CN113169775A

CN113169775A - Communication method and device

Info

Publication number: CN113169775A
Application number: CN201880099739.9A
Authority: CN
Inventors: 高翔; 刘鹍鹏; 张瑞齐
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-12-14
Filing date: 2018-12-14
Publication date: 2021-07-23
Anticipated expiration: 2038-12-14
Also published as: WO2020118728A1; CN113169775B

Abstract

The application provides a communication method and device, relates to the technical field of communication, and can reduce PMI overhead in an MIMO system. The method comprises the following steps: the terminal determines K beams from the 2L-1 beams, and sends precoding matrix indicator PMI to the access network equipment, the PMI is used for indicating the combining coefficients corresponding to 2L-1 beams on each spatial layer, the combining coefficients corresponding to 2L-1 beams on each spatial layer comprise the combining coefficients corresponding to each beam of the K beams at least two frequency domain units, and combining coefficients respectively corresponding to each beam except the K beams in the 2L-1 beams in at least two frequency domain units, or the combining coefficients corresponding to the 2L-1 beams respectively comprise the combining coefficients corresponding to each beam in the K beams respectively in at least two frequency domain units, and the broadband combination coefficient corresponding to each beam except the K beams in the 2L-1 beams. L, K are all positive integers.

Description

Communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and apparatus.

Background

In a Long Term Evolution (LTE) system and a New Radio (NR) of the fifth generation (5G), in order to increase system capacity, a Multiple Input and Multiple Output (MIMO) technology is introduced. MIMO improves communication quality by using a plurality of transmitting antennas and receiving antennas at a transmitting end and a receiving end, respectively, so that signals are transmitted and received through the plurality of antennas of the transmitting end and the receiving end. The multi-antenna multi-transmission multi-receiving system can fully utilize space resources, realize multi-transmission and multi-reception through a plurality of antennas, and improve the system channel capacity by times under the condition of not increasing frequency spectrum resources and antenna transmitting power.

In MIMO, data of a user may be mapped onto different spatial domains through Precoding (Precoding), so that the data of the user is transmitted through different antenna ports. In the precoding process, a precoding matrix is required to be used for processing the transmitted signals. The manner in which the base station acquires the precoding matrix may be different for different systems. Specifically, for a Time Division Duplex (TDD) system, the base station may estimate a downlink precoding matrix according to an uplink channel by using uplink and downlink reciprocity of a wireless channel. For a Frequency Division Duplex (FDD) system, uplink and downlink adopt different frequency bands, and an uplink channel cannot be used to obtain a downlink Precoding Matrix, generally, a terminal feeds back a Precoding Matrix Indicator (PMI) to a base station, and the base station obtains a downlink optimal Precoding Matrix according to the PMI. The PMI contains the indexes of a plurality of beams selected by the terminal, the characteristics of each beam in different frequency domain sub-bands and the like, and the overhead is high. Therefore, a method for reducing PMI overhead is desired.

Disclosure of Invention

The embodiment of the application provides a communication method and device, so as to promote PMI overhead in a MIMO system.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, an embodiment of the present application provides a communication method, where the method is applied to a terminal or a chip in the terminal, and the method includes: the terminal determines K wave beams from the 2L-1 wave beams, and the terminal sends precoding matrix indication PMI to the access network equipment.

Wherein L, K are positive integers, and K is less than 2L-1. Optionally, L is greater than or equal to 2. The PMI is configured to indicate a combining coefficient corresponding to each of 2L-1 beams on each spatial layer, the combining coefficient corresponding to each of the 2L-1 beams includes a combining coefficient corresponding to each of the K beams in at least two frequency domain units, and a combining coefficient corresponding to each of the 2L-1 beams except the K beams in at least two frequency domain units, or the combining coefficient corresponding to each of the 2L-1 beams includes a combining coefficient corresponding to each of the K beams in at least two frequency domain units, and a wideband combining coefficient corresponding to each of the 2L-1 beams except the K beams.

The frequency domain unit in the present application mainly refers to the frequency domain granularity of the PMI. Alternatively, the frequency domain unit may refer to a sub-band, that is, the bandwidth of the frequency domain unit is the same as the bandwidth of the sub-band, or the bandwidth of the frequency domain unit may be 1/2 of the bandwidth of the sub-band, or the bandwidth of the frequency domain unit may be 1/4 of the bandwidth of the sub-band. Of course, as communication protocols progress, frequency domain units may also have other granularity of partitioning.

By adopting the method for reporting the combining coefficient of the low-priority beam by the terminal, in an implementation manner, on each spatial layer, the low-priority beam which has less influence on the performance of the MIMO system is reported by the terminal, and the terminal reports the combining coefficients at the same frequency domain units and only indicates the indexes of the same frequency domain units, so that on one hand, the bit overhead for indicating the indexes of the frequency domain units is reduced, and on the other hand, compared with the prior art, only reports the broadband amplitude of the beam for the beam with small broadband amplitude, in the embodiment of the application, the amplitude of partial frequency domain units of the low-priority beam can be reported, the characteristics of the frequency domain units of the combining coefficients can be reflected more finely, and the system performance loss is reduced. In another implementation, the terminal reports the wideband combining coefficients of the low-priority beams, that is, for each low-priority beam, only one wideband combining coefficient is reported without reporting the frequency domain unit index or reporting multiple frequency domain unit combining coefficients, thereby further reducing the overhead of reporting the PMI.

In a possible design, before the terminal sends the PMI to the access network device, the following steps may be further performed: on each spatial layer, for the first beam, the terminal starts from N_SBDetermining M frequency domain units, N_SBThe number of frequency domain units contained in the system bandwidth; for the second beam, the terminal is from N_SBN frequency domain units are determined from the plurality of frequency domain units.

In one possible design, the terminal may further perform the following steps: on each spatial layer, the terminal selects from N for the third beam_SBDetermining P frequency domain units in the frequency domain units; for the fourth beam, the terminal is from N_SBAnd determining P frequency domain units from the frequency domain units, wherein each of the P frequency domain units of the third beam and the P frequency domain units of the fourth beam is respectively the same.

In a second aspect, the present application provides a communication method, applied to an access network device or a chip in the access network device, where the method includes: the access network equipment receives a Precoding Matrix Indicator (PMI) from the terminal, and determines respective combining coefficients of 2L-1 beams on each spatial layer according to the PMI. The combining coefficients corresponding to the 2L-1 beams respectively include combining coefficients corresponding to each of the K beams in at least two frequency domain units, and combining coefficients corresponding to each of the 2L-1 beams except the K beams in at least two frequency domain units, respectively, or the combining coefficients corresponding to the 2L-1 beams respectively include combining coefficients corresponding to each of the K beams in at least two frequency domain units, and wideband combining coefficients of each of the 2L-1 beams except the K beams.

In a third aspect, the present application provides a communication device, which may be the terminal or a chip in the terminal. The communication device includes a processor and a transceiver.

A processor for determining K beams from the 2L-1 beams on each spatial layer. A transceiver, configured to send a precoding matrix indicator PMI to the access network device.

Wherein L, K are positive integers, and K is less than 2L-1. Optionally, L is greater than or equal to 2. The PMI is configured to indicate, on each spatial layer, a combining coefficient corresponding to each of 2L-1 beams, where the combining coefficient corresponding to each of 2L-1 beams includes a combining coefficient corresponding to each of the K beams in at least two frequency domain units, and a combining coefficient corresponding to each of the 2L-1 beams except the K beams in at least two frequency domain units, or the combining coefficient corresponding to each of 2L-1 beams includes a combining coefficient corresponding to each of the K beams in at least two frequency domain units, and a wideband combining coefficient corresponding to each of the 2L-1 beams except the K beams.

In one possible design, the processor is further configured to, on each spatial layer, select N beams for the first beam_SBDetermining M frequency domain units, N_SBThe number of frequency domain units contained in the system bandwidth; for the second beam, from N_SBN frequency domain units are determined from the plurality of frequency domain units.

In one possible design, the processor is further configured to, on each spatial layer, for a third beam, from N_SBDetermining P frequency domain units in the frequency domain units; for the fourth beam, from N_SBAnd determining P frequency domain units from the frequency domain units, wherein each of the P frequency domain units of the third beam and the P frequency domain units of the fourth beam is respectively the same.

In a fourth aspect, the present application provides a communication apparatus, which may be the above-mentioned access network device or a chip in the access network device, and includes a transceiver and a processor.

A transceiver for receiving a precoding matrix indication, PMI, from a terminal. And the processor is used for determining the combining coefficients corresponding to the 2L-1 beams on each spatial layer according to the PMI received by the transceiver. The combining coefficients corresponding to the 2L-1 beams respectively include combining coefficients corresponding to each of the K beams in at least two frequency domain units, and combining coefficients corresponding to each of the 2L-1 beams except the K beams in at least two frequency domain units, respectively, or the combining coefficients corresponding to the 2L-1 beams respectively include combining coefficients corresponding to each of the K beams in at least two frequency domain units, and wideband combining coefficients of each of the 2L-1 beams except the K beams.

In one possible design of any of the above aspects, the combining coefficients are represented by amplitude coefficients and phase coefficients; the amplitude coefficients comprise frequency domain unit amplitudes and broadband amplitudes; the phase coefficients include frequency domain unit phases and wideband phases.

In a possible design of any of the above aspects, the combining coefficients corresponding to each of the K beams in at least two frequency domain units respectively include: the combining coefficients corresponding to the first beams in each of the M frequency domain units and the combining coefficients corresponding to the second beams in each of the N frequency domain units, M, N, are integers greater than or equal to 2; m, N are the same, and each of the M frequency domain elements of the first beam and the N frequency domain elements of the second beam are the same, or different ones of the M frequency domain elements and the N frequency domain elements exist.

The wideband combining coefficients for each of the 2L-1 beams except the K beams include: the broadband combination coefficient of the third beam and the broadband combination coefficient of the fourth beam.

Wherein the first beam and the second beam are any two beams of the K beams, and the third beam and the fourth beam are any two beams of the 2L-1 beam except the K beams.

In a possible design of any of the above aspects, the index of a single frequency domain unit in the M frequency domain units and the N frequency domain units and the frequency domain unit amplitude of the combining coefficient at the single frequency domain unit correspond to an interpolation point, and each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit amplitude of the combining coefficient, or the index of a single frequency domain unit in the M frequency domain units and the N frequency domain units and the frequency domain unit phase of the combining coefficient of the single frequency domain unit correspond to an interpolation point, and each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit phase of the combining coefficient.

In one possible design of any of the above aspects, the PMI comprises: each spatial layer corresponds to a bin amplitude of a combining coefficient of the first beam in each bin of the M bins, an index of the M bins, a bin amplitude of a combining coefficient of the second beam in each bin of the N bins, an index of the N bins, a wideband amplitude of a combining coefficient of the third beam, and a wideband amplitude of a combining coefficient of the fourth beam.

By adopting the method for reporting the combination coefficient of the high-priority beam by the terminal, the high-priority beam with larger influence on the system performance adopts a more refined mode of reporting the combination coefficient, namely the combination coefficient of the beam reported by the terminal at the frequency domain unit can more accurately reflect the precoding vectors in different frequency domain units, so that the precoding vectors are more matched with the channel characteristics of the frequency domain unit, and the accuracy of the precoding result is improved. By adopting the method for reporting the merging coefficient of the low-priority beam, the terminal reports the broadband merging coefficient of the low-priority beam, namely, only one broadband merging coefficient is reported for each low-priority beam without reporting the index of the frequency domain unit or reporting the merging coefficients of a plurality of frequency domain units, thereby further reducing the cost of reporting the PMI.

In one possible design of any of the above aspects, the PMI comprises: each spatial layer corresponds to a frequency domain unit phase of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit phase of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a wideband phase of a combining coefficient of the third beam, and a wideband phase of a combining coefficient of the fourth beam.

In a possible design of any of the above aspects, the combining coefficients corresponding to each of the K beams in at least two frequency domain units respectively include: a combining coefficient corresponding to the first beam in each of the M frequency domain units, and a combining coefficient corresponding to the second beam in each of the N frequency domain units.

Combining coefficients respectively corresponding to each beam of the 2L-1 beams except the K beams in at least two frequency domain units include: and the combining coefficient corresponding to the third beam in each of the P frequency domain units and the combining coefficient corresponding to the fourth beam in each of the P frequency domain units.

In one possible design of any of the above aspects, P is an integer greater than or equal to 2; the index of a single frequency domain unit in the P frequency domain units and the frequency domain unit amplitude of the combining coefficient of the single frequency domain unit correspond to an interpolation point, each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit amplitude of the combining coefficient, or the index of the single frequency domain unit in the P frequency domain units and the frequency domain unit phase of the combining coefficient of the single frequency domain unit correspond to an interpolation point, and each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit phase of the combining coefficient.

In one possible design of any of the above aspects, the PMI comprises: for each spatial layer, the bin amplitude of the combining coefficient of the first beam in each bin of the M bins, the index of the M bins, the bin amplitude of the combining coefficient of the second beam in each bin of the N bins, the index of the N bins, the bin amplitude of the combining coefficient of the third beam in each bin of the P bins, the bin amplitude of the combining coefficient of the fourth beam in each bin of the P bins, and the index of the P bins.

In one possible design of any of the above aspects, the PMI comprises: for each spatial layer, the bin phase of the combining coefficient of the first beam in each bin of the M bins, the index of the M bins, the bin phase of the combining coefficient of the second beam in each bin of the N bins, the index of the N bins, the bin phase of the combining coefficient of the third beam in each bin of the P bins, the bin phase of the combining coefficient of the fourth beam in each bin of the P bins, and the index of the P bins.

By adopting the method for reporting the combination coefficient of the high-priority beam by the terminal, the high-priority beam with larger influence on the system performance adopts a more refined mode of reporting the combination coefficient, namely the terminal can select the combination coefficients at different frequency domain units for reporting by different high-priority beams, so that the precoding vectors of different beams in different frequency domain units can be more accurately reflected, the channel characteristics of different beams can be better reflected, and the accuracy of precoding results is improved. By adopting the method for reporting the combining coefficient of the low-priority beam by the terminal, the low-priority beam with less influence on the performance of the MIMO system reports the combining coefficients at the same frequency domain units, and only the indexes of the same frequency domain units are indicated for all the low-priority beams, so that on one hand, the bit overhead of indicating the indexes of the frequency domain units is reduced, and on the other hand, compared with the prior art, only the broadband amplitude of the beam is reported for the beam with small broadband amplitude.

In a possible design of any of the above aspects, the K beams are K beams with the largest wideband amplitude of the combining coefficients in the 2L-1 beams, or the K beams are K beams with the wideband amplitude of the combining coefficients in the 2L-1 beams greater than or equal to an amplitude threshold.

When the wideband amplitude of the combining coefficient of the beam is large, the beam usually occupies a higher weight in the linear combination, which indicates that the beam has a larger influence on the precoding performance, and therefore, in the embodiment of the present application, K beams having a larger influence on the precoding performance are considered to be selected as high-priority beams.

In a possible design of any of the above aspects, the K beams are K beams with the smallest number of interpolation points in the 2L-1 beams, or the K beams are K beams with a number of interpolation points in the 2L-1 beams being less than or equal to an interpolation point number threshold.

When the number of interpolation points corresponding to the beam is small, and the terminal reports the PMI to the base station, the frequency domain unit index and the frequency domain unit amplitude which are correspondingly reported are correspondingly small, and the cost of reporting the PMI by the terminal is reduced. In the embodiment of the present application, the K high priority beams may be beams with fewer interpolation points.

In a possible design of any of the above aspects, the K beams are K beams with the largest average difference value between the frequency domain unit amplitude of the combining coefficient and the wideband amplitude of the combining coefficient, among the 2L-1 beams; or the K beams are K beams in which an average difference between the frequency domain unit amplitude of the combining coefficient and the wideband amplitude of the combining coefficient is greater than or equal to a distance threshold value, among the 2L-1 beams.

When the average difference between the frequency domain unit amplitude of the combining coefficient corresponding to the beam and the broadband amplitude of the combining coefficient corresponding to the beam is large, it indicates that the difference between the frequency domain unit amplitudes of the combining coefficient of the beam in different frequency domain units is large, and the frequency domain exhibits severe changes. If only the wideband amplitude of the combining coefficient of the beam is reported, the characteristics of the beam in the frequency domain cannot be reflected finely, thereby causing a severe loss of performance. In the embodiment of the present application, similar beams, that is, K beams having a larger average difference value from the broadband amplitude of the combining coefficient are taken as high-priority beams.

In a possible design of any of the above aspects, the number of bits used to indicate the frequency domain unit index corresponding to the interpolation point is equal to

Wherein, the inter is the number of interpolation points corresponding to a single beam, N_SBNum _ sb is the number of interpolation points in the system bandwidth.

The number of the predetermined interpolation points may be predetermined, that is, the combining coefficients at one or more frequency domain units are predetermined to be reported. Optionally, the number of interpolation points is preset to be 2. Optionally, if the frequency domain unit index starts from 0, the frequency domain unit indexes corresponding to the two preset interpolation points are respectively 0 and N_SB-1. Optionally, if the frequency domain unit index starts from 1, the frequency domain unit indexes corresponding to the two preset interpolation points are 1 and N respectively_SB. Hereinafter, the frequency domain units are mainly taken as subbands for example, and are uniformly described here, which is not described in detail again.

For example, taking an example that the system bandwidth includes 72 RBs, one sub-band includes 4 RBs, the system bandwidth includes 18 sub-bands, and the combining coefficient at the 1 st sub-band and the combining coefficient at the 18 th sub-band are predefined to be reported. Thus, referring to fig. 5, if the terminal needs to report the merging coefficients at 7 subbands shown in fig. 5, it only needs to indicate the subband indexes except for the 1 st subband and the 18 th subband, that is, the indexes of the

subbands

2, 4, 5, 8, and 13, and the number of bits used for indicating the indexes of the 5 subbands is equal to

Bit overhead indicating subband index is reduced.

In one possible design of any of the above aspects, the terminal is selected from N_SBDetermining M subbands from among the subbands, including: the terminal starts from the first sub-band and every timeSelecting one sub-band by a preset number of sub-bands until M sub-bands are determined, wherein the last sub-band in the M sub-bands is the second sub-band.

For example, the system bandwidth includes 18 subbands, where the first subband is subband 1, and starting from subband 1, the terminal selects a subband corresponding to an interpolation point every 2 subbands, and the last subband, that is, the second subband is subband 16, that is, selects

subbands

1, 4, 7, 10, 13, and 16, and indicates the index of these 6 subbands. Or, in another implementation manner, the terminal only indicates the index 1 of the starting subband and the index 16 of the last subband, and the base station can know that every 2 subbands are subbands corresponding to one interpolation point according to the preset number 2, that is, subbands corresponding to the interpolation point are subbands 1, 4, 7, 10, 13, and 16 in sequence.

In a possible design of any one of the above aspects, the number of interpolation points of a single beam is 1, and the combining coefficient of the single beam is a wideband combining coefficient of the single beam.

In a fifth aspect, an embodiment of the present application provides a communication apparatus having a function of implementing the communication method of any one of the above aspects. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a sixth aspect, a communication apparatus is provided, including: a processor and a memory; the memory is used for storing computer-executable instructions, and when the communication device runs, the processor executes the computer-executable instructions stored by the memory to enable the communication device to execute the communication method according to any one of the above aspects.

In a seventh aspect, a communication apparatus is provided, including: a processor; the processor is configured to be coupled to the memory, and after reading the instructions in the memory, execute the communication method according to any one of the above aspects according to the instructions.

In an eighth aspect, a computer-readable storage medium is provided, having stored therein instructions, which when run on a computer, cause the computer to perform the communication method of any of the above aspects.

A ninth aspect provides a computer program product containing instructions which, when run on a computer, cause the computer to perform the communication method of any one of the preceding aspects.

In a tenth aspect, there is provided circuitry comprising processing circuitry configured to perform the communication method of any one of the above aspects.

In an eleventh aspect, there is provided a chip comprising a processor, a memory coupled to the processor, the memory storing program instructions that when executed by the processor implement the communication method of any one of the above aspects.

In a twelfth aspect, a communication system is provided, where the communication system includes the terminal (or the chip in the terminal) in any of the above aspects, and the access network device (or the chip in the access network device) in any of the above aspects.

For technical effects brought by any one of the design manners in the second aspect to the twelfth aspect, reference may be made to technical effects brought by different design manners in the first aspect, and details are not described herein.

Drawings

Fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application;

fig. 2 is a schematic architecture diagram of a communication device according to an embodiment of the present application;

fig. 3 is a schematic flowchart of a communication method according to an embodiment of the present application;

FIG. 4 is a graph illustrating the relationship between frequency domain unit amplitude and frequency domain unit amplitude provided in an embodiment of the present application;

FIG. 5 is a graph illustrating the relationship between frequency domain unit amplitude and frequency domain unit amplitude provided in an embodiment of the present application;

fig. 6 is a flowchart illustrating a communication method according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

First, technical terms related to embodiments of the present application are given:

1. merging coefficients: as a possible precoding manner, the terminal feeds back a PMI to the base station, where the PMI indicates a plurality of beam vectors and indicates a combining coefficient corresponding to each beam vector in the plurality of beam vectors on each frequency domain unit of each spatial layer, so that the base station determines a downlink precoding vector corresponding to each frequency domain unit of each spatial layer according to each beam vector and the combining coefficient corresponding to each beam vector, and then the base station precodes a signal sent to the terminal according to the precoding vector, so as to improve transmission performance of the system.

Taking the number of spatial layers (rank) as 1 as an example, assume that the base station is configured with N in the horizontal direction and the vertical direction_1*N ₂Each antenna and dual-polarized antenna array are used, and the terminal presets N in each polarization direction according to channel conditions or other strategies₁N ₂L wave beams are selected from the orthogonal wave beams, the two polarization directions total 2L wave beams, correspondingly, in a spatial layer, a frequency domain unit, the two polarization directions, and the combination coefficients corresponding to the 2L wave beams are also selected. As such, the precoding vector can be represented by a linear combination of beams:

wherein, a_iRepresenting N from preset₁N ₂The ith beam (i is more than or equal to 0 and less than or equal to L-1) selected from the orthogonal beams, b_l,i,kThe "l" 1 spatial layer and the "k" polarization direction indicate the combining coefficient corresponding to the i-th orthogonal beam selected, and the combining coefficient corresponds to the weight of the beam in the linear combination of the beams. Therefore, the merging coefficients are sometimes referred to as weights herein, and are described in a unified manner herein, and will not be described in detail below.

The frequency domain unit mentioned in the embodiments of the present application may refer to a sub-band, that is, the bandwidth of the frequency domain unit is the same as the bandwidth of the sub-band, or the bandwidth of the frequency domain unit may be 1/2 of the bandwidth of the sub-band, or the bandwidth of the frequency domain unit may be 1/4 of the bandwidth of the sub-band. Of course, as the protocol evolves, the frequency domain units may also be frequency domain resources of other granularities.

It should be noted that the above-mentioned combining coefficient is a complex number, and the combining coefficient may be represented by an amplitude coefficient and a phase coefficient. The amplitude coefficients include frequency domain cell amplitudes and wideband amplitudes, and the phase coefficients include frequency domain cell phases and wideband phases. For a specific concept of frequency domain cell amplitude, wideband amplitude, frequency domain cell phase, wideband phase, see below.

Illustratively, the combining coefficients may be expressed in the form of amplitude coefficients and phase coefficients as follows:

wherein p is_l,i,kThe frequency domain unit amplitude of the combining coefficient corresponding to the kth polarization direction, the ith spatial layer (rank) and the ith orthogonal beam,

the phase of the combining coefficient corresponding to the kth polarization direction, the l spatial layer (rank), and the i-th orthogonal beam is shown. Correspondingly, when reporting the combining coefficient to the base station, the terminal can quantize and report the combining coefficient of each sub-band. Taking a frequency domain unit as an example of a sub-band, when reporting the sub-band amplitude of the combining coefficient corresponding to the beam 1 to the base station, the terminal quantizes the sub-band amplitude 1 of the beam 1 at the sub-band 1 by 3 bits and reports the quantized value 1 to the base station, and quantizes the sub-band amplitude 2 of the beam 1 at the sub-band 2 by 3 bits and reports the quantized value 2 to the base station.

In another example, p is as described above_l,i,kCan be expressed by the following formula:

wherein,

represents the broadband amplitude of the combining coefficient corresponding to the kth polarization direction, the ith spatial layer (rank), and the ith orthogonal beam,

and the frequency domain unit difference amplitude of the combination coefficient corresponding to the kth polarization direction, the ith spatial layer (rank) and the ith orthogonal beam is shown. When the frequency-domain units are sub-bands,

and the subband differential amplitude of the combining coefficient corresponding to the kth polarization direction, the ith spatial layer (rank) and the ith orthogonal beam is represented, and the subband differential amplitude is used for representing the deviation amount relative to the broadband amplitude.

Correspondingly, when the frequency domain unit amplitude of the combining coefficient is represented as the form shown in (3), taking the frequency domain unit as a subband as an example, the terminal reports the combining coefficient corresponding to the beam 1, and the method can be implemented as follows: and the terminal reports the broadband amplitude (quantized by using 3 bits) of the combining coefficient corresponding to the beam 1 to the base station, and reports the sub-band differential amplitude (quantized by using 1 bit) of the beam 1 at the sub-band 1 and the sub-band differential amplitude (quantized by using 1 bit) of the beam 1 at the sub-band 2 to the base station. In this way, the base station may obtain a quantized value of the subband amplitude of the beam 1 at the subband 1 according to the wideband amplitude and the subband differential amplitude at the subband 1, for example, by multiplying the wideband amplitude and the subband differential amplitude. Similarly, the base station may obtain a quantized value of the subband amplitude of beam 1 at subband 2 based on the wideband amplitude and the subband differential amplitude at subband 2.

It should be noted that, in this embodiment of the application, the terminal reports the subband amplitude or the subband phase to the base station, which may be according to the process corresponding to the above (2), that is, the terminal directly quantizes and reports the subband amplitude or the subband phase of each subband. Of course, the terminal reports the subband amplitude or the subband phase to the base station, and may also report the wideband amplitude to the base station according to the corresponding procedure of (3), and report the respective subband differential amplitudes of different subbands to the base station, so that the base station may obtain actual quantized values of the subband amplitude or the subband phase corresponding to different subbands.

In addition, in this embodiment, the terminal reports the subband amplitude to the base station, where the subband amplitude may refer to the subband amplitude p in formula (2)_l,i,kThe subband differential amplitude in the formula (3) can also be used

The description is not repeated herein.

Similarly, when referring to subband phases, we may also refer to subband differential phases.

In this embodiment, when feeding back the PMI to the base station, the terminal quantizes the frequency domain unit amplitude, the wideband amplitude, the frequency domain unit phase, and the wideband phase of the combining coefficient, respectively, to obtain quantized bits, and reports the quantized frequency domain unit amplitude, the wideband amplitude, the frequency domain unit phase, and the wideband phase of the combining coefficient.

It should be noted that in precoding, a beam in a spatial domain may be represented by a vector, and therefore, in this document, a beam vector and a beam are the same concept, and when referring to a beam, a beam vector may be referred to, and when referring to a beam vector, a beam may be referred to, which is stated herein in a unified manner and is not described in detail below. Of course, the beam vectors involved in the embodiments of the present application may also be referred to as orthogonal spatial basis vectors.

It should be noted that the merging coefficients referred to in the embodiments of the present application include frequency domain unit merging coefficients and wideband merging coefficients. The frequency domain unit combining coefficients and the wideband combining coefficients are separately described as follows.

2. Frequency domain unit merging coefficients: as a possible implementation manner, different frequency domain units may correspond to different channel conditions, and therefore, the terminal may use different precoding vectors when transmitting signals in different frequency domain units, that is, in different frequency domain units, 2L beams may correspond to different combining coefficients. For example, when the terminal transmits signals on frequency domain unit 1, the precoding vector is

When the terminal transmits signals on the frequency domain unit 2, the precoding vector is

It can be seen that for two 2L beams a with the same polarization direction₀To a_L-1Each beam in different frequency domain units may correspond to a different combining coefficient, so that different precoding vectors may be used in different frequency domain units. For a certain beam, the combining coefficient of the beam corresponding to the frequency domain unit is called as the frequency domain unit combining coefficient. For example, in this paragraph, b_1,1,2May be referred to as beam a₁The corresponding frequency domain units merge the coefficients.

It should be noted that the frequency-domain unit merging coefficients can be represented by frequency-domain unit amplitudes and frequency-domain unit phases. Therefore, when reporting the frequency domain unit combining coefficient of the beam, the terminal needs to report the quantized value of the frequency domain unit amplitude and the quantized value of the frequency domain unit phase.

3. Frequency domain unit amplitude of the combining coefficient: the amplitude of the frequency domain unit merging coefficient is called the frequency domain unit amplitude of the merging coefficient, and can also be called the frequency domain unit amplitude for short.

4. Frequency domain unit phase of the combining coefficient: the phase of the frequency domain unit combining coefficient is referred to as the frequency domain unit phase of the combining coefficient, and may also be referred to as the frequency domain unit phase.

5. Broadband merging coefficient: as a possible implementation manner, each frequency domain unit uses the same precoding vector in the whole system bandwidth, that is, for each beam of the selected 2L beams, the combining coefficient of the beam in each frequency domain unit is the same. For example, if the system bandwidth includes 2 frequency domain units, when the terminal transmits signals in frequency domain unit 1, for a certain beam of the 2L beams, the corresponding combining coefficient is the same as that of the beam when transmitting signals in frequency domain unit 2. In this case, the combining coefficient of the beam corresponding to the entire system bandwidth is referred to as a wideband combining coefficient. This means that given the wideband combining coefficient of a certain beam, the frequency domain unit combining coefficient corresponding to each frequency domain unit of the system bandwidth of the beam can be known. For example, if the system bandwidth includes 2 frequency domain units (frequency domain unit 1 and frequency domain unit 2), and the wideband combining coefficient of beam 1 is denoted as coefficient 1, the combining coefficient of beam 1 in the frequency domain unit of frequency domain unit 1 is coefficient 1, and the combining coefficient of beam 1 in the frequency domain unit corresponding to frequency domain unit 2 is also coefficient 1.

In the present embodiment, the wideband combining coefficient may be represented by a wideband amplitude and a wideband phase. This means that when the terminal reports the wideband combining coefficient corresponding to the beam, the wideband amplitude quantization value and the wideband phase quantization value of the beam need to be reported.

6. Wideband amplitude of the combining coefficients: the amplitude of the wideband combining coefficient is referred to as the wideband amplitude of the combining coefficient, and may also be referred to simply as the wideband amplitude.

7. Wideband phase of the combining coefficients: the phase of the wideband combining coefficient is referred to as the wideband phase of the combining coefficient, and may also be referred to simply as the wideband phase.

8. Reference beam: the method is used for normalization, that is, the amplitude or phase of the combining coefficient corresponding to the single beam needs to be normalized with respect to the amplitude or phase of the combining coefficient corresponding to the reference beam, so as to obtain the relative frequency domain unit amplitude, the relative wideband amplitude, the relative frequency domain unit phase, and the relative wideband phase of the combining coefficient.

In the embodiment of the application, one reference beam is selected from the 2L beams, and when the terminal reports the combining coefficient to the base station, the combining coefficients corresponding to the other 2L-1 beams except the reference beam need to be reported. And the merging coefficient reported by the terminal is the normalized merging coefficient. That is, when the terminal reports the combining coefficient corresponding to a certain beam in the frequency domain unit, the relative frequency domain unit amplitude and the relative frequency domain unit phase corresponding to the beam are reported, and when the terminal reports the wideband combining coefficient of a certain beam, the relative wideband amplitude and the relative wideband phase corresponding to the beam are reported.

When the terminal reports the amplitude of the combining coefficient, the reference beam is the beam with the maximum broadband amplitude of the combining coefficient in the 2L beams. Relative frequency domain element amplitude of combining coefficients of beam j

Can be calculated by the following formula:

wherein,

the frequency domain unit amplitude of the combining coefficient corresponding to beam j,

is the frequency domain unit amplitude of the combining coefficient corresponding to the reference beam.

Similarly, the relative wideband amplitude of the combining coefficients of beam j

Can be calculated by the following formula:

wherein,

for the wideband magnitude of the combining coefficient corresponding to beam j,

is the wideband amplitude of the combining coefficient corresponding to the reference beam.

Relative frequency domain unit phase of combining coefficients of beam j

Can be calculated by the following formula:

wherein,

the relative frequency domain unit phase of the combining coefficient corresponding to beam j,

the frequency domain unit phase of the combining coefficient corresponding to beam j,

is the frequency domain unit phase of the combining coefficient corresponding to the reference beam.

Relative wideband phase of combining coefficients for beam j

Can be calculated by the following formula:

wherein,

for the relative wideband phase of the combining coefficient corresponding to beam j,

for the wideband phase of the combining coefficient corresponding to beam j,

is the wideband phase of the combining coefficient corresponding to the reference beam.

The terms "first" and "second" and the like in the description and drawings of the present application are used for distinguishing different objects or for distinguishing different processes for the same object, and are not used for describing a specific order of the objects. Furthermore, the terms "including" and "having," and any variations thereof, as referred to in the description of the present application, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

The communication method provided by the embodiment of the application can be applied to a MIMO system. In particular, the method is applied to the precoding process of MIMO. Referring to fig. 1, an exemplary system architecture to which the embodiments of the present application are applicable is shown. The system comprises access network equipment and a plurality of terminals (such as terminal 1 to terminal 6 in fig. 1) communicating with the access network equipment, and the communication system can also comprise subsystems, for example, the terminal 4, the terminal 5 and the terminal 6 can form a subsystem, and the terminal 4, the terminal 5 and the terminal 6 can communicate with each other in the subsystem.

The access network device according to the embodiment of the present application is a device deployed in a radio access network to provide a wireless communication function. The access network device may include various macro base stations, micro base stations (also referred to as small stations), relays, Transmission Reception Points (TRPs), next Generation network nodes (g Node bs, gnbs), evolved Node bs (ng-enbs) connected to a next Generation core network, and the like, and may further include a wireless access network device of a non-third Generation Partnership Project (3 GPP) system, such as a Wireless Local Area Network (WLAN) access device.

Optionally, the terminal (terminal) referred to in the embodiments of the present application may include various handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem; and may also include subscriber units (subscriber units), cellular phones (cellular phones), smart phones (smart phones), wireless data cards, Personal Digital Assistants (PDAs), tablet computers, wireless modems (modems), handheld devices (dhhandles), laptop computers (laptop computers), Machine Type Communication (MTC) terminals (terminal), User Equipment (UE), terminal devices (terminal devices), Customer Premise Equipment (CPE), and the like. For convenience of description, the above-mentioned devices are collectively referred to as a terminal in this application.

The communication system may be applied to a Long Term Evolution (LTE) system or an LTE-Advanced (LTE-a) system at present, may also be applied to a 5G network currently being established or other networks in the future, and may also be applied to other WIreless communication systems, such as WIreless-FIdelity (Wi-Fi), Worldwide Interoperability for Microwave Access (wimax), and other cellular systems related to 3GPP, which is not particularly limited in this embodiment of the present application. In which the access network device and the terminal in the above communication system may correspond to different names in different networks, and those skilled in the art will understand that the names do not limit the device itself.

Optionally, the terminal and the access network device in this embodiment may be implemented by the communication device in fig. 2. Fig. 2 is a schematic diagram illustrating a hardware structure of a communication device according to an embodiment of the present application. The communication device 200 includes at least one processor 201, communication lines 202, memory 203, and at least one transceiver 204.

The processor 201 may be a general processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more ics for controlling the execution of programs in accordance with the present invention.

The communication link 202 may include a path for transmitting information between the aforementioned components.

The transceiver 204 may be any device, such as a transceiver, for communicating with other devices or communication networks, such as an ethernet, a Radio Access Network (RAN), a Wireless Local Area Network (WLAN), etc.

The memory 203 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 (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to these. The memory may be separate and coupled to the processor via communication line 202. The memory may also be integral to the processor.

The memory 203 is used for storing computer execution instructions for executing the scheme of the application, and is controlled by the processor 201 to execute. The processor 201 is configured to execute computer-executable instructions stored in the memory 203, so as to implement the communication method provided by the following embodiments of the present application.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which are not specifically limited in the embodiments of the present application.

In particular implementations, processor 201 may include one or more CPUs such as CPU0 and CPU1 in fig. 2, for example, as one embodiment.

In particular implementations, communication device 200 may include multiple processors, such as processor 201 and processor 207 in fig. 2, for example, as an example. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions).

In particular implementations, communication device 200 may also include an output device 205 and an input device 206, as one embodiment. The output device 205 is in communication with the processor 201 and may display information in a variety of ways. For example, the output device 205 may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device 206 is in communication with the processor 201 and may receive user input in a variety of ways. For example, the input device 206 may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.

The communication device 200 described above may be a general purpose device or a special purpose device. The embodiment of the present application does not limit the type of the communication device 200. The terminal and the access network device can be devices with similar structures in fig. 2.

Referring to fig. 3, a communication method provided in an embodiment of the present application includes the following steps:

s301, the terminal selects 2L orthogonal beams from the codebook.

The codebook is a set of preset orthogonal beam vectors. For a specific implementation manner in which the terminal selects 2L beams from the codebook, reference may be made to the prior art, which is not described in this embodiment.

It should be noted that, the combining coefficient reporting method according to the embodiment of the present application is described by taking a spatial layer granularity as an example, for a first spatial layer, 2L beams may be selected, and for a second spatial layer, 2L beams that are the same as the first spatial layer may be selected. Alternatively, as the protocol evolves, different spatial layers may choose different 2L beams.

S302, for each spatial layer, a reference beam of the 2L beams is determined.

It should be noted that, the terminal reports the PMI to the base station, where the PMI includes an amplitude quantization value and a phase quantization value of the combining coefficient of the selected beam corresponding to each spatial layer, and hereinafter, a process of reporting the amplitude quantization value of the combining coefficient by the terminal is mainly described, and a process of reporting the phase quantization value of the combining coefficient by the terminal may refer to a description about reporting the amplitude quantization value of the combining coefficient, which is described in a unified manner here and is not described in detail below.

When the terminal reports the amplitude of the combining coefficient, the reference beam is the beam with the maximum broadband amplitude of the combining coefficient in the 2L beams.

And S303, for each spatial layer, the terminal determines K beams from the 2L-1 beams.

Wherein K is a positive integer and L is a positive integer. K < 2L-1. Optionally, L is greater than or equal to 2. The 2L-1 beams are the beams of the 2L beams except for the reference beam.

As described above, the terminal may perform normalization processing on the amplitude and the phase of the combining coefficient corresponding to each beam of the 2L-1 beams with the amplitude and the phase of the combining coefficient corresponding to the reference beam as a reference, so as to obtain a normalized relative amplitude and a normalized relative phase. Subsequently, when reporting the PMI to the base station, the terminal may only report the relative amplitude and the relative phase of the combining coefficient of 2L-1 beams. Therefore, hereinafter, when referring to the frequency domain unit amplitude of the combining coefficient, it may also refer to the relative frequency domain unit amplitude of the combining coefficient, when referring to the wideband amplitude of the combining coefficient, it may also refer to the relative wideband amplitude of the combining coefficient, when referring to the frequency domain unit phase of the combining coefficient, it may also refer to the relative frequency domain unit phase of the combining coefficient, when referring to the wideband phase of the combining coefficient, it may also refer to the relative wideband phase of the combining coefficient. The description is unified here and will not be repeated below. For the description of the relative frequency domain unit amplitude, the relative wideband amplitude, the relative frequency domain unit phase, and the relative wideband phase of the combining coefficient, reference may be made to the above, and details are not described here.

In the embodiment of the present application, the 2L-1 beams are divided into two sets of beams, i.e., a high priority beam set and a low priority beam set. In S303, K beams selected by the terminal from the 2L-1 beams are beams in the high-priority beam set.

Optionally, according to different application scenarios, the high-priority K beams are flexibly selected in different ways:

mode 1: the selected K wave beams are K wave beams with the maximum broadband amplitude of the combining coefficients in the 2L-1 wave beams, or the K wave beams are K wave beams with the broadband amplitude of the combining coefficients in the 2L-1 wave beams being larger than or equal to the amplitude threshold value. For example, if 2L-6 is taken as an example, the reference beam is beam 1, and in 2L-1-5 beams except the reference beam, the wideband amplitudes of the combining coefficients corresponding to

beams

2, 3, and 4 are all the wideband amplitudes

The wideband amplitude of the combining coefficient corresponding to beam 5 is

The wideband amplitude of the combining coefficient corresponding to beam 6 is

If K is 2, then the selected K-2 high priority beams are beams 5, 6 and the low priority beams are

beams

2, 3, 4.

When the wideband amplitude of the combining coefficient of the beam is large, the beam usually occupies a higher weight in the linear combination, which indicates that the beam has a larger influence on the precoding vector, and therefore, the embodiment of the present application considers that K beams having a larger influence on the precoding performance are selected as the high-priority beams.

Mode 2: the K wave beams are the K wave beams with the minimum number of interpolation points in the 2L-1 wave beams, or the K wave beams are the K wave beams with the number of interpolation points in the 2L-1 wave beams being smaller than or equal to the threshold value of the number of interpolation points.

In the embodiment of the present application, the combining coefficient may be expressed in the form of amplitude and phase, and the relationship between the frequency domain unit amplitude of the combining coefficient and the frequency domain unit may be expressed by an amplitude-frequency domain unit curve, and the relationship between the frequency domain unit phase and the frequency domain unit of the combining coefficient may be expressed by a phase-frequency domain unit curve, thereby expressing the relationship between the combining coefficient and the frequency domain unit.

It should be noted that, the following description mainly takes the frequency domain unit as the subband as an example, and the description is unified here and is not repeated herein. Referring to fig. 4, assuming 2L to 4, a graph of the relationship between subband amplitudes and subbands of the combining coefficients of the beam 1 to the beam 4 is shown. Wherein beam 1 is the reference beam. For a beam other than the reference beam, such as beam 2, the subband amplitudes of the combining coefficients follow the subband variationBecause of the better linear characteristic, it is considered that only the amplitudes corresponding to a part of sub-bands are reported (for example, points with a larger slope change in the change curve of the sub-band amplitudes of the combining coefficients along with the sub-bands), and a linear interpolation method is used to fit the ideal curve of the beam 2 to the adjacent interpolation points reported by the beam 2 by a straight line. The ideal curve is the relationship between the non-quantized ideal frequency domain unit amplitude of the beam 2 at each frequency domain unit and each frequency domain unit. Specifically, a plurality of interpolation points may be selected on the ideal curve of the beam 2 according to a slope variation trend of the ideal curve in which the subband amplitude of the combining coefficient changes with the subband, and the subband index and the quantized subband amplitude corresponding to each of the interpolation points may be reported to the base station. Each interpolation point is determined by an index of one frequency domain unit (for example, the index of the 2 nd frequency domain unit is 2) and the frequency domain unit amplitude of the corresponding combining coefficient of the frequency domain unit, and every two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the amplitude of the combining coefficient. By two adjacent interpolation points, the corresponding frequency domain unit amplitude at each frequency domain unit (such as 2 nd frequency domain unit) between the two interpolation points can be approximately obtained by an interpolation algorithm. Thus, the base station obtains the frequency domain unit amplitudes corresponding to the wave beam in all the frequency domain units by a linear interpolation method according to each frequency domain unit index and the frequency domain unit amplitude corresponding to the received wave beam. It should be noted that the frequency domain unit amplitude corresponding to a certain frequency domain unit reported by the terminal generally refers to a quantized amplitude value, and therefore, may be different from the frequency domain unit amplitude at the frequency domain unit on an ideal curve. For example, for the beam 2, the terminal selects 5 interpolation points as shown in fig. 4, the frequency domain unit indexes corresponding to the interpolation points are respectively the frequency domain unit 1, the frequency domain unit 2, the frequency domain unit 8, the frequency domain unit 13, and the frequency domain unit 18, and the terminal reports the frequency domain unit amplitudes corresponding to the 5 frequency domain units to the base station. Where, on the ideal curve for beam 2, frequency domain unit amplitude at frequency domain unit 1 is 0.48, frequency domain unit amplitude at frequency domain unit 2 is 0.72, frequency domain unit amplitude at frequency domain unit 8 is 0.11, frequency domain unit amplitude at frequency domain unit 13 is 0.27, and frequency domain unit amplitude at frequency domain unit 18 is 0.48The amplitude was 0.015. On the interpolated straight line for beam 2, the bin amplitude at bin 1 is 0.5 and the bin amplitude at bin 2 is 0

The frequency domain unit amplitude at frequency domain unit 8 is

The frequency domain unit amplitude at frequency domain unit 13 is 0.25 and the frequency domain unit amplitude at frequency domain unit 18 is 0. It can be seen that, for the beam 2, the frequency domain unit amplitudes at the

frequency domain units

1, 2, 8, 13, and 18 reported by the terminal are not exactly the same as the frequency domain unit amplitudes at the

frequency domain units

1, 2, 8, 13, and 18 on the ideal curve of the beam 2. Taking the quantized value of the frequency domain unit amplitude reported by the terminal as an example, the quantization of the interpolation point frequency domain unit amplitude can be performed by adopting 3 bits, wherein the selectable quantized value comprises

Still referring to fig. 4, the number of interpolation points used for fitting the relationship curve of the beam 2 is 5, the frequency domain unit indexes corresponding to the interpolation points are

frequency domain units

1, 2, 8, 13, and 18, respectively, the number of interpolation points used for fitting the relationship curve of the beam 3 is 7, the frequency domain unit indexes corresponding to the interpolation points are

frequency domain units

1, 3, 4, 5, 14, 17, and 18, respectively, the number of interpolation points used for fitting the relationship curve of the beam 4 is 6, and the frequency domain unit indexes corresponding to the interpolation points are

frequency domain units

1, 4, 8, 12, 16, and 18, respectively. If K is 2, the K with the smallest number of interpolation points is 2 beams, that is, the beam 2 and the beam 4 are selected as high priority beams, and the beam 3 is selected as a low priority beam.

Also for example, e.g. 2L beam pairsThe number of interpolation points is Mj, 2L-1 is 5 when { M }₁,M ₂,M ₃,M ₄,M ₅And if the preset interpolation point number threshold is 4, then K is 3 beams, which are beam 1, beam 2, and beam 4, respectively.

Mode 3: the K wave beams are the K wave beams with the largest average difference value between the frequency domain unit amplitude of the combination coefficient and the broadband amplitude of the combination coefficient in 2L-1 wave beams; or the K wave beams are the K wave beams with the average difference value between the frequency domain unit amplitude of the combining coefficient and the broadband amplitude of the combining coefficient larger than or equal to the distance threshold value in the 2L-1 wave beams.

Wherein, as described above, the frequency domain unit amplitude of the merged coefficient may refer to the relative frequency domain unit amplitude of the merged coefficient

The wideband amplitude of the combining coefficient may refer to the relative wideband amplitude of the combining coefficient

For beam J, the average difference can be calculated as follows:

wherein N is_SBFor the number of frequency domain units included in the system bandwidth, | | | | is a symbol for calculating an absolute value, and n represents the nth frequency domain unit.

As an example, 2L-4, in 3 beams except for the reference beam, the average difference of the beam 2 is 3, the average difference of the beam 3 is 2, the average difference of the beam 4 is 1, and if K is 2, the terminal selects the beam 2 and the beam 3 as the high priority beams.

Of course, the terminal may also select a beam with a large deviation between the frequency domain unit amplitude and the wideband amplitude of the combining coefficient as the high-priority beam. For example, the variance between the wideband amplitude and the amplitude of each frequency domain cell is calculated:

wherein,

in order to combine the wide-band amplitudes of the coefficients,

frequency domain unit amplitude, N, for the combined coefficient_SBThe number of frequency domain units included in the system bandwidth.

Or, the terminal may calculate the deviation degree between the frequency domain unit amplitude and the wideband amplitude in other manners, and select K beams with larger deviation degree as the high-priority beams.

When the average difference between the frequency domain unit amplitude of the combining coefficient corresponding to the beam and the broadband amplitude of the combining coefficient corresponding to the beam is large, it indicates that the difference between the frequency domain unit amplitudes of the combining coefficients of the beam in different frequency domain units is large.

Of course, the terminal may also select K beams in combination with any two or three of the

above modes

1, 2, and 3. For example, K ═ 4, the terminal selects 2 beams with the largest wideband amplitude of the combining coefficients and 2 beams with the smallest interpolation points as K high-priority beams. Or, K is 4, the terminal selects 4 beams with the largest wideband amplitude of the combining coefficient and the smaller number of the interpolation points as the high-priority beams, that is, the terminal comprehensively considers two factors, namely the wideband amplitude and the number of the interpolation points.

Of course, the terminal may also select K beams in other manners, which is not listed here in this embodiment of the present application.

Optionally, the terminal indicates the selected K beams to the base station. Wherein the number of bits used to indicate the K beams is

And S304, the terminal determines the combining coefficients corresponding to the 2L beams.

Exemplarily, after the terminal determines 2L beams in one spatial layer, one frequency domain unit, and two polarization directions, it needs to select the combining coefficients corresponding to the 2L beams. For the process in which the terminal selects the respective combining coefficients corresponding to the 2L beams, reference may be made to the prior art, which is not described herein again.

S305, the terminal sends a Precoding Matrix Indicator (PMI) to the access network equipment.

Accordingly, the access network device receives the PMI from the terminal.

Wherein, the PMI is used for indicating the combining coefficient corresponding to each spatial layer (rank)2L-1 beams. The combining coefficients corresponding to the 2L-1 beams respectively comprise the combining coefficients corresponding to the K high-priority beams respectively and the combining coefficients corresponding to the 2L-1-K low-priority beams respectively. It should be noted that, because the high-priority beam has a large influence on the system performance, the method for reporting the combining coefficient of the high-priority beam by the terminal may be different from the method for reporting the combining coefficient of the low-priority beam by the terminal.

Specifically, for K high-priority beams, when reporting the respective corresponding combining coefficients of the K beams, the terminal reports the respective corresponding combining coefficients of each beam in two or more frequency domain units.

In K beamsThe first beam and the second beam are used as examples to describe a manner in which the terminal reports the combining coefficient of the high-priority beam. When the terminal reports the combining coefficient of the first beam, the N contained in the slave system bandwidth_SBM frequency domain units corresponding to the first wave beam are selected from the frequency domain units, and the terminal reports the combining coefficient corresponding to the first wave beam of each frequency domain unit in the M frequency domain units. When the terminal reports the merging coefficient of the second beam, the terminal reports the merging coefficient of the second beam from N_SBAnd selecting N frequency domain units corresponding to the second wave beams from the frequency domain units, and reporting the combining coefficients corresponding to the second wave beams of each of the N frequency domain units by the terminal. Accordingly, S305 is specifically implemented as: the terminal sends PMI to the access network equipment, and the PMI comprises: the index of the M frequency domain elements, the frequency domain element amplitude of the first beam at each of the M frequency domain elements, the index of the N frequency domain elements, and the frequency domain element amplitude of the second beam at each of the N frequency domain elements.

Wherein M, N are each an integer of 2 or more, M<N _SBAnd N is<N _SB(ii) a M, N are the same and each of the M frequency domain elements of the first beam are the same as each of the N frequency domain elements of the second beam, or there are different frequency domain elements in the M frequency domain elements and the N frequency domain elements. Here, the first beam and the second beam are any two of the K beams.

Taking the frequency domain unit as the subband as an example, referring to fig. 4, the case where there are different subbands in M subbands and N subbands is described. Alternatively, the value of M, N may be different. For example, in fig. 4, the number of interpolation points for the beam 2 is 5, the subband index corresponding to each interpolation point is subband 1, subband 2, subband 8, subband 13, and subband 18 in sequence, the number of interpolation points for the beam 3 is 7, and the subbands corresponding to each interpolation point are subbands 1, 3, 4, 5, 14, 17, and 18, respectively. Correspondingly, the terminal indicates the combining coefficient of the beam 2 and the beam 3 to the base station, which is specifically realized as follows: the terminal transmits to the base station a PMI including indexes of 5 subbands corresponding to the beam 2 (i.e., quantized values of subband 1, subband 2, subband 8, subband 13, subband 18), subband amplitudes at 5 subbands, indexes of 7 subbands corresponding to the beam 3, and subband amplitudes at 7 subbands. Of course, M, N may have the same value. For example, the number of interpolation points for the first beam is 3, the subbands corresponding to the interpolation points are subbands 1, 2, and 3, respectively, and the number of interpolation points for the second beam is also 3, but the subbands corresponding to the interpolation points are subbands 4, 5, and 6, respectively. Correspondingly, the terminal indicates the combining coefficient of the first beam and the second beam to the base station, which is specifically implemented as follows: the terminal transmits a PMI, which includes indexes of 3 subbands corresponding to the first beam (i.e., quantized values of subband 1, subband 2, and subband 3), subband amplitudes at the 3 subbands, indexes of 3 subbands corresponding to the second beam, and subband amplitudes at the 3 subbands, to the base station.

Optionally, in this embodiment of the present application, the number of bits of the frequency domain unit index corresponding to the interpolation point for indicating a certain beam selection is equal to

Optionally, if multiple beams need to report the combining coefficients corresponding to different frequency domain unit indexes, the terminal needs to report the frequency domain unit index corresponding to the interpolation point of the beam for each beam. If multiple beams report the same combination coefficients at the several frequency domain unit indexes, the terminal needs to report the frequency domain unit indexes corresponding to the several common interpolation points.

Wherein, the inter is the number of interpolation points corresponding to a single beam, N_SBThe number of frequency domain units included in the system bandwidth, num _ sb is the number of predetermined interpolation points,

is from N_SB-num _ sb elements of the inter-num _ sb element combination formula, Ceiling [, [ solution ] ]]Indicating a ceiling operation. The number of the preset interpolation points can be predefined, that is, the number of the combining coefficients corresponding to one or more frequency domain units to be reported is predefined. The frequency domain unit is taken as an example for explanation. For example, taking the system bandwidth including 72 RBs as an example, one sub-band includes 4 RBs, the system bandwidth includes 18 sub-bands,and presetting to report the merging coefficient corresponding to the 1 st subband and the merging coefficient corresponding to the 18 th subband. Thus, referring to fig. 5, if the terminal needs to report the merging coefficients corresponding to the 7 subbands shown in fig. 5, it only needs to indicate the subband indexes except for the 1 st subband and the 18 th subband, that is, the indexes of the

subbands

Bit overhead indicating subband index is reduced.

Optionally, the terminal determines an interpolation point for fitting a relationship curve between the frequency domain unit index and the frequency domain unit amplitude and determines a frequency domain unit index corresponding to the interpolation point, where the terminal selects one frequency domain unit every preset number of frequency domain units from the first frequency domain unit, and the last frequency domain unit selected is the second frequency domain unit. For example, the system bandwidth includes 18 frequency domain units, the terminal selects a frequency domain unit index corresponding to one interpolation point every 2 frequency domain units, the starting frequency domain unit, that is, the first frequency domain unit is frequency domain unit 1, the last frequency domain unit, that is, the second frequency domain unit is frequency domain unit 16, that is,

frequency domain units

1, 4, 7, 10, 13, and 16 are selected, and the indexes of the 6 frequency domain units are indicated. Or, in another implementation, the terminal only indicates the index 1 of the starting frequency domain unit and the index 16 of the last frequency domain unit, and the base station can know that 2 frequency domain units are the frequency domain units corresponding to one interpolation point every interval according to the preset number 2, that is, the frequency domain units corresponding to the interpolation points are the

frequency domain units

1, 4, 7, 10, 13, and 16 in sequence. Of course, as another implementation manner, the terminal may further include an indication bit in the PMI, where the indication bit is used to indicate the index 1 of the starting frequency domain unit and the index 16 of the last frequency domain unit, and indicate an interval used when selecting the frequency domain units (for example, indicate that a frequency domain unit corresponding to one interpolation point is selected every 2 frequency domain units). Or, in another implementation, the terminal includes an indication bit in the PMI, which is used to indicate an index 1 of the starting frequency domain unit, and indicate an interval (e.g., 2), and indicate the number of the selected frequency domain unit indexes (e.g., 6), and the base station may determine, according to the indication bit, that the frequency domain units corresponding to the interpolation point are the

frequency domain units

1, 4, 7, 10, 13, and 16 in sequence.

Of course, the terminal may also determine the interpolation points of the beams in other manners, for example, select several interpolation points with the best fitting degree as interpolation points of the linear interpolation. Or, the terminal determines the interpolation point in other ways, which is not limited in this embodiment of the present application.

Taking the frequency domain units as the subbands, referring to fig. 5, the value of M, N is the same, and each of the M subbands of the first beam and the N subbands of the second beam is the same. That is, for all high priority beams, the terminal reports the combining coefficients at the same several subbands. For example, in fig. 5, assume that 2L is 4, the reference beam is beam 1, and of beams 2 to 4, beam 2 and beam 3 are high priority beams. For high priority beams 2 and 3, the terminal selects

subbands

1, 2, 4, 5, 8, 12, 13, 18. Correspondingly, the terminal indicates the combining coefficients corresponding to the beam 2 and the beam 3 to the base station, which may be specifically implemented as: the terminal sends PMI to the base station, where the PMI includes indices of

subbands

1, 2, 4, 5, 8, 13, 18, subband amplitude corresponding to beam 2 at each selected subband, and subband amplitude corresponding to beam 3 at each selected subband. Thus, for K high priority beams, the terminal only needs to report the same M (or N) subband indexes, thereby reducing the overhead of reporting the PMI.

By adopting the method for reporting the combination coefficient of the high-priority beam by the terminal, the high-priority beam with larger influence on the system performance adopts a more refined mode of reporting the combination coefficient, namely the combination coefficient of the beam reported by the terminal at the sub-band, so that the precoding vectors in different sub-bands can be more accurately reflected, and the accuracy of the precoding result is improved.

It should be noted that, in this embodiment of the present application, reporting the subband amplitude by the terminal may refer to reporting an actual subband amplitude by the terminal, or may refer to indicating the actual subband amplitude by reporting the wideband amplitude and the subband differential amplitude by the terminal, where the actual subband amplitude may be represented in a form of formula (3). Similarly, the terminal reporting the sub-band phase may refer to the terminal reporting an actual sub-band phase, or may refer to the terminal indicating the actual sub-band phase by reporting the wideband phase and the sub-band differential phase.

The following describes a manner in which the terminal reports the combining coefficient of the low-priority beam.

Optionally, for a low-priority beam, when the terminal reports the combining coefficient of a certain beam, the combining coefficients corresponding to the beam in two or more frequency domain units are reported.

Taking any two of the low priority beams, such as the third beam and the fourth beam, as an example, the terminal is at N_SBP frequency domain units are selected from the frequency domain units. And when the terminal reports the coefficient of the third beam, reporting the combination coefficient of the third beam at each frequency domain unit in the P frequency domain units. And when the terminal reports the coefficient of the fourth beam, reporting the combination coefficient of the fourth beam at each frequency domain unit in the P frequency domain units. Wherein P is an integer greater than or equal to 2. Optionally, P<M, and P<And N is added. That is, the terminal selects the same P frequency domain units for all low priority beams and reports the combining coefficients of the low priority beams at the required frequency domain units. For example, referring to fig. 5, suppose beams 3 and 4 are low-priority beams, and P subbands selected by the terminal are subbands 1, 2, 4, 5, 8, 12, 13, and 18. Correspondingly, the terminal sends the combining coefficient of the beams 3 and 4 to the base station, which can be specifically realized as follows: the terminal transmits to the base station a PMI including indices of

subbands

1, 2, 4, 5, 8, 12, 13, 18, subband amplitude of beam 3 at each subband, and subband amplitude of beam 4 at each subband.

Optionally, for a low-priority beam, when the terminal reports the combining coefficient of a certain beam, the terminal reports the wideband combining coefficient of the beam, that is, the beam is N_SBThe subband amplitude at each of the subbands is the same. Still taking any two beams of the low priority beams, such as the third beam and the fourth beam as an example, the terminal indicates the combining coefficients of the third beam and the fourth beam to the base station, and may be implemented as: terminal orientation baseThe station transmits a PMI that includes wideband magnitudes of the combining coefficients of the third beam and wideband magnitudes of the combining coefficients of the fourth beam.

Alternatively, since two adjacent interpolation points can determine an interpolation straight line, that is, when the number of interpolation points is greater than or equal to 2, the relationship between the subband index and the subband amplitude can be determined. Therefore, when the terminal reports the combining coefficient of the low-priority beam, if the number of interpolation points corresponding to a certain low-priority beam is 1, the terminal can be implicitly instructed to report the combining coefficient of the low-priority beam by adopting a mode of reporting broadband amplitude and broadband phase, so that the cost of reporting the PMI by the terminal can be reduced.

By adopting the method for reporting the combination coefficient of the low-priority beam by the terminal, in an implementation mode, the low-priority beam has less influence on the performance of the MIMO system, the terminal reports the combination coefficients at the same sub-bands, and only indexes of the same sub-bands are indicated, so that on one hand, the bit overhead of indicating the sub-band indexes is reduced, and on the other hand, compared with the prior art, the method only reports the broadband amplitude of the beam for the beam with small broadband amplitude. In another implementation, the terminal reports the wideband combining coefficients of the low-priority beams, that is, for each low-priority beam, only one wideband combining coefficient is reported without reporting a subband index or reporting multiple subband combining coefficients, thereby further reducing the overhead of reporting the PMI.

The above mainly takes the amplitude of the combining coefficient reported by the terminal as an example, and it should be noted that the process of reporting the phase of the combining coefficient by the terminal may refer to the process of reporting the amplitude, which is not described herein again. The amplitude and phase of the combining coefficients together are used to represent the complete combining coefficient.

S306, the access network equipment determines the respective combining coefficient of the 2L-1 wave beams according to the PMI.

Specifically, for the case that the terminal reports the sub-band characteristics (including sub-band amplitude and sub-band phase) of the combining coefficient, the access network device obtains the combining coefficients at all sub-bands by using a linear interpolation method according to the received sub-band index and the sub-band amplitude at each sub-band. For the situation that the terminal reports the broadband characteristics (including broadband amplitude and broadband phase) of the combining coefficient, the access network equipment determines the combining coefficient corresponding to the beam in the whole system bandwidth according to the received beam broadband amplitude and broadband phase.

In the communication method provided by the embodiment of the application, the terminal determines K beams from the 2L-1 beams and sends the PMI to the access network device to indicate the respective combining coefficients of the 2L-1 beams. For K beams, when the terminal reports the combining coefficient of the beam, the combining coefficient of the beam at the frequency domain unit (that is, the combining coefficient of the frequency domain unit) is reported, and for 2L-1-K beams, when the terminal reports the combining coefficient of the beam, the combining coefficient of the beam at the frequency domain unit is reported, or the wideband combining coefficient of the beam is reported. That is to say, for different beams, the modes of reporting the combining coefficients by the terminal may be different, so that the overhead occupied by the PMI may be reduced on the premise of not affecting the performance of the MIMO system.

The communication method provided by the embodiment of the application can be applied to a process that a terminal reports Channel State Information (CSI) to a base station. Referring to fig. 6, the process includes the following steps:

s601, the access network equipment sends a Channel State Information Reference Signal (CSI-RS) to the terminal.

Accordingly, the terminal receives the CSI-RS from the access network device.

And S602, the terminal acquires the CSI according to the CSI-RS.

The specific implementation of S601 and S602 may refer to the prior art, and is not described herein again.

S603, the terminal sends CSI to the access network equipment.

Accordingly, the access network device receives the CSI from the terminal.

Wherein the CSI includes a PMI. For the description of PMI, see above for details, it is not repeated here. And then, the access network equipment determines a precoding matrix corresponding to the downlink signal according to the PMI included in the CSI, and finishes precoding the downlink signal.

It is to be understood that, in order to implement the above functions, the network element in the embodiments of the present application includes a corresponding hardware structure and/or software module for performing each function. The elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein may be embodied in hardware or in a combination of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present teachings.

In the embodiment of the present application, the network element may be divided into the functional units according to the above method example, for example, each functional unit may be divided corresponding to each function, or two or more functions may be integrated into one processing unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit. It should be noted that the division of the unit in the embodiment of the present application is schematic, and is only a logic function division, and there may be another division manner in actual implementation.

Fig. 7 shows a schematic block diagram of a communication apparatus provided in an embodiment of the present application, where the communication apparatus may be the terminal or the access network device described above. The communication means 700 may be in the form of software and may also be a chip usable for devices. The communication apparatus 700 includes: a processing unit 702 and a communication unit 703. Optionally, the communication unit 703 may be further divided into a transmitting unit (not shown in fig. 17) and a receiving unit (not shown in fig. 17). Wherein, the sending unit is configured to support the communication apparatus 700 to send information to other network elements. A receiving unit, configured to support the communication apparatus 700 to receive information from other network elements.

Optionally, the communication device 700 may further include a storage unit 701 for storing program codes and data of the communication device 700, which may include, but is not limited to, raw data or intermediate data, etc.

If the communication apparatus 700 is a terminal as mentioned above, the processing unit 702 may be configured to support the terminal to perform S301, S302, S303, S304 in fig. 3, S602 in fig. 6, and/or the like, and/or other processes for the schemes described herein. The communication unit 703 is configured to support communication between the terminal and another network element (e.g., the access network device described above, etc.), for example, the terminal is supported to perform S305 in fig. 3, S601, S603 in fig. 6, and the like. Optionally, the sending unit is configured to support the terminal to send information to another network element, where the communication unit is divided into the sending unit and the receiving unit. Such as supporting the terminal to perform S603 in fig. 6, etc., and/or other processes for the schemes described herein. A receiving unit, configured to support the terminal to receive information from other network elements. For example, the support terminal may perform S601 in fig. 6, etc., and/or other processes for the schemes described herein.

If the communications apparatus 700 is an access network device, the processing unit 702 may be configured to support the access network device to perform S306 in fig. 3, and/or other processes for the schemes described herein. The communication unit 703 is configured to support communication between the access network device and another network element (e.g., the terminal described above, etc.), for example, support the access network device to perform S305 in fig. 3, S601, S603 in fig. 6, and so on. Alternatively, in the case of dividing the communication unit into a transmitting unit and a receiving unit, the transmitting unit may be, for example, used to support the access network device to perform S601 in fig. 6 and/or other processes for the schemes described herein. The receiving unit, for example, may be configured to support the access network device to perform S603 in fig. 6.

In one possible approach, the Processing Unit 702 may be a controller or the processor 201 or the processor 207 shown in fig. 2, and may be, for example, a Central Processing Unit (CPU), a general-purpose processor, a Digital Signal Processing (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. A processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, a DSP and a microprocessor, or the like. The communication unit 703 may be the transceiver 204 shown in fig. 2, a transceiver circuit, or the like. The memory unit 701 may be the memory 203 shown in fig. 2.

Those of ordinary skill in the art will understand that: in the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, 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 loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device including one or more available media integrated servers, data centers, and the like. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., Digital Video Disk (DVD)), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

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

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may also be distributed on multiple network devices (e.g., terminal devices). Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each functional unit may exist independently, or two or more units may be integrated into one unit. The integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

Through the above description of the embodiments, those skilled in the art will clearly understand that the present application can be implemented by software plus necessary general hardware, and certainly, the present application can also be implemented by hardware, but in many cases, the former is a better implementation. Based on such understanding, the technical solutions of the present application may be substantially implemented or a part of the technical solutions contributing to the prior art may be embodied in the form of a software product, where the computer software product is stored in a readable storage medium, such as a floppy disk, a hard disk, or an optical disk of a computer, and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute the methods described in the embodiments of the present application.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and all changes and substitutions within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A method of communication, comprising:

the terminal determines K beams from 2L-1 beams, wherein L, K are positive integers;

the terminal sends a Precoding Matrix Indicator (PMI) to an access network device, where the PMI is used to indicate a combining coefficient corresponding to each of 2L-1 beams on each spatial layer, and the combining coefficient corresponding to each of 2L-1 beams on each spatial layer includes a combining coefficient corresponding to each of the K beams in at least two frequency domain units, and a combining coefficient corresponding to each of the 2L-1 beams except the K beams in at least two frequency domain units, or the combining coefficient corresponding to each of the 2L-1 beams includes a combining coefficient corresponding to each of the K beams in at least two frequency domain units, and a wideband combining coefficient corresponding to each of the 2L-1 beams except the K beams.
The communication method according to claim 1, wherein the combining coefficients corresponding to the single beam in the frequency domain unit are represented by frequency domain unit amplitude and frequency domain unit phase; the broadband merging coefficient corresponding to the single beam is represented by broadband amplitude and broadband phase;

combining coefficients respectively corresponding to each beam in the K beams in at least two frequency domain units, including: the combining coefficients corresponding to the first beams in each of the M frequency domain units and the combining coefficients corresponding to the second beams in each of the N frequency domain units, M, N, are integers greater than or equal to 2; m, N, and each of the M frequency domain elements of the first beam and the N frequency domain elements of the second beam are the same, or there are different frequency domain elements in the M frequency domain elements and the N frequency domain elements; the indexes of single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit amplitude of the combining coefficient at the single frequency domain unit correspond to an interpolation point, each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit amplitude of the combining coefficient, or the indexes of single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit phase of the combining coefficient of the single frequency domain unit correspond to an interpolation point, and each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit phase of the combining coefficient;

the wideband combining coefficients of each beam of the 2L-1 beams on each spatial layer except the K beams include: the broadband combination coefficient of the third beam and the broadband combination coefficient of the fourth beam;

wherein the first beam and the second beam are any two beams of the K beams, and the third beam and the fourth beam are any two beams of the 2L-1 beam except the K beams.
The communication method according to claim 2, wherein the PMI comprises: a frequency domain unit amplitude of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit amplitude of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a wideband amplitude of a combining coefficient of the third beam, and a wideband amplitude of a combining coefficient of the fourth beam.
The communication method according to claim 2, wherein the PMI comprises: a frequency domain unit phase of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit phase of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a wideband phase of a combining coefficient of the third beam, and a wideband phase of a combining coefficient of the fourth beam.
The communication method according to claim 1,

combining coefficients respectively corresponding to each beam in the K beams in at least two frequency domain units, including: a combining coefficient corresponding to the first beam of each of the M frequency domain units and a combining coefficient corresponding to the second beam of each of the N frequency domain units, M, N are integers greater than or equal to 2; m, N, and each of the M frequency domain elements of the first beam and the N frequency domain elements of the second beam are the same, or there are different frequency domain elements in the M frequency domain elements and the N frequency domain elements; the indexes of the single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit amplitude of the merging coefficient of the single frequency domain unit correspond to an interpolation point, every two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit indexes and the frequency domain unit amplitude of the merging coefficient, or the indexes of the single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit phase of the merging coefficient of the single frequency domain unit correspond to an interpolation point, and every two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit indexes and the frequency domain unit phase of the merging coefficient;

combining coefficients respectively corresponding to each beam of the 2L-1 beams except the K beams in at least two frequency domain units include: combining coefficients corresponding to the third beam in each of the P frequency domain units and combining coefficients corresponding to the fourth beam in each of the P frequency domain units; p is an integer greater than or equal to 2; the index of a single frequency domain unit in the P frequency domain units and the frequency domain unit amplitude of the combining coefficient of the single frequency domain unit correspond to an interpolation point, each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit amplitude of the combining coefficient, or the index of a single frequency domain unit in the P frequency domain units and the frequency domain unit phase of the combining coefficient of the single frequency domain unit correspond to an interpolation point, and each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit phase of the combining coefficient;

wherein the first beam and the second beam are any two beams of the K beams, and the third beam and the fourth beam are any two beams of the 2L-1 beam except the K beams.
The communications method of claim 5, wherein the PMI comprises: a frequency domain unit amplitude of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit amplitude of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a frequency domain unit amplitude of a combining coefficient corresponding to a third beam in each of the P frequency domain units, a frequency domain unit amplitude of a combining coefficient corresponding to a fourth beam in each of the P frequency domain units, and an index of the P frequency domain units.
The communications method of claim 5, wherein the PMI comprises: a frequency domain unit phase of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit phase of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a frequency domain unit phase of a combining coefficient corresponding to a third beam in each of the P frequency domain units, a frequency domain unit phase of a combining coefficient corresponding to a fourth beam in each of the P frequency domain units, and an index of the P frequency domain units.
The communication method according to any one of claims 2 to 7, wherein before the terminal sends PMI to the access network device, the method further comprises:

for the first beam, the terminal is from N_SBDetermining M frequency domain units, N_SBThe number of frequency domain units contained in the system bandwidth;

for the second beam, the terminal is from N_SBN frequency domain units are determined from the plurality of frequency domain units.
The communication method according to any one of claims 2 to 8, characterized in that the method further comprises:

for the third beam, the terminal is from N_SBDetermining P frequency domain units in the frequency domain units;

for the fourth beam, the terminal is from N_SBAnd determining P frequency domain units from the frequency domain units, wherein each of the P frequency domain units of the third beam and the P frequency domain units of the fourth beam is respectively the same.
The communication method according to any one of claims 1 to 9, wherein the K beams are K beams with the largest wideband amplitude of the combining coefficients in the 2L-1 beams, or wherein the K beams are K beams with the wideband amplitude of the combining coefficients in the 2L-1 beams greater than or equal to an amplitude threshold.
The communication method according to any one of claims 1 to 9, wherein the K beams are K beams with the smallest number of interpolation points among the 2L-1 beams, or K beams with the number of interpolation points smaller than or equal to a threshold number of interpolation points among the 2L-1 beams.
The communication method according to any one of claims 1 to 9, wherein the K beams are K beams with the largest average difference value between the frequency domain unit amplitude of the combining coefficient and the wideband amplitude of the combining coefficient among the 2L-1 beams; or the K beams are K beams in which an average difference between the frequency domain unit amplitude of the combining coefficient and the wideband amplitude of the combining coefficient is greater than or equal to a distance threshold value, among the 2L-1 beams.
The communication method according to any of claims 1 to 12, wherein the number of bits for indicating the frequency domain unit index corresponding to the interpolation point is
Wherein, the inter is the number of interpolation points corresponding to a single beam, N_SBNum _ sb is the number of interpolation points in the system bandwidth.
Communication method according to any of claims 1 to 12, wherein said terminal is selected from N_SBDetermining M frequency domain units from the plurality of frequency domain units, including: the terminal selects one frequency domain unit from the first frequency domain unit at intervals of a preset number of frequency domain units until M frequency domain units are determined, wherein the last frequency domain unit in the M frequency domain units is the second frequency domain unit.
The communication method according to any one of claims 2 to 14, wherein the number of interpolation points of a single beam is 1, and the combining coefficient of the single beam is a wideband combining coefficient of the single beam.
A method of communication, comprising:

the access network equipment receives a Precoding Matrix Indicator (PMI) from a terminal;

the access network equipment determines respective combining coefficients of 2L-1 wave beams on each spatial layer according to the PMI; the combining coefficients corresponding to the 2L-1 beams respectively include combining coefficients corresponding to each of the K beams in at least two frequency domain units, and combining coefficients corresponding to each of the 2L-1 beams except the K beams in at least two frequency domain units, respectively, or the combining coefficients corresponding to the 2L-1 beams respectively include combining coefficients corresponding to each of the K beams in at least two frequency domain units, and wideband combining coefficients of each of the 2L-1 beams except the K beams.
The communication method according to claim 16, wherein the combining coefficients corresponding to the single beam in the frequency domain unit are represented by frequency domain unit amplitude and frequency domain unit phase; the broadband merging coefficient corresponding to the single beam is represented by broadband amplitude and broadband phase;

combining coefficients respectively corresponding to each beam in the K beams in at least two frequency domain units, including: the combining coefficients corresponding to the first beams in each of the M frequency domain units and the combining coefficients corresponding to the second beams in each of the N frequency domain units, M, N, are integers greater than or equal to 2; m, N, and each of the M frequency domain elements of the first beam and the N frequency domain elements of the second beam are the same, or there are different frequency domain elements in the M frequency domain elements and the N frequency domain elements; the indexes of the single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit amplitude of the merging coefficient of the single frequency domain unit correspond to an interpolation point, every two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit indexes and the frequency domain unit amplitude of the merging coefficient, or the indexes of the single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit phase of the merging coefficient of the single frequency domain unit correspond to an interpolation point, and every two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit indexes and the frequency domain unit phase of the merging coefficient;

the wideband combining coefficients for each of the 2L-1 beams except the K beams include: the broadband combination coefficient of the third beam and the broadband combination coefficient of the fourth beam;

wherein the first beam and the second beam are any two beams of the K beams, and the third beam and the fourth beam are any two beams of the 2L-1 beam except the K beams.
The communications method of claim 16, wherein the PMI comprises: a frequency domain unit amplitude of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit amplitude of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a wideband amplitude of a combining coefficient of the third beam, and a wideband amplitude of a combining coefficient of the fourth beam.
The communications method of claim 16, wherein the PMI comprises: a frequency domain unit phase of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit phase of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a wideband phase of a combining coefficient of the third beam, and a wideband phase of a combining coefficient of the fourth beam.
The communication method according to claim 16,

combining coefficients respectively corresponding to each beam in the K beams in at least two frequency domain units, including: a combining coefficient corresponding to the first beam of each of the M frequency domain units and a combining coefficient corresponding to the second beam of each of the N frequency domain units, M, N are integers greater than or equal to 2; m, N, and each of the M frequency domain elements of the first beam and the N frequency domain elements of the second beam are the same, or there are different frequency domain elements in the M frequency domain elements and the N frequency domain elements; the indexes of the single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit amplitude of the merging coefficient of the single frequency domain unit correspond to an interpolation point, every two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit indexes and the frequency domain unit amplitude of the merging coefficient, or the indexes of the single frequency domain units in the M frequency domain units and the N frequency domain units and the frequency domain unit phase of the merging coefficient of the single frequency domain unit correspond to an interpolation point, and every two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit indexes and the frequency domain unit phase of the merging coefficient;

combining coefficients respectively corresponding to each beam of the 2L-1 beams except the K beams in at least two frequency domain units include: combining coefficients corresponding to the third beam in each of the P frequency domain units and combining coefficients corresponding to the fourth beam in each of the P frequency domain units; p is an integer greater than or equal to 2; the index of a single frequency domain unit in the P frequency domain units and the frequency domain unit amplitude of the combining coefficient of the single frequency domain unit correspond to an interpolation point, each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit amplitude of the combining coefficient, or the index of a single frequency domain unit in the P frequency domain units and the frequency domain unit phase of the combining coefficient of the single frequency domain unit correspond to an interpolation point, and each two adjacent interpolation points are used for fitting a relation curve between the frequency domain unit index and the frequency domain unit phase of the combining coefficient;

wherein the first beam and the second beam are any two beams of the K beams, and the third beam and the fourth beam are any two beams of the 2L-1 beam except the K beams.
The communications method of claim 20, wherein the PMI comprises: a frequency domain unit amplitude of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit amplitude of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a frequency domain unit amplitude of a combining coefficient corresponding to a third beam in each of the P frequency domain units, a frequency domain unit amplitude of a combining coefficient corresponding to a fourth beam in each of the P frequency domain units, and an index of the P frequency domain units.
The communications method of claim 20, wherein the PMI comprises: a frequency domain unit phase of a combining coefficient of the first beam in each of the M frequency domain units, an index of the M frequency domain units, a frequency domain unit phase of a combining coefficient of the second beam in each of the N frequency domain units, an index of the N frequency domain units, a frequency domain unit phase of a combining coefficient corresponding to a third beam in each of the P frequency domain units, a frequency domain unit phase of a combining coefficient corresponding to a fourth beam in each of the P frequency domain units, and an index of the P frequency domain units.
The communication method according to any of claims 16 to 22, wherein the K beams are K beams with the largest wideband amplitude of the combining coefficients in the 2L-1 beams, or wherein the K beams are K beams with wideband amplitude of the combining coefficients in the 2L-1 beams greater than or equal to an amplitude threshold.
The communication method according to any one of claims 16 to 22, wherein the K beams are K beams with the smallest number of interpolation points among the 2L-1 beams, or K beams with the number of interpolation points smaller than or equal to a threshold number of interpolation points among the 2L-1 beams.
The communication method according to any one of claims 16 to 22, wherein the K beams are K beams with the largest average difference value between the frequency domain element amplitude of the combining coefficients and the wideband amplitude of the combining coefficients, among the 2L-1 beams; or the K beams are K beams in which an average difference between the frequency domain unit amplitude of the combining coefficient and the wideband amplitude of the combining coefficient is greater than or equal to a distance threshold value, among the 2L-1 beams.
The communication method according to any of claims 16 to 25, wherein the number of bits used to indicate the frequency domain unit index corresponding to the interpolation point is equal to
Wherein, the inter is the number of interpolation points corresponding to a single beam, N_SBNum _ sb is the number of interpolation points in the system bandwidth.
Communication method according to any of claims 16 to 25, wherein said terminal is selected from N_SBDetermining M frequency domain units from the plurality of frequency domain units, including: the terminal selects one frequency domain unit from the first frequency domain unit at intervals of a preset number of frequency domain units until M frequency domain units are determined, wherein the last frequency domain unit in the M frequency domain units is the second frequency domain unit.
The communication method according to any one of claims 17 to 27, wherein the number of interpolation points of a single beam is 1, and the combining coefficient of the single beam is a wideband combining coefficient of the single beam.
The communication method according to any one of claims 17 to 28, wherein the determining, by the access network device, the combining coefficients of each of the 2L-1 beams according to the PMI comprises:

the access network equipment determines a combination coefficient corresponding to each wave beam in the K wave beams in each frequency domain unit through a linear interpolation mode according to two or more interpolation points corresponding to each wave beam in the K wave beams;

the access network equipment determines a combination coefficient corresponding to each wave beam in the 2L-1-K wave beams in each frequency domain unit through a linear interpolation mode according to two or more interpolation points corresponding to each wave beam in the 2L-1-K wave beams; or, the access network device determines, according to the wideband combining coefficient corresponding to each beam of the 2L-1-K beams, a combining coefficient corresponding to each beam of the 2L-1-K beams in each frequency domain unit.
A communication apparatus for supporting the execution of the communication method according to any one of claims 1 to 15.
A communication apparatus for supporting the execution of the communication method according to any one of claims 16 to 29.