TWI622276B - Channel state information acquisition method, channel state information feedback method and device - Google Patents

Abstract

The invention discloses a channel state information acquisition method, a channel state information feedback method and a device, comprising: the terminal performs channel estimation according to the received pilot signal, and obtains channel estimation values of A antennas, and the A antennas are networks. The device transmits A antennas of the pilot signals; the terminal determines Q antennas according to the channel estimation values of the A antennas, L Q A, L is the value of the RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal; the terminal determines the number according to the Q antenna The first level precoding matrix indicates information, and the channel state information CSI including the first level precoding matrix indication information is returned to the network device, where the first level precoding matrix indication information is used to indicate that the Q antennas are in the The index in the A antennas of the transmitted pilot signal.

Description

Channel state information acquisition method, channel state information feedback method and device

The invention belongs to the field of communication technologies, in particular to a channel state information acquisition method, a channel state information feedback method and device.

In the existing multi-input multi-output (MIMO) antenna system based on Frequency Division Duplexing (FDD), the number of antennas of the network equipment is relatively small, and the terminal measures the complete MIMO channel matrix without problems. . The pilot used to measure the channel state information (CSI) usually configures an antenna port for each antenna to transmit a pilot signal.

The pilot used to measure CSI is referred to as a reference signal, including a cell-specific reference signal (CRS), in an LTE-Advanced (LTE-Advanced is an evolution of LTE, LTE is an abbreviation for Long Term Evolution, Chinese is a long-term evolution) system. , Cell-specific Reference Signal) and Channel Status Information Reference Signal (CSI-RS). The terminal determines an optimal channel level indication (RI, Rank Indication), a precoding matrix indicator (PMI), and a channel quality indicator (CQI) based on the measured CSI, and reports to the network through the feedback channel. Road equipment.

Massive MIMO technology can effectively improve spatial resolution and system capacity by arranging large-scale antenna arrays on network devices, usually hundreds of antennas. The same day When the line is arranged in a two-dimensional uniform rectangular array (URA, Uniform Rectangular Array), high three-dimensional (level and vertical) resolution can be achieved.

At present, there is no technical solution for CSI feedback and acquisition for large-scale MIMO systems.

The embodiment of the invention provides a channel state information acquisition method, a channel state information feedback method and a device, which are used for implementing feedback and acquisition of channel state information.

The channel state information feedback method provided by the embodiment of the present invention includes: the terminal performs channel estimation according to the received pilot signal, and obtains channel estimation values of A antennas, and the A antennas transmit pilot signals for the network device. A antenna 埠; the terminal determines Q antenna 根据 according to the channel estimation value of the A antenna 埠, wherein, L Q A, L is the value of the RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal; the terminal determines the number according to the Q antenna The first level precoding matrix indicates information, and the channel state information CSI including the first level precoding matrix indication information is fed back to the network device, where the first level precoding matrix indication information is used to indicate that the Q antennas are transmitting The index in the A antennas of the pilot signal.

An embodiment of the present invention provides a terminal, including a processor, a memory, and a transceiver. The processor is configured to read a program in the memory, and perform the following process: performing channel estimation according to the received pilot signal. Obtaining channel estimation values of A antennas 埠, the A antennas are A antennas for transmitting pilot signals by the network device; and determining Q antennas according to channel estimation values of the A antennas, wherein, L Q A, L is the value of the level indication RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal; and is used to determine the number according to the Q antennas The first level precoding matrix indicates information, and the channel state information CSI including the first level precoding matrix indication information is fed back to the network device, where the first level precoding matrix indication information is used to indicate that the Q antennas are transmitting An index in the A antennas of the pilot signal; the transceiver is used to receive and transmit data.

According to the channel state information feedback method and terminal provided by the embodiment of the present invention, the terminal performs channel estimation on the received pilot signal, and determines Q from the A antennas of the network device according to the estimated equivalent channel. Antenna 用于 for channel status information measurement to obtain channel status information. When the above embodiment is applied to the MIMO channel matrix measurement process, the terminal converts the measurement of the MIMO channel matrix into Q antennas for channel state information measurement from among the A antennas of the network device, which is equivalent to All the pilot antennas of the network device measure the signal and select the antenna to determine the channel status information of the terminal.

The embodiment of the present invention provides a channel state information acquiring method, where the method includes: the network device receives the channel state information CSI fed back by the terminal, where the CSI includes at least a first level precoding matrix indication information, and the first level precoding matrix The indication information is used to indicate an index of the Q antennas in the A antennas that transmit the pilot signals, where the first level precoding matrix indication information is the Q antennas determined by the terminal according to the channel estimation values of the A antennas. , determined according to the Q antennas, L Q A, L is the value of the RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal; the network device according to the received CSI And determining, by the beamforming vector corresponding to the A antennas, a first level precoding matrix; and determining, by the network device, the transmitting precoding matrix according to the first level precoding matrix.

An embodiment of the present invention provides a network device, including a processor, a memory, and a transceiver. The processor is configured to read a program in the memory, and perform the following process: receiving channel state information CSI of the terminal feedback. The CSI includes at least a first level precoding matrix indication information, where the first level precoding matrix indication information is used to indicate an index of the Q antennas in the A antennas of the pilot signal, the first level pre The coding matrix indication information is determined by the Q antennas determined by the terminal according to the channel estimation values of the A antennas, and is determined according to the Q antennas, L Q A, L is a value indicating the RI used by the network device to send downlink data to the terminal, or L is a value of the channel level indication RI determined by the terminal; and is used according to the received CSI and the A beamforming vector corresponding to the A antennas determines a first level precoding matrix; and is configured to determine a transmission precoding matrix according to the first level precoding matrix; the transceiver is configured to receive and send data.

According to the channel state information acquiring method and the network device provided by the embodiment of the present invention, the channel state information of the terminal feedback received by the network device includes at least a first level precoding matrix. Instructing information that the first-level precoding matrix indication information is determined by the Q antennas determined by the terminal according to the channel estimation values of the A antennas, and can reflect the channel state information of each terminal to a certain extent, thereby When the above embodiment is applied to a massive MIMO system, the design and implementation of the massive MIMO system is simplified by utilizing the characteristics of the massive MIMO system.

Steps 101-103, 401-403, 501-507, 601-603, 701-703‧‧

201‧‧‧ dotted line

202‧‧‧solid line

601‧‧‧ receiving unit

602‧‧‧First determination unit

603‧‧‧Second determination unit

701‧‧‧channel estimation unit

702‧‧‧Determining unit

703‧‧‧Send unit

800‧‧‧ processor

810‧‧‧ transceiver

820‧‧‧ memory

900‧‧‧ processor

910‧‧‧ transceiver

920‧‧‧ memory

930‧‧‧User interface

1 is a schematic flowchart of a method for acquiring channel state information according to an embodiment of the present invention; FIG. 2 is a schematic diagram of a spatial range that a spatial beam direction should cover; FIG. 3 is a schematic diagram of an antenna device in a network device transmitting on all antennas according to an embodiment of the present invention; FIG. 4 is a schematic flowchart of a channel state information feedback method according to an embodiment of the present invention; FIG. 5 is a schematic flowchart of a method for acquiring channel state information according to an embodiment of the present invention; FIG. 7 is a structural diagram of a terminal according to an embodiment of the present invention; FIG. 8 is a structural diagram of a base station according to an embodiment of the present invention; A structural diagram of a user device.

In the embodiment of the present invention, an Orthogonal Frequency Division Multiplexing (OFDM) system is taken as an example. For example, an LTE-Advanced system, all descriptions are directed to one subcarrier unless otherwise specified. In the embodiment of the present invention, the lowercase bold letters represent column vectors, and the uppercase bold letters represent matrixes, ” denotes Kronecker product, superscript “ T ” denotes transpose of matrix or vector, superscript “ H ” denotes conjugate transpose of matrix or vector. As shown in Fig. 1, the embodiment of the invention provides A channel state information obtaining method, the method comprising:

Step 101: The network device receives the CSI fed back by the terminal, where the CSI includes at least a first level precoding matrix indication information, where the first level precoding matrix indication information is used to indicate that the Q antennas are transmitting the pilot signal. An index in the antenna 埠, the first-stage precoding matrix indication information is Q antennas determined according to the channel estimation values of the A antennas, and determined according to the Q antennas, L Q A, L is the value of the level indication RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal.

It should be noted that there are various methods for determining the value of the RI determined by the terminal, which is not limited by the embodiment of the present invention. After determining the value of the RI, the terminal may also send the value of the RI to the network device as part of the CSI. The network device may determine the data layer used when transmitting the downlink data to the terminal according to the value of the received RI. (Layer) and the number of data layers.

The value of L can be determined according to the actual situation.

For example, in a SU-MIMO (Single-User MIMO) system, the data layer and the data layer used by the network device to send downlink data to the terminal are generally equal to the value of the RI sent by the terminal. At this time, L is the value of the RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal.

For example, in MU-MIMO (Multi-User MIMO, multi-user In the MIMO system, the data layer and the data layer used by the network device to send downlink data to the terminal may not be equal to the value of the RI sent by the terminal. In this case, L is the value of the channel level indication RI determined by the terminal. .

Step 102: The network device determines a first-stage precoding matrix according to the received CSI and a beamforming vector corresponding to the A antennas.

Step 103: The network device determines to send a precoding matrix according to the first level precoding matrix.

Before step 101, the network device sends a pilot signal to the terminal through A antennas.

Optionally, the process of the network device sending the pilot signal to the terminal through the A antennas is as follows:

Step 1: The network device determines A antennas that transmit pilot signals, spatial beam directions corresponding to each antenna 以及, and resources used to transmit pilot signals, where each antenna 埠 corresponds to a spatial beam direction.

Specifically, in step 1, the network device needs to determine the antenna corresponding to each pilot antenna to transmit the pilot signal and the required time-frequency resource while determining the A antennas used for transmitting the pilot signal. Each antenna 埠 corresponds to all or part of the antennas of the network device. If more spatial beam directions need to be formed than configurable antenna parameters, multiple sets of pilot processes, such as LTE CSI-RS process (CSI-RS process), may be set. ) transmitting all pilot processes with orthogonal time-frequency resources. At the same time, all spatial beam directions corresponding to the antennas included in all pilot processes should cover the entire space that needs to be covered, as shown in Figure 2. The dotted line 201 in Fig. 2 is the spatial range that all spatial beam directions should cover, and the solid line 202 is a spatial beam direction coverage. The range of space.

The network device can determine the spatial beam direction, the number of beams in each direction, and the beam width of each antenna frame according to the distribution of the terminals. Each antenna 埠 occupies at least one time-frequency resource. When multiple antennas are in Code Division Multiple (CDM) mode, each antenna 埠 can occupy more than one time-frequency resource.

Step 2: The network device determines, for each antenna A of the A antennas, a beamforming vector of the spatial beam direction corresponding to each antenna 在 in the first dimension, and a beamforming vector in the second dimension. And determining a three-dimensional spatial beamforming vector of the beam corresponding to the antenna 根据 according to the beamforming vector in the first dimension and the beamforming vector in the second dimension.

MIMO systems in large-scale, network device arrangement a two-dimensional antenna array is generally uniform rectangular array, comprising a total of N _T transmit antennas, there are N _x and N _y antennas on a first dimension and a second dimension, respectively, the There is N _T = N _x N _y , wherein the first dimension is a vertical dimension and the second dimension is a level dimension, or the first dimension is a level dimension and the second dimension is a vertical dimension.

In step 2, when the network device sends the pilot signal, the set of A antennas included in all pilot processes is ω _A = {1, 2, ..., A }, for any antenna 埠a ω _A occupies M 1 time-frequency resource. Below is the antenna 埠a ω _A , and the antenna corresponding to the antenna 埠a is described as an example of all antennas of the network device.

When the antenna corresponding to the antenna 埠a is all the antennas of the network device, the spatial beamforming vector of the spatial beam direction corresponding to the antenna 埠a in the first dimension is:

among them, The corresponding weight of the uth antenna in the antenna 埠a in the first dimension, 1 u Nx.

The spatial beamforming vector of the spatial beam direction corresponding to the antenna 埠a in the second dimension is:

among them, The corresponding weight of the uth antenna in the antenna 埠a in the second dimension, 1 u Ny.

Then the three-dimensional spatial beamforming vector of the beam corresponding to the antenna 埠a is:

Then, the pilot signal vector of the antenna 埠a transmitted on the mth time-frequency resource and subjected to all antenna beamforming is s ^{( a , m )} = w ^{( a )} p ^{( a , m )} , where p ^{( a , m )} is the pilot symbol on the mth time-frequency resource.

Specifically, shown in Figure 3, Figure 3 illustrates a process of a network device, an antenna port transmits a pilot signal in all N _T antennas. In FIG. 3, when the pilot symbol p ^{( a , m ) of the} antenna 埠a on the mth time-frequency resource is mapped to each antenna, each antenna will be based on the shaped weight coefficient on the pilot symbol p ^{( a , m )} performing a multiplication operation to form a pilot signal vector that is shaped by all antenna beams. In Figure 3, The corresponding weighting factor for the jth antenna in the antenna 埠a , a pilot signal transmitted on the corresponding time-frequency resource of the j-th antenna in the antenna 埠a , 1 j N _T .

In step 2, the pilot signal transmitted by the antenna 埠a on the mth time-frequency resource may also be transmitted through a part of the antenna in the spatial beam direction corresponding to the antenna 埠a , for example, two-dimensionally uniform for cross-polarization. A design of an antenna 埠 of a rectangular antenna array in which all or part of the antennas of the same polarization direction are used.

When the antenna corresponding to the antenna 埠a is a partial antenna of the network device, the beamforming vector w ^{( a )} only has a shaping weight coefficient on the corresponding partial antenna. ,among them, For the jth weighting coefficient of the antenna participating in the formation of the antenna 埠a , it can be considered that the shaping weight coefficient of the other antenna not participating in the formation of the antenna 埠a is zero. For example, in the design implementation of an antenna 埠 of a cross-polarized two-dimensional uniform rectangular antenna array, any antenna 埠a _i , a _j ω _A is transmitted by antennas of the same polarization direction to form corresponding spatial beam directions. The beamforming vector can be written as follows:

among them , Representing the beamforming vectors of the two polarization directions corresponding to the antennas 埠a _i , a _j , respectively , Representing the beamforming vectors of the first dimension and the second dimension in the polarization direction corresponding to the antenna 埠a _i , respectively, , The beamforming vectors of the first dimension and the second dimension in the polarization direction corresponding to the antenna 埠a _j are respectively indicated.

Step 3: The network device performs beamforming and transmitting on the pilot signal according to the three-dimensional spatial beamforming vector of each antenna A of the A antennas and the time-frequency resources used by the pilot signals.

In step 3, the network device transmits the pilot signal of each antenna 通过 through the antenna corresponding to the antenna 埠.

According to the process described above, the network device can convert the measurement of the MIMO channel matrix into the measurement and selection of the spatial beam direction by reducing the spatial beam direction of each antenna, thereby reducing the overhead of the terminal CSI measurement pilot. .

In step 101, the CSI received by the network device includes at least a first-level precoding matrix indication information, and the network device can determine, according to the first-level precoding matrix indication information, that the antenna is in the A antenna that transmits the pilot signal, and the terminal Which Q antenna is selected, so according to the end The Q beamforming vectors corresponding to the Q antennas selected by the terminal form a first level precoding matrix.

Further, the CSI received by the network device may further include one or a combination of the following information: the second level precoding matrix indication information, and the second level precoding matrix indication information is used to indicate that the second level precoding matrix is in the second The index in the codebook collection. The second-stage precoding matrix is a power-normalized Q × L -dimensional matrix, which is represented by V _{L in the} embodiment of the present invention. The second-stage precoding matrix V _L can be obtained by calculating a Singular Value Decomposition (SVD), a matrix composed of L singular vectors corresponding to the largest L singular values, and performing power normalization and quantization processing, or The information and the RI are indicated from the second level codebook set according to the second level precoding matrix.

RI, the RI is a channel level indication reported by the terminal to the network device, and the terminal can determine the effective data layer of the physical downlink shared channel (PDSCH) supported by the terminal by reporting the RI. The method for determining the level indication reported by the terminal to the network device is various, and is not limited in this embodiment of the present invention, and details are not described herein again.

The channel quality indicates CQI, and the CQI is a quantized value of Signal to Interference plus Noise Ratio (SINR). Determining the CQI according to the first level precoding matrix indication information, determining a first equivalent channel formed by the Q channel estimation values corresponding to the Q antennas, and indicating information and RI according to the second level precoding matrix Determining a second-stage precoding matrix, determining a second equivalent channel according to the first equivalent channel and the second level precoding matrix, and determining an SINR according to the second equivalent channel, the power of the interference signal, and the power of the noise signal The CQI is determined based on the SINR.

When the level is 1, the Q antennas selected by the terminal are a ₁ , a ₂ , ..., a _Q , and the second-stage precoding matrix is a Q × 1 dimensional column vector v ₁ , where N _R is the receiving antenna of the terminal The number, SINR can be calculated according to the following formula:

Where γ ₁ is the calculated SINR, To interfere with the power of the signal, For the power of the noise signal, ∥. ∥ denotes the norm of the matrix, For the first equivalent channel, the dimension is N _R × Q , which is obtained by the terminal directly measuring and selecting the A antennas, wherein For the first a ( a ω _A ) The estimated channel value of the antenna ,, the dimension is N _R ×1. H is the channel matrix on one subcarrier, and the dimension is N _R × N _T .

Generally, the CSI of the terminal feedback received by the network device includes the first-level precoding matrix indication information, the number Q of antennas selected by the terminal, the second-level precoding matrix indication information, the RI, the CQI, and the like. When the network device specifies that the network device sends downlink data to the terminal, the value of the RI indicator is 1, and the terminal is configured to select only one antenna after measuring A antennas, that is, Q=1. In this case, the CSI of the terminal feedback may not include the number Q of antennas selected by the terminal, and the second-level precoding matrix indication information.

In step 102, after receiving the CSI including the first-level precoding matrix indication information sent by the terminal, the network device determines, according to the first-level precoding matrix indication information, that the antenna antenna is transmitting the pilot signal. The Q antennas selected by the terminal are formed, and the first level precoding matrix is formed according to the Q beamforming vectors corresponding to the Q antennas selected by the terminal.

Specifically, the first stage precoding matrix indicates that the Q antennas selected by the terminal indicated by the information are a ₁ , a ₂ , . . . , a _Q , and then the first level precoding matrix obtained by the network device is:

Where W ₁ is the first-stage precoding matrix, w ^{( a )} is the antenna 埠a ( a ω _A ) Corresponding beamforming vector.

In the design implementation of the antenna 埠 of the cross-polarized two-dimensional uniform rectangular antenna array, any one antenna 发送 is transmitted by the same polarization direction antenna to form a corresponding spatial beam direction, and the antenna serial number is in a certain dimension in one polarization direction. Sorting, then sorting by the same dimension in another polarization direction, the first level precoding matrix can be further written as:

Here, the antennas 埠a ₁ , . . . , a _i correspond to one polarization direction, and the antennas 埠a _{i +1} , . . . , a _Q correspond to the other polarization direction.

In step 103, the network device determines to transmit the precoding matrix according to the first level precoding matrix.

Specifically, the network device can determine the sending precoding matrix according to the following formula:

Where W is the transmission precoding matrix, W ₁ is the first level precoding matrix, the dimension is N _T × Q , V _L is the second level precoding matrix, and the dimension is Q × L , where L is the value of RI , Normalize the factor for power.

After the network device determines that the precoding matrix is transmitted, the network device to the channel matrix of the terminal may be reconstructed according to the sending precoding matrix. When the network device needs to reconstruct the channel matrix of the network device to the terminal, the network device can determine the channel matrix of the network device to the terminal according to the following formula:

among them, For the channel matrix, W is the transmit precoding matrix.

Based on the pilot signals transmitted by the network device in the A antenna ports described above, each antenna frame corresponds to a spatial beam direction, so the terminal can convert the MIMO channel matrix measurement into a spatial beam direction in which each terminal is located. problem. The terminal can select multiple spatial beam directions according to actual conditions, and can calculate channel quality (CQI) according to selected multiple spatial beams. Generally, the number of spatial beams selected by the terminal is much smaller than the number of large-scale antennas of the network device, so that the pilot CSI measurement pilot overhead can be reduced.

As shown in FIG. 4, an embodiment of the present invention provides a channel state information feedback method, where the method includes:

Step 401: The terminal performs channel estimation according to the received pilot signal to obtain channel estimation values of the A antennas, and the A antennas are A antennas for transmitting the pilot signals by the network device.

Step 402: The terminal determines Q antennas according to channel estimation values of the A antennas, where L Q A, L is the value of the level indication RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal.

It should be noted that there are various methods for determining the value of the RI determined by the terminal, which is not limited by the embodiment of the present invention.

For the value of L, refer to the description in step 101, and details are not described herein again.

Step 403: The terminal determines, according to the Q antennas, the first level precoding matrix indication information, and feeds the CSI including the first level precoding matrix indication information to the network device, where the first level precoding matrix indicates information. A for indicating that the Q antennas are transmitting a pilot signal The index in the antenna 埠.

In the foregoing process, the process of transmitting the pilot signal by the network device may be as described in FIG. 1 above, and the pilot signal may be sent in other manners, which is not limited in this embodiment of the present invention.

In the embodiment of the present invention, the number of receiving antennas of the terminal is N _R , N _{R is} greater than or equal to 1, and the antenna 埠a occupying the mth time-frequency resource belongs to the set of A antennas of the network device ω _A ={1 , 2, ..., a}, and the antenna port corresponding to a transmitting antenna to all network devices N _T antennas, the transmit antenna N _T is a two-dimensional rectangular array with uniform polarization; transmitting antenna or as a cross The two-dimensional uniform rectangular array is polarized, and the antenna corresponding to the antenna 埠a is the same polarization direction antenna in the network device. At the same time, the pilot symbol corresponding to the antenna 埠a is the normalized power.

In step 401, the pilot signal received by the terminal is sent by the network device through A antennas, wherein each of the antennas A corresponds to a spatial beam direction, and each antenna 埠 occupies at least one time frequency. Resources, when multiple antennas are used in code division multiplexing, each antenna can occupy more than one time-frequency resource. At the same time, the three-dimensional spatial beamforming vector corresponding to the spatial beam direction of each antenna 是 is determined according to the beamforming vector of the antenna 第一 in the first dimension and the beamforming vector in the second dimension, wherein The first dimension is a vertical dimension, the second dimension is a level dimension, or the first dimension is a level dimension and the second dimension is a vertical dimension.

Antenna 埠a ( a ω _A ) The pilot signal vector over all antenna beamforming transmitted on the mth time-frequency resource is s ^{( a , m )} = w ^{( a )} p ^{( a , m )} , where w ^{( a )} is The three-dimensional spatial beamforming vector of the beam corresponding to the antenna 埠a , p ^{( a , m )} is the pilot symbol on the mth time-frequency resource. At this time, the channel matrix of the network device to the terminal on one subcarrier is a matrix H of N _R × N _T dimensions. The terminal receives the pilot signal as a vector of N _R ×1 dimension on the mth time-frequency resource occupied by the antenna 埠a :

Where s ^{( a , m )} is the N _T ×1 dimensional pilot signal vector that is transmitted by the antenna 埠a on the mth time-frequency resource and is shaped by all antenna beams, i ^{( a , m )} , n ^{( a , m )} are N _R × 1 dimensional interference signal vectors and noise signal vectors, respectively.

Combining the pilot signals on the time-frequency resources occupied by each antenna, the terminal obtains the A channel estimation values corresponding to the A antennas of the network device to transmit the pilot signals. The channel estimate for antenna 埠a is:

Wherein, w ^(a) an antenna port of a three-dimensional beamforming vectors, E ^(a) is an antenna port of a channel estimation error matrix, a ω _A . The terminal obtains the channel estimation value of A antenna 埠 , ,..., .

In step 402, the terminal needs to select Q antennas from the A antennas according to the channel estimation values of the A antennas to determine the CSI feedback to the network device.

Considering that the terminal determines the computational complexity of CSI according to the selected Q antennas, the terminal can select only one antenna to determine the CSI. However, considering many scatterers present on the propagation path, the pilot signal received by the terminal is likely to be a superposition of signals passing through multiple propagation paths. Therefore, in order to obtain a highly accurate CSI, the number of terminals in the antenna 需要 is required. Within the range of values, all possible antenna combinations are determined, and among all possible antenna combinations, Q channels that maximize the channel throughput or capacity between the terminal and the network device or the pilot signal received by the terminal are determined. Antenna 埠, wherein each possible antenna 埠 combination corresponding channel throughput or capacity or pilot signal received power of the terminal is estimated according to the channel corresponding to the possible antenna 埠 combination The value is determined.

The value of the number of antennas is generally greater than or equal to the level L of the channel and less than or equal to A. The network device can also specify the upper limit of the range of the number of antennas. For example, the number of antennas specified by the network device ranges from Q _max .

At the same time, the network device can also specify the number of antenna ports to be selected for the terminal, for example, the number of designated antenna ports is Q, and L Q A. At this time, the terminal only needs to select a combination of Q antennas in the A antennas to make the channel transmission capacity or capacity between the terminal and the network device or the signal receiving power of the terminal to be the largest. When the network device does not specify the upper limit of the number of antennas or the number of antennas to be selected, the lower limit of the range of the number of antennas selected by the terminal is greater than or equal to L, and the upper limit of the range is The number of antennas that the network device sends the pilot signal, that is, less than or equal to A.

Regardless of whether the network device specifies the number of antenna ports to be selected for the terminal, there are many combinations of antenna ports in the A antenna ports for terminal selection. Taking the calculation of the amount or capacity of the terminal and the network device as an example, the terminal selects the set ω _Q of the Q antennas with the largest amount of transmission or capacity among the A antennas, according to the following method:

among them, In order to calculate the function of the amount or capacity of the transmission between the terminal and the network device, the function is a function well known to those skilled in the art, and the function will not be described in detail herein, only the function of the function will be described, and Q _max is selected by the terminal. The upper limit of the range of the number of antennas, L Q _max A , ω _k denotes a set of _k antennas selected among A antennas, and Ω _k denotes a set of all possible ω _k when k antennas are selected among A antennas, L k Q _max , Indicates the first equivalent channel formed by the channel estimation values corresponding to the k antennas selected in the A antennas, and V _L can be calculated The singular value decomposition obtains a matrix composed of L singular vectors corresponding to the largest L singular values and performs power normalization and quantization processing, and can also be selected from the second-level codebook set, where i is an interference signal vector, n For the noise signal vector, P ' is the power normalization factor of the precoding matrix.

When L =1, the second-stage precoding matrix degenerates into a column vector of Q × 1. When L =1 and the network device specifies Q _max =1, the second-stage precoding matrix is further degenerated into a scalar ν ₁ =1. At this time, the above problem can be simplified to select channel estimation values from A antennas. The square of the norm is the largest, that is, the antenna that receives the most power.

The terminal calculates each possible antenna 埠 combination of each A antenna ,, and then selects a Q antenna 埠 combination that makes the channel transmission amount or capacity between the terminal and the network device or the signal receiving power of the terminal maximum. The amount of calculation for this process is very large. In order to reduce the computational complexity, the greedy method is used in the embodiment of the present invention to search. The basic idea is to increase the number of antennas used one by one until the transmission amount or capacity or the pilot signal receiving power of the terminal no longer increases or reaches the maximum. The level of selection is up to now. Specifically, the detailed description of the greedy law is as follows.

As shown in FIG. 5, a schematic diagram of a greedy method according to an embodiment of the present invention includes the following steps: Step 501: Determine a value range of the number of antennas for CSI measurement; Step 502, set k=1, T ₀ = 0; Step 503: Calculate a transmission amount or capacity corresponding to each possible antenna 埠 combination or a pilot signal received power of the terminal when selecting k antenna 埠 from among A antenna ,, and select a transmission amount or A combination of the capacity or the maximum receiving power of the pilot signal of the terminal; step 504, if k < Q _max , then proceeds to step 505, otherwise proceeds to step 507, where Q _max is the upper limit of the range of values, L Q _max A; Step 505, if T _k >T _k-1 , then go to step 506, otherwise, go to step 507; where T _k is the amount of transmission or capacity when k antennas are selected from A antennas The receiving signal amount or capacity of the antenna 埠 combination of the terminal having the largest receiving power of the terminal or the pilot signal receiving power of the terminal, and T _k-1 is when _k-1 antenna 埠 is selected from the A antenna 埠The transmission amount or capacity or the pilot signal receiving power of the terminal or the pilot signal receiving power of the terminal is the same as the transmission amount or capacity or the pilot signal receiving power of the terminal; step 506, set k=k+1, and go to step 503. Step 507: Determine the antenna 中 in the antenna 埠 combination of the currently determined transmission amount or capacity or the pilot signal receiving power of the terminal to be the antenna 埠 for CSI measurement.

After the terminal determines the Q antennas for the CSI measurement, it can determine the CSI fed back to the network device. Specifically, in step 403, the CSI determined by the terminal includes at least a first level precoding matrix indication information, and the first level precoding matrix indication information is used to indicate that the Q antennas used for CSI measurement are transmitting pilots. The index in the A antennas of the signal. Further, the CSI determined by the terminal may further include one or a combination of the following information: a second level precoding matrix indication information, where the second level precoding matrix indication information is used to indicate that the second level precoding matrix is at the second level. The index in the codebook set; the second level precoding matrix V _L is a power normalized Q × L dimension matrix; the second level precoding matrix V _L can be obtained by calculating the singular value decomposition, corresponding to the maximum L singular values The matrix consisting of L singular vectors is obtained by power normalization and quantization processing, and may also be selected from the second-level codebook set; RI, the RI is a channel level indication reported by the terminal to the network device, and the terminal passes Evaluating the effective data layer of the PDSCH supported by the RI through the network device terminal; CQI; determining the CQI according to the following method: determining Q channel estimation values corresponding to the Q antennas according to the first level precoding matrix indication information Forming a first equivalent channel, determining a second level precoding matrix according to the second level precoding matrix indication information and the RI, and determining a second according to the first equivalent channel and the second level precoding matrix Channel effect, according to the second equivalent channel noise power and the signal power of interference signal determines the SINR, the CQI based on the determined SINR.

In general, the CSI of the terminal feedback includes the first-level precoding matrix indication information, the number Q of antennas selected by the terminal, the second-level precoding matrix indication information, the RI, the channel quality indication CQI, and the like. When the network device specifies that the network device sends downlink data to the terminal, the value of the RI is 1, and the terminal specifies that only one antenna can be selected in the A antennas for CSI measurement. The CSI of the network device may not include the number Q of antennas selected by the terminal, and the second-level precoding matrix indication information.

For the foregoing method, the embodiment of the present invention further provides a network device and a terminal. The specific content of the network device and the terminal may be implemented by referring to the foregoing method, and details are not described herein again.

As shown in FIG. 6 , an embodiment of the present invention provides a network device, including: a receiving unit 601, configured to receive channel state information CSI fed back by a terminal, where the CSI includes at least a first level precoding matrix indication information, where the The first-level precoding matrix indication information is used to indicate an index of the Q antennas in the A antennas that transmit the pilot signals, and the first-stage precoding matrix indication information is a Q determined according to the channel estimation values of the A antennas. After the antenna is ,, according to the Q antenna 埠, L Q A, L is a value of the level indication RI used by the network device to send downlink data to the terminal, or L is a value of the channel level indication RI determined by the terminal; the first determining unit 602 is configured to receive according to The CSI and the beamforming vector corresponding to the A antennas are determined to determine a first level precoding matrix, and the second determining unit 603 is configured to determine a transmission precoding matrix according to the first level precoding matrix.

Optionally, the CSI received by the receiving unit 601 further includes one or a combination of the following information: a second level precoding matrix indication information, where the second level precoding matrix indication information is used to indicate that the second level precoding matrix is in the first The index in the secondary codebook set; RI; the channel quality indicates the CQI.

Optionally, the second determining unit 603 is specifically configured to: determine the sending precoding matrix according to the following formula:

Where W is the transmission precoding matrix, W _{1 is} the first level precoding matrix, and V _L is a second level precoding matrix, and the second level precoding matrix is indicated by the second level precoding matrix. The indicated matrix, Normalize the factor for power.

Optionally, the receiving unit 601 is further configured to: determine, by the network device, A antennas that transmit pilot signals, transmit antennas corresponding to each antenna, spatial beams, and resources used to transmit pilot signals, where each Days The line 埠 corresponds to a spatial beam; the network device determines, for each antenna 埠 of the A antennas, a beamforming vector of the spatial beam corresponding to each antenna 在 in the first dimension, and in the second dimension a beamforming vector, and determining a three-dimensional spatial beamforming vector of the beam corresponding to the antenna 根据 according to the beamforming vector in the first dimension and the beamforming vector in the second dimension; the network device according to the A The three-dimensional spatial beamforming vector of each antenna 埠 in the antenna 以及 and the resources used by the pilot signals are beamformed and transmitted at all or part of the transmitting antenna.

Optionally, the first determining unit 602 is specifically configured to: determine, according to the distribution of the terminal, a direction of a spatial beam corresponding to each antenna 、, a number of beams in each direction, and a beam width.

As shown in FIG. 7 , an embodiment of the present invention provides a terminal, including: a channel estimation unit 701, configured to perform channel estimation according to the received pilot signal, to obtain channel estimation values of A antennas, and the A antennas are The network device sends the A antennas of the pilot signals; the determining unit 702 is configured to determine Q antennas according to the channel estimation values of the A antennas, where Q A, L is the value of the RI used by the network device to send the downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal; the sending unit 703 is configured to use the Q The antenna 埠 determines the first-stage precoding matrix indication information, and feeds the channel state information CSI including the first level precoding matrix indication information to the network device, where the first level precoding matrix indication information is used to indicate the Q The index of the antenna 埠 in the A antenna 发送 transmitting the pilot signal.

Optionally, the CSI that the sending unit 703 feeds back to the network device further includes one or a combination of the following information: a second level precoding matrix indication information, where the second level precoding matrix indication information is used to indicate the second level precoding. The index of the matrix in the second level codebook set; RI; the channel quality indicates the CQI.

Optionally, the CQI is determined according to the following manner: determining, according to the first-level precoding matrix indication information, a first equivalent channel formed by the Q channel estimation values corresponding to the Q antennas; according to the second Level precoding matrix indication information and the RI determine a second level precoding matrix; determining a second equivalent channel according to the first equivalent channel and the second level precoding matrix; according to the second equivalent channel, the interference signal The power and the power of the noise signal determine the signal to interference and noise ratio SINR; the CQI is determined according to the SINR.

Optionally, the determining unit 702 is specifically configured to: determine, within a range of values of the number of antennas, all possible antenna combinations, and determine, in the possible combinations of the antennas, the terminal and the network device. Between the channel throughput or capacity or the terminal antenna receiving power of the terminal, the maximum number of Q antennas, wherein each possible antenna 埠 combination corresponds to the channel throughput or capacity or the terminal's pilot signal received power according to The channel estimates corresponding to the possible antenna combinations are determined.

Optionally, the determining unit 702 is specifically configured to: determine Q antennas according to the following steps: Step A: determine a value range of the number of antennas for CSI measurement; step B, set k=1, T ₀ = 0; Step C: When calculating k antennas from among A antennas, determining the amount of transmission or capacity corresponding to each possible antenna combination or the pilot signal receiving power of the terminal, and selecting the amount of transmission or A combination of the capacity or the maximum received power of the pilot signal of the terminal; step D, if k < Q _max , then proceeds to step E, otherwise proceeds to step G, where Q _max is the upper limit of the range of values, L Q _max A; Step E, if T _k >T _k-1 , then go to step F, otherwise, go to step G; where T _k is the amount of transport or capacity when k antennas are selected from A antennas The receiving signal amount or capacity of the antenna 埠 combination of the terminal having the largest receiving power of the terminal or the pilot signal receiving power of the terminal, and T _k-1 is when _k-1 antenna 埠 is selected from the A antenna 埠The amount or capacity of the transmission or the capacity of the antenna or the receiving power of the pilot signal of the terminal is the largest, or the pilot signal receiving power of the terminal; step F, let k=k+1, and go to step C. Step G: The antenna 中 in the antenna 埠 combination of the currently determined transmission amount or capacity or the pilot signal receiving power of the terminal is determined as the antenna 用于 for CSI measurement.

For the foregoing method, the embodiment of the present invention further provides a network device and a terminal. The specific content of the network device and the terminal may be implemented by referring to the foregoing method, and details are not described herein again.

As shown in FIG. 8 , an embodiment of the present invention provides a network device, including: a processor 800, configured to read a program in the memory 820, and perform the following process: receiving channel status information CSI of the terminal feedback, where The CSI includes at least a first level precoding matrix indication information, where the first level precoding matrix indication information is used to indicate an index of the Q antennas in the A antennas of the transmission pilot signal, the first level precoding matrix The indication information is determined based on the channel estimation values of the A antennas, and then determined according to the Q antennas, L Q A, L is a value indicating the RI used by the network device to send downlink data to the terminal, or L is a value of the channel level indication RI determined by the terminal; and is used according to the received CSI and the A beamforming vector corresponding to the A antennas determines a first level precoding matrix; a transmitting precoding matrix is determined according to the first level precoding matrix; and a transceiver 810 is configured to receive and transmit data under the control of the processor 800.

Optionally, the CSI received by the transceiver 810 further includes one or a combination of the following information: a second level precoding matrix indication information, where the second level precoding matrix indication information is used to indicate that the second level precoding matrix is in the first The index in the secondary codebook set; RI; the channel quality indicates the CQI.

Optionally, the processor 800 is specifically configured to: determine the sending precoding matrix according to the following formula:

Where W is the transmission precoding matrix, W _{1 is} the first level precoding matrix, and V _L is a second level precoding matrix, and the second level precoding matrix is indicated by the second level precoding matrix. The indicated matrix, Normalize the factor for power.

Optionally, the processor 800 is further configured to: determine A antennas that transmit pilot signals, transmit antennas corresponding to each antenna, spatial beams, and resources used to transmit pilot signals, where each antenna corresponds to a spatial beam; for each antenna 埠 of the A antennas, determining a beamforming vector of the spatial beam corresponding to each antenna 在 in a first dimension, and a beamforming vector in a second dimension, and Determining, according to the beamforming vector in the first dimension and the beamforming vector in the second dimension, a three-dimensional spatial beamforming vector of a beam corresponding to the antenna ;; according to the three-dimensional shape of each antenna 该 in the A antenna 埠The spatial beamforming vector and the resources used by the pilot signal beamform the pilot signal and transmit it at all or part of the transmit antenna.

Optionally, the processor 800 is specifically configured to: determine, according to the distribution of the terminal, a direction of a spatial beam corresponding to each antenna, a number of beams in each direction, and a beam width.

In FIG. 8, the bus bar architecture may include any number of interconnected bus bars and bridges, specifically connected by one or more processors represented by the processor 800 and various circuits of the memory represented by the memory 820. The busbar architecture can also couple various other circuits, such as peripherals, voltage regulators, and power management circuits, as is well known in the art, and therefore, will not be further described herein. The bus interface provides an interface. Transceiver 810 can be a plurality of components, including a transmitter and a transceiver, providing means for communicating with various other devices on a transmission medium. The processor 800 is responsible for managing the bus architecture and usually The memory 820 can store the data used by the processor 800 in performing the operations.

As shown in FIG. 9, an embodiment of the present invention provides a terminal, including: a processor 900, configured to read a program in the memory 920, and perform the following process: performing channel estimation according to the received pilot signal, and obtaining A Channel estimation value of the antenna 埠, the A antenna 埠 is an antenna 发送 for transmitting a pilot signal by the network device; and determining Q antenna 根据 according to the channel estimation value of the A antenna 埠, where, L Q A, L is the value of the level indication RI used by the network device to send downlink data to the terminal, or L is the value of the channel level indication RI determined by the terminal; and is used to determine the number according to the Q antennas The first level precoding matrix indicates information, and the channel state information CSI including the first level precoding matrix indication information is fed back to the network device, where the first level precoding matrix indication information is used to indicate that the Q antennas are transmitting An index in the A antennas of the pilot signals; a transceiver 910 for receiving and transmitting data under the control of the processor 900.

Optionally, the CSI fed back to the network device by the transceiver 910 further includes one or a combination of the following information: a second level precoding matrix indication information, where the second level precoding matrix indication information is used to indicate the second level precoding. The index of the matrix in the second level codebook set; RI; the channel quality indicates the CQI.

Optionally, the CQI is determined according to the following manner: determining, according to the first-level precoding matrix indication information, a first equivalent channel formed by the Q channel estimation values corresponding to the Q antennas; according to the second Level precoding matrix indication information and the RI determine the second level pre-editing a code matrix; determining a second equivalent channel according to the first equivalent channel and the second level precoding matrix; determining a signal to interference and noise ratio SINR according to the second equivalent channel, the power of the interference signal, and the power of the noise signal; The CQI is determined based on the SINR.

Optionally, the processor 900 is specifically configured to: determine, within a range of values of the number of antennas, all possible antenna combinations, and determine, in the possible combinations of the antennas, the terminal and the network device. Between the channel throughput or capacity or the terminal antenna receiving power of the terminal, the maximum number of Q antennas, wherein each possible antenna 埠 combination corresponds to the channel throughput or capacity or the terminal's pilot signal received power according to The channel estimates corresponding to the possible antenna combinations are determined.

Optionally, the processor 900 is specifically configured to: determine Q antennas according to the following steps: Step A: determine a value range of the number of antennas for CSI measurement; step B, set k=1, T ₀ = 0; Step C: When calculating k antennas from among A antennas, determining the amount of transmission or capacity corresponding to each possible antenna combination or the pilot signal receiving power of the terminal, and selecting the amount of transmission or A combination of the capacity or the maximum received power of the pilot signal of the terminal; step D, if k < Q _max , then proceeds to step E, otherwise proceeds to step G, where Q _max is the upper limit of the range of values, L Q _max A; Step E, if T _k >T _k-1 , then go to step F, otherwise, go to step G; where T _k is the amount of transmission or capacity when k antennas are selected from A antennas The receiving signal amount or capacity of the antenna 埠 combination of the terminal having the largest receiving power of the terminal or the pilot signal receiving power of the terminal, and T _k-1 is when _k-1 antenna 埠 is selected from the A antenna 埠The amount or capacity of the transmission or the capacity of the antenna or the receiving power of the pilot signal of the terminal is the largest, or the pilot signal receiving power of the terminal; step F, let k=k+1, and go to step C. Step G: The antenna 中 in the antenna 埠 combination of the currently determined transmission amount or capacity or the pilot signal receiving power of the terminal is determined as the antenna 用于 for CSI measurement.

In FIG. 9, the bus bar architecture may include any number of interconnected bus bars and bridges, specifically connected by one or more processors represented by the processor 900 and various circuits of the memory represented by the memory 920. The busbar architecture can also couple various other circuits, such as peripherals, voltage regulators, and power management circuits, as is well known in the art, and therefore, will not be further described herein. The bus interface provides an interface. Transceiver 910 can be a plurality of components, including a transmitter and a receiver, providing means for communicating with various other devices on a transmission medium. For different user devices, the user interface 930 may also be an interface capable of externally connecting the required devices, including but not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

The processor 900 is responsible for managing the bus bar architecture and the usual processing, and the memory 920 can store the data used by the processor 900 when performing operations.

In summary, according to the method provided by the embodiment of the present invention, the terminal selects at least one antenna A from the A antennas that transmit the pilot signal from the network device, thereby reducing the CSI measurement. The cost of the pilot is as good as possible to ensure a certain CSI measurement accuracy and simplify the system design. Generally, the number of antennas selected by the terminal is much smaller than the number of large-scale antennas of the network device, so the CSI measurement pilot overhead can be reduced, and the terminal can also select multiple spatial beam directions and their optimal weighting coefficients to be more accurate. Estimate CSI.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Thus, the present invention can take the form of a fully hardware embodiment, a fully software embodiment, or an embodiment combining soft and hardware aspects. Moreover, the present invention can take the form of a computer program product embodied on one or more computer usable storage media (including but not limited to disk memory and optical memory, etc.) including computer usable code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus, and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing device to produce a machine for executing instructions by a processor of a computer or other programmable data processing device Means are provided for implementing the functions specified in one or more of the flow or in one or more blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can boot a computer or other programmable data processing device to operate in a particular manner, such that instructions stored in the computer readable memory produce an article of manufacture including the instruction device. The instruction means implements the functions specified in one or more blocks of the flow or in a flow or block diagram of the flowchart.

These computer program instructions can also be loaded into a computer or other programmable data. Processing devices that perform a series of operational steps on a computer or other programmable device to produce computer-implemented processing such that instructions executed on a computer or other programmable device are provided for implementation in a flow or flow The steps of a function specified in a block or blocks in a flow and/or block diagram.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims (20)

A channel state information feedback method includes: the terminal performs channel estimation according to the received pilot signal, and obtains channel estimation values of A antennas, and the A antennas are two-dimensional used when the network device transmits the pilot signals. A antenna 埠 of the antenna array; the terminal determines Q antenna 根据 according to the channel estimation value of the A antenna 埠, wherein, L Q A, L is a value of a level indication (RI) used by the network device to send downlink data to the terminal, or L is a value of a channel level indication (RI) determined by the terminal; the terminal is based on the Q The antenna 埠 determines the first level precoding matrix indication information, and feeds the channel state information (CSI) including the first level precoding matrix indication information to the network device, where the first level precoding matrix indication information is used to indicate the The index of the Q antennas in the A antennas that transmit the pilot signals. The channel state information feedback method of claim 1, wherein the CSI fed back to the network device by the terminal further includes one or a combination of the following information: a second level precoding matrix indication information, the second level precoding matrix indication The information is used to indicate an index of the second-level precoding matrix in the second-level codebook set; a channel level indication (RI), the RI is a channel level indication reported by the terminal to the network device; and a channel quality indicator (CQI); And the number Q of antennas selected by the terminal. The channel state information feedback method according to claim 1, wherein the CSI that the terminal feeds back to the network device includes a CQI, and the CQI is determined according to the following manner: determining the Q according to the first level precoding matrix indication information. Q antennas corresponding to antennas a first equivalent channel formed by the channel estimation value; determining a second level precoding matrix according to the second level precoding matrix indication information and the RI; wherein the second level precoding matrix indication information is used to indicate the second level pre An index of the coding matrix in the second-level codebook set; determining a second equivalent channel according to the first equivalent channel and the second-stage precoding matrix; according to the second equivalent channel, the power of the interference signal, and the noise The power of the signal determines a signal to interference and noise ratio (SINR); the CQI is determined based on the SINR. The channel state information feedback method according to any one of claims 1 to 3, wherein the terminal determines the Q antennas according to the channel estimation values of the A antennas, including: the number of the antennas in the antenna Within the range of values, all possible antenna combinations are determined, and in all possible antenna combinations, the channel throughput or capacity between the terminal and the network device or the pilot signal received power of the terminal is determined to be the largest. Q antennas, wherein the corresponding channel throughput or capacity of each possible antenna combination or the pilot signal received power of the terminal is determined according to the channel estimation corresponding to the possible antenna combinations. The channel state information feedback method according to claim 4, wherein the terminal determines all possible antenna 埠 combinations within a range of values of the number of antenna ,, and determines the terminal in all possible antenna 埠 combinations The Q antennas with the channel transmission capacity or capacity or the terminal receiving signal power of the terminal are the following steps: Step A: determining the value range of the number of antennas for CSI measurement Step B, let k=1, T ₀ =0; Step C, calculate k to select k antennas from among A antennas, determine the corresponding transmission amount or capacity of each possible antenna combination or the terminal The pilot signal receives power, and selects an antenna 埠 combination in which the transmission amount or capacity or the pilot signal receiving power of the terminal is the largest; step D, if k < Q _max , then proceeds to step E, otherwise proceeds to step G, Q _max is the upper limit of the range of values, L Q _max A; Step E, if T _k >T _k-1 , then go to step F, otherwise, go to step G; where T _k is the amount of transport or capacity when k antennas are selected from A antennas The receiving signal amount or capacity of the antenna 埠 combination of the terminal having the largest receiving power of the terminal or the pilot signal receiving power of the terminal, and T _k-1 is when _k-1 antenna 埠 is selected from the A antenna 埠The amount or capacity of the transmission or the capacity of the antenna or the receiving power of the pilot signal of the terminal is the largest, or the pilot signal receiving power of the terminal; step F, let k=k+1, and go to step C. Step G: The antenna 中 in the antenna 埠 combination of the currently determined transmission amount or capacity or the pilot signal receiving power of the terminal is determined as the antenna 用于 for CSI measurement. A channel state information obtaining method includes: receiving, by a network device, channel state information (CSI) of a terminal feedback, where the CSI includes at least a first level precoding matrix indication information, where the first level precoding matrix indication information is used for indicating Q antennas are indexes in the A antennas of the two-dimensional antenna array used when the network device transmits the pilot signals, and the first-stage precoding matrix indication information is determined by the terminal according to the channel estimation values of the A antennas After the Q antennas are determined, according to the Q antennas, L is determined. Q A, L is a value of a level indication (RI) used by the network device to send downlink data to the terminal, or L is a value of a channel level indication (RI) determined by the terminal; The CSI and the beamforming vector corresponding to the A antennas determine a first level precoding matrix; and the network device determines the transmitting precoding matrix according to the first level precoding matrix. The channel state information obtaining method according to claim 6, wherein the CSI received by the network device further includes one or a combination of the following information: a second level precoding matrix indication information, and the second level precoding matrix indication information An index indicating a second level precoding matrix in the second level codebook set; a channel level indication (RI), the RI is a channel level indication reported by the terminal to the network device; a channel quality indicator (CQI); The number Q of antennas selected by the terminal. The channel state information obtaining method according to claim 6 or 7, wherein the network device determines the transmitting precoding matrix according to the first level precoding matrix, comprising: the network device determining the transmitting precoding matrix according to the following formula: : Where W is the transmission precoding matrix, W _{1 is} the first level precoding matrix, and V _L is a second level precoding matrix, and the second level precoding matrix is indicated by the second level precoding matrix. The indicated matrix, Normalize the factor for power. The channel state information obtaining method according to claim 6, wherein before the network device receives the CSI fed back by the terminal, the network device further comprises: determining, by the network device, the A antennas that transmit the pilot signals, and the corresponding antennas of each antenna a transmitting antenna, a spatial beam, and a resource for transmitting a pilot signal, wherein each antenna 埠 corresponds to a spatial beam; The network device determines, for each antenna 埠 of the A antennas, a beamforming vector of the spatial beam corresponding to each antenna 在 in a first dimension, and a beamforming vector in a second dimension, and Determining, according to the beamforming vector in the first dimension and the beamforming vector in the second dimension, a three-dimensional spatial beamforming vector of a beam corresponding to the antenna ;; the network device according to each of the A antenna 埠The three-dimensional beamforming vector of the antenna 以及 and the resources used by the pilot signal beamform the pilot signal and transmit it in all or part of the transmitting antenna. The channel state information obtaining method according to claim 9, wherein the network device determines a spatial beam corresponding to each antenna, comprising: determining, by the network device, a spatial beam corresponding to each antenna according to a distribution of the terminal Direction, number of beams in each direction, and beamwidth. A terminal includes a processor, a memory, and a transceiver; wherein the processor is configured to read a program in the memory, and perform the following process: performing channel estimation based on the received pilot signal to obtain an antenna 埠Channel estimation value, the A antennas are A antennas of the two-dimensional antenna array used when the network device transmits the pilot signals; and are used to determine Q antennas according to the channel estimation values of the A antennas, Among them, L Q A, L is a value of a level indication (RI) used by the network device to send downlink data to the terminal, or L is a value of a channel level indication (RI) determined by the terminal; and is used according to the Q The antenna 埠 determines the first level precoding matrix indication information, and feeds the channel state information (CSI) including the first level precoding matrix indication information to the network device, where the first level precoding matrix indication information is used to indicate the The index of the Q antennas in the A antennas that transmit the pilot signals; the transceiver is used to receive and transmit data. The terminal according to claim 11, wherein the CSI further includes one or a combination of the following information: a second level precoding matrix indication information, where the second level precoding matrix indication information is used to indicate that the second level precoding matrix is The index in the second level codebook set; the channel level indication (RI), which is the channel level indication reported by the terminal to the network device; the channel quality indicator (CQI); and the number Q of antennas selected by the terminal. The terminal according to claim 11, wherein the CSI further includes a CQI, where the CQI is determined according to: determining, according to the first-level precoding matrix indication information, Q channel estimation values corresponding to the Q antennas Constructing a first equivalent channel; determining a second level precoding matrix according to the second level precoding matrix indication information and the RI; the second level precoding matrix indication information is used to indicate that the second level precoding matrix is in the second An index in the set of codebooks; determining a second equivalent channel according to the first equivalent channel and the second level precoding matrix; determining a signal according to the second equivalent channel, the power of the interference signal, and the power of the noise signal Dry noise ratio (SINR); the CQI is determined based on the SINR. The terminal according to any one of claims 11 to 13, wherein the processor is specifically configured to: determine, within a range of values of the number of antennas, all possible antenna combinations, and all possible antennas Determining the channel between the terminal and the network device in the 埠 combination The amount of transmission or capacity or the Q antennas of the terminal receiving the highest received power of the pilot signal, wherein each possible antenna combination is corresponding to the channel throughput or capacity or the pilot signal received power of the terminal according to the possible The channel estimation value corresponding to the antenna 埠 combination is determined. The terminal according to claim 14, wherein the processor is specifically configured to: determine Q antennas according to the following steps: Step A: determine a value range of the number of antennas for CSI measurement; step B, set k =1, T ₀ =0; Step C, when calculating k antennas A from among A antennas, determining the corresponding transmission amount or capacity of each possible antenna 埠 combination or the pilot signal receiving power of the terminal, And selecting an antenna 埠 combination in which the transmission amount or capacity or the pilot signal receiving power of the terminal is the largest; step D, if k < Q _max , then proceeds to step E, otherwise proceeds to step G, where Q _{max is} the value Upper limit of range, L Q _max A; Step E, if T _k >T _k-1 , then go to step F, otherwise, go to step G; where T _k is the amount of transport or capacity when k antennas are selected from A antennas The receiving signal amount or capacity of the antenna 埠 combination of the terminal having the largest receiving power of the terminal or the pilot signal receiving power of the terminal, and T _k-1 is when _k-1 antenna 埠 is selected from the A antenna 埠The amount or capacity of the transmission or the capacity of the antenna or the receiving power of the pilot signal of the terminal is the largest, or the pilot signal receiving power of the terminal; step F, let k=k+1, and go to step C. Step G: The antenna 中 in the antenna 埠 combination of the currently determined transmission amount or capacity or the pilot signal receiving power of the terminal is determined as the antenna 用于 for CSI measurement. A network device includes a processor, a memory, and a transceiver; wherein the processor is configured to read a program in the memory, and perform the following process: channel state information (CSI) for receiving feedback from the terminal, where The CSI includes at least a first level precoding matrix indication information, where the first level precoding matrix indication information is used to indicate that the Q antennas are in the A antenna array of the two-dimensional antenna array used when the network device transmits the pilot signal. Index, the first level precoding matrix indication information is determined by the Q antennas determined by the terminal according to the channel estimation values of the A antennas, and determined according to the Q antennas, L Q A, L is a value of a level indication (RI) used by the network device to send downlink data to the terminal, or L is a value of a channel level indication (RI) determined by the terminal; The CSI and the beamforming vector corresponding to the A antennas determine a first level precoding matrix; and are configured to determine a transmitting precoding matrix according to the first level precoding matrix; the transceiver is configured to receive and send data. The network device of claim 16, wherein the CSI further comprises one or a combination of the following information: a second level precoding matrix indication information, the second level precoding matrix indication information is used to indicate the second level precoding The index of the matrix in the second-level codebook set; the channel level indication (RI), which is the channel level indication reported by the terminal to the network device; the channel quality indicator (CQI); and the number of antennas selected by the terminal Q. The network device of claim 16 or 17, wherein the processor is specifically configured to: determine the transmit precoding matrix according to the following formula: Where W is the transmission precoding matrix, W _{1 is} the first level precoding matrix, and V _L is a second level precoding matrix, and the second level precoding matrix is indicated by the second level precoding matrix. The indicated matrix, Normalize the factor for power. The network device of claim 16, wherein before receiving the CSI, the processor is further configured to: determine A antennas that transmit pilot signals, transmit antennas corresponding to each antenna, spatial beams, and transmit a resource used by the pilot signal, wherein each antenna 埠 corresponds to a spatial beam; for each of the A antenna 埠, a beamforming vector of the spatial beam corresponding to each antenna 在 in the first dimension is determined And a beamforming vector in the second dimension, and determining a three-dimensional spatial beamforming vector of the beam corresponding to the antenna 根据 according to the beamforming vector in the first dimension and the beamforming vector in the second dimension; The pilot signals are beamformed and transmitted in all or part of the transmit antennas based on the three-dimensional spatial beamforming vectors of each of the A antenna frames and the resources used by the pilot signals. The network device of claim 19, wherein the processor is specifically configured to: determine a direction of a spatial beam corresponding to each antenna 、, a number of beams in each direction, and a beam width according to a distribution of the terminal.