Channel information feedback method, terminal, medium, and program product

Abstract

Embodiments of the present application provide a channel information feedback method, a terminal, a medium, and a program product. The method comprises: on the basis of a measurement result of a reference signal, determining a codeword group for configuring a sub-band; on the basis of the codeword group of the sub-band, determining a codeword group for configuring at least another sub-band; and sending feedback information, so that a base station establishes communication with a terminal on the basis of the feedback information.

Description

Channel information feedback method, terminal, medium and program product

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202410174489.8 and application date of February 7, 2024, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The embodiments of the present application relate to the field of wireless communication technologies, and in particular to a channel information feedback method, terminal, storage medium, and computer program product. Background Art

[0004] Multiple Input Multiple Output (MIMO) is a key physical layer technology in fourth-generation (4G) and fifth-generation (5G) mobile communications. It can achieve higher spatial division multiplexing and spectrum efficiency, further improving cell capacity.

[0005] Ultra-large-scale MIMO is a further development of MIMO technology. By adopting larger antenna arrays, it achieves higher spatial multiplexing gain and more precise beamforming, thereby further improving the system capacity and spectrum efficiency. It can be applied to future wireless communication systems.

[0006] However, ultra-large-scale MIMO typically has higher channel dimensions and is used in wireless communications with larger bandwidths. This requires more channel state feedback resources, resulting in increased feedback overhead. Therefore, reducing the feedback overhead of high-frequency, large-bandwidth, ultra-large-scale MIMO systems is an urgent issue.

[0007] Summary of the Invention

[0008] The embodiments of the present application provide a channel information feedback method, terminal, storage medium and computer program product, aiming to design a suitable channel feedback method and device / terminal to implement a communication technology with lower feedback overhead.

[0009] In a first aspect, an embodiment of the present application provides a method for feedback of channel information, the method comprising: receiving a reference signal; measuring the reference signal to obtain channel state information; determining, from a codebook based on the channel state information, a first codeword group for configuring a subband; determining, based on the first codeword group, a second codeword group for configuring at least another subband; selecting, from the codeword groups corresponding to each subband, a codeword corresponding to each subband; and sending feedback information, wherein the feedback information includes at least codeword indication information corresponding to a codeword of one subband.

[0010] In a second aspect, an embodiment of the present application further provides a terminal, at least one processor; at least one memory for storing at least one program; and when at least one of the programs is executed by at least one of the processors, the channel information feedback method as described in the first aspect is implemented.

[0011] In a third aspect, an embodiment of the present application further provides a computer-readable storage medium storing a program executable by a processor, wherein the program executable by the processor is used to implement the channel information feedback method as described in the first aspect when executed by the processor.

[0012] In a fourth aspect, an embodiment of the present application further provides a computer program product, comprising a computer program or computer instructions, wherein the computer program or the computer instructions are stored in a computer-readable storage medium, a processor of a computer device reads the computer program or the computer instructions from the computer-readable storage medium, and the processor executes the computer program or the computer instructions, so that the computer device performs the channel information feedback method as described in the first aspect.

[0013] According to the channel information feedback method, terminal, storage medium and computer program product provided in the embodiments of the present application, determining another codeword group by one codeword group in the codebook can not only reduce the impact of dispersion but also compress feedback overhead. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG1 is a schematic diagram of the structure of a typical MIMO system in the related art.

[0015] FIG2 is a schematic diagram of a communication system applicable to MIMO technology provided in an embodiment of the present application.

[0016] FIG3 is a flowchart of a method for feeding back channel information provided by an embodiment of the present application.

[0017] FIG4 is a flowchart of a method for feeding back channel information provided by an embodiment of the present application.

[0018] FIG5 is a flowchart of a method for feeding back channel information provided by an embodiment of the present application.

[0019] FIG6 is a schematic diagram showing the relationship between sub-bands and codeword groups according to an embodiment of the present application.

[0020] FIG7 is a schematic diagram of a terminal according to an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0022] It should be noted that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and so on, in the specification, claims, and drawings, are used to distinguish similar items and are not necessarily used to describe a specific sequence or precedence.

[0023] In the description of the embodiments of the present application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense. Technical personnel in the relevant technical field can reasonably determine the specific meanings of the above terms in the embodiments of the present application based on the specific content of the technical solution.

[0024] In the embodiments of the present application, words such as "further," "exemplarily," or "optionally" are used to indicate examples, illustrations, or descriptions and should not be interpreted as being more preferred or advantageous over other embodiments or designs. The use of words such as "further," "exemplarily," or "optionally" is intended to present related concepts in a concrete manner.

[0025] The base station side device in the embodiments of the present application may be an evolved NodeB (eNB), a transmission point (TRP), a next generation NodeB (gNB) in an NR system, a base station in other future mobile communication systems, or an access node in a Wireless Fidelity (WiFi) system. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device.

[0026] In the embodiments of the present application, the user equipment and user terminal are entities on the user side for receiving or transmitting signals, such as mobile phones. The terminal side device can also be called a terminal device (terminal), user equipment (UE), mobile station (MS), mobile terminal device (MT), etc. The terminal device can be a car with communication function, a smart car, a mobile phone, a wearable device, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control (industrial control), a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in smart grid (smart grid), a wireless terminal device in transportation safety (transportation safety), a wireless terminal device in smart city (smart city), a wireless terminal device in smart home (smart home), etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal.

[0027] Multiple Input Multiple Output (MIMO) is a key physical layer technology in fourth-generation (4G) and fifth-generation (5G) mobile communications. To greatly increase channel capacity, multiple antennas are used at both the transmitting and receiving ends of communications.

[0028] Figure 1 is a schematic diagram of a typical MIMO system in related art. As shown in Figure 1, the transmitter (TX) and receiver (RX), respectively, have M transmit antenna elements and N receive antenna elements, forming a transmit / receive channel (H). Compared to traditional antenna systems, MIMO technology achieves higher spatial division multiplexing and spectral efficiency, further increasing cell capacity.

[0029] MIMO technology relies on channel information for beamforming, which focuses the signal in a specific direction to increase signal strength and quality. To implement beamforming, both the transmitter and receiver need to understand the channel state information (CSI), which is the channel characteristics between the transmitter and receiver. Before communication, the receiver can obtain channel information by measuring pilot signals. Pilot signals are typically transmitted as part of reference signals (such as CSI-RS), and the receiver uses them to estimate channel parameters such as fading, amplitude, and phase. The receiver can obtain information about the channel state by measuring and processing the pilot signals. Downlink channel information is obtained by the terminal by measuring the downlink reference signal and fed back to the base station. For example, the optimal codeword is fed back to the base station in the form of precoding matrix indicator (PMI). The base station then configures the downlink precoding matrix based on the received PMI, ensuring that the optimal precoding matrix is ​​used for downlink transmission. This maximizes the channel characteristics and improves system performance and capacity.

[0030] Ultra-large-scale MIMO is a further development of MIMO technology. It uses larger antenna arrays to achieve higher spatial multiplexing gain and more precise beamforming, thereby further improving system capacity and spectrum efficiency.

[0031] However, ultra-large-scale MIMO arrays can further enhance the dispersion effect of beams. This means that when the same precoding is used across the entire bandwidth, the beam directions of different subcarriers will shift. This increased transmission bandwidth further exacerbates the effects of dispersion. High-frequency wireless communications have greater bandwidth. If the number of subbands across the full bandwidth remains unchanged, the bandwidth of each subband will increase. If the same channel feedback is used within each subband, performance may deteriorate due to dispersion.

[0032] In related technologies, the above problem can be alleviated by increasing the number of subbands in the full bandwidth. However, more subbands require more time-frequency resources for feeding back channel state information, resulting in increased feedback overhead.

[0033] Based on this, the present application provides a channel information feedback method, terminal, storage medium, and computer program product. The channel information feedback method provided in one embodiment of the present application determines, based on the measurement results of a reference signal, a codeword group (i.e., a codeword set) used to configure a subband; determines, based on the codeword group of the aforementioned subband, a codeword group used to configure at least another subband, and sends feedback information so that the base station establishes communication with the terminal based on the feedback information. By establishing a relationship between codeword groups, not only can the impact of dispersion effects be reduced and the feedback overhead during the channel information feedback process be reduced, but the difficulty of searching for codewords can also be reduced.

[0034] The technical solution of the present application is applicable to various communication systems. Therefore, the following description is not limited to a specific communication system. For example, the fifth generation (5th Generation, 5G) system, or the sixth generation (6th Generation, 6G) system New Radio (New Radio, NR), etc. In particular, it is applicable to scenarios where channel information between the transmitter TX and the receiver RX needs to be obtained before communication. In order to facilitate the understanding of the technical solution of the present application, the following is a further explanation of the feedback method of channel information, the terminal, the storage medium, and the computer program product based on an application scenario of the technical solution of the present application.

[0035] FIG2 is a schematic diagram of a communication system applicable to MIMO technology provided in an embodiment of the present application. As shown in FIG2 , the communication system 200 includes a terminal side device, such as a smart terminal 210 , and a base station side device, such as a transmitting base station 220 .

[0036] Figure 3 is a flow chart of a channel information feedback method provided by an embodiment of the present application. As shown in Figure 3, the channel information feedback method can be executed by the terminal side 210. The steps of the channel information feedback method may include but are not limited to steps S100, S200, S300, S400, S500, and S600.

[0037] Step S100: receiving a reference signal;

[0038] In one embodiment, the reference signal is a channel status information reference signal (CSI-RS).

[0039] CSI-RS is a reference signal used for channel estimation. Terminals can use CSI-RS to estimate channel parameters such as fading, amplitude, and phase, enabling effective signal detection and decoding. CSI-RS is typically distributed within the system bandwidth in specific time slots and frequency domain resources and transmitted periodically as needed. CSI-RS can be used to help user equipment (UE) (e.g., terminals) provide feedback on channel state information to the base station, enabling the base station to perform downlink adaptive transmission.

[0040] In another embodiment, the reference signal is a synchronization signal (SS). The SS is a reference signal used for clock synchronization and system positioning, helping the receiving end to synchronize time and frequency and determine the location of the base station. Synchronization signals are typically distributed within the system bandwidth using specific time slots and frequency domain resources and transmitted at fixed intervals. The receiving end detects and decodes the synchronization signal to recover clock counts and system positioning information, thereby achieving synchronization with the base station.

[0041] The reference signal can also be one or more of the above, such as the cell-specific reference signal (CRS), the demodulation reference signal (DMRS), and the positioning reference signal (PRS). CRS is a common reference signal used for all user equipment in the cell. DMRS is a reference signal specifically used for a user equipment and is used for data demodulation of the user equipment. PRS is a reference signal used to support user equipment positioning. It is sent on specific time and frequency resources and has a high transmit power so that the user equipment can accurately measure its location information.

[0042] Step S200: measuring a reference signal to obtain channel state information (CSI);

[0043] In one embodiment, the CSI may include one or more of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), a layer 1 reference signal received power (L1-RSRP), or a layer 1 signal to interference and noise ratio (L1-SINR).

[0044] CQI is an indicator measured by the UE and reported to the base station. It is used to reflect the quality of the downlink channel and is used to help the base station determine the appropriate modulation and coding scheme (MCS) to adapt to the current channel conditions. PMI can indicate the precoding matrix that the UE recommends the base station to use. Precoding is usually obtained by processing the signal at the transmitting end, such as the base station, to improve the signal quality at the receiving end and reduce interference. LI can indicate the number of layers used in actual transmission. It is related to RI but not necessarily equal. The number of layers actually transmitted may be limited by other factors. RI represents the rank of the channel matrix, which is used to reflect the maximum number of spatial multiplexing layers or data streams that can be supported under the current channel conditions.

[0045] In one embodiment, the reference signal at the receiving end can be expressed as follows: y=Hx+n

[0046] Where x is the reference signal, H is the channel matrix, n is the noise term, and y is the received vector.

[0047] Step S300: determining a first codeword group for configuring a subband from a codebook according to channel state information;

[0048] In one embodiment, a communication bandwidth can be divided into multiple subbands. Each subband can be assigned a codeword group. Subcarriers within the subband can only select codewords from the codeword group for feedback. Limiting the codeword selection range for each subband—that is, assigning a corresponding codeword group—can reduce the codeword search space within the subband and improve feedback efficiency. A subband can be a portion of bandwidth (BWP), a set of resource blocks (RBs) within a BWP, a set of subcarriers within a BWP, or a specified communication bandwidth within a BWP.

[0049] In order to complete the channel estimation, the receiving end can design a receiving processing matrix W to process the y vector, that is, y'=Wy

[0050] In one embodiment, W is obtained using one of MMSE, LMMSE, and maximum likelihood estimation. The channel matrix H can be determined based on the processed received vector y', and the codeword group or codeword set used to configure at least one subband can be determined. Once the codeword set used to configure a subband is determined, the subcarriers in that subband can only select codewords from the determined codeword group for beamforming configuration.

[0051] In one embodiment, a channel matrix H may be obtained based on a received reference signal, and a first codeword group for configuring the first subband may be determined based on the channel matrix H. After the first codeword group is determined, codewords in the first subband may only be selected from the first codeword group.

[0052] The received reference signal is typically a known signal sequence. The receiving end compares the received reference signal with the known transmitted signal and estimates the channel using a signal processing algorithm. This channel estimation allows the receiving end to obtain channel state information, which reflects the characteristics of the channel. Based on the channel characteristics reflected in the channel state information, a set of preselected codewords that best correlate with these channel characteristics is selected from a codebook. This correlation can be understood as meaning that when a codeword from this codeword set is used to configure downlink transmission, the receiving end can achieve better receive gain, signal-to-noise ratio, or a higher transmission rate.

[0053] A codebook is a collection of codewords that can be used to configure precoding for a MIMO array to achieve specific beamforming effects, such as forming a directional beam for a transmitted signal.

[0054] A codebook can be a set of precoding matrices predefined according to system requirements and communication standards. Each precoding matrix corresponds to a codeword and is used for multi-antenna transmission in wireless communication systems. It provides a variety of precoding matrix options to adapt to different channel conditions and transmission requirements.

[0055] Step S400: Determine, based on the first codeword group, a second codeword group for configuring at least another subband;

[0056] In one embodiment, the second codeword group of the second subband may be configured according to the first codeword group of the first subband.

[0057] Specifically, assuming that the first codeword group corresponding to the first subband S1 is C1, the second codeword group C2 corresponding to the second subband S2 can be determined based on C1. The correspondence means that the codewords for subband S1 can only be selected from codeword group C1, and the codewords for second subband S2 can only be selected from second codeword group C2.

[0058] In one embodiment, the second codeword group used to configure at least another subband may be determined according to a codeword index corresponding to at least one codeword in the first codeword group.

[0059] Specifically, assuming a codeword W1 in the first codeword group C1 of the first sub-band S1, whose index is {i1, i2}, the second codeword group C2 of the second sub-band S2 can be determined based on the index {i1, i2} of the codeword W1.

[0060] In another embodiment, a mapping relationship may be established between a codeword index corresponding to at least one codeword in the first codeword group and each codeword index in the second codeword group to determine the second codeword group for configuring at least another subband.

[0061] There are many ways to establish a specific mapping relationship, including a fixed mapping relationship and a flexibly configurable mapping relationship, etc. This embodiment may include various implementations of determining the second codeword group C2 of the second subband S2 through the index {i1, i2} of M1, which are not limited here.

[0062] In one embodiment, the first codeword group may include a sub-codeword group. A second codeword group configured for at least another subband may be determined according to a sub-codeword group index corresponding to the sub-codeword group.

[0063] Specifically, assuming that a sub-codeword group N1 in the first codeword group C1 of the first sub-band S1 has an index i1, the second codeword group C2 of the second sub-band S2 can be determined according to the index i1 of the sub-codeword group N1.

[0064] In another embodiment, a mapping relationship may be established between the codeword index corresponding to at least one codeword in the sub-codeword group and each codeword index in the second codeword group to determine the second codeword group for configuring at least another subband.

[0065] There are many ways to establish a specific mapping relationship, including a fixed mapping relationship and a flexibly configurable mapping relationship, etc. This embodiment may include various implementations of determining the second codeword group C2 of the second subband S2 by the index {i1} of the subcodeword group N1, which are not limited here.

[0066] In one embodiment, the index of a codeword can be represented as {i1, i2}, where the parameter i1 can represent the index of the codeword group or sub-codeword group to which the codeword belongs. That is, the position of the codeword group in the codebook can be determined based on i1, and the parameter i2 can represent the position of the codeword in the codeword group indicated by i1. Therefore, the position of the codeword in the codebook can be determined based on the index {i1, i2}.

[0067] In the feedback method proposed in this embodiment, the codeword group corresponding to one subband can be used to determine the codeword group corresponding to at least one other subband. In some cases, the codeword group index i1 of one subband can be used to determine the codeword group index of at least another subband. That is, in the feedback from the terminal side, the codewords of at least two subbands can share the indication information i1 during feedback.

[0068] In the related art, the codeword group of one subband cannot be determined based on the codeword group of another subband. Each subband needs to separately feedback the indication information i1 of its corresponding codeword group, which increases the feedback overhead. However, the method proposed in this embodiment can effectively reduce the overhead.

[0069] In some applications, to mitigate the dispersion effects of ultra-large array precoding, larger subband bandwidths require larger corresponding codeword groups, which in turn increases the length of the codeword's i2 indicator information and feedback overhead. However, the method proposed in this embodiment can be used to divide a subband into several subbands. The codeword groups corresponding to at least one subband can be used to determine the codeword groups corresponding to other subbands. This subband division reduces the bandwidth and codeword groups, thereby compressing the length of the codeword's i2 indicator information without increasing the i1 indicator information, thereby reducing feedback overhead.

[0070] In one embodiment, i1 and i2 in the codeword index {i1, i2} may be composed of one or a group of numbers, or may be determined based on the order or storage structure of the codewords in the codebook. As an example, if a codebook contains 16 rows and 16 columns of codewords, the index of a codeword may be determined based on the row and column numbers of the codeword in the codebook, in which case i1 and i2 may correspond to the row and column numbers. As another example, if a codebook can be divided into 16 codeword groups, i1=8 may indicate that the codeword belongs to the 8th codeword group, and i2=2 may indicate that the codeword is the 2nd codeword in the 8th group.

[0071] In another embodiment, the codeword index may include more than three parameters, namely {i1, i2, i3, ...}. For example, when the codewords in the codebook can be divided into multi-level codeword groups, multiple parameters are required for indexing.

[0072] In one embodiment, the codeword index can be directly used as feedback information. In another embodiment, the codeword index needs to be converted into codeword indication information according to a predetermined mapping relationship before being fed back.

[0073] FIG4 is a flow chart of a method for feeding back channel information provided by an embodiment of the present application. As shown in FIG4 , step S400 further includes steps S411 and S412.

[0074] Step S411: determining a configuration parameter according to a codeword index corresponding to at least one codeword in the first codeword group;

[0075] Step S412: Determine a second codeword group for configuring at least another subband according to the configuration parameters;

[0076] In one embodiment, the configuration parameters are fixed configuration parameters.

[0077] Specifically, assume a codeword W1 in the first codeword group C1 of the first subband S1. The index of codeword W1 is {i1, i2}. Fixed configuration parameters are N1 and N2, which can be preset integers. Then, the second codeword group C2 of the second subband S2 can be determined based on the index {i1, i2} of codeword W1 and the fixed configuration parameters N1 and N2.

[0078] As an example, assuming that the codeword index corresponding to the initial codeword (i.e., the first codeword) of the second codeword group C2 can be {i1+N1, i2+N2}, the codeword index corresponding to the codeword in the first row and second column of the second codeword group C2 can be {i1+N1, i2+N2+1}, the codeword index corresponding to the codeword in the second row and first column of the second codeword group C2 can be {i1+N1+1, i2+N2}, and so on, to determine the codeword of the second codeword group.

[0079] As another example, the first codeword group C1 is a codeword group used to configure the first subband S1. A codeword in the first codeword group C1 is Subscript {i1, i2} is the codeword The index of , then the codeword set of the second subband S2 is:

[0080] Wherein N1, N2, M1 and M2 are preset integers. In this example, the optional codeword range of the second subband S2 can be determined according to a codeword in the optional codeword range of the first subband S1.

[0081] In one embodiment, the configuration parameter is a variable configuration parameter.

[0082] Specifically, assume that a codeword W1 is included in the first codeword group C1 of the first subband S1. The index of codeword W1 is {i1, i2}. Variable configuration parameters N1 and N2 are provided. Then, the second codeword group C2 of the second subband S2 can be determined based on the index {i1, i2} of codeword W1 and the variable configuration parameters N1 and N2.

[0083] As an example, assume that the codeword index corresponding to the initial codeword (i.e., the first codeword) of the second codeword group C2 can be {i1+N1, i2+N2}, the codeword index corresponding to the codeword in the first row and second column of the second codeword group C2 can be {i1+N1, i2+N2+1}, the codeword index corresponding to the codeword in the second row and first column of the second codeword group C2 can be {i1+N1+1, i2+N2}, and so on, thereby determining the codeword of the second codeword group. N1 and N2 can be values ​​that vary depending on i1 and i2. When the codeword selected from the first codeword group C1 of the first subband S1 is different, i1 and i2 also change accordingly, and the codeword selected for configuring the second codeword group also changes accordingly.

[0084] In another embodiment, the configuration parameters may include a first configuration parameter and a second configuration parameter, wherein the first configuration parameter is used to determine a relative offset of a starting codeword of the second codeword group relative to a codeword of the first codeword group, and the second configuration parameter is used to determine the number of codewords in the second codeword group.

[0085] FIG5 is a flow chart of a method for feeding back channel information provided by an embodiment of the present application. As shown in FIG5 , step S400 further includes steps S421 and S422.

[0086] Step S421: determining configuration parameters according to the sub-codeword group index corresponding to the sub-codeword group;

[0087] Step S422: Determine a second codeword group for configuring at least another subband according to the configuration parameters;

[0088] In one embodiment, the configuration parameters are fixed configuration parameters.

[0089] Specifically, assume a sub-codeword group W1 in the first codeword group C1 of the first sub-band S1. The index of the sub-codeword group W1 is {i1, i2}. The fixed configuration parameters are N1 and N2, which can be preset integers. Then, the second codeword group C2 of the second sub-band S2 can be determined based on the index {i1, i2} of the sub-codeword group W1 and the fixed configuration parameters N1 and N2.

[0090] As an example, assuming that the codeword index corresponding to the initial sub-codeword group (i.e., the first codeword) of the second codeword group C2 can be {i1+N1, i2+N2}, the codeword index corresponding to the sub-codeword group in the first row and second column of the second codeword group C2 can be {i1+N1, i2+N2+1}, the codeword index corresponding to the sub-codeword group in the second row and first column of the second codeword group C2 can be {i1+N1+1, i2+N2}, and so on, to further determine the codeword of the second codeword group. In some cases, the sub-codeword group may be composed of codewords having the same beam direction but different polarization phases.

[0091] As another example, the first codeword group C1 is a sub-codeword group W1 used to configure the first sub-band S1. A codeword in the first codeword group C1 is Subscript {i1, i2} is the codeword The index of , then the codeword set of the second subband S2 is:

[0092] Wherein N1, N2, M1 and M2 are preset integers.

[0093] In one embodiment, the configuration parameter is a variable configuration parameter.

[0094] Specifically, assuming a sub-codeword group W1 in the first codeword group C1 of the first sub-band S1, the index of the sub-codeword group W1 is {i1, i2}, and the variable configuration parameters N1 and N2 are provided. Then, the second codeword group C2 of the second sub-band S2 can be determined based on the index {i1, i2} of the sub-codeword group W1 and the variable configuration parameters N1 and N2.

[0095] In one embodiment, the values ​​of N1 and N2 are associated with the values ​​of i1 and i2, that is, the values ​​of N1 and N2 change with the values ​​of i1 and i2.

[0096] As an example, when {i1, i2} belongs to set P1, N1 and N2 can be determined to use a corresponding set of configuration values. When {i1, i2} belongs to another set P2, N1 and N2 need to use another set of configuration values. In other words, when the codeword or sub-codeword group index {i1, i2} of the first subband takes different values, the number of codewords included in the codeword group corresponding to the second subband also varies.

[0097] Step S500: Selecting a codeword corresponding to each subband from the codeword group corresponding to each subband;

[0098] In one embodiment, a codeword corresponding to each subband is selected from a codeword group corresponding to each subband according to the channel state information.

[0099] Specifically, each subband can obtain the channel state information of the subband based on the reference signal measurement result, and select a suitable codeword from the corresponding codeword group for feedback based on the subband channel state information. For example, the matching degree between the codeword in the codeword group and the subband channel can be determined, and the matching degree can be determined based on indicators such as received power and signal-to-noise ratio.

[0100] Step S600: Send feedback information, where the feedback information includes at least codeword indication information corresponding to a codeword of a subband.

[0101] In one embodiment, the feedback information may be codeword indication information corresponding to the codewords of all sub-bands.

[0102] In another embodiment, the feedback information may be codeword indication information corresponding to codewords of some sub-bands.

[0103] As an example, it is assumed that the system includes S1, S2, S3, ..., S n sub-bands, and the codeword groups corresponding to each sub-band are C1, C2, C3..., C n , the code words corresponding to each sub-band are W1, W2, W3..., W n , where W1, W2, W3..., W n From C1, C2, C3..., C n Select from the drop-down list.

[0104] The feedback information may include code words W1, W2, W3..., W n The corresponding codeword indication information; the feedback information can also include only codewords W1, W3, W5..., W n' The corresponding codeword indication information; the feedback information can also include only codewords W2, W4, W6..., W n " respectively correspond to codeword indication information, where n is a positive integer, n' is an odd number, and n" is an even number.

[0105] Since the codeword group of at least one subband can be determined by the codeword group of another subband, the indication information of at least two codewords in the fed-back codeword indication information can share a portion of the indication information, thereby reducing feedback overhead.

[0106] As an example, the codeword indication information of a subband is {i1, i 21}, the codeword indication information of the other subband is {i1, i 22}, at this time, the two codewords can share the i1 indication information for joint feedback, that is, the indication information becomes {i1, {i 21 ,i 22}}, thereby reducing the overhead of one indication information. If the codewords of multiple sub-bands share the i1 indication information, a similar method can be used to reduce the overhead.

[0107] In one embodiment, a subband may be divided into several next-level subbands, such as RB groups, and each next-level subband may select a codeword from a codeword group for feedback.

[0108] During the channel measurement and feedback process, the terminal needs to select an appropriate codeword from the codebook based on the measurement results and feed it back to the base station. However, when the MIMO array has a large number of antennas and the beam oversampling factor is large, the number of codewords in the codebook becomes very large, and searching for the appropriate codeword among these large numbers of codewords is time-consuming. Furthermore, due to the effects of dispersion, a wideband signal cannot be transmitted using only a single codeword. Different codewords must be configured for different subbands based on the frequency-domain channel characteristics, further increasing feedback overhead and the complexity of codeword selection.

[0109] In this embodiment, the codeword group of at least one subband is determined based on the codeword group of at least one other subband. For example, in some cases, a mapping or function relationship is established between the codeword groups of different subbands. This eliminates the overhead required for one subband and the overhead for representing the mappings or functions of other subbands, thereby enabling the representation of all subbands. This eliminates the need for corresponding codeword indication information for each subband, thereby reducing the required feedback overhead. Furthermore, it simplifies codeword selection and improves search efficiency.

[0110] In order to further illustrate the method provided in the embodiments of the present application, the following examples are given to provide further detailed description.

[0111] Example 1: A channel information feedback method

[0112] The feedback method proposed in this example includes the following implementation steps:

[0113] Step 1: Receive reference signal

[0114] The reference signal may be a channel information reference signal (CSI-RS) or a synchronization signal SS. The reference signal arriving at the receiving end may be expressed as follows: y = Hx + n (1)

[0115] Where x is the reference signal, H is the channel matrix, n is the noise term, and y is the received vector.

[0116] Step 2: Determine the codebook for feedback and determine the codeword set for configuring the subband from the codebook

[0117] The subband group is composed of a group of subcarriers, for example, a subcarrier set within a subbandwidth within the communication bandwidth. A subband can be a BWP or a subcarrier subset within a BWP.

[0118] In order to perform channel estimation, the receiving end can design a receiving processing matrix W to process the y vector, that is, y'=Wy (2)

[0119] W can be obtained using common methods such as MMSE, LMMSE, maximum likelihood estimation, etc. The channel matrix H can be determined based on the processed received vector y', and further a codeword set for configuring at least one subband can be determined.

[0120] Once the codeword set used to configure a subband is determined, the subcarriers in the subband can only select codewords from the aforementioned codeword set for beamforming configuration.

[0121] The codeword set used to configure at least one subband can be used to determine the codeword set of at least one other subband. That is, there is a dependency between the codeword sets used by different subbands, and the codeword set applicable to other subbands can be determined based on the dependency.

[0122] Step 3: Select codewords from the subband codeword set

[0123] According to the reference signal measurement result, a codeword for configuring subband precoding is selected from the codeword set of each subband.

[0124] In some cases, the appropriate codeword can be determined based on the projection of the corresponding subcarrier component of the reference signal under different codewords. In other cases, the appropriate codeword can be determined based on the subcarrier signal received power or signal-to-noise ratio.

[0125] Step 4: Send feedback information, that is, feedback the indication information of the selected codeword

[0126] After determining the subband codeword based on the reference signal measurement results and the subband codeword group configuration information, the terminal feeds back the codeword indication information and codeword configuration information to the base station. The base station configures the MIMO array precoding based on the feedback information for MIMO array beamforming during downlink communication.

[0127] In this example, the codeword group for one subband is used to determine the codeword group for another subband, thereby requiring less overhead to represent all subbands. This eliminates the need for corresponding codeword indication information for each subband, reduces the required feedback overhead, simplifies codeword selection, and improves search efficiency.

[0128] Example 2: Codeword Structure

[0129] In one example, the codewords in the codebook satisfy the following form:

[0130] in

[0131] The index of the codeword {l, m, n} can be determined based on the codeword indication information {i 11 ,i 12 ,i2} is determined, and i 11 ∈{0,1,…N1O1 / s1-1},i 12 ∈{0,1,…N2O2 / s2-1}, N1, N2, O1, O2, s1, s2 are preset parameters.

[0132] In some cases, n can be used to indicate polarization phase information, and the value range of n can be determined according to actual conditions. For example, in some cases, n can be an integer value between 0 and 3.

[0133] From formula (4), we can see that the codeword W l,m,n Belongs to a codeword group W l,m .

[0134] In some cases, the codeword indication information {i 11 ,i 12 {i1, i2} can indicate a sub-codeword group in the codebook. The indication information i2 further indicates the position of the selected codeword in the sub-codeword group. For example, {i1, i2} can indicate the starting position or ending position of a codeword group of a continuous region in the codebook.

[0135] In some cases, a subband needs to be selected from 16 beams. If there are four polarization options, the codeword group used to configure the subband contains 64 codewords. In this case, i2 requires at least 6 bits to fully feedback the codeword information.

[0136] By adopting the feedback method proposed in the embodiment / example of the present application, the length of the indication information i2 can be effectively compressed. On the one hand, the subband can be divided into several next-level subbands (secondary subbands) to weaken the dispersion effect, and then the required number of beams can be compressed, for example, to 4, so that the number of codewords used to configure the next-level subband is reduced to 16. The length of the indication information i2 can be compressed to 4 bits. On the other hand, since the codeword set of at least one other next-level subband can be determined based on the codeword set of at least one next-level subband. Therefore, the increase in the number of next-level subbands does not require the addition of more additional indication information, that is, the indication information {i 11 ,i 12}No information or only a small amount of information may be added, so that the feedback length of the indication information can be effectively compressed.

[0137] In some cases, a codeword in multi-layer transmission can be written as follows

[0138] where v l，m Determined by formula (7), Determined by formula (5), K is the number of transmission layers and PCSI-RS is the number of ports. At this time, a codeword requires more indication information to determine, and the codeword indication information corresponds one-to-one with the codeword index.

[0139] The channel measurement and feedback methods proposed in the embodiments / examples of this application can still determine the codeword group for at least one other subband based on the codeword group for at least one subband in different subbands using the codeword group for the codebook described above. Therefore, less indication information can be used in the feedback information to determine the codeword group information for multiple subbands.

[0140] Example 3: Fixed configuration between codeword groups

[0141] To better utilize frequency domain resources, a communication bandwidth can generally be divided into multiple subbands. A subband can be a collection of subcarriers, for example, consisting of several subbands within a continuous bandwidth. Figure 6 illustrates the relationship between subbands and codeword groups in one embodiment of the present application. As shown in Figure 6, the subbands can include a serving cell, a BWP, a group of RBs within a BWP, a group of subcarriers within a BWP, and so on.

[0142] During the channel measurement and feedback process, the terminal needs to select an appropriate codeword from the codebook based on the measurement results and feed it back to the base station. Firstly, when the MIMO array has a large number of antennas and the beam oversampling factor is large, searching for the appropriate codeword within the codebook is time-consuming due to the large number of codewords. Secondly, due to the effects of dispersion, it is difficult to transmit a wideband signal using only a single codeword. Different codewords must be configured for different subbands based on the frequency domain channel characteristics, further increasing the complexity of codeword selection.

[0143] To improve efficiency, a codeword group can be determined for each subband based on the reference signal measurement results. The corresponding subband can only select codewords from this codeword group, which reduces the codeword search range and improves search efficiency. For example, subcarriers in subband S1 can only select codewords from codeword group C1.

[0144] However, when chromatic dispersion is significant, the frequency domain channel within a subband may also experience significant fluctuations. In this case, to ensure broadband transmission performance, a larger codeword group must be designed. Increasing the codeword group size increases the difficulty of codeword search and also increases feedback overhead.

[0145] In order to solve the above problem, this example proposes a channel measurement and feedback method, including determining the codeword group of at least one other subband based on the codeword group of at least one subband. In some cases, there is an explicit functional relationship between the codeword groups of different subbands.

[0146] In the above formula, K1 codeword groups can be determined by the other K2 codeword groups in the codebook according to the function f, where K1 ≥ 1 and K2 ≥ 1. Based on this mapping relationship, feedback overhead can be compressed during the channel information feedback process.

[0147] A codeword group contains several codewords, each of which corresponds to a codeword index. A codeword index can be a combination of a group of numbers or a combination of other identifiers. A codeword index can indicate the position of a codeword in a preset codebook.

[0148] In some applications, a subband S i Codeword group C i Contains a codeword The subband S can be determined based on the index {i1, i2} of the codeword j Codeword group C j For example, in some cases, C j The codeword set is the following codeword determined by {i1, i2}

[0149] Among them, N1, N2, M1 and M2 are preset integers. j The index {j1, j2} of the codeword at row m1 and column m2 in the table has the following functional relationship with {i1, i2}: j1 = i1 + N1 + m1, j2 = i2 + N2 + m2,

[0150] Where m1∈[0,M1], m2∈[0,M2]. According to the above relationship, we only need to preset N1, N2, M1 and M2, and we can get the code word group C i A plurality of other codeword groups are determined, each codeword group being used for codeword selection within a subband.

[0151] In other cases, N1 and N2 can be used to configure the codeword group C in the codebook. j The starting codeword is relative to the codeword group C i Medium code word The relative offset of M1 and M2 can be used to configure the codeword group Cj The number of code words.

[0152] In other cases, different codeword groups may be configured with different N1, N2, M1, and M2 parameters.

[0153] In some applications, a subband S i Codeword group C i Contains a subcodeword group The index {i1, i2} indicates the position of the codeword group in the preset codebook. Therefore, the subband S can be determined based on the index {i1, i2}. j Codeword group C j For example, in some cases, codeword group C j It is composed of the following sub-codeword groups,

[0154] Among them, N1, N2, M1 and M2 are preset integers, and the aforementioned preset values ​​can be determined by the configuration signaling sent by the base station, or can be determined by the terminal according to a preset rule.

[0155] At this time, C j The sub-codeword group in row m1 and column m2 The index {j1, j2} and {i1, i2} have the following functional relationship: j1 = i1 + N1 + m1, j2 = i2 + N2 + m2,

[0156] Where m1∈[0,M1], m2∈[0,M2]. According to the above relationship, we only need to preset N1, N2, M1 and M2, and we can get the code word group C i A plurality of other codeword groups are determined, each codeword group being used for codeword selection within a subband.

[0157] Example 4: Fixed configuration between codeword groups

[0158] In one example, a terminal may determine a codeword group for configuring at least one other subband based on a codeword group for configuring at least one subband. For a given subband, when the codeword group for at least one subband changes, the codeword group for at least one other subband determined based on the codeword group needs to be changed accordingly. The change may include the number of codewords in the codeword group, the position of the starting codeword in the codeword group, and so on.

[0159] For example, according to the method for configuring a subband S i Codeword group C i The index information {i1, i2} of a codeword in can determine the other subband S jThe configuration parameters {N1, N2, M1, M2} of the codeword group can be determined based on the index information {i1, i2} and the determined set of configuration parameters {N1, N2, M1, M2} for configuring the subband S j Codeword group C j for

[0160] In some cases, N1 and N2 can be used to configure the codeword group C in the codebook. j The starting codeword is relative to the codeword group C i Medium code word The relative offset of M1 and M2 can be used to configure the codeword group C j When used to configure subband S i At least one codeword in the codeword group changes, that is, the value of {i1, i2} changes, then the subband S j The configuration parameters {N1, N2, M1, M2} of the codeword group are changed accordingly, and then used to configure the subband S j Codeword group C j The number of code words in the codebook and the position of the starting code word in the preset codebook change accordingly.

[0161] FIG7 is a schematic diagram of a terminal according to an embodiment of the present application. As shown in FIG7 , the terminal includes: a memory 1000, a processor 1100, and a computer program stored in the memory 1000 and executable on the processor 1100. When the processor 1100 executes the computer program, the codebook configuration method provided in any embodiment of the present application is implemented.

[0162] An embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the method provided in any embodiment of the present application.

[0163] An embodiment of the present application further provides a computer program product, including a computer program or computer instructions, and the computer can execute the computer program or computer instructions to perform the method provided in any embodiment of the present application.

[0164] The system architecture and application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of the system architecture and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are equally applicable to similar technical problems.

[0165] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0166] In a hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0167] As used in this specification, the terms "component," "module," "system," and the like are used to refer to computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. By way of illustration, both applications running on a computing device and a computing device can be components. One or more components can reside in a process or execution thread, and a component can be located on a single computer or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, through local or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component on a local system, a distributed system, or a network, such as the Internet interacting with other systems via signals).

[0168] The above description of some embodiments of the present application with reference to the accompanying drawings does not limit the scope of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present application shall be within the scope of the present application.

Claims

1. A method for feeding back channel information, comprising: receiving a reference signal; measuring the reference signal to obtain channel state information; determining, from a codebook according to the channel state information, a first codeword group for configuring a subband; determining, based on the first codeword group, a second codeword group for configuring at least another subband; Selecting codewords corresponding to the subbands from the codeword groups corresponding to the subbands; Feedback information is sent, wherein the feedback information includes at least codeword indication information corresponding to a codeword of a subband.

2. The feedback method according to claim 1, wherein: The selecting, from the codeword groups corresponding to the subbands, the codewords corresponding to the subbands respectively include: According to the channel state information, codewords corresponding to the subbands are respectively selected from codeword groups corresponding to the subbands.

3. The feedback method according to claim 1 or 2, wherein: The determining, based on the first codeword group, a second codeword group for configuring at least another subband includes: A second codeword group for configuring at least another subband is determined according to a codeword index corresponding to at least one codeword in the first codeword group.

4. The feedback method according to claim 1 or 2, wherein: The first codeword group includes at least one sub-codeword group; The determining, based on the first codeword group, a second codeword group for configuring at least another subband includes: A second codeword group for configuring at least another subband is determined according to the subcodeword group index corresponding to the subcodeword group.

5. The feedback method according to claim 3, wherein: The determining, according to a codeword index corresponding to at least one codeword in the first codeword group, a second codeword group for configuring at least another subband includes: determining a configuration parameter according to a codeword index corresponding to at least one codeword in the first codeword group; A second codeword group for configuring at least another subband is determined according to the configuration parameters.

6. The feedback method according to claim 4, wherein: The determining, according to the sub-codeword group index corresponding to the sub-codeword group, the second codeword group for configuring at least another subband includes: Determining a configuration parameter according to a sub-codeword group index corresponding to the sub-codeword group; The second codeword group used to configure at least another subband is determined according to the configuration parameters.

7. The feedback method according to claim 5 or 6, wherein: The feedback information also includes configuration indication information corresponding to the configuration parameters.

8. The feedback method according to claim 1, wherein: The sub-band is any of the following: A partial bandwidth BWP; At least one resource block RB in a bandwidth fraction BWP; A set of at least one subcarrier in a partial bandwidth BWP.

9. The method according to claim 5 or 6, wherein: The configuration parameters include a first configuration parameter and a second configuration parameter; The first configuration parameter is used to determine a relative offset of a starting codeword of the second codeword group relative to at least one codeword of the first codeword group; The second configuration parameter is used to determine the number of codewords in the second codeword group.

10. The feedback method according to claim 3, wherein: The determining, according to a codeword index corresponding to at least one codeword in the first codeword group, a second codeword group for configuring at least another subband includes: A mapping relationship is established between a codeword index corresponding to at least one codeword in the first codeword group and each codeword index in the second codeword group to determine a second codeword group for configuring at least another subband.

11. The feedback method according to claim 4, wherein: The determining, according to the sub-codeword group index corresponding to the sub-codeword group, a second codeword group for configuring at least another subband includes: A mapping relationship is established between a codeword index corresponding to at least one codeword in the sub-codeword group and each codeword index in the second codeword group to determine a second codeword group for configuring at least another subband.

12. A terminal comprising: at least one processor; at least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the channel information feedback method according to any one of claims 1 to 11 is implemented.

13. A computer-readable storage medium storing a program executable by a processor, wherein the program executable by the processor is used to implement the channel information feedback method according to any one of claims 1 to 11 when executed by the processor.

14. A computer program product, comprising a computer program or computer instructions, wherein the computer program or the computer instructions are stored in a computer-readable storage medium, and a processor of a computer device reads the computer program or the computer instructions from the computer-readable storage medium, and the processor executes the computer program or the computer instructions, so that the computer device performs the channel information feedback method according to any one of claims 1 to 11.

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