. The solution of the present application achieves a balance between system performance and terminal device feedback overhead.

In a fourth aspect, an embodiment of the present application provides a base station, where the base station has a function of implementing a base station behavior in the foregoing method. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

The base station includes:

a receiving unit, configured to receive a rank of the terminal device feedback and a precoding matrix indication;

a processing unit, configured to: when the base station receives the precoding matrix indication from a physical uplink shared channel, the base station indicates, according to the precoding matrix, in a first precoding matrix set corresponding to the rank Determining a first precoding matrix; and

When the base station receives the precoding matrix indication from the physical uplink control channel, the base station determines the second precoding according to the precoding matrix indication in the second precoding matrix set corresponding to the rank. a matrix, the second precoding matrix set being a true subset of the first precoding matrix set;

Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B. Since the base station receives the PMI on the PUSCH, the precoding can be obtained with greater degree of freedom; the PMI is received on the PUCCH, and the performance of the precoding is optimized in the case of receiving fewer PMI bits. The solution of the present application achieves a balance between system performance and terminal device feedback overhead.

In the first to fourth aspects, there are also the following alternative designs.

Optionally, each precoding matrix W in the first precoding matrix set satisfies W=W ₁ W ₂ ,

Where W _{1 is} satisfied

or

or

among them,

Is a N ₁ ×L ₁ matrix,

Any of the columns v _l can be expressed as

Is a N ₂ × L ₂ matrix,

Any of the columns can be expressed as Wherein N ₁ , N ₂ , L ₁ , L ₂ are positive integers,

Means Kronecker,

Representation matrix

a matrix consisting of Z columns in the L ₁ ×L ₂ column, Z being a positive integer; and

Where W _{2 is} satisfied

Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

The number of columns in the middle, or Y is

The number of columns in the middle, or Y is

The number of columns in the middle; or Y is

The number of columns in the middle. W ₁ can be long-term / wide-band feedback, W ₂ can be short-term / narrow-band feedback, which can reduce the overhead of feedback

Optionally, when the rank is equal to 1, each precoding matrix W in the first precoding matrix set further satisfies:

Y ₁ , Y ₂ ∈{e _i }

Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

The number of columns in the middle, or Y is

The number of columns in the middle, or Y is

The number of columns in the middle; or Y is

The number of columns in the middle.

Optionally, each precoding matrix in the second precoding matrix set satisfies W=W ₁ W ₂ ,

Where W _{1 is} satisfied

or

with

Where W _{2 is} satisfied

Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

The number of columns in the middle; or Y is

The number of columns in the middle.

Optionally, when the rank is equal to 1, each precoding matrix W in the second precoding matrix set further satisfies:

Y ₁ ∈{e _i }

Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

The number of columns in the middle, or Y is

The number of columns in the middle. W ₂ is only Y _1, no Y _2, the feedback bits can be saved

Optionally, the precoding matrix indication includes a first precoding matrix indication and a second precoding matrix indication, where the first precoding matrix indicates a corresponding W ₁ , and the second precoding matrix indicates a corresponding W ₂ .

Optionally, the first precoding matrix indication includes a third precoding matrix indication and a fourth precoding matrix indication, and the combination of the third precoding matrix indication and the fourth precoding matrix

Correspondingly, the third precoding matrix indicates

Correspondingly, the fourth precoding matrix indicates

correspond.

Optionally, the third precoding matrix indication and the fourth precoding matrix indication are indicated by means of difference. Feedback bits can be saved by differential feedback.

Optionally, the second precoding matrix indication includes a fifth precoding matrix indication and a sixth precoding matrix indication, by combining the fifth precoding matrix indication and the sixth precoding matrix

Correspondingly, the fifth precoding matrix indication corresponds to Y ₁ , and the sixth precoding matrix indication corresponds to Y ₂ .

Optionally, the fifth precoding matrix indication and the sixth precoding matrix indication are indicated by means of difference. Feedback bits can be saved by differential feedback.

In the third to fourth aspects, the transmitting unit may be a transmitter, the receiving unit may be a receiver, and the processing unit may be a processor.

The embodiment of the invention further provides a system, which comprises the terminal device and the base station in the above embodiment.

In the present application, the beam direction of a set of polarized antennas refers to a beam pattern obtained by weighting the set of polarized antennas using a set of weight vector/weighted precoding matrices. If the two sets of polarized antennas each use a set of weighting values, the obtained beam patterns are the same, and it is considered that after using the weighting vector/weighted precoding matrix, the two sets of polarized antennas have the same beam direction.

The solution provided by the embodiment of the present application includes a precoding matrix when the terminal device feeds back a Precoding Matrix Indicator (PMI) on the physical uplink shared channel. The corresponding precoding matrix set indicates that the two sets of dual-polarized antennas have the same beam direction precoding matrix, and the two sets of dual-polarized antennas have different precoding matrices of different beam directions; when the terminal device is in physical uplink control When the precoding matrix is indicated on the Physical Uplink Control Channel (PUCCH), the corresponding precoding matrix set indicated by the precoding matrix includes only two pre-coding matrices with the same beam direction. And the precoding matrix fed back in the physical uplink control channel indicates that the corresponding precoding matrix set is a true subset of the precoding matrix set corresponding to the precoding matrix fed back in the physical uplink shared channel. Through the solution provided by the present application, a greater degree of freedom can be obtained when the PMI is fed back on the PUSCH; the PMI is fed back on the PUCCH, and the performance is optimized with a small number of feedback bits. The solution of the present application achieves a balance between system performance and terminal device feedback overhead.

DRAWINGS

Figure 1 is a schematic diagram of a dual polarized antenna.

Figure 2a is a schematic diagram of four antenna ports of a passive antenna.

Figure 2b Schematic diagram of a 3D MIMO antenna port.

FIG. 3 is a schematic diagram of a communication system according to an embodiment of the present invention.

FIG. 4 is a schematic flowchart of a method for feeding back a precoding matrix indication according to an embodiment of the present invention.

FIG. 5 is a schematic block diagram of a terminal device according to an embodiment of the present invention.

FIG. 6 is a schematic block diagram of a base station according to an embodiment of the present invention.

FIG. 7 is another schematic block diagram of a terminal device according to another embodiment of the present invention.

FIG. 8 is another schematic block diagram of a base station according to another embodiment of the present invention.

detailed description

The network architecture and the service scenario described in the embodiments of the present invention are used to more clearly illustrate the technical solutions of the embodiments of the present invention, and do not constitute a limitation of the technical solutions provided by the embodiments of the present invention. The technical solutions provided by the embodiments of the present invention are equally applicable to similar technical problems.

It should be understood that the technical solutions of the embodiments of the present invention can be applied to various communication systems, for example, Global System of Mobile communication ("GSM") system, Code Division Multiple Access (Code Division Multiple Access, referred to as "CDMA") system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service ("GPRS"), Long Term Evolution (Long Term Evolution, Referred to as "LTE" system, LTE frequency division duplex (Freq terminal equipment ncy Division Duplex, referred to as "FDD") system, LTE time division duplex ("TDD"), universal mobile communication system ( Universal Mobile Telecommunication System (UMTS) or Worldwide Interoperability for Microwave Access (WiMAX) communication system.

It should be understood that, in the embodiment of the present invention, a terminal equipment may be referred to as a terminal, or may be a user equipment (UE), a mobile station (MS), and a mobile terminal ( Mobile terminal), a notebook computer, etc., the terminal device can communicate with one or more core networks via a radio access network (RAN), for example, the terminal device can be a mobile phone (or "cellular" phone Or a computer or the like having a mobile terminal, for example, the terminal device may also be a portable, pocket-sized, handheld, computer-integrated or in-vehicle mobile device that exchanges voice and/or data with the wireless access network.

In the embodiment of the present invention, the base station may be a base station (Base Transceiver Station, abbreviated as "BTS") in GSM or CDMA, or may be a base station (NodeB, referred to as "NB") in WCDMA, or may be in LTE. The present invention is not limited to an evolved base station (Evolutional Node B, referred to as "eNB or e-NodeB"). However, for convenience of description, the following embodiments will be described by taking an eNB as an example.

The embodiment of the present invention proposes a solution based on the communication system shown in FIG. 3 for use in PUSCH and When the PUCCH feeds back the PMI, the balance between system performance and terminal device feedback overhead is achieved. The embodiment of the invention provides a communication system 100. The communication system 100 includes at least one base station and a plurality of terminal devices. The plurality of terminal devices communicate with the base station. In the downlink, the base station communicates with the terminal device through the downlink control channel and the downlink data channel. Taking FIG. 3 as an example, the base station 20 communicates with the terminal device 10, and the terminal device 10 includes the terminal devices 10A and 10B. In the uplink, the terminal device communicates with the base station through the uplink control channel and the uplink data channel. The downlink refers to the direction in which the base station transmits data to the terminal device, and the uplink refers to the direction in which the terminal device transmits data to the base station. The base station transmits control information, such as scheduling information for the terminal device, on the downlink control channel. The uplink control channel may be a physical uplink control channel (PUCCH). In the LTE system, the terminal device may send a rank indication (RI), a precoding matrix indicator (PMI), and a channel quality indication (CQI) base station on the PUCCH. The uplink data channel may be a physical uplink control channel (PUSCH). In the LTE system, the terminal device transmits uplink service data to the base station on the PUSCH. Moreover, the terminal device can also send the RI, PMI, and CQI to the base station through the PUSCH.

FIG. 4 shows a schematic flow chart of a method for determining a precoding matrix according to an embodiment of the present invention. As shown in FIG. 4, the method includes:

In step 101, a rank is determined.

In step 101, the terminal device determines a rank indicating the number of transmission layers. Optionally, the terminal device may determine a rank for indicating the number of transmission layers based on channel state information (CSI) or the like. Optionally, the base station sends a CRS (Cell-specific Reference Signal) to the terminal device, or sends a CSI-RS. (Channel State Information Reference Signal, channel state information reference signal or channel state information measurement pilot). The terminal device obtains the downlink channel estimation and the downlink interference estimation according to the CRS, or the CSI-RS, and then determines the number of layers that the terminal device desires to transmit, that is, the rank, according to the two. It should be understood that the terminal device may determine the rank by a method well known to those skilled in the art, and for brevity, no further details are provided herein.

Step 102, determining a precoding matrix indication.

At step 102, the terminal device determines a precoding matrix indication for indicating the first precoding matrix. Since there is a one-to-one correspondence between the precoding matrix indication and the precoding matrix, when the precoding matrix used by the base station is determined by the terminal device, the corresponding precoding matrix indication is also determined. The determining, by the terminal device, the precoding matrix refers to determining the first precoding matrix in the precoding set corresponding to the rank.

In step 102, the terminal device terminal device may determine, according to a reference signal such as a CSI-RS, a first precoding matrix used by the terminal device when the base station expects the base station to transmit downlink data in the precoding set corresponding to the rank. All precoding matrices included in the precoding set corresponding to the rank may be represented by a set indicated by the first precoding matrix. In the first precoding matrix indication set, one precoding matrix indication represents a precoding matrix. There is a one-to-one correspondence between the precoding matrix indication and the precoding matrix.

Step 103: Send the rank and the precoding matrix indication to a base station.

In step 103, the terminal device sends the determined rank and a precoding matrix indication to the base station by using a physical uplink shared channel or a physical uplink control channel;

When the terminal device sends the precoding matrix indication by using a physical uplink shared channel, the precoding matrix indication is used to indicate a first precoding matrix corresponding to the precoding matrix in the first precoding matrix set;

When the terminal device sends the precoding matrix indication by using a physical uplink control channel, the precoding matrix indication is used to indicate a second precoding matrix corresponding to the precoding matrix in the second precoding matrix set, The second precoding matrix set is a true subset of the first precoding matrix set; the first precoding matrix set and the second precoding matrix set correspond to the rank.

Each column of each precoding matrix W included in the first precoding matrix set is satisfied with:

Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r For rank.

The weight vector of the above antenna port on this column, denoted by A, B in C. That is, A is a weight vector for one polarization direction antenna port, and B is a weight vector for another polarization direction antenna port. When all of the precoding matrices satisfy A equal to B, the bits of the feedback PMI can be saved while limiting the use of the same weight vector in both polarization directions. When the precoding matrix is allowed to have A not equal to B, the introduction of two polarization directions may use different weighting vectors, which increases the degree of freedom of precoding, but increases the bits of the feedback PMI. When the bits of the feedback PMI increase, it means that the number of medium precoding matrices of the precoding set increases. If only the two polarization directions are used to limit the two polarization directions, when the number of precoding matrices is increased to a certain extent, increasing the number of precoding matrices does not greatly improve the performance. At this time, the use of different weighting vectors that allow the introduction of two polarization directions can further increase performance. In LTE/LTE-A, the feedback of the PMI can be fed back on the PUSCH or fed back on the PUCCH. More bits can be fed back on the PUSCH to represent the PMI than feedback on the PUCCH.

Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B. The second precoding matrix set and the first precoding matrix set satisfy the foregoing relationship, and may obtain a greater degree of freedom in precoding when the PMI is fed back on the PUSCH; feedback PMI on the PUCCH, with less feedback In the case of the number of bits, the performance of the precoding is optimized. This balances system performance with terminal device feedback overhead.

Optionally, each precoding matrix W in the first precoding matrix set satisfies W=W ₁ W ₂ . W ₁ is long-term/wideband feedback, and W ₂ is short-term/narrowband feedback, which reduces feedback overhead. W ₁ gives a vector group or beam group. The role of W ₂ is the beam selection and the phase adjustment (Co-phasing) of the weight vector between the dual-polarized antennas. In the formula (1), taking the rank 1 as an example, it is assumed that the antenna port is in the form of 4H2V in Fig. 2b. Then the precoding matrix is

W is a matrix of 8 rows and 1 column, and A and B are vectors of 4 rows and 1 column. A corresponds to the weight vector of the antenna ports numbered 1-4 in Fig. 2b (45° polarization direction), and B corresponds to the weight vector of the antenna port numbered 1-4 (-45° polarization direction) in Fig. 2b. W _{1 is} satisfied

or

or

Is a N ₁ ×L ₁ matrix,

Any of the columns v _l can be expressed as

Is a N ₂ × L ₂ matrix,

Any of the columns can be expressed as

Wherein N ₁ , N ₂ , L ₁ , L ₂ , Q ₁ , Q ₂ , l are positive integers,

Means Kronecker,

Representation matrix

A matrix consisting of Z columns in the L ₁ × L ₂ column, and Z is a positive integer. Take 16 antenna ports (8H2V) as an example, including 8 horizontal ports and 2 vertical ports. This is shown as 8H2V in Figure 2b. In Figure 2b, the same polarization direction has 4 antennas in the horizontal direction and 2 antennas in the vertical direction. Suppose that within a W ₁ , there are 4 DFT vectors in the horizontal direction and 2 DFT vectors in the vertical direction.

or

Contains 8 vectors.

W ₂ satisfied

Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

The number of columns in the middle, or Y is

The number of columns in the middle, or Y is

The number of columns in the middle; or Y is

The number of columns in the middle. The main function of W ₂ is direction selection and phase adjustment between dual-polarized antennas.

In 3GPP Release 10 (version 10), the 8-antenna precoding matrix is designed primarily for horizontal emissions of the antenna array and optimized for horizontal antenna spacing of 0.5 times the wavelength. In the 8-ant precoding matrix of Release 10, the precoding matrix W can be expressed as W = W ₁ W ₂ . The two polarization directions of W ₁ contain the same beam direction. In the actual 3D-MIMO antenna array, there are the following characteristics: in the horizontal direction, the spacing between the antenna elements can be 0.5 times the wavelength, and the vertical direction is 0.8 times the wavelength. Moreover, when the number of arrays is larger than the number of antenna ports, it is generally virtualized vertically. For example, if you want to virtualize to 8 antenna ports, you can virtualize them into 2 antenna ports, and then you can virtualize the first 4 frames into one port. The last 4 frames are virtualized into one port. Moreover, the greater the spacing between the antenna elements, the weaker the correlation between the channels between the antenna elements. While the probability of W _1, two polarization directions using the same beam direction becomes smaller.

When W _{1 is} satisfied

When you can save feedback bits. However, when the bit representing W ₁ is increased to a certain extent, only the same vector group or beam group is limited in both polarization directions. There is no significant increase in performance. However, the introduction of two polarization directions can use different beam direction groups.

Can improve performance even better.

Optionally, when the rank is equal to 1, each precoding matrix W in the first precoding matrix set further satisfies:

Y ₁ , Y ₂ ∈{e _i }

Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

The number of columns in the middle, or Y is

The number of columns in the middle, or Y is

The number of columns in the middle; or Y is

The number of columns in the middle.

Optionally, when the rank is equal to 1, each precoding matrix W in the first precoding matrix set further satisfies:

Y ₁ , Y ₂ ∈{e _i }

Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

The number of columns in the middle, or Y is

The number of columns in the middle, or Y is

The number of columns in the middle; or Y is

The number of columns in the middle.

16 to FIG. 2b 8H2V antenna port, for example, vectors or a set of beam directions in the polarization direction of the group W ₁ Y = 8 vectors. The vector group or beam direction group refers to

or

or

or

At this time, e _i represents a column vector having a dimension of 8×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{1, 2, 3, 4, 5, 7, 8 }; A is a normalization constant, such as A = 1/4. σ _n = e ^jπn/2 and n = 0, 1, 2 or 3. If Y ₁ or Y _{2 is} required to represent 3 bits separately, it means that σ _n requires 2 bits. It means that W ₂ needs a total of 8 bits. When the PMI is fed back in the PUSCH, the vectors selected by the two polarization directions are individually selected, and according to the above example, 8 bits are required.

Optionally, each precoding matrix in the second precoding matrix set satisfies W=W ₁ W ₂ ,

Where W _{1 is} satisfied

or

with

Where W _{2 is} satisfied

Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

The number of columns in the middle; or Y is

The number of columns in the middle. Two polarization direction antenna ports, using the same beamforming vector, can save feedback bits

Optionally, when the rank is equal to 1, each precoding matrix W in the second precoding matrix set further satisfies:

Y ₁ ∈{e _i }

Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

The number of columns in the middle, or Y is

The number of columns in the middle. For example, if Y=8, then W ₂ needs 3 bits for column selection to select the column in W ₁ , σ _n =e ^jπn/2 , and n=0, 1, 2 or 3. It means that σ _n requires 2 bits. A total of 5 bits represent W ₂ , which is three bits less than the example of the feedback PMI on the PUSCH described above. Two polarization direction antenna ports use the same beamforming vector, saving the bit of feedback.

Optionally, the precoding matrix indication includes a first precoding matrix indication and a second precoding matrix indication, where the first precoding matrix indicates a corresponding W ₁ , and the second precoding matrix indicates a corresponding W ₂ . A precoding matrix indication can consist of one or more indicator values or index values. For example, a precoding matrix indication is represented only by index i1 (an indicator value or an index value). Or a precoding matrix indication is represented by indices i1 and i2 (two indicator values or index values). The base station may configure the terminal device to feed back a Precoding Matrix Indicator (PMI) on a Physical Uplink Shared Channel (PUSCH), or feed back a precoding on a Physical Uplink Control Channel (PUCCH). Matrix indication. Sending, by the terminal device, the rank and the first precoding matrix indication, the rank may be sent before the first precoding matrix indicates the sending; or may be sent together with the part indicated by the first precoding matrix; All of the coding matrix indications are sent together. The rank and the first precoding matrix indicate that there is no sequential restriction on the transmission.

Optionally, the first precoding matrix indication includes a third precoding matrix indication and a fourth precoding matrix indication, and the combination of the third precoding matrix indication and the fourth precoding matrix

Correspondingly, the third precoding matrix indicates

Correspondingly, the fourth precoding matrix indicates

correspond.

Optionally, the third precoding matrix indication and the fourth precoding matrix indication are indicated by means of difference. Any one of the precoding matrix sets may be represented as W = W ₁ W ₂ . among them

but

with

It is not represented separately, but is represented by differential means, which saves feedback bits. For example, each

Contains 4 column vectors, a total of 16 different

Requires 4 bits to represent

Through feedback, get

Contains 4 column vectors,

And

N ₁ , Q ₁ is an integer. In this embodiment,

Pass and

Differential representation, representation and

Adjacent vector groups, such as

Expressed by two bits

In this way, the representation

with

Requires 6 bits, and independent representation

with

Requires 4+4=8 bits, saving two bits. Correct

with

The same method can be used to save feedback bits.

Since the role of W ₁ is to include a vector group or a beam direction group, although the vector group or the beam direction group included between the two polarization directions may be different, the direction groups included in the two polarization directions are not completely independent. However, there is a certain correlation, so the difference can save feedback overhead, and the basic performance remains unchanged.

Optionally, the second precoding matrix indication includes a fifth precoding matrix indication and a sixth precoding matrix indication, by combining the fifth precoding matrix indication and the sixth precoding matrix

Correspondingly, the fifth precoding matrix indication corresponds to Y ₁ , and the sixth precoding matrix indication corresponds to Y ₂ .

Optionally, the fifth precoding matrix indication and the sixth precoding matrix indication are indicated by means of difference.

For example, a set of precoding matrices in which two polarization directions use different precoding vectors can also be expressed as

W=W ₁ W ₂

In formula (2), the value of i is an integer ranging from 1, 2, ..., up to

The number of columns. In equation (2), the two polarization directions of W ₁ contain the same vector group or beam direction group. However, the specific beam direction is selected by Y ₁ , Y ₂ . Y ₁ and Y ₂ can be represented in a differential manner. such as

There are 8 columns and 3 bits represent Y ₁ . make

To represent Y ₁ . Y ₂ can be represented by 2 bits, and the range of values is e _{((i-2) mod8+1)} , e _i , e _{((i) mod8) +1} , e _{((i) mod8) + 2} . Where "mod" means modulo, for example, 9 modulo 8 is equal to 1, and -1 modulo 8 is equal to 7. For example, the representation of Y ₁ is

Then the four possible values of Y ₂ are e ₈ , e ₁ , e ₂ , e ₃ . The benefit of differential feedback is that the feedback is reduced while performance is not substantially reduced.

Alternatively, in an embodiment of the invention, the rank is equal to one.

Therefore, the method for the feedback precoding matrix indication in the embodiment of the present invention can obtain a greater degree of freedom for the precoding matrix when the PMI is fed back on the PUSCH; and feed back the PMI on the PUCCH, in the case of a small number of feedback bits. , optimize performance. Achieve a balance between performance and overhead.

At the base station side, in step 104, the base station receives the rank fed back by the terminal device and the precoding matrix indication. Wherein, the rank may be received before the first precoding matrix indication; may also be received together with a part of the first precoding matrix indication; or may be received together with all indicated by the first precoding matrix. The order indicated by the rank and first precoding matrix has no sequential restrictions.

Step 105: The base station determines a first precoding matrix. When the base station receives the precoding matrix indication from a physical uplink shared channel, the base station is in the first precoding moment corresponding to the rank In the array set, the first precoding matrix is determined according to the precoding matrix indication. When the base station receives the precoding matrix indication from the physical uplink control channel, the base station determines the second according to the precoding matrix indication in the second precoding matrix set corresponding to the rank Precoding matrix.

In step 106, the base station transmits data.

Optionally, in step 106, the base station sends data to the terminal device. The base station can transmit data to the terminal device on the PDSCH (Physical Downlink Shared Channel). The precoding matrix used by the base station when transmitting data may be a precoding matrix indicated by the terminal device to indicate a corresponding precoding matrix. Alternatively, another precoding matrix obtained may be obtained by transforming according to the precoding matrix, for example, considering a zero-forcing algorithm at the transmitting end between multi-user MIMO.

The method according to an embodiment of the present invention is described in detail above with reference to FIG. 4, and a terminal device and a base station according to an embodiment of the present invention will be described in detail below with reference to FIG. 5 to FIG.

As shown in FIG. 5, the embodiment of the present invention provides a terminal device 10 as shown in FIG. 1 , which may be 10A or 10B. The terminal device 10 includes:

The processing unit 501 is configured to determine a rank and a precoding matrix indication.

In the processing unit 501, a rank for indicating the number of transmission layers is determined. Optionally, the terminal device may determine a rank for indicating the number of transmission layers based on channel state information (CSI) or the like. Optionally, the base station sends a CRS (Cell-specific Reference Signal) to the terminal device, or sends a CSI-RS (Channel State Information Reference Signal, channel state information reference signal or channel state information measurement pilot). The terminal device obtains the downlink channel estimation and the downlink interference estimation according to the CRS, or the CSI-RS, and then determines the number of layers that the terminal device desires to transmit, that is, the rank, according to the two. It should be understood that The terminal device can determine the rank by a method well known to those skilled in the art, and for brevity, no further details are provided herein.

The sending unit 502 is configured to send, by the terminal device, the determined rank and a precoding matrix indication by using a physical uplink shared channel or a physical uplink control channel;

The precoding matrix indication is used to indicate the first precoding corresponding to the precoding matrix in the first precoding matrix set, when the terminal device sends the precoding matrix indication by using a physical uplink shared channel. a matrix; when the terminal device sends the precoding matrix indication by using a physical uplink control channel, the precoding matrix indication is used to indicate a first precoding corresponding to the precoding matrix in a second precoding matrix set a matrix, the second precoding matrix set is a true subset of the first precoding matrix set; the first precoding matrix set and the second precoding matrix set correspond to the rank;

Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B.

For a detailed description of the first precoding matrix set, the second precoding matrix set, the precoding matrix, the precoding matrix indication, and the like, refer to the description of the embodiment in step 103 on the terminal device side, and details are not described herein.

Therefore, the terminal device that determines the precoding matrix in the embodiment of the present invention can have a greater degree of freedom when feeding back the PMI on the PUSCH; feed the PMI on the PUCCH, and optimize the precoding in the case of a small number of feedback bits. Performance. This balances system performance with terminal device feedback overhead.

It should be understood that a terminal device according to an embodiment of the present invention may correspond to a terminal device that performs a method of feeding back a precoding matrix indication according to an embodiment of the present invention, and the above-described respective modules in the terminal device The operation and/or function of the method in order to implement the corresponding process of the method in FIG. 4 will not be repeated here for brevity.

As shown in FIG. 6, the embodiment of the present invention provides a base station 20 as shown in FIG. 1, and the base station 20 includes:

The receiving unit 601 is configured to receive a rank of the terminal device feedback and a precoding matrix indication.

The processing unit 602 is configured to: when the base station receives the precoding matrix indication from the physical uplink shared channel, the base station is in the first precoding matrix set corresponding to the rank, according to the precoding matrix Instructing to determine a first precoding matrix; and

When the base station receives the precoding matrix indication from the physical uplink control channel, the base station determines the second precoding according to the precoding matrix indication in the second precoding matrix set corresponding to the rank. a matrix, the second precoding matrix set being a true subset of the first precoding matrix set;

Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B.

For a detailed description of the first precoding matrix set, the second precoding matrix set, the precoding matrix, the precoding matrix indication, and the like, refer to the embodiment in step 103 of the terminal device side method in FIG. 4 . Said, no longer repeat them.

Therefore, the base station determining the precoding matrix in the embodiment of the present invention can obtain a greater degree of freedom in precoding when receiving the PMI on the PUSCH; in the case of receiving the PMI on the PUCCH, in the case of a smaller number of feedback bits, Optimize the performance of precoding. This balances system performance with terminal device feedback overhead.

The terminal device 10 including the processor 701, the transmitter 702, and the receiver 703 is as shown in FIG. A base station 20 including a processor 802, a transmitter 803, and a receiver 801 is shown in FIG.

The processing unit 501 may be specifically a processor 701. The processing unit 602 may be specifically a processor 802. The receiving unit 503 may be the receiver 703; the receiving unit 801 may be the receiver 801. The transmitting unit 502 can be the transmitter 702; the transmitting unit 603 can be the transmitter 803.

It should be understood that, in the embodiment of the present invention, the processor 701, 802 may be a central processing unit ("CPU"), and the processor 701, 802 may also be other general-purpose processors, digital signal processing. (DSP), application specific integrated circuit (ASIC), off-the-shelf programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like.

The specific embodiments of the present invention have been described in detail with reference to the preferred embodiments of the present invention. The scope of the protection, any modifications, equivalent substitutions, improvements, etc., which are made on the basis of the technical solutions of the present invention, are included in the scope of the present invention.

Claims (40)

1. A method of determining a precoding matrix, the method comprising:

   Receiving, by the base station, a rank fed back by the terminal device and a precoding matrix indication;

   When the base station receives the precoding matrix indication from the physical uplink shared channel, the base station determines the first precoding according to the precoding matrix indication in the first precoding matrix set corresponding to the rank. Matrix; and

   When the base station receives the precoding matrix indication from the physical uplink control channel, the base station determines the second precoding according to the precoding matrix indication in the second precoding matrix set corresponding to the rank. a matrix, the second precoding matrix set being a true subset of the first precoding matrix set;

   Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

   

   Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

   Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B.
2. The method of claim 1, wherein each of the precoding matrices W in the first set of precoding matrices satisfies W = W ₁ W ₂ ,

   Where W _{1 is} satisfied

   

   or

   

   or

   

   among them,

   

   Is a N ₁ ×L ₁ matrix,

   

   Any of the columns v _l can be expressed as

   

   Is a N ₂ × L ₂ matrix,

   

   

   Any of the columns can be expressed as

   

   Wherein N ₁ , N ₂ , L ₁ , L ₂ are positive integers,

   

   Means Kronecker,

   

   Representation matrix

   

   a matrix consisting of Z columns in the L ₁ ×L ₂ column, Z being a positive integer; and

   Where W _{2 is} satisfied

   

   Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

   

   α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

   

   The number of columns in the middle, or Y is

   

   The number of columns in the middle, or Y is

   

   The number of columns in the middle; or Y is

   

   The number of columns in the middle.
3. The method of claim 2, wherein, when the rank is equal to 1, each precoding matrix W in the first precoding matrix set further satisfies:

   

   Y ₁ , Y ₂ ∈{e _i }

   Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

   

   The number of columns in the middle, or Y is

   

   The number of columns in the middle, or Y is

   

   The number of columns in the middle; or Y is

   

   The number of columns in the middle.
4. The method according to claim 1, wherein each precoding matrix in said second precoding matrix set satisfies W = W ₁ W ₂ ,

   Where W _{1 is} satisfied

   

   or

   

   with

   Where W _{2 is} satisfied

   

   Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

   

   α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

   

   The number of columns in the middle; or Y is

   

   The number of columns in the middle.
5. The method of claim 4, wherein when the rank is equal to 1, each precoding matrix W in the second set of precoding matrices further satisfies:

   

   Y ₁ ∈{e _i }

   Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

   

   The number of columns in the middle, or Y is

   

   The number of columns in the middle.
6. The method according to any one of claims 2 to 5, wherein the precoding matrix indication comprises a first precoding matrix indication and a second precoding matrix indication, wherein the first precoding matrix indicates a correspondence W ₁ , the second precoding matrix indicates a corresponding W ₂ .
7. The method according to claim 6, wherein the first precoding matrix indication comprises a third precoding matrix indication and a fourth precoding matrix indication, the third precoding matrix indication and a fourth precoding matrix Combination and

   

   Correspondingly, the third precoding matrix indicates

   

   Correspondingly, the fourth precoding matrix indicates

   

   correspond.
8. The method of claim 7 wherein said third precoding matrix indication and said fourth precoding matrix indication are indicated by differential means.
9. The method according to claim 6, wherein the second precoding matrix indication comprises a fifth precoding matrix indication and a sixth precoding matrix indication, by the fifth precoding matrix indication and the sixth precoding Matrix combination

   

   Correspondingly, the fifth precoding matrix indication corresponds to Y ₁ , and the sixth precoding matrix indication corresponds to Y ₂ .
10. The method of claim 9, wherein the fifth precoding matrix indication and the sixth precoding matrix indication are indicated by differential means.
11. A method of determining a precoding matrix, the method comprising:

    The terminal device determines the rank and the precoding matrix indication; and

    Transmitting, by the terminal device, the determined rank and a precoding matrix indication by using a physical uplink shared channel or a physical uplink control channel;

    The precoding matrix indication is used to indicate the first precoding corresponding to the precoding matrix in the first precoding matrix set, when the terminal device sends the precoding matrix indication by using a physical uplink shared channel. matrix;

    When the terminal device sends the precoding matrix indication by using a physical uplink control channel, the precoding matrix indication is used to indicate a second precoding matrix corresponding to the precoding matrix in the second precoding matrix set, The second precoding matrix set is a true sub of the first precoding matrix set a set of the first precoding matrix and the second precoding matrix set corresponding to the rank;

    Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

    

    Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

    Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B.
12. The method according to claim 11, wherein each of the precoding matrices W in the first precoding matrix set satisfies W = W ₁ W ₂ ,

    Where W _{1 is} satisfied

    

    or

    

    or

    

    among them,

    

    Is a N ₁ ×L ₁ matrix,

    

    Any of the columns v _l can be expressed as

    

    Is a N ₂ × L ₂ matrix,

    

    

    Any of the columns can be expressed as

    

    Wherein N ₁ , N ₂ , L ₁ , L ₂ are positive integers,

    

    Means Kronecker,

    

    Representation matrix

    

    a matrix consisting of Z columns in the L ₁ ×L ₂ column, Z being a positive integer; and

    Where W _{2 is} satisfied

    

    Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2,...r}; D _{f is} satisfied

    

    α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
13. The method of claim 12, wherein, when the rank is equal to 1, each precoding matrix W in the first set of precoding matrices further satisfies:

    

    Y ₁ , Y ₂ ∈{e _i }

    Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
14. The method according to claim 11, wherein each precoding matrix in said second precoding matrix set satisfies W = W ₁ W ₂ ,

    Where W _{1 is} satisfied

    

    or

    

    with

    Where W _{2 is} satisfied Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

    

    α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
15. The method of claim 14, wherein each of the precoding matrices W in the second set of precoding matrices further satisfies:

    

    Y ₁ ∈{e _i }

    Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle.
16. The method according to any one of claims 12-15, wherein the precoding matrix indication comprises a first precoding matrix indication and a second precoding matrix indication, wherein the first precoding matrix indicates a correspondence W ₁ , the second precoding matrix indicates a corresponding W ₂ .
17. The method according to claim 16, wherein the first precoding matrix indication comprises a third precoding matrix indication and a fourth precoding matrix indication, the third precoding matrix indication and the fourth precoding matrix Combination and

    

    Correspondingly, the third precoding matrix indicates

    

    Correspondingly, the fourth precoding matrix indicates

    

    correspond.
18. The method of claim 17 wherein said third precoding matrix indication and said fourth precoding matrix indication are indicated by differential means.
19. The method according to claim 16, wherein the second precoding matrix indication comprises a fifth precoding matrix indication and a sixth precoding matrix indication, by the fifth precoding matrix indication and the sixth precoding Matrix combination

    

    Correspondingly, the fifth precoding matrix indication corresponds to Y ₁ , and the sixth precoding matrix indication corresponds to Y ₂ .
20. The method of claim 19 wherein said fifth precoding matrix indication And the sixth precoding matrix indication is indicated by a differential manner.
21. A terminal device comprising:

    a processing unit, configured to determine a rank and a precoding matrix indication;

    a sending unit, configured to send, by the terminal device, the determined rank and a precoding matrix indication by using a physical uplink shared channel or a physical uplink control channel;

    The precoding matrix indication is used to indicate the first precoding corresponding to the precoding matrix in the first precoding matrix set, when the terminal device sends the precoding matrix indication by using a physical uplink shared channel. a matrix; when the terminal device sends the precoding matrix indication by using a physical uplink control channel, the precoding matrix indication is used to indicate a first precoding corresponding to the precoding matrix in a second precoding matrix set a matrix, the second precoding matrix set is a true subset of the first precoding matrix set; the first precoding matrix set and the second precoding matrix set correspond to the rank;

    Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

    

    Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

    Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B.
22. The terminal device according to claim 21, wherein each of the precoding matrices W in the first precoding matrix set satisfies W=W ₁ W ₂ ,

    Where W _{1 is} satisfied

    

    or

    

    or

    

    among them,

    

    Is a N ₁ ×L ₁ matrix,

    

    Any of the columns v _l can be expressed as

    

    Is a N ₂ × L ₂ matrix,

    

    

    Any of the columns can be expressed as

    

    Wherein N ₁ , N ₂ , L ₁ , L ₂ are positive integers,

    

    Means Kronecker,

    

    Representation matrix

    

    a matrix consisting of Z columns in the L ₁ ×L ₂ column, Z being a positive integer; and

    Where W _{2 is} satisfied

    

    Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

    

    α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
23. The terminal device according to claim 22, wherein when the rank is equal to 1, each precoding matrix W in the first precoding matrix set further satisfies:

    

    Y ₁ , Y ₂ ∈{e _i }

    Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
24. The terminal device according to claim 21, wherein each precoding matrix in the second precoding matrix set satisfies W=W ₁ W ₂ ,

    Where W _{1 is} satisfied

    

    or

    

    with

    Where W _{2 is} satisfied

    

    Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

    

    α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
25. The terminal device according to claim 22, wherein when the rank is equal to 1, each precoding matrix W in the second precoding matrix set further satisfies:

    

    Y ₁ ∈{e _i }

    Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle.
26. The terminal device according to any one of claims 22-25, wherein the precoding matrix indication comprises a first precoding matrix indication and a second precoding matrix indication, wherein the first precoding matrix indication Corresponding to W ₁ , the second precoding matrix indicates a corresponding W ₂ .
27. The terminal device according to claim 26, wherein the first precoding matrix indication comprises a third precoding matrix indication and a fourth precoding matrix indication, the third precoding matrix indication and the fourth precoding Matrix combination

    

    Correspondingly, the third precoding matrix indicates

    

    Correspondingly, the fourth precoding matrix indicates

    

    correspond.
28. The terminal device according to claim 27, wherein the third precoding matrix indication and the fourth precoding matrix indication are indicated by means of difference.
29. The terminal device according to claim 26, wherein the second precoding matrix indication comprises a fifth precoding matrix indication and a sixth precoding matrix indication, by the fifth precoding matrix indication and the sixth pre Combination of coding matrices

    

    Correspondingly, the fifth precoding matrix indication corresponds to Y ₁ , and the sixth precoding matrix indication corresponds to Y ₂ .
30. The terminal device according to claim 29, wherein said fifth precoding matrix indication and said sixth precoding matrix indication are indicated by means of difference.
31. A base station, comprising:

    a receiving unit, configured to receive a rank of the terminal device feedback and a precoding matrix indication;

    a processing unit, configured to: when the base station receives the precoding matrix indication from a physical uplink shared channel, the base station indicates, according to the precoding matrix, in a first precoding matrix set corresponding to the rank Determining a first precoding matrix; and

    When the base station receives the precoding matrix indication from the physical uplink control channel, the base station determines the second precoding according to the precoding matrix indication in the second precoding matrix set corresponding to the rank. a matrix, the second precoding matrix set being a true subset of the first precoding matrix set;

    Wherein each column of each precoding matrix W included in the first precoding matrix set satisfies:

    

    Where C is an N×1 matrix, N is the number of antenna ports, and N is an even number, and N is greater than or equal to 4; A and B are (N/2)×1 matrices, and σ is a complex number; the first precoding matrix Each column of at least one precoding matrix in the set satisfies A equal to B, and at least one column of at least one other precoding matrix in the first precoding matrix set satisfies that A is not equal to B; W is an N×r matrix, r Rank

    Each column of each precoding matrix in the second set of precoding matrices satisfies A equal to B.
32. The base station according to claim 31, wherein each of the precoding matrices W in the first precoding matrix set satisfies W=W ₁ W ₂ ,

    Where W _{1 is} satisfied

    

    or

    

    or

    

    among them,

    

    Is a N ₁ ×L ₁ matrix,

    

    Any of the columns v _l can be expressed as

    

    Is a N ₂ × L ₂ matrix,

    

    

    Any of the columns can be expressed as

    

    Wherein N ₁ , N ₂ , L ₁ , L ₂ are positive integers,

    

    Means Kronecker,

    

    Representation matrix

    

    a matrix consisting of Z columns in the L ₁ ×L ₂ column, Z being a positive integer; and

    Where W _{2 is} satisfied

    

    Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

    

    α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
33. The base station according to claim 32, characterized in that, when the rank is equal to 1, each precoding matrix W in the first precoding matrix set further satisfies:

    

    Y ₁ , Y ₂ ∈{e _i }

    Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
34. The base station according to claim 31, wherein each precoding matrix in the second precoding matrix set satisfies W=W ₁ W ₂ ,

    Where W _{1 is} satisfied

    

    or

    

    with

    Where W _{2 is} satisfied

    

    Where B is a constant, D _f is any column of W ₂ , f ∈ {1, 2, ... r}; D _{f is} satisfied

    

    α _f is a complex number, Y ₁ , Y ₂ ∈{e _i }, and e _i represents a column vector having a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈{ 1,2,...Y}, Y is

    

    The number of columns in the middle; or Y is

    

    The number of columns in the middle.
35. The base station according to claim 34, wherein each of the precoding matrices W in the second precoding matrix set further satisfies when the rank is equal to one:

    

    Y ₁ ∈{e _i }

    Where A is a constant, σ _n =e ^jπn/2 , n is an integer, e _i represents a column vector with a dimension of Y×1, the i-th element in the e _i is 1, and the remaining elements are all 0, and i∈ {1,2,...Y}, Y is

    

    The number of columns in the middle, or Y is

    

    The number of columns in the middle.
36. The base station according to any one of claims 32-35, wherein the precoding matrix indication comprises a first precoding matrix indication and a second precoding matrix indication, wherein the first precoding matrix indicates a corresponding W ₁ , the second precoding matrix indicates a corresponding W ₂ .
37. The base station according to claim 36, wherein the first precoding matrix indication comprises a third precoding matrix indication and a fourth precoding matrix indication, the third precoding matrix indication and a fourth precoding matrix Combination and

    

    Correspondingly, the third precoding matrix indicates

    

    Correspondingly, the fourth precoding matrix indicates

    

    correspond.
38. The base station according to claim 37, wherein said third precoding matrix indication and said fourth precoding matrix indication are indicated by means of difference.
39. The base station according to claim 36, wherein the second precoding matrix indicates to include a fifth precoding matrix indication and a sixth precoding matrix indication, the fifth precoding matrix indication and the sixth pre Combination of coding matrices

    

    Correspondingly, the fifth precoding matrix indication corresponds to Y ₁ , and the sixth precoding matrix indication corresponds to Y ₂ .
40. The base station according to claim 39, wherein said fifth precoding matrix indication and said sixth precoding matrix indication are indicated by means of difference.

Images