WO2020063287A1

WO2020063287A1 - Method and apparatus for feeding back channel state information, and terminal, and base station

Info

Publication number: WO2020063287A1
Application number: PCT/CN2019/104420
Authority: WO
Inventors: 李辉; 高秋彬
Original assignee: 电信科学技术研究院有限公司
Priority date: 2018-09-27
Filing date: 2019-09-04
Publication date: 2020-04-02
Also published as: CN110958043A; CN110958043B

Abstract

Disclosed are a method and apparatus for feeding back channel state information, and a terminal, and a base station. The method for feeding back channel state information comprises: a terminal determining PMI groups in PMI information of N sub-bands, where N is the number of sub-bands configured by a base station for the terminal to report channel state information (CSI); and for one PMI group, the terminal selecting M sub-bands from the N sub-bands according to a functional relationship between PMI information in the PMI group, and feeding back PMI information of the M sub-bands and sub-band indication information to the base station, wherein 0＜M≤N, and the sub-band indication information is used for indicating the M sub-bands.

Description

Channel state information feedback method and device, terminal and base station

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on September 27, 2018, with an application number of 201811132990.9 and an invention name of "a method and device for channel state feedback, terminal and base station". Incorporated by reference in this application.

Technical field

The present application relates to the field of wireless communication technologies, and in particular, to a method and device for feeding back channel state information, a terminal, and a base station.

Background technique

In the NR (New Radio Access Technology) system, because it needs to support a large number of antenna ports, it is also required to improve MU-MIMO (Multi-User Multiple-Input Multiple-Output, Multi-User Multiple-Input Multiple-Output Performance), so more complex codebooks need to be designed. Specifically, there are three types of codebooks: a type I single panel (panel) codebook, a type I multi-panel codebook, and a type II single panel codebook. Among them, the type I codebook has low quantization accuracy for the channel, and the PMI feedback overhead is small (on the order of tens of bits); while the type II codebook is designed for MU-MIMO, which has higher channel quantization accuracy and PMI The feedback overhead is large (on the order of hundreds of bits).

The type II codebook is generated based on the beam combining method, which is generated after L beams are weighted by amplitude and phase, and can be configured with L = 2, L = 3, or L = 4.

The terminal calculates channel state information (Channel State Information) through downlink channel measurement. The CSI includes Channel Quality Indication (CQI), Rank Indication (RI), and Precoding Matrix Indicator (PMI), and may also include a channel state information reference signal (also referred to as sounding). Reference Signal (CSI-RS) resource indicates the CRI information.

The feedback of the type II codebook includes a wideband part and a subband part, wherein the wideband part performs parameter calculation and feedback for the entire configured bandwidth, and the subband part performs parameter calculation and feedback for each subband. When the number of subbands is large, the feedback overhead of the type II codebook is mainly determined by the subband portion. When the uplink resource capacity allocated by the base station for CSI reporting is small, the current NR system allows to discard half of the subband PMI information (discard odd subband PMI information) or all subband PMI information to ensure that the remaining CSI can be allocated at the base station. Reporting of uplink resources. However, this discarding method is based on the principle of uniform sampling. It cannot be adjusted according to the characteristics of the actual channel. When the channel characteristics are poor, the discarded subband PMI cannot be accurately recovered, which will cause system performance degradation.

Summary of the Invention

The embodiments of the present application provide a method and a device for feeding back channel state information, which are used to solve a technical problem that a subband PMI discarded when an existing channel state is bad cannot be accurately recovered.

The specific technical solutions provided in the embodiments of the present application are as follows:

An embodiment of the present application provides a method for feeding back channel state information, including:

The terminal determines the PMI group in the PMI information of N subbands, where N is the number of subbands configured by the base station for the terminal to report channel state information CSI;

For a PMI packet, the terminal selects M subbands from the N subbands according to a functional relationship between the PMI information in the PMI packet, and sets the PMI information and the subband indication information of the M subbands. Feedback to the base station, where 0 <M ≦ N, and the subband indication information is used to indicate the M subbands.

In the embodiment of the present application, the base station configures the terminal for the number of subbands for CSI reporting, and the terminal determines the PMI group in the PMI information of the N subbands. For a PMI packet, the terminal selects and reports M subbands from N subbands according to the functional relationship between the PMI information in the PMI packet, where 0 <M ≦ N. The terminal feeds back the PMI information and the subband indication information of the M subbands of each PMI group to the base station, where the subband indication information is used to indicate the M subbands. In this way, the base station can use the functional relationship between the PMI information to determine the PMI information of the remaining NM subbands based on the received PMI information of the M subbands, to ensure that the PMI information of the discarded subbands is recovered more accurately, and System performance. At the same time, the number of reported sub-bands M can also be adjusted by the terminal according to the capacity of the uplink resource, and has a high degree of flexibility.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only for the present application. Some embodiments.

FIG. 1 provides a system architecture diagram according to an embodiment of the present application;

2 is a schematic flowchart of a method for feeding back channel state information according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a feedback method for channel state information according to an embodiment of the present application; FIG.

4 is a schematic diagram of a feedback method for channel state information according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a feedback method for channel state information according to an embodiment of the present application; FIG.

6 is a schematic structural diagram of a device according to an embodiment of the present application;

7 is a schematic structural diagram of another device according to an embodiment of the present application;

8 is a schematic structural diagram of a circuit system according to an embodiment of the present application;

FIG. 9 is a schematic structural diagram of another circuit system according to an embodiment of the present application.

detailed description

The embodiments of the present application provide a method and a device for feeding back channel state information, which are used to solve a technical problem that an existing channel state information feedback method has a large overhead and even affects system performance.

The following describes the system operating environment of this application. The technology described in this application can be applied to LTE systems, such as LTE / LTE-A / eLTE systems, or other wireless communication systems using various wireless access technologies, such as using code division multiple Address (code division multiple access, CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) , Single carrier frequency division multiple access (single carrier-frequency division multiple access, SC-FDMA) and other access technology systems are also suitable for subsequent evolution systems, such as the fifth generation 5G (also known as new radio (new radio) , NR)) system, etc., can also be extended to similar wireless communication systems, such as wifi, wimax, and 3gpp related cellular systems.

Figure 1 shows a schematic diagram of a communication system. The communication system may include at least one base station 100 (only one is shown) and one or more terminals 200 connected to the base station 100.

The base station 100 may be a device capable of communicating with the terminal 200. The base station 100 may be any device having a wireless transmitting and receiving function. Including but not limited to: base station NodeB, eNodeB evolved base station, base station in the fifth generation (5G) communication system, base station or base station in future communication system, access node in WiFi system, wireless relay node , Wireless backhaul nodes, etc. The base station 100 may also be a wireless controller in a cloud radio access network (CRAN) scenario. The base station 100 may also be a base station in a 5G network or a base station in a future evolved network; it may also be a wearable device or a vehicle-mounted device. The base station 100 may also be a small station, a transmission node (TRP), or the like. Of course this application is not limited to this.

Terminal 200 is a device with wireless transceiver function that can be deployed on land, including indoor or outdoor, handheld, wearable, or vehicle-mounted; it can also be deployed on the water (such as a ship); it can also be deployed in the air (such as an airplane, a balloon, etc.) And satellites). The terminal may be a mobile phone, a tablet, a computer with a wireless transmitting and receiving function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, or an industrial control. Wireless terminal in self-driving, wireless terminal in self-driving, wireless terminal in remote medical, wireless terminal in smart grid, wireless terminal in transportation safety, Wireless terminals in smart cities, wireless terminals in smart homes, and so on. The embodiment of the present application does not limit the application scenario. A terminal may also be called a user equipment (UE), an access terminal, a UE unit, a UE station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a UE terminal, a terminal, a wireless communication device, a UE Agent or UE device, etc.

Multiple-input multiple-output (MIMO) technology uses multiple antennas to send multiple channels of data in parallel to obtain additional spatial multiplexing gain. In order to make better use of the complex channel space characteristics, the transmitted data stream is generally pre-coded, and the signal is pre-processed at the transmitting end using channel state information to improve the signal transmission quality.

In the NR system, a Type II codebook is defined, and beamforming is implemented based on a linear combination of the beams in the combined beam set. The beams in the combined beam set are selected from a candidate beam set. Type II codebooks can support codebooks with rank = 1 and rank = 2. When Rank = 1, the precoding matrix W can be expressed as:

When Rank = 2, the precoding matrix W can be expressed as:

Among them, the coefficients in the precoding matrix can be expressed as

L represents the number of beams in the combined beam set,

Represents the beam whose index number is (k1, k2) in the candidate beam set. Each beam in the candidate beam set can be represented by a 2-dimensional DFT vector, which is obtained by a Kronecker product of the DFT vector of the first dimension and the DFT vector of the second dimension, and the beam index k1 represents the index of the DFT vector of the first dimension. The index k2 represents the index of the second dimension DFT vector. The candidate beam set is determined according to the port configuration and the oversampling rate on the base station side. Specifically, the number of antenna ports in each polarization direction of the first dimension is defined as N1, and K1 first-dimensional DFT vectors are generated by using DFT vectors that are oversampled by O1 times, that is, K1 = N1 × O1, the K1 first dimensions In the beam vector, two beam vectors spaced at intervals of O1 beam vectors are orthogonal to each other. Define the number of antenna ports in each polarization direction in the second dimension as N2, and use the DFT vector that is O2 times oversampled to generate K2 second-dimensional beam vectors, that is, K2 = N2 × O2. Among the K2 second-dimensional beam vectors, The two beam vectors of each interval of O2 beam vectors are mutually orthogonal. In this way, the total number of beams in the candidate beam set is K = K1 × K2. For dual-polarized antenna arrays, this beam vector is used for an antenna port in one polarization direction.

The first polarization direction r = 0 and the second polarization direction r = 1 in the dual-polarization antenna array, and l = 0, 1 represent layers, and each layer corresponds to each column of the precoding matrix.

Represents the beam i in the combined beam set, the broadband amplitude factor in the polarization direction r and the first layer;

Represents the subband amplitude factor acting on beam i in the combined beam set in the polarization direction r and layer l; c _{r, l, i} means acting on beam i in the combined beam set, in the polarization direction r and layer l Subband phase factor. The number of antenna ports supported by the codebook structure of the Type II codebook is {4,8,12,16,24,32}.

For each layer, linearly weight all the beams in the combined beam set independently, and quantize the amplitude and phase in the linear weighting coefficients separately to obtain a precoding matrix.

The feedback information of the terminal for the Type II codebook may include a broadband part and a subband part, where the broadband part is to calculate the weighting coefficient parameters for the configured entire bandwidth and feedback the broadband amplitude factor. Specifically, for the Type II codebook, if the base station is configured For wideband amplitude feedback (the weighting coefficient parameter subbandAmplitude is set to 'false'), for the wideband part, the terminal needs to feedback the wideband amplitude factor of each beam over the entire bandwidth; for the subband part, the weighting coefficient parameters are performed for each subband Calculate and feed back the subband amplitude factor and subband phase factor of each beam on each subband. Specifically, if the base station is configured for subband amplitude feedback (the weighting coefficient parameter subbandAmplitude is configured as 'true'), for each subband, the terminal needs to feed back the subband amplitude factor and the subband phase factor of each beam. When the number of subbands is large, the feedback overhead of the Type II codebook is large. Therefore, the feedback overhead of the Type II codebook is mainly determined by the overhead required for the subband part.

When the uplink resource capacity allocated by the base station for CSI reporting is small, the current NR system allows to discard half of the subband PMI information (discard odd subband PMI information) or all subband PMI information to ensure that the remaining CSI can be allocated at the base station. Reporting of uplink resources. However, this discarding method is based on the principle of uniform sampling. It cannot be adjusted according to the characteristics of the actual channel. When the channel characteristics are poor, the discarded subband PMI cannot be accurately recovered, which will cause system performance degradation. In addition, the current discarding method adopts a fixed discarding granularity (or discards half of the subband PMI, or discards all of the subband PMI), and cannot be adjusted according to the capacity of the uplink resource, which has poor flexibility.

In view of the above problem, as shown in FIG. 2, the present application provides a method for feeding back channel state information, including:

Step 201: The terminal determines the PMI group in the PMI information of N subbands, where N is the number of subbands configured by the base station for the terminal to perform CSI reporting.

Step 202: For a PMI packet, the terminal selects M subbands from the N subbands according to a functional relationship between PMI information in the PMI packet, where 0 <M ≦ N.

Step 203: The terminal feeds back the PMI information and the subband indication information of the M subbands to the base station, where the subband indication information is used to indicate the M subbands.

Step 204: The base station receives the PMI information and the subband indication information of the M subbands of the PMI packet fed back by the terminal, where the subband indication information is used to indicate the M subbands.

Step 205: The base station determines the PMI information of the remaining N-M subbands according to the PMI information of the M subbands and the functional relationship.

In step 201, the terminal determining a PMI group in the PMI information of the N subbands includes: determining, by the terminal, a subband amplitude coefficient and / or a subband phase coefficient of the same layer as a PMI group, Or the terminal determines all subband amplitude coefficients of the same layer and / or all subband phase coefficients of the same layer as a PMI packet, or the terminal determines all subband amplitude coefficients of all layers and / or all layers All the subband phase coefficients are a PMI packet.

Specifically, for the number L of different synthetic beams, the system stipulates the number K of subband amplitude coefficients, and the number of subband phase coefficients is 2L. When RI = 1, that is, the number of layers is 1, the PMI information can be expressed in the following form:

The subband amplitude coefficient is:

The subband phase coefficient is:

Among them, p _{K, 1} (N) is the Kth subband amplitude coefficient of the Nth subband, and c _{2L, 1} (N) is the 2Lth subband phase coefficient of the Nth subband, where 1 represents RI = 1.

Then for a subband amplitude coefficient of the same layer is a PMI group, matrix 1 can be divided into K-1 PMI groups, respectively: [p _2,1 (1) p _2,1 (2) p _2,1 ( 3)… p _2,1 (N)], [p _3,1 (1) p _3,1 (2) p _3,1 (3)… p _3,1 (N)],…, [p _{K , 1} (1) p _{K, 1} (2) p _{K, 1} (3)… p _{K, 1} (N)]. That is, for matrix 1, each row is grouped as a PMI. Similarly, a subband phase coefficient for the same layer is a PMI group, that is, for matrix 2, it can be divided into 2L-1 PMI groups, and each row in matrix 2 is used as a PMI group.

In addition, the same subband amplitude coefficient and subband phase coefficient of the same layer can also be used as one PMI group. Since the subband amplitude coefficient is K-1 and the subband phase coefficient is 2L-1, the first subband amplitude coefficient and the first subband phase coefficient are a PMI group, and the second subband amplitude coefficient and the first The two subband phase coefficients are a PMI packet, and so on. Represented by a matrix, the PMI groups are:

...

Among them, if K = 2L, the last PMI packet is

If K is not equal to 2L, the preceding PMI packet may include the subband amplitude coefficient and the subband phase coefficient, and the subsequent PMI packet may include only the subband amplitude coefficient or only the subband phase coefficient.

For all subband amplitude coefficients of the same layer or all subband phase coefficients of the same layer, it is a PMI group. Since there is only one layer when RI = 1, all subband amplitude coefficients of this layer are one PMI group, that is, Matrix 1 acts as a PMI group. In the same way, all subband phase coefficients in this layer are grouped into another PMI, that is, matrix 2 is used as a PMI group.

For all subband amplitude coefficients of the same layer and all subband phase coefficients of the same layer, it is a PMI group. Since there is only one layer when RI = 1, then all subband amplitude coefficients and all subband phases of this layer The coefficient is a PMI group, and matrix 1 and matrix 2 are regarded as the same PMI group, that is, all subband PMI information is regarded as one PMI group at this time.

When RI = 2, that is, the number of layers is 2, the PMI information of the subband can be expressed as follows:

Subband amplitude coefficient of the first layer:

Sub-band amplitude coefficient of the second layer:

The subband phase coefficient of the first layer:

The subband phase coefficient of the second layer:

Among them, p _{K, 1} (N) is the Kth subband amplitude coefficient of the Nth subband in the first layer, p _{K, 2} (N) is the Kth subband amplitude coefficient of the Nth subband in the second layer, c _{2L , 1} (N) is the 2L subband phase coefficient of the Nth subband in the first layer, and c _{2L, 2} (N) is the 2L subband phase coefficient of the Nth subband in the second layer.

For a subband amplitude coefficient of the same layer as a PMI group, matrix 3 can be divided into K-1 PMI groups, which are: [p _2,1 (1) p _2,1 (2) p _2,1 (3 )… P _2,1 (N)], [p _3,1 (1) p _3,1 (2) p _3,1 (3)… p _3,1 (N)], ..., [p _{K, 1} (1) p _{K, 1} (2) p _{K, 1} (3)… p _{K, 1} (N)]. Matrix 5 can be divided into K-1 PMI groups, which are: [p _2,2 (1) p _2,2 (2) p _2,2 (3)… p _2,2 (N)], [p _{3 , 2} (1) p _3,2 (2) p _3,2 (3)… p _3,2 (N)], ..., [p _{K, 2} (1) p _{K, 2} (2) p _{K, 2} (3)… p _{K, 2} (N)]. That is, for matrix 3, each row is grouped as a PMI; for matrix 5, each row is grouped as a PMI.

Similarly, a subband phase coefficient for the same layer is a PMI group, that is, for matrix 4, it can be divided into 2L-1 PMI groups, and each row in matrix 4 is used as a PMI group; for matrix 6, it can be divided into 2L-1 PMI groups, each row in matrix 6 is regarded as a PMI group.

In addition, the same subband amplitude coefficient of the same layer and the same subband phase coefficient of the same layer can also be used as one PMI group. Specifically, the first subband amplitude coefficient of the first layer and the first subband phase coefficient of the first layer are used as one PMI group, and the second subband amplitude coefficient of the first layer and the second layer of the first layer Each subband phase coefficient is a PMI packet, and so on. Use the first subband amplitude coefficient of the second layer and the first subband phase coefficient of the second layer as a PMI group, and the second subband amplitude coefficient of the second layer and the second subband phase of the second layer The coefficients are a PMI group, and so on.

For all subband amplitude coefficients of the same layer or all subband phase coefficients of the same layer, it is a PMI packet. For RI = 2, a PMI packet includes all subband amplitude coefficients or subband phase coefficients of the first layer. A PMI packet includes all subband amplitude coefficients or subband phase coefficients of the second layer, that is, matrix 3, matrix 4, matrix 5, and matrix 6 are one PMI packet, respectively.

For all subband amplitude coefficients of the same layer and all subband phase coefficients of the same layer as one PMI packet, all subband amplitude coefficients of the first layer and all subband phase coefficients of the first layer are one PMI packet. All subband amplitude coefficients of the second layer and all subband phase coefficients of the second layer are one PMI group, that is, matrix 3 and matrix 5 are one PMI group, and matrix 4 and matrix 6 are one PMI group.

For all subband amplitude coefficients of all layers or all subband phase coefficients of all layers, it is a PMI group, that is, all subband amplitude coefficients of all layers are a PMI group, that is, matrix 3 and matrix 4 are the same PMI. Grouping; all subband phase coefficients of all layers are a PMI group, that is, matrix 5 and matrix 6 are the same PMI group.

For all the subband amplitude coefficients of all layers and all the subband phase coefficients of all layers, it is a PMI group, that is, matrix 3, matrix 4, matrix 5, and matrix 6 are the same PMI group, that is, all the The subband PMI information is treated as a PMI packet.

In step 202, the terminal selects M subbands from the N subbands according to the functional relationship between the PMI information in the PMI packet. The M subbands may be uniformly distributed or non-uniformly distributed in the N subbands. According to the frequency selectivity of the channel, the same subband amplitude coefficient and / or subband phase coefficient can be approximated by a certain function, such as an approximately linear distribution, or an approximately piecewise linear distribution, that is, in the PMI grouping, the subband amplitude coefficient and / or subband The band phase coefficient has a functional relationship between multiple subbands. Therefore, according to the functional relationship, M subbands can be selected from the N subbands to be reported, the PMI information of the M subbands can be reported, and the PMI information of the remaining N-M subbands can be discarded, thereby saving PMI information feedback. At the same time, since the M subbands are selected from N subbands according to the functional relationship, the base station can derive the PMI information of the remaining NM subbands based on the received PMI information of the M subbands and the corresponding functional relationship. This ensures that the PMI information of the discarded subbands is accurately recovered and system performance is guaranteed.

Further, the terminal receives the value of M configured by the base station for the terminal; or the terminal determines the value of M and feeds it back or not to the base station.

In the specific implementation process, the value of M can be determined by the terminal according to the uplink resources, it can also be configured for the terminal by the base station, or it can be predefined for the system, which is not limited here. In the embodiment of the present application, the number M of the reported subbands can be adjusted according to the capacity of the uplink resource, and the flexibility is high.

In the embodiment of the present application, the functional relationship between the PMI information is sent by the base station to the terminal, or is predefined by the system, that is, it is predefined between the terminal and the base station, or determined by the terminal, which is not limited herein.

Further, the subband indication information in the embodiments of the present application may be: the indexes of the M subbands or the indexes of the remaining NM subbands, or the bit pattern indications or addresses of the M subbands in the N subbands. The bit pattern indication of the remaining NM subbands in the N subbands, or the sampling factor and offset value of the M subbands in the N subbands, or the remaining NM subbands in the N subbands Sampling factor and offset values in.

In a specific implementation process, the subband indication information may indicate M subbands, and the base station directly determines the M subbands reported by the terminal according to the subband indication information, and derives the remaining NM subband indication information from the subband indication information; or The indication information may indicate the remaining NM subbands, and the base station may directly determine the NM subbands discarded by the terminal according to the subband indication information, and derive the indication information of the M subbands reported by the terminal from the subband indication information.

In addition, in the embodiment of the present application, the form of the subband indication information may be an index of the subband, such as N in the matrix 1 to the matrix 6. Or the form of the subband indication information may be a bit pattern indication of the subband. For example, if N bits are used, where M bits are set to 1, indicating the reported M subbands, and the remaining NM bits are set to 0, it indicates discard. NM subbands. The subband coefficients circled by the rectangular frame shown in FIG. 3 are the PMI information of the M subbands reported in one PMI packet, and can be expressed as 01001 ... (N bits in total). Or the form of the subband indication information may be a sampling factor and an offset value, and the terminal or the base station may determine the position of the reported subband coefficient and the value of M according to the sampling factor and the offset value. For example, in FIG. 3, the base station configures the terminal to feedback N = 16 subbands. According to the uplink resources allocated by the base station and the code rate requirements agreed upon by the system, the terminal determines that the sampling factor is 3, that is, it is selected from every 3 subbands of the N = 16 subbands. One subband reports PMI information. In addition, the terminal determines that the offset value is 1, and the offset value can be obtained by determining an appropriate sampling point according to the distribution of the subband amplitude coefficient and the subband phase coefficient. Then the selected M subbands are N = {2,5,8,11,14}, and the value of M is 5.

In order to understand this application more clearly, the above process will be described in detail in the following specific embodiments.

Example one

It is assumed that the base station configures the terminal to feedback Type = II CSI information of N = 16 subbands, and allocates uplink resources to the terminal for CSI feedback. The number of synthetic beams in the Type II codebook configured by the base station is L = 4 (at this time, the system specifies the number of subband amplitude coefficients K = 6).

The terminal receives the codebook configuration information of the base station, and determines the PMI information of the N = 16 subbands. Assume that the terminal determines that RI = 2, and the subband amplitude coefficient and subband phase coefficient included in the PMI information of N = 16 subbands in the corresponding CSI information are as follows:

Subband amplitude coefficient of the first layer:

Sub-band amplitude coefficient of the second layer:

The subband phase coefficient of the first layer:

The subband phase coefficient of the second layer:

If the system agrees, a PMI packet includes all subband amplitude coefficients of all layers and all subband phase coefficients of all layers; it is agreed that M subbands are uniformly distributed, and the indication information of the subbands is the sampling factor and offset value. The terminal determines that the sampling factor is 3 according to the uplink resources allocated by the base station and the agreed code rate requirements of the system, that is, the PMI information is reported from every 3 subbands of the N = 16 subbands. The offset value can be obtained by determining appropriate sampling points according to the distribution of the subband amplitude coefficient and the subband phase coefficient (for example, according to the piecewise linear characteristic of the subband coefficient). For example, if the terminal determines that the offset value is 1, it selects the PMI information of the subbands with N = {2,5,8,11,14}, such as the subband coefficients in the box of FIG. 3, for reporting. At this time, the value of M is 5. The PMI information of the remaining subbands is discarded.

The base station receives the above PMI information of M = 5 subbands, and at the same time receives the sampling factor and offset value reported by the terminal. The base station uses a linear interpolation method to determine the subband amplitude coefficients and subband phase coefficients of the 11 discarded subbands.

Example two

Subband amplitude coefficient of the first layer:

Sub-band amplitude coefficient of the second layer:

The subband phase coefficient of the first layer:

The subband phase coefficient of the second layer:

If it is determined that all the subband amplitude coefficients of the same layer and all the subband phase coefficients of the same layer are a PMI group, all the subband coefficients are divided into two groups. The system stipulates that the M subbands are non-uniformly distributed, and the indication information of the subbands is the index value of the M subbands of each layer. The terminal determines M = 4 according to the uplink resources allocated by the base station and the code rate requirements agreed by the system. And the index value of the subband can be obtained by determining appropriate sampling points according to the distribution of the subband amplitude coefficient and the subband phase coefficient (for example, according to the piecewise linear characteristic of the subband coefficient). For example, the terminal determines that the M subbands of the first layer are N = {1,2,5,16}, and the M subbands of the second layer are N = {1,3,4,16}, as shown in the box in FIG. 4 Subband coefficient of. For the remaining subbands, the subband PMI information in the CSI information is discarded. The terminal reports the indexes of the M subbands of each layer to the base station.

For each PMI packet (that is, each layer), the base station receives the above-mentioned PMI information of M = 4 subbands, and simultaneously receives the index of M = 4 subbands of each layer reported by the terminal. The base station uses a linear interpolation method to determine the subband amplitude coefficients and subband phase coefficients of the 12 discarded subbands in each layer.

Example three

The terminal receives the codebook configuration information of the base station, and determines the Type II CSI of the N = 16 subbands. Assume that the terminal determines that RI = 1, that is, the number of layers is 1. The subband amplitude coefficient and subband phase coefficient included in the corresponding CSI information of N = 16 subband PMIs are as follows:

Subband amplitude coefficient:

Subband phase coefficient:

If it is determined that a subband amplitude coefficient of the same layer or a subband phase coefficient of the same layer is a PMI group, all subband coefficients are divided into K-1 + 2L-1 groups. Assume that the system stipulates that the M subbands are non-uniformly distributed, and the subband indication information is the index values of the M subbands. The terminal determines M = 4 according to the uplink resources allocated by the base station and the code rate requirements agreed by the system. An index value of each subband coefficient may be obtained by determining an appropriate sampling point according to a distribution of the subband coefficient (for example, according to a piecewise linear characteristic of the subband coefficient). For example, the terminal determines that the M subbands of the PMI packet [p _2,1 (1) p _2,1 (2) p _2,1 (3)… p _2,1 (N)] are N = {1,2,5, 16}, M = 4 subbands of PMI grouping [p _{K, 1} (1) p _{K, 1} (2) p _{K, 1} (3)… p _{K, 1} (N)] are {1,3,4, 5}, and so on. The subband coefficients are shown in the box in FIG. 5. That is, subband selection is performed independently for each subband coefficient of each layer. The subband PMI information of the remaining subbands is discarded. The terminal reports the M subband indexes of each PMI packet to the base station.

The base station receives the subband PMI information of the above M subbands, and at the same time receives the index of M = 4 subbands of each subband PMI information reported by the terminal. The base station determines the subband PMI information of the 12 discarded subbands by using a linear interpolation method.

Based on the same application concept, as shown in FIG. 6, an apparatus 20 provided in an embodiment of the present application includes at least one processor 21, a communication bus 22, a memory 23, and at least one communication interface 24.

Exemplarily, the terminal 200 in FIG. 1 may also be the device 20 shown in FIG. 6. The device 20 may implement the steps related to the terminal in the method for feeding back channel state information in the embodiment of the present application through the processor 21.

For example, the base station 100 in FIG. 1 may also be the device 20 shown in FIG. 6. The device 20 may implement the steps related to the network device in the method for feeding back channel state information in the embodiment of the present application through the processor 21.

The processor 21 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the solution of the present application.

The communication bus 22 may include a path for transmitting information between the aforementioned components. The communication interface 24 uses any device such as a transceiver to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), WALN, and the like.

The memory 23 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (random access memory, RAM), or other types that can store information and instructions The dynamic storage device can also be electrically erasable programmable read-only memory (EEPROM-ready-only memory (EEPROM)), compact disc (read-only memory (CD-ROM)) or other optical disk storage, optical disk storage (Including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), disk storage media or other magnetic storage devices, or can be used to carry or store the desired program code in the form of instructions or data structures and can be used by Any other media that the device accesses, but is not limited to. The memory may exist independently and be connected to the processor through a bus. The memory can also be integrated with the processor.

The memory 23 is configured to store application program code that executes the solution of the present application, and is controlled and executed by the processor 21. The processor 21 is configured to execute application program code stored in the memory 23.

In a specific implementation, as an embodiment, the processor 21 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 6.

In a specific implementation, as an embodiment, the apparatus 20 may include multiple processors, such as the processor 21 and the processor 28 in FIG. 7. Each of these processors may be a single-CPU processor or a multi-CPU processor. A processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (such as computer program instructions).

In the embodiment of the present application, the function module of the device shown in FIG. 6 may be divided according to the foregoing method example. For example, each function module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. . The above integrated modules may be implemented in the form of hardware or software functional modules. It should be noted that the division of the modules in the embodiments of the present application is schematic, and is only a logical function division. In actual implementation, there may be another division manner.

In this embodiment, the device shown in FIG. 6 is presented in the form of dividing each functional module corresponding to each function, or the device is presented in the form of dividing each functional module in an integrated manner. "Module" herein may refer to application-specific integrated circuits (ASICs), circuits, processors and memories that execute one or more software or firmware programs, integrated logic circuits, and / or other functions that may provide the above functions Device.

For example, in a case where each functional module is divided corresponding to each function, FIG. 7 shows a possible structural schematic diagram of the device involved in the foregoing embodiment, and the device 900 may be a terminal or a network device in the foregoing embodiment. The device 900 includes a processing unit 901 and a transceiving unit 902. The transceiver unit 902 is configured to transmit and receive signals to and from the processing unit 901. The method executed by the processing unit 901 in FIG. 7 may be implemented by the processor 21 (and / or the processor 28) and the memory 23 of FIG. 6. Specifically, the method executed by the processing unit 901 may be performed by the processor 21 ( And / or the processor 28) to call the application program code stored in the memory 23 for execution, which is not limited in the embodiment of the present application.

In specific implementation, taking the device 900 as an example of the terminal in the foregoing embodiments, an embodiment of the present application provides a feedback device for channel state information, including:

A processing unit 901 is configured to determine a PMI group in the PMI information of N subbands, where N is the number of subbands configured by the base station for the terminal to perform channel state information CSI reporting; for a PMI group, according to the PMI in the PMI group A functional relationship between the information, and M subbands are selected from the N subbands; where 0 <M ≦ N, the subband indication information is used to indicate the M subbands;

The transceiver unit 902 is configured to feed back the PMI information and the subband indication information of the M subbands to the base station.

In a possible implementation manner, the processing unit 901 is specifically configured to determine a subband amplitude coefficient of the same layer and / or a subband phase coefficient of the same layer as a PMI group, or determine all subband amplitude coefficients of the same layer. And / or all subband phase coefficients of the same layer are one PMI group, or it is determined that all subband amplitude coefficients of all layers and / or all subband phase coefficients of all layers are one PMI group.

In a possible implementation manner, the subband indication information is: an index of the M subbands or indexes of the remaining NM subbands, or a bit pattern indication of the M subbands in the N subbands or the A bit pattern indication of the remaining NM subbands in the N subbands, or a sampling factor and an offset value of the M subbands in the N subbands, or the remaining NM subbands in the N subbands Sampling factor and offset.

In a possible implementation manner, the transceiver unit 902 is further configured to receive the value of M configured by the base station; or feedback or not feedback the value of M to the base station.

In a possible implementation manner, the functional relationship is sent by the base station to the terminal, or is predefined by a system, or determined by the terminal.

Based on the same application concept, an embodiment of the present application further provides a circuit system. FIG. 8 is a schematic structural diagram of the circuit system provided in the embodiment of the present application (for example, an access point or a communication device such as a base station, a site, or a terminal).

As shown in FIG. 8, the circuit system 1200 may be implemented by using the bus 1201 as a general bus architecture. Depending on the specific application of the circuit system 1200 and the overall design constraints, the bus 1201 may include any number of interconnected buses and bridges. The bus 1201 connects various circuits together, and these circuits include a processor 1202, a storage medium 1203, and a bus interface 1204. Optionally, the circuit system 1200 uses the bus interface 1204 to connect the network adapter 1205 and the like via the bus 1201. The network adapter 1205 may be used to implement signal processing functions of a physical layer in a wireless communication network, and to transmit and receive radio frequency signals through an antenna 1207. The user interface 1206 can be connected to a user terminal, such as a keyboard, a display, a mouse, or a joystick. The bus 1201 can also be connected with various other circuits, such as a timing source, a peripheral device, a voltage regulator, or a power management circuit. These circuits are well known in the art, and therefore will not be described in detail.

Alternatively, the circuit system 1200 may also be configured as a chip or a system-on-chip, the chip or system-on-chip including: one or more microprocessors that provide processor functions; and external memory that provides at least a portion of the storage medium 1203, all of which All are connected to other supporting circuits through an external bus architecture.

Alternatively, the circuit system 1200 may be implemented using: an ASIC (Application Specific Integrated Circuit) having a processor 1202, a bus interface 1204, and a user interface 1206; and at least a portion of a storage medium 1203 integrated in a single chip, or, The circuit system 1200 may be implemented using one or more FPGAs (field programmable gate arrays), PLDs (programmable logic devices), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, Or any combination of circuits capable of performing the various functions described throughout this application.

Among them, the processor 1202 is responsible for managing the bus and general processing (including executing software stored on the storage medium 1203). The processor 1202 may be implemented using one or more general-purpose processors and / or special-purpose processors. Examples of processors include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Software should be interpreted broadly to mean instructions, data, or any combination thereof, whether it be referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

The storage medium 1203 is shown as separate from the processor 1202 in the following figure, however, it is easy for those skilled in the art to understand that the storage medium 1203 or any part thereof may be located outside the circuit system 1200. For example, the storage medium 1203 may include a transmission line, a carrier wave waveform modulated with data, and / or a computer product separated from a wireless node. All of these media may be accessed by the processor 1202 through the bus interface 1204. In the alternative, the storage medium 1203 or any portion thereof may be integrated into the processor 1202, for example, it may be a cache and / or a general-purpose register.

The processor 1202 may execute the signal state information feedback method in any of the foregoing embodiments of the present application, and specific details are not described herein again.

FIG. 9 is another schematic structural diagram of a circuit system according to an embodiment of the present application. The circuit system may be a processor. The processor may be embodied as a chip or a system on chip (SOC), and is disposed in a base station or terminal of the wireless communication system in the embodiment of the present application, so that the base station or terminal implements channel state information in the embodiment of the present application. Feedback method. As shown in FIG. 9, the circuit system 60 includes: an interface unit 601, a control and operation unit 602, and a storage unit 603. The interface unit is used to communicate with other components of the base station or terminal, the storage unit 603 is used to store computer programs or instructions, and the control and operation unit 602 is used to decode and execute these computer programs or instructions. It should be understood that these computer programs or instructions may include the foregoing terminal function programs, and may also include the foregoing base station function programs. When the terminal function program is decoded and executed by the control and operation unit 602, the terminal can enable the terminal to implement the method for indicating the uplink subband precoding matrix in the embodiment of the present application, and the functions of the terminal. When the base station function program is decoded and executed by the control and operation unit 602, the base station can be caused to implement the function of the base station in the signal state information feedback method in the embodiment of the present application.

In one possible design, these terminal function programs or base station function programs are stored in a memory external to the circuit system 60. When the terminal function program or the base station function program is decoded and executed by the control and operation unit 602, the storage unit 603 temporarily stores part or all of the terminal function program, or temporarily or partly or partially stores the base station function program.

In another optional implementation manner, these terminal function programs or base station function programs are provided in a storage unit 603 stored in the circuit system 60. When the terminal function program is stored in the storage unit 603 inside the circuit system 60, the circuit system 60 may be set in the terminal 200 of the wireless communication system in the embodiment of the present application. When the base station function program is stored in the storage unit 603 inside the circuit system 60, the circuit system 60 may be set in the base station 100 of the wireless communication system in the embodiment of the present application.

In another optional implementation manner, part of the content of these terminal function programs or base station function programs is stored in a memory external to the circuit system 60, and content of these terminal function programs or other parts of the base station function program is stored in the circuit system 60. In the storage unit 603.

Based on the same concept, the present application provides a computer-readable storage medium. The computer-readable storage medium stores instructions that, when run on a computer, cause the computer to execute the various embodiments and terminals of the present application. Related method steps.

Based on the same concept, the present application provides a computer-readable storage medium. The computer-readable storage medium stores instructions that, when run on a computer, causes the computer to execute the base station and the base station in various embodiments involved in the present application. Related method steps.

Based on the same concept, this application provides a computer program product containing instructions that, when run on a computer, causes the computer to execute the method-related steps of the terminal in the various embodiments involved in this application.

Based on the same concept, the present application provides a computer program product containing instructions, which when executed on a computer, causes the computer to execute the method steps related to the base station in the various embodiments involved in the present application.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be from a website site, computer, server, or data center Transmission by wire (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) to another website site, computer, server, or data center. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, a data center, and the like that includes one or more available medium integration. The available medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (Solid State Disk (SSD)), and the like.

Those skilled in the art can clearly understand that the descriptions of the embodiments provided in this application can refer to each other. For the convenience and brevity of description, the functions of the devices and equipment and the steps performed by the embodiments of this application can be described. With reference to the related description of the method embodiments of the present application, details are not described herein.

Although the present application is described in conjunction with the embodiments herein, in the process of implementing the claimed application, those skilled in the art can understand and understand by viewing the drawings, the disclosure, and the appended claims. Other variations of the disclosed embodiments are implemented. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude the case of a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. Certain measures are recited in mutually different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

Those skilled in the art should understand that the embodiments of the present application may be provided as a method, an apparatus (device), or a computer program product. Therefore, this application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects, which are collectively referred to herein as a "module" or "system". Moreover, this application may take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The computer program is stored / distributed in a suitable medium, provided with or as part of the hardware, or in other distributed forms, such as via the Internet or other wired or wireless telecommunications systems.

Those skilled in the art can also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the various illustrative components and steps described above have generically described their functions. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art can use various methods to implement the described functions for each specific application, but such implementation should not be construed as beyond the scope of protection of the embodiments of the present application.

Various illustrative logic blocks, modules, and circuits described in the embodiments of the present application may be implemented by a general-purpose processing unit, a digital signal processing unit, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic. Devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above are designed to implement or operate the described functions. The general-purpose processing unit may be a micro-processing unit. Alternatively, the general-purpose processing unit may also be any conventional processing unit, controller, microcontroller, or state machine. The processing unit may also be implemented by a combination of computing devices, such as a digital signal processing unit and a micro processing unit, multiple micro processing units, one or more micro processing units combined with a digital signal processing unit core, or any other similar configuration. achieve.

In one or more exemplary designs, the above functions described in the embodiments of the present application may be implemented in hardware, software, firmware, or any combination of the three. If implemented in software, these functions can be stored on a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media and communication media that facilitates transfer of computer programs from one place to another. Storage media can be any available media that can be accessed by a general purpose or special computer. For example, such computer-readable media may include, but is not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other device or instructions that can be used to carry or store instructions or data structures and Other media that can be read by a general or special computer or a general or special processing unit. In addition, any connection can be appropriately defined as a computer-readable medium, for example, if the software is from a web site, server, or other remote resource via a coaxial cable, fiber optic computer, twisted pair, digital subscriber line (DSL) Or transmitted wirelessly such as infrared, wireless, and microwave are also included in the defined computer-readable media. The disks and discs include compact disks, laser disks, optical disks, DVDs, floppy disks and Blu-ray disks. Disks usually copy data magnetically, and disks usually copy data optically with lasers. A combination of the above may also be contained in a computer-readable medium.

The above description of the specification of this application can make any technology in the art can utilize or implement the content of this application. Any modification based on the disclosed content should be considered as obvious in the art. The basic principles described in this application can be applied to other variations. Without departing from the nature and scope of the application. Therefore, the content disclosed in this application is not limited to the described embodiments and designs, but can also be extended to the maximum extent consistent with the principles of this application and the new features disclosed.

Claims

A method for feeding back channel state information includes:

The terminal determines the PMI group in the precoding matrix indicating the PMI information of the N subbands, where N is the number of subbands configured by the base station for the terminal to report channel state information CSI;

For a PMI packet, the terminal selects M subbands from the N subbands according to a functional relationship between the PMI information in the PMI packet, and sets the PMI information and the subband indication information of the M subbands. Feedback to the base station, where 0 <M ≦ N, and the subband indication information is used to indicate the M subbands.
The method according to claim 1, wherein the determining the PMI group in the PMI information of the N subbands comprises:

Determining, by the terminal, a subband amplitude coefficient and / or a subband phase coefficient of the same layer as a PMI packet, or

The terminal determines that all subband amplitude coefficients of the same layer and / or all subband phase coefficients of the same layer are one PMI packet, or

The terminal determines that all subband amplitude coefficients of all layers and / or all subband phase coefficients of all layers are a PMI packet.
The method of claim 1, wherein:

The subband indication information is an index of the M subbands or the indexes of the remaining N-M subbands, or

The subband indication information is a bit pattern indication of the M subbands in the N subbands, or the subband indication information is a bit pattern indication of the remaining NM subbands in the N subbands, or

The subband indication information is a sampling factor and an offset value of the M subbands in the N subbands, or the subband indication information is a sample of the remaining NM subbands in the N subbands Factor and offset values.
The method according to any one of claims 1 to 3, further comprising:

Receiving, by the terminal, the value of M configured by the base station for the terminal;

Alternatively, the terminal determines the value of M and feeds back or not feeds back to the base station.
The method according to any one of claims 1 to 3, wherein the functional relationship is sent by the base station to the terminal, or is predefined by a system, or determined by the terminal.
A method for feeding back channel state information includes:

The base station receives the PMI information and the subband indication information of the M subbands of the precoding matrix indicated by the terminal, and the subband indication information is used to indicate the M subbands;

The PMI information of the M subbands is that the terminal selects the PMI information of the M subbands from the N subbands according to the functional relationship between the PMI information in the PMI packet, where N is the base station and the PMI information is the The number of subbands configured by the terminal for CSI reporting, 0 <M≤N.
The method according to claim 6, wherein after the base station receives the PMI information and the subband indication information of the M subbands fed back by the terminal, further comprising:

The base station determines PMI information of the remaining N-M subbands according to the PMI information of the M subbands and the functional relationship.
The method according to claim 6, wherein a subband amplitude coefficient of the same layer and / or a subband phase coefficient of the same layer is a PMI packet, or

All subband amplitude coefficients of the same layer and / or all subband phase coefficients of the same layer are a PMI packet, or

All subband amplitude coefficients of all layers and / or all subband phase coefficients of all layers are a PMI packet.
The method according to claim 6, characterized in that:

The subband indication information is an index of the M subbands or the indexes of the remaining N-M subbands, or

The subband indication information is a bit pattern indication of the M subbands in the N subbands, or the subband indication information is a bit pattern indication of the remaining NM subbands in the N subbands, or

The subband indication information is a sampling factor and an offset value of the M subbands in the N subbands, or the subband indication information is a sample of the remaining NM subbands in the N subbands Factor and offset values.
The method according to any one of claims 6 to 9, further comprising:

Configuring, by the base station, the value of M for the terminal, and sending the value to the terminal;

Alternatively, the base station receives the value of M determined by the terminal.
The method according to any one of claims 6 to 9, wherein the functional relationship is sent by the terminal to the base station, or is predefined by a system, or determined by the base station itself.
A feedback device for channel state information, comprising:

A processing unit, configured to determine a PMI group in a precoding matrix indicating PMI information of N subbands; where N is the number of subbands configured by the base station for the terminal to perform channel state information CSI reporting; for one PMI group, according to the PMI The functional relationship between the PMI information in the packet is to select M subbands from the N subbands; where 0 <M ≦ N, the subband indication information is used to indicate the M subbands;

The transceiver unit is configured to feed back the PMI information and the subband indication information of the M subbands to the base station.
A feedback device for channel state information, comprising:

A transceiver unit for receiving PMI information of the M subbands of the precoding matrix indicated by the terminal and PMI packets and subband indication information, where the subband indication information is used to indicate the M subbands; the PMI of the M subbands The information is that the terminal selects PMI information of M subbands from N subbands according to a functional relationship between the PMI information in the PMI packet, where N is a CSI report configured by the base station for the terminal. Number of subbands, 0 <M≤N;

A processing unit, configured to determine the PMI information of the remaining N-M subbands according to the PMI information of the M subbands and the functional relationship.
A terminal, comprising: a processor, a memory, and a bus interface, wherein the processor and the memory are connected through the bus interface;

The processor is configured to determine a precoding matrix indicating PMI grouping in the PMI information of N subbands, where N is the number of subbands configured by the base station for the terminal to perform channel state information CSI reporting; for one PMI group, The functional relationship between the PMI information in the PMI packet, and M subbands are selected from the N subbands; where 0 <M≤N, the subband indication information is used to indicate the M subbands; and

Feedback the PMI information and the subband indication information of the M subbands to the base station;

The memory is configured to store one or more executable programs and store data used by the processor when performing operations;

The bus interface is used to provide an interface.
The terminal according to claim 14, wherein the processor is specifically configured to:

Determine a subband amplitude coefficient and / or a subband phase coefficient of the same layer as a PMI packet, or

Determine all subband amplitude coefficients of the same layer and / or all subband phase coefficients of the same layer as a PMI packet, or

It is determined that all subband amplitude coefficients of all layers and / or all subband phase coefficients of all layers are a PMI packet.
The terminal according to claim 14, wherein:

The subband indication information is an index of the M subbands or the indexes of the remaining N-M subbands, or

The subband indication information is a bit pattern indication of the M subbands in the N subbands, or the subband indication information is a bit pattern indication of the remaining NM subbands in the N subbands, or

The subband indication information is a sampling factor and an offset value of the M subbands in the N subbands, or the subband indication information is a sample of the remaining NM subbands in the N subbands Factor and offset values.
The terminal according to any one of claims 14 to 16, wherein the processor is further configured to:

Receiving the value of M configured by the base station for the terminal;

Alternatively, the value of M is determined and fed back or not fed back to the base station.
A base station, comprising: a processor, a memory, and a bus interface, wherein the processor and the memory are connected through the bus interface;

The processor is configured to receive the PMI information of the M subbands of the precoding matrix indicated by the terminal and PMI packets and subband indication information, and the subband indication information is used to indicate the M subbands; the M subbands The PMI information of the terminal is based on the functional relationship between the PMI information in the PMI packet, and the PMI information of M subbands is selected from N subbands, where N is the CSI configured by the base station for the terminal. Number of reported subbands, 0 <M≤N; and

Determining PMI information of the remaining N-M subbands according to the PMI information of the M subbands and the functional relationship;

The memory is configured to store one or more executable programs and store data used by the processor when performing operations;

The bus interface is used to provide an interface.
The base station according to claim 18, wherein the processor is further configured to:

After receiving the PMI information and the subband indication information of the M subbands fed back by the terminal, the PMI information of the remaining N-M subbands is determined according to the PMI information of the M subbands and the functional relationship.
The base station according to claim 18, wherein a subband amplitude coefficient and / or a subband phase coefficient of the same layer is a PMI packet, or

All subband amplitude coefficients of the same layer and / or all subband phase coefficients of the same layer are a PMI packet, or

All subband amplitude coefficients of all layers and / or all subband phase coefficients of all layers are a PMI packet.
The base station according to claim 18, wherein:

The subband indication information is an index of the M subbands or the indexes of the remaining N-M subbands, or

The subband indication information is a bit pattern indication of the M subbands in the N subbands, or the subband indication information is a bit pattern indication of the remaining NM subbands in the N subbands, or

The subband indication information is a sampling factor and an offset value of the M subbands in the N subbands, or the subband indication information is a sample of the remaining NM subbands in the N subbands Factor and offset values.
The base station according to any one of claims 18 to 21, wherein the processor is further configured to:

Configure the value of M for the terminal, and send the value to the terminal;

Or, receiving the value of M determined by the terminal.
The base station according to any one of claims 18 to 21, wherein the functional relationship is sent by the terminal to the base station, or is predefined by a system, or determined by the base station itself.