Method, terminal device and network device for feedback codebook

Abstract

The embodiment of the present application discloses a feedback codebook method, a terminal device and a network device, the method comprising: a terminal device selecting M frequency domain DFT vectors from a discrete Fourier transform (DFT) array; the terminal device determining a first frequency domain DFT vector indication set from a plurality of frequency domain DFT vector indication sets according to the M frequency domain DFT vectors, the indication of the M frequency domain DFT vectors being equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, M being a positive integer; and the terminal device sending an indication message to a network device, the indication message being used for indicating the first frequency domain DFT vector indication set. The method of the embodiment of the present application is beneficial to reducing the signaling overhead when the terminal device feeds back a codebook.

Description

[0001] This application is a divisional application of the application with the application number 2019800755341 and the application name "Method of feedback codebook, terminal device and network device", the application date of which is February 26, 2019. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the field of communication, in particular to a method of feedback codebook, a terminal device and a network device. BACKGROUND

[0003] In R16, a new radio (NR) type II codebook can be expressed as wherein W1 indicates 2L spatial beams, is used to indicate M frequency domain DFT vectors. (2L*M) indicates a weighting coefficient of an arbitrary spatial beam, frequency domain DFT vector pair.

[0004] The channel state information (CSI) content reported by the terminal device to the network device includes L beams of W1, M frequency domain DFT vectors indicated by and quantized For The reporting of includes the reporting of M frequency domain DFT vectors.

[0005] At present, the terminal device indicates the positions of M frequency domain DFT vectors by , wherein N3 represents the number of columns of When N3 is large, there is a problem of signaling overhead for the reporting of M frequency domain DFT vectors. SUMMARY

[0006] Embodiments of the present application provide a method of feedback codebook, a terminal device and a network device, which are beneficial to reduce the signaling overhead when the terminal device feeds back the codebook.

[0007] In a first aspect, a method of feedback codebook is provided, which includes: a terminal device selecting M frequency domain DFT vectors from a discrete Fourier transform (DFT) array; the terminal device determining a first frequency domain DFT vector indication set from a plurality of frequency domain DFT vector indication sets according to the M frequency domain DFT vectors, an indication of the M frequency domain DFT vectors being equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, M being a positive integer; and the terminal device sending an indication message to a network device, the indication message being used to indicate the first frequency domain DFT vector indication set.

[0008] In a second aspect, a method for feeding back a codebook is provided, which includes: a terminal device sending an indication message to a network device, the indication message being used to indicate a position in a discrete Fourier transform (DFT) array corresponding to a strongest coefficient of a spatial-frequency domain weight coefficient array of a codebook in a specific frequency domain DFT vector.

[0009] In a third aspect, a method for feeding back a codebook is provided, which includes: a network device receiving an indication message sent by a terminal device, the indication message being used to indicate a first frequency domain DFT vector indication set in a plurality of frequency domain DFT vector indication sets; and the network device recovering a downlink channel according to any frequency domain DFT vector indication equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set.

[0010] In a fourth aspect, a method for feeding back a codebook is provided, which includes: a network device receiving an indication message sent by a terminal device, the indication message being used to indicate a position in a discrete Fourier transform (DFT) array corresponding to a strongest coefficient of a spatial-frequency domain weight coefficient array of a codebook in a specific frequency domain DFT vector.

[0011] In a fifth aspect, a terminal device is provided, which is configured to perform the method in the first aspect or any implementation manner thereof.

[0012] Specifically, the terminal device includes function modules configured to perform the method in the first aspect or any implementation manner thereof.

[0013] In a sixth aspect, a terminal device is provided, which is configured to perform the method in the second aspect or any implementation manner thereof.

[0014] Specifically, the terminal device includes function modules configured to perform the method in the second aspect or any implementation manner thereof.

[0015] In a seventh aspect, a network device is provided, which is configured to perform the method in the third aspect or any implementation manner thereof.

[0016] Specifically, the network device includes function modules configured to perform the method in the third aspect or any implementation manner thereof.

[0017] In an eighth aspect, a network device is provided, which is configured to perform the method in the fourth aspect or any implementation manner thereof.

[0018] Specifically, the network device includes function modules configured to perform the method in the fourth aspect or any implementation manner thereof.

[0019] In a ninth aspect, a network device is provided, comprising a processor and a memory. The memory is configured to store a computer program, and the processor is configured to invoke and run the computer program stored in the memory to execute the method in the first aspect to the second aspect or the implementation manner thereof.

[0020] In a tenth aspect, a network device is provided, comprising a processor and a memory. The memory is configured to store a computer program, and the processor is configured to invoke and run the computer program stored in the memory to execute the method in the third aspect to the fourth aspect or the implementation manner thereof.

[0021] In an eleventh aspect, a chip is provided, configured to implement the method in any one of the first aspect to the fourth aspect or the implementation manner thereof.

[0022] In particular, the chip comprises a processor configured to invoke and run a computer program from a memory, so that a device installed with the chip executes the method in any one of the first aspect to the fourth aspect or the implementation manner thereof.

[0023] In a twelfth aspect, a computer readable storage medium is provided, configured to store a computer program, which causes a computer to execute the method in any one of the first aspect to the fourth aspect or the implementation manner thereof.

[0024] In a thirteenth aspect, a computer program product is provided, comprising computer program instructions, which cause a computer to execute the method in any one of the first aspect to the fourth aspect or the implementation manner thereof.

[0025] In a fourteenth aspect, a computer program is provided, which, when running on a computer, causes the computer to execute the method in any one of the first aspect to the fourth aspect or the implementation manner thereof. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 FIG. 1 is a schematic diagram of a communication system architecture provided by an embodiment of the present application.

[0027] Figure 2 FIG. 2 shows a schematic diagram for indicating selected M frequency domain DFT vectors.

[0028] Figure 3 FIG. 3 shows a schematic diagram of cyclically shifted M frequency domain DFT vectors.

[0029] Figure 4 FIG. 4 is a schematic diagram of a feedback codebook method provided by an embodiment of the present application.

[0030] Figure 5 FIG. 5 shows another schematic diagram for indicating selected M frequency domain DFT vectors.

[0031] Figure 6 A mapping diagram of DFT vectors and codebook restriction types is shown.

[0032] Figure 7 A mapping diagram of DFT vectors, frequencies, and codebook restriction types is shown.

[0033] Figure 8 is another schematic diagram of the method for feedback codebook provided by the embodiments of the present application.

[0034] Figure 9 is a schematic diagram of the DFT vector position corresponding to the strongest coefficient of the embodiments of the present application.

[0035] Figure 10 is another schematic diagram of the DFT vector position corresponding to the strongest coefficient of the embodiments of the present application.

[0036] Figure 11 is another schematic diagram of the method for feedback codebook provided by the embodiments of the present application.

[0037] Figure 12 is another schematic diagram of the method for feedback codebook provided by the embodiments of the present application.

[0038] Figure 13 is a schematic block diagram of a terminal device provided by the embodiments of the present application.

[0039] Figure 14 is a schematic block diagram of a terminal device provided by the embodiments of the present application.

[0040] Figure 15 is a schematic block diagram of a network device provided by the embodiments of the present application.

[0041] Figure 16 is a schematic block diagram of a network device provided by the embodiments of the present application. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0043] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, for example: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, New Radio (NR) or future 5G system, etc.

[0044] In particular, the technical solutions of the embodiments of the present application can be applied to various communication systems based on non-orthogonal multiple access technology, for example, Sparse Code Multiple Access (SCMA) system, Low Density Signature (LDS) system, etc., of course, the SCMA system and the LDS system can also be referred to as other names in the communication field; further, the technical solutions of the embodiments of the present application can be applied to multi-carrier transmission systems using non-orthogonal multiple access technology, for example, Orthogonal Frequency Division Multiplexing (OFDM) using non-orthogonal multiple access technology, Filter Bank Multi-Carrier (FBMC), Generalized Frequency Division Multiplexing (GFDM), Filtered-OFDM (F-OFDM) system, etc.

[0045] For example, the communication system 100 to which the embodiments of the present application are applied is as follows Figure 1As shown. The communication system 100 can include a network device 110, which can be a device communicating with a terminal device 120 (or called a communication terminal, terminal). The network device 110 can provide communication coverage for a specific geographic area and can communicate with terminal devices located within the coverage area. Optionally, the network device 110 can be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, a base station (NodeB, NB) in a WCDMA system, an evolved base station (eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (Cloud Radio Access Network, CRAN), or the network device can be a mobile switching center, a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a network device gNB in a 5G network, or a network device in a future evolved public land mobile network (Public Land Mobile Network, PLMN) and the like.

[0046] The communication system 100 also includes at least one terminal device 120 located within the coverage of the network device 110. As used herein, "terminal device" includes, but is not limited to, a user equipment (User Equipment, UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user apparatus. The access terminal can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication functions, a computing device, or other processing devices connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a future 5G network, or a terminal device in a future evolved public land mobile network (Public Land Mobile Network, PLMN) and the like, and the embodiments of the present application are not limited.

[0047] Optionally, the terminal devices 120 can communicate with each other through Device to Device (D2D) communication.

[0048] Optionally, the 5G system or 5G network can also be referred to as a New Radio (New Radio, NR) system or NR network.

[0049] Figure 1 Exemplarily, one network device and two terminal devices are shown, optionally, the communication system 100 can include multiple network devices and each network device can include other number of terminal devices within the coverage range of the network device, and the embodiments of the present application do not limit this.

[0050] Optionally, the communication system 100 can further include a network controller, a mobile management entity and other network entities, and the embodiments of the present application do not limit this.

[0051] It should be understood that the devices with communication functions in the network / system in the embodiments of the present application can be referred to as communication devices. For example, Figure 1 For example, the communication system 100 shown in the figure, the communication devices can include network devices 110 and terminal devices 120 with communication functions, and the network devices 110 and the terminal devices 120 can be the specific devices described above, which will not be described here; the communication devices can also include other devices in the communication system 100, such as network controllers, mobile management entities and other network entities, and the embodiments of the present application do not limit this.

[0052] It should be understood that the terms "system" and "network" are often used interchangeably in this paper. The term "and / or" in this paper is only used to describe the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents an "or" relationship between the associated objects before and after it.

[0053] For each layer of the multi-layer codebook, the NR type II codebook is independently coded in the frequency domain (each sub-band), and due to the high spatial quantization accuracy, it will result in too much feedback amount. By feeding back the frequency-domain-space joint codebook, the feedback amount can be greatly saved under the condition of ensuring the performance of NR. Specifically, the R16 NR type II codebook can be expressed as the following formula (1):

[0054]

[0055] wherein, W 1 can be used to indicate 2L spatial beams (beams); may be used to indicate M frequency domain Discrete Fourier Transformation (DFT) basis vectors; (2L*M matrix) indicates the weighting coefficients of any spatial beam, frequency domain DFT vector pair.

[0056] The channel state information (CSI) reported by the UE can include W 1 L beams indicated, M DFT bases indicated, and quantized The base station obtains the downlink CSI of each layer by the triple product.

[0057] For W1, and The main parameters involved in the reporting include: the value of L, i.e., the number of spatial basis DFT vectors; the value of M (related to the reported frequency domain bandwidth), i.e., the number of frequency basis DFT vectors reported; the value of K0, which is used to constrain the maximum number of reported elements; the number of non-zero elements in and / or the position in is determined by a bitmap and / or an indication; the quantization accuracy in is determined by one or more sets of (amplitude, phase) parameters, for example, the amplitude can be quantized by 3 / 4 bits, and the phase can also be quantized by 3 / 4 bits. For example, for a part of elements with larger energy (e.g., the first 50%), the amplitude is quantized by 4 bits, and the phase is quantized by 3 bits; while the amplitude of the smaller part can be quantized by 2 bits, and the phase is quantized by 2 bits; or for the weighting coefficient corresponding to the 0th frequency basis, the amplitude and the phase are both quantized by 4 bits, while for the weighting coefficient corresponding to other frequency bases, the amplitude and the phase are both quantized by 3 bits.

[0058] The value of M is the number of columns of , and the M frequency bases are selected by the UE from N3 columns of DFT vectors, for example, as shown in Figure 2 , [0 4 9] are selected from 13 columns.

[0059] Cyclic shift of inverse discrete Fourier transform (IDFT) / DFT: after the sequence is cyclically shifted, the DFT is equal to the DFT of the non-shifted sequence multiplied by a linear phase.

[0060] If X k = DFT({x} n ) k

[0061] After x is cyclically shifted by d, the DFT result is

[0062]

[0063] That is, the DFT result is just frequency domain multiplied by a linear phase, and the amplitude is unchanged.

[0064] If the same cyclic shift is applied to each row of W2 (Type II codebook is selected by column), a phase is multiplied when recovering the channel at the base station end, but it has no effect on the MIMO channel.

[0065] Under this condition, it can be considered that when the M columns of the two selected code words belong to the cyclic shift relationship, the two code words are equivalent.

[0066] As shown in Figure 3 , the case of cyclic shift (right shift) d = 0 / 1 / 3 / 4, if for d = 0, the code word is X k , then the remaining code words are (k is the frequency domain index). Then it can be considered that the four shifts are the same code word.

[0067] The number of shift registers Cycle: for a binary sequence of length n, where there are a 1s and n-a 0s, when two sequences belong to the cyclic shift, it is considered that the two sequences are equivalent, then a total of groups of sequences

[0068] Where the factor d of gcd(a, n-a) is the number of repeated sub-sequences, d | n means that d is a factor of n; gcd is the greatest common divisor, the function phi is the Euler function, and () represents the combination number. Special, when n and a are coprime, That is, there are n different sequences in each set that satisfy the cyclic shift.

[0069] Figure 4 A schematic block diagram of a method 200 of a feedback codebook according to an embodiment of the present application is shown. As Figure 4 shown, the method 200 can be performed by a terminal device, and the method 200 includes the following parts or all of them:

[0070] S210, the terminal device selects M frequency domain DFT vectors from a discrete Fourier transform DFT array;

[0071] S220, the terminal device determines a first frequency domain DFT vector indication set from a plurality of frequency domain DFT vector indication sets according to the M frequency domain DFT vectors, the indication of the M frequency domain DFT vectors is equivalent to the first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, and M is a positive integer;

[0072] S230, the terminal device sends an indication message to the network device, the indication message being used to indicate the first frequency domain DFT vector indication set.

[0073] Optionally, the indication corresponding sequence of the M frequency domain DFT vectors is different from the indication corresponding sequence of the first frequency domain DFT vector, and the indication corresponding sequence of the M frequency domain DFT vectors has a cyclic shift relationship with the indication corresponding sequence of the first frequency domain DFT vector.

[0074] The first frequency domain DFT vector indication set includes a plurality of frequency domain DFT vector indications, any two frequency domain DFT vector indications in the plurality of frequency domain DFT vector indications have a cyclic shift relationship, and the first frequency domain DFT vector indication set includes the indication of the M frequency domain DFT vectors.

[0075] Optionally, the frequency domain DFT vector indications in any two frequency domain DFT vector indication sets in the plurality of frequency domain DFT vector indication sets are not equivalent, and the number of the plurality of frequency domain DFT vector indication sets is determined by , where N3 is the number of columns of the DFT array, gcd(M, N3-M) is the greatest common divisor of M and (N3-M), is the Euler function, () is the combination number function, ∑ is the summation function, and d is a factor of the greatest common divisor of M and (N3-M).

[0076] Optionally, the sequence value of the indication corresponding sequence of the first frequency domain DFT vector is the minimum value or the maximum value in the N3 frequency domain DFT vector indication corresponding sequences obtained by performing N3 cyclic shift operations on the indication corresponding sequence of the M frequency domain DFT vectors, where N3 is the number of columns of the DFT array.

[0077] Optionally, the method further includes: determining the indication message according to the indication corresponding sequence of the first frequency domain DFT vector, the indication corresponding sequence of the first frequency domain DFT vector having a corresponding relationship with the value of the indication message.

[0078] Optionally, the bit width of the indication message is , where log is the logarithm function.

[0079] Optionally, each bit in the indication message is used to indicate any bit in the indication corresponding sequence of the first frequency domain DFT vector except a default bit.

[0080] Specifically,

[0081] 1. Divide the M column selection cases into a plurality of groups, each group containing at most N3 cases, which satisfy the relationship of being cyclically shifted with each other.

[0082] ●The relationship between cyclic shifts of binary sequences means that one sequence can be obtained by left (or right) cyclic shifting another sequence.

[0083] ■x0=00001111,x1=00011110,…,x7=10000111 satisfy the cyclic shift relationship.

[0084] ●Can be divided into Group, each group has at most n sequences and M DFT vectors, and the selection results are reported

[0085] 2. After the UE selects column M, it finds the group it reported and reports an indication, through which the network can know the group number it belongs to;

[0086] a) Since there are multiple sequences in each group, the UE can find its corresponding group through cyclic shift

[0087] i. Cyclic shift the sequence selected by the UE n times and take the minimum value

[0088] ii. Through an indication message, the bit width is The value of the indication message is obtained by predefining the correspondence between the minimum value and the indication message and reported to the base station.

[0089] iii. A message with a bit width of This corresponds to the information in addition to the most significant and least significant bits. The base station combines the default values ​​of the most significant and least significant bits to determine the final value. nchoosek represents the selection of k combinations from n, N3 is the number of columns in the DFT array, M is the number of DFT vectors selected by the UE, and x and y are positive integers.

[0090] After receiving the group number, the base station can restore the downlink channel.

[0091] Example 1:

[0092] Further decomposition of the existing Type II codebook, considering the impact of cyclic shift, the codebook can be decomposed into

[0093]

[0094] in is the DFT vector, and d is used to indicate the cyclic shift in the frequency domain.

[0095] Example 2:

[0096] N3=8,M=4,then there are 70 choices in total, which can be divided into Each group, the codebook within the group is cyclically shifted, and each case is represented by binary (the highest bit corresponds to basis 0) (1 represents the presence of selection frequency basis in its position). The codebook within each group with equivalent relationship is shown in Table 1.

[0097] Table 1

[0098]

[0099] When the UE selects M columns, the columns 【3 5 6 7】 are selected, as shown in Figure 5 . When reporting, [00010111] is found to be the 3rd group (which can be indexed by the minimum value corresponding to the leading codeword (00011101)), and the indication is 3 (because in the range of the 3rd row, the base station can recover the channel with any one). This embodiment is based on the convenient use of bitmap to indicate the selection of DFT vector, but if the implementation method of combinatorial number is adopted, the operation process is consistent, only the binary sequence is corresponding to the combinatorial number.

[0100] Considering the calculation complexity of calculating the correspondence between the reporting indication and the group number, after 00011101 is obtained, only the middle 6 bits are coded (the highest bit must be 0, and the lowest bit must be 1), that is, the message can be coded by , and the base station can recover the message after recovering the middle bits and filling 1 in the low bits.

[0101] Embodiment 3 (ignore the codebook with a period less than N3):

[0102] For N3=8, M=4, since GCD(N3, M)=[1 2 4], there are sequence repetition cases with 2 units and 4 units (i.e. group 7 and group 9), as shown in Table 2.

[0103] Table 2

[0104]

[0105] Among them, group 7 is twice repetition of 4-bit units {0011, 0110, 1001, 1100}

[0106] Group 9 is four times repetition of 2 units {01, 10};

[0107] In order to simplify the complexity of implementation, the network omits the codebooks of group 7 and group 9, that is, the group numbers allowed to be reported by the UE are shown in Table 3.

[0108] Table 3

[0109]

[0110] Embodiment 4

[0111] For N3=13, M=ceil(1 / 2*N3)=7, then N3 and M are co-prime, the factor of GCD(N3, M) is only [1], there is no case of sequence repetition less than N3, the codebook can be completely divided into N3 groups, and the best compression efficiency is achieved, as shown in Table 4.

[0112] Table 4

[0113]

[0114] Embodiment 5

[0115] The network side limits the candidate set of the UE in a predefined manner, as shown in Table 5.

[0116] Table 5

[0117] Group number Sequence Group number Sequence Group number Sequence Group number Sequence Group number Sequence Group number Sequence 0 ′1111111000000′ 24 ′1111011010000′ 48 ′1111100100010′ 72 ′1110110101000′ 96 ′1110010100110′ 120 ′1101011001100′ 1 ′1111110000010′ 25 ′1111100110000′ 49 ′1111100011000′ 73 ′1110111001000′ 97 ′1110110010100′ 121 ′1101101001100′ 2 ′1111100000110′ 26 ′1111101010000′ 50 ′1111000110010′ 74 ′1111001011000′ 98 ′1111010010100′ 122 ′1110101001100′ 3 ′1111000001110′ 27 ′1111110010000′ 51 ′1110001100110′ 75 ′1111001101000′ 99 ′1111001010100′ 123 ′1101100110100′ 4 ′1111011100000′ 28 ′1111110001000′ 52 ′1110110001100′ 76 ′1111010011000′ 100 ′1110010101010′ 124 ′1110100110100′ 5 ′1111101100000′ 29 ′1111100010010′ 53 ′1111010001100′ 77 ′1111010101000′ 101 ′1101100101010′ 125 ′1110011010100′ 6 ′1111110100000′ 30 ′1111000100110′ 54 ′1111000110100′ 78 ′1111011001000′ 102 ′1110100101010′ 126 ′1101010101100′ 7 ′1111110000100′ 31 ′1110111000100′ 55 ′1110001101010′ 79 ′1111100101000′ 103 ′1110010101100′ 127 ′1101010110100′ 8 ′1111100001010′ 32 ′1111011000100′ 56 ′1101100011010′ 80 ′1111101001000′ 104 ′1101011001010′ 128 ′1101011010100′ 9 ′1111000010110′ 33 ′1111101000100′ 57 ′1110100011010′ 81 ′1111100100100′ 105 ′1101101001010′ 129 ′1101101010100′ 10 ′1110111000010′ 34 ′1111100010100′ 58 ′1110001101100′ 82 ′1111001001010′ 106 ′1110011001010′ 130 ′1110101010100′ 11 ′1111011000010′ 35 ′1111000101010′ 59 ′1101101011000′ 83 ′1110010010110′ 107 ′1110101001010′ 131 ′1101010101010′ 12 ′1111101000010′ 36 ′1110001010110′ 60 ′1101101101000′ 84 ′1110110010010′ 108 ′1110010110010′ 13 ′1111100001100′ 37 ′1110110001010′ 61 ′1110011000110′ 85 ′1111010010010′ 109 ′1101100101100′ 14 ′1111000011010′ 38 ′1111010001010′ 62 ′1110101000110′ 86 ′1111001001100′ 110 ′1110100101100′ 15 ′1110000110110′ 39 ′1111000101100′ 63 ′1111001000110′ 87 ′1110010011010′ 111 ′1110010110100′ 16 ′1110110000110′ 40 ′1110001011010′ 64 ′1111000111000′ 88 ′1101101100100′ 112 ′1101010110010′ 17 ′1111010000110′ 41 ′1101101100010′ 65 ′1110010111000′ 89 ′1110100100110′ 113 ′1101011010010′ 18 ′1111000011100′ 42 ′1110100010110′ 66 ′1110011011000′ 90 ′1110011100100′ 114 ′1101100110010′ 19 ′1110101110000′ 43 ′1110011100010′ 67 ′1110100011100′ 91 ′1110101100100′ 115 ′1101101010010′ 20 ′1110110110000′ 44 ′1110101100010′ 68 ′1110100111000′ 92 ′1110110100100′ 116 ′1110011010010′ 21 ′1110111010000′ 45 ′1110110100010′ 69 ′1110101011000′ 93 ′1111001100100′ 117 ′1110100110010′ 22 ′1111001110000′ 46 ′1111001100010′ 70 ′1110101101000′ 94 ′1111010100100′ 118 ′1110101010010′ 23 ′1111010110000′ 47 ′1111010100010′ 71 ′1110110011000′ 95 ′1111001010010′ 119 ′1110011001100′

[0118] The difference from the previous embodiment is that the embodiment also has a mapping relationship between the sequence bitmap and the physical DFT vector:

[0119] 1. The sequence mapping (from high bit to low bit) corresponds to DFT [0, 2pi], as shown in Figure 6 .

[0120] 2. The sequence mapping (from high bit to low bit) corresponds to DFT from low frequency to high frequency, as shown in Figure 7 .

[0121] The network can ensure that the feedback accuracy of CSI on the low frequency is higher through the ways 1 or 2.

[0122] The UE selects the optimal codebook from a limited set (the embodiment selects from 132 codebooks, and if there is no limitation, there are 1716 candidate codebooks) and feeds back to the base station.

[0123] Figure 8 A schematic block diagram of a method 300 of feeding back a codebook according to an embodiment of the present application is shown. As shown in Figure 8 , the method 300 can be performed by a terminal device, and the method 300 includes the following parts or all of them:

[0124] S310, the terminal device sends an indication message to the network device, and the indication message is used to indicate that the strongest coefficient of the spatial-frequency domain weighted coefficient array of the codebook corresponds to the position in the specific frequency domain DFT vector in the discrete Fourier transform (DFT) array.

[0125] Optionally, a bit width of the indication message is log2(2*L), where 2*L is a number of rows in the spatial-frequency domain matrix.

[0126] Optionally, a bit width of the indication message is where Lnz is a number of rows in the spatial-frequency domain matrix occupied by non-zero coefficients.

[0127] Optionally, the method further comprises: the terminal device performing a cyclic shift operation on a frequency domain DFT vector corresponding to a non-zero coefficient in the spatial-frequency domain matrix, so that the strongest coefficient corresponds to a specific frequency domain DFT vector in the DFT array.

[0128] Optionally, the specific frequency domain DFT vector is a first frequency domain DFT vector or a last frequency domain DFT vector in the DFT array.

[0129] Specifically,

[0130] 1. UE needs to report W2 in Knz<=K0 position, generally can be reported by a message with a length of ; for this scheme, since the absolute position of the frequency domain has no effect on the performance, by the cyclic shift of the UE, the frequency domain position of the strongest coefficient is moved to a fixed position (such as 0), then:

[0131] a) the strongest coefficient must appear in a fixed position (such as 0)

[0132] b) only need to indicate the position of the strongest coefficient by bit or or Lnz bit bitmap.

[0133] i. Where 2L represents all 2L space bases Lnz represents only from the space containing non-zero elements corresponding to the number of space bases.

[0134] Embodiment 7

[0135] Enhance the efficiency of indicating the strongest coefficient, as Figure 9 shown, the left is the conventional scheme, UE indicates Knz=12 non-zero coefficients through 2LM bitmap, and then determines the position of the strongest coefficient by 4 bits in a combinatorial number way according to the appearance of the strongest coefficient in the (red) 5th position. The right of this scheme, based on the left, the selection of M DFT vectors [3 4 5 6 7] is cyclically shifted to [0 1 2 6 7], and then only 2 bits (in the 0th DFT vector) are needed to indicate the number of rows of the strongest coefficient (log2(2L)).

[0136] Or also can adoptFigure 10 The scheme is shown in Table 1. When the UE gets non-zero coefficients on the row of [0 1 4 5] when indicating the strongest coefficient, the strongest coefficient is on the fourth spatial basis, which can be indicated by 4 bits of [0 0 1 0].

[0137] Figure 11 A schematic block diagram of a method 400 of a feedback codebook of an embodiment of the application is shown. As shown, the method 400 can be performed by a network device, and the method 400 includes some or all of the following: Figure 11

[0138] S410, the network device receives an indication message sent by a terminal device, the indication message being used to indicate a first frequency domain DFT vector indication set in a plurality of frequency domain DFT vector indication sets;

[0139] S420, the network device recovers a downlink channel according to any frequency domain DFT vector indication equivalent to the first frequency domain DFT vector indication in the first frequency domain DFT vector indication set.

[0140] Optionally, the first frequency domain DFT vector indication set does not include a second frequency domain DFT vector indication, and a corresponding sequence of the second frequency domain DFT vector indication has a cyclic shift relationship with a corresponding sequence of the first frequency domain DFT vector indication; or the first frequency domain DFT vector indication set includes a plurality of frequency domain DFT vector indications, and a corresponding sequence of any two frequency domain DFT vector indications in the plurality of frequency domain DFT vector indications has a cyclic shift relationship.

[0141] Figure 12 A schematic block diagram of a method 500 of a feedback codebook of an embodiment of the application is shown. As shown, the method 500 can be performed by a network device, and the method 500 includes some or all of the following: Figure 12

[0142] S510, the network device receives an indication message sent by a terminal device, the indication message being used to indicate a position in a specific frequency domain DFT vector in a discrete Fourier transform DFT array corresponding to a strongest coefficient of a spatial-frequency weighted coefficient array of a codebook.

[0143] It should be understood that the network device described on the network side interacts with the terminal device and related features, functions, etc. and the related features, functions of the terminal device correspond. And the related content has been described in detail in the above methods 200 and 300. For the sake of brevity, it will not be repeated here.

[0144] ​​It should also be understood that the size of the sequence number of the above processes does not mean the order of execution in various embodiments of the present application, and the execution order of the processes should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0145] The method of the feedback codebook according to the embodiments of the present application is described in detail above, and the apparatus of the feedback codebook according to the embodiments of the present application will be described below in combination with Figure 13 and Figure 16 The technical features described in the method embodiments are applicable to the following apparatus embodiments.

[0146] Figure 13 A schematic block diagram of a terminal device 600 according to an embodiment of the present application is shown. As shown in Figure 13 The terminal device 600 includes:

[0147] The processing unit 610 is configured to select M frequency domain DFT vectors from a discrete Fourier transform (DFT) array, and determine a first frequency domain DFT vector indication set from a plurality of frequency domain DFT vector indication sets according to the M frequency domain DFT vectors, an indication of the M frequency domain DFT vectors being equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, M being a positive integer.

[0148] The communication unit 620 is configured to send an indication message to a network device, the indication message being used to indicate the first frequency domain DFT vector indication set.

[0149] It should be understood that the terminal device 600 according to the embodiments of the present application can correspond to the terminal device in the method embodiments of the present application, and the above and other operations and / or functions of each unit in the terminal device 600 are respectively used to implement the corresponding processes of the terminal device in the method. Figure 4 For brevity, they will not be described here again.

[0150] Figure 14 A schematic block diagram of a terminal device 700 according to an embodiment of the present application is shown. As shown in Figure 14 The terminal device 700 includes:

[0151] The communication unit 710 is configured to send an indication message to a network device, the indication message being used to indicate the position of a specific frequency domain DFT vector in a discrete Fourier transform (DFT) array corresponding to the strongest coefficient of the spatial-frequency domain weighted coefficient array of the codebook.

[0152] It should be understood that the terminal device 700 according to the embodiments of the present application can correspond to the terminal device in the method embodiments of the present application, and the above and other operations and / or functions of each unit in the terminal device 700 are respectively used to implement the corresponding processes of the terminal device in the method. Figure 8The corresponding process of the terminal device in the method will not be repeated here for brevity.

[0153] Figure 15 A schematic block diagram of the network device 800 according to an embodiment of the present application is shown. As shown, the network device 800 includes: Figure 15

[0154] The communication unit 810 is configured to receive an indication message sent by the terminal device, where the indication message is used to indicate a first frequency domain DFT vector indication set in a plurality of frequency domain DFT vector indication sets.

[0155] The processing unit 820 is configured to recover a downlink channel according to any frequency domain DFT vector indication equivalent to the first frequency domain DFT vector indication in the first frequency domain DFT vector indication set.

[0156] It should be understood that the network device 800 according to the embodiments of the present application can correspond to the network device in the method embodiments of the present application, and the above and other operations and / or functions of each unit in the network device 800 are respectively implemented to achieve the corresponding process of the network device in the method embodiments of the present application. Figure 11 The corresponding process of the network device in the method will not be repeated here for brevity.

[0157] Figure 16 A schematic block diagram of the network device 900 according to an embodiment of the present application is shown. As shown, the network device 900 includes: Figure 16

[0158] The communication unit 910 is configured to receive an indication message sent by the terminal device, where the indication message is used to indicate a position in a specific frequency domain DFT vector in a DFT array corresponding to the strongest coefficient of a spatial-frequency weighted coefficient array of a codebook.

[0159] It should be understood that the network device 900 according to the embodiments of the present application can correspond to the network device in the method embodiments of the present application, and the above and other operations and / or functions of each unit in the network device 900 are respectively implemented to achieve the corresponding process of the network device in the method embodiments of the present application. Figure 12 The corresponding process of the network device in the method will not be repeated here for brevity.

[0160] ​​It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly implemented as a hardware decoding processor, or can be implemented by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0161] It is to be understood that the memory in the embodiments of the present application can be a volatile memory or a nonvolatile memory, or can include both volatile and nonvolatile memory. Among them, the nonvolatile memory can be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM, PROM), an erasable programmable read-only memory (Erasable PROM, EPROM), an electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or a flash memory. The volatile memory can be a random access memory (Random Access Memory, RAM) used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (Synchlink DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM). It should be noted that the memory of the system and method described herein is intended to include, but not limited to, these and any other suitable types of memory.

[0162] It should be understood that the above-mentioned memory is exemplary but not limiting, for example, the memory in the embodiments of the present application can also be static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synch link DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM) and the like. That is, the memory in the embodiments of the present application is intended to include, but not limited to, these and any other suitable types of memory.

[0163] The embodiment of the present application further provides a computer readable storage medium for storing the computer program.

[0164] Optionally, the computer readable storage medium can be applied to the network device in the embodiment of the present application, and the computer program makes the computer execute the corresponding process realized by the network device in the various methods of the embodiment of the present application. For the sake of brevity, details are not described herein.

[0165] Optionally, the computer readable storage medium can be applied to the terminal device in the embodiment of the present application, and the computer program makes the computer execute the corresponding process realized by the mobile terminal / terminal device in the various methods of the embodiment of the present application. For the sake of brevity, details are not described herein.

[0166] The embodiment of the present application further provides a computer program product comprising computer program instructions.

[0167] Optionally, the computer program product can be applied to the network device in the embodiment of the present application, and the computer program instructions make the computer execute the corresponding process realized by the network device in the various methods of the embodiment of the present application. For the sake of brevity, details are not described herein.

[0168] Optionally, the computer program product can be applied to the terminal device in the embodiment of the present application, and the computer program instructions make the computer execute the corresponding process realized by the mobile terminal / terminal device in the various methods of the embodiment of the present application. For the sake of brevity, details are not described herein.

[0169] The embodiment of the present application further provides a computer program.

[0170] Optionally, the computer program can be applied to the network device in the embodiment of the present application, and when the computer program runs on the computer, makes the computer execute the corresponding process realized by the network device in the various methods of the embodiment of the present application. For the sake of brevity, details are not described herein.

[0171] Optionally, the computer program can be applied to the terminal device in the embodiment of the present application, and when the computer program runs on the computer, makes the computer execute the corresponding process realized by the terminal device in the various methods of the embodiment of the present application. For the sake of brevity, details are not described herein.

[0172] Those skilled in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized in electronic hardware or in combination of computer software and electronic hardware. Whether the functions are realized in hardware or software mode depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0173] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0174] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0175] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0176] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0177] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the essential part or part of the technical solutions that make contributions to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program code storage media.

[0178] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for feeding back a codebook, characterized in that: include: The terminal device sends an indication message to the network device, where the indication message is used to indicate the position in a specific frequency domain DFT vector in the discrete Fourier transform DFT array corresponding to the strongest coefficient of the space-frequency domain weighted coefficient array of the codebook; The terminal device performs a cyclic shift operation on the frequency domain DFT vector corresponding to the non-zero coefficient in the space-frequency domain matrix so that the strongest coefficient corresponds to a specific frequency domain DFT vector in the DFT array; The specific frequency-domain DFT vector is the first frequency-domain DFT vector or the last frequency-domain DFT vector in the DFT array.

2. The method according to claim 1, characterized in that The bit width of the indication message is log2(2*L), where 2*L is the number of rows in the space-frequency domain matrix.

3. The method according to claim 1, characterized in that The bit width of the indication message is Where Lnz is the number of rows occupied by non-zero coefficients in the space-frequency domain matrix.

4. A method for feeding back a codebook, characterized in that: include: The network device receives an indication message sent by the terminal device, wherein the indication message is used to indicate the position of a specific frequency domain DFT vector in the discrete Fourier transform DFT array corresponding to the strongest coefficient of the space-frequency domain weighted coefficient array of the codebook; The strongest coefficient corresponds to a specific frequency domain DFT vector in the DFT array, which is obtained by the terminal device performing a cyclic shift operation on the frequency domain DFT vector corresponding to the non-zero coefficient in the space-frequency domain matrix; The specific frequency-domain DFT vector is the first frequency-domain DFT vector or the last frequency-domain DFT vector in the DFT array.

5. The method according to claim 4, characterized in that The bit width of the indication message is log2(2*L), where 2*L is the number of rows in the space-frequency domain matrix.

6. The method according to claim 4, characterized in that The bit width of the indication message is Where Lnz is the number of rows occupied by non-zero coefficients in the space-frequency domain matrix.

7. A terminal device, characterized in that: include: a communication unit, configured to send an indication message to a network device, wherein the indication message is used to indicate a position in a specific frequency domain DFT vector in a discrete Fourier transform DFT array corresponding to the strongest coefficient of the space-frequency domain weighted coefficient array of the codebook; a processing unit configured to perform a cyclic shift operation on the frequency domain DFT vectors corresponding to the non-zero coefficients in the space-frequency domain matrix so that the strongest coefficient corresponds to a specific frequency domain DFT vector in the DFT array; The specific frequency-domain DFT vector is the first frequency-domain DFT vector or the last frequency-domain DFT vector in the DFT array.

8. The terminal device according to claim 7, characterized in that The bit width of the indication message is log2(2*L), where 2*L is the number of rows in the space-frequency domain matrix.

9. The terminal device according to claim 7, characterized in that The bit width of the indication message is Where Lnz is the number of rows occupied by non-zero coefficients in the space-frequency domain matrix.

10. A network device, characterized in that: include: A communication unit, configured to receive an indication message sent by a terminal device, wherein the indication message is used to indicate a position in a specific frequency domain DFT vector in a discrete Fourier transform DFT array corresponding to the strongest coefficient of the space-frequency domain weighted coefficient array of the codebook; The strongest coefficient corresponds to a specific frequency domain DFT vector in the DFT array, which is obtained by the terminal device performing a cyclic shift operation on the frequency domain DFT vector corresponding to the non-zero coefficient in the space-frequency domain matrix; The specific frequency-domain DFT vector is the first frequency-domain DFT vector or the last frequency-domain DFT vector in the DFT array.

11. The network device according to claim 10, wherein: The bit width of the indication message is log2(2*L), where 2*L is the number of rows in the space-frequency domain matrix.

12. The network device according to claim 10, wherein: The bit width of the indication message is Where Lnz is the number of rows occupied by non-zero coefficients in the space-frequency domain matrix.

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