A channel measurement method and communication device

Abstract

The present application provides a channel measurement method and communication device, which can obtain more accurate CQI feedback, which is conducive to reasonably determining the MCS suitable for the downlink channel, thereby improving the transmission performance. The method includes: determining and sending the channel quality indication CQI of the first subband according to the channel information of the first subband and the precoding information of the broadband; wherein the broadband includes multiple subbands, and the first subband is one of the multiple subbands; the precoding information of the broadband is determined based on the channel information of the multiple subbands, and the precoding information of the broadband can be applied to any subband of the multiple subbands; the channel information of the first subband is obtained by channel measurement based on multiple precoding reference signals, and each precoding reference signal is obtained by precoding the reference signal based on at least one delay vector.

Description

Technical Field

[0001] The present application relates to the field of communications, and more specifically, to a channel measurement method and a communication device. Background Art

[0002] Channel quality indicator (CQI) is one of the important parameters that describe channel state information (CSI). For example, in downlink transmission, the network device can determine the modulation coding scheme (MCS) corresponding to the channel quality based on the CQI fed back by the terminal device. Therefore, whether the feedback of CQI is accurate affects whether the determination of MCS is reasonable, and thus affects the downlink transmission quality.

[0003] Normally, the terminal device can determine the subband precoding matrix based on the measured subband channel, and then determine the subband CQI. However, this method of determining the subband CQI is not accurate enough in some cases. For example, when the pilot is precoded, such as frequency domain precoding, directly determining the subband precoding matrix based on the measured subband channel does not seem to be a true precoding matrix, and the accuracy of the subband CQI determined by this method also needs to be improved. Summary of the invention

[0004] The present application provides a channel measurement method and a communication device, in order to improve the feedback accuracy of sub-band CQI.

[0005] In a first aspect, a channel measurement method is provided, which may be executed by a terminal device, or may be executed by a component (such as a circuit, a chip, or a chip system, etc.) configured in the terminal device.

[0006] Specifically, the method includes: determining the CQI of the first subband according to the channel information of the first subband and the precoding information of the broadband; wherein the broadband includes multiple subbands, and the first subband is one of the multiple subbands; the precoding information of the broadband is determined based on the channel information of the multiple subbands; the channel information of the first subband is obtained by performing channel measurement based on multiple precoding reference signals, wherein each precoding reference signal is obtained by precoding a reference signal based on at least one delay vector; and sending the CQI of the first subband.

[0007] It should be understood that the precoding information of the broadband can be used to determine the precoding matrix of each subband in the broadband. The precoding matrix of the broadband can be used as the precoding matrix of each subband. In other words, the network device can determine the precoding matrix used for downlink data transmission based on the subband in the broadband according to the precoding matrix of the broadband fed back by the terminal device.

[0008] Since the reference signal is precoded based on the delay vector, the delay loaded on each subband is different for the same reference signal port. Therefore, it is necessary to obtain the linear superposition coefficient corresponding to each reference signal port by full-band accumulation. The linear superposition coefficient corresponding to each reference signal port can be used to determine the precoding matrix of the broadband. When the network device performs downlink data transmission in the future, the precoding matrix on each subband can be determined based on the precoding matrix of the broadband.

[0009] However, if the terminal device still follows the traditional method of determining the precoding matrix of the subband, such as performing singular value decomposition (SVD) on the subband channel, it cannot obtain the broadband precoding matrix determined by the above linear superposition coefficients. In other words, the subband precoding matrix guessed by the terminal device based on the subband channel is inaccurate, and the CQI of the subband determined thereby is also inaccurate.

[0010] In an embodiment of the present application, the terminal device applies the precoding information of the broadband to each subband in the broadband, and determines the CQI of the subband in combination with the channel information of the subband. Since the determination of the CQI takes into account the precoding information of the broadband, rather than the precoding of the subband determined by the channel of the subband, it matches the channel loaded with the delay vector. Therefore, the terminal device can obtain a more accurate CQI for feedback. The network device can determine a reasonable MCS for downlink transmission based on the more accurate CQI. This is conducive to improving downlink transmission performance, and then to improving system performance.

[0011] In combination with the first aspect, in certain implementations of the first aspect, determining the CQI of the first subband based on the channel information of the first subband and the precoding information of the wideband includes: determining the power of the equivalent channel of the first subband based on the channel information of the first subband and the precoding information of the wideband, wherein the equivalent channel of the first subband is an equivalent channel determined based on the channel information of the first subband determined by the channel measurement and the precoding information of the wideband; determining the CQI of the first subband based on the power of the equivalent channel of the first subband.

[0012] It should be noted that the equivalent channel mentioned here may specifically refer to a channel obtained by assuming that the precoding matrix determined by the terminal device based on channel measurement is loaded onto the channel. It can be seen that in this process, the downlink channel is not actually loaded with the precoding matrix, but is assumed to be loaded with the precoding matrix. The terminal device only uses this assumption to guess the equivalent channel obtained after the network device precodes the downlink data during the subsequent downlink data transmission process. Therefore, the equivalent channel can be understood as a virtual equivalent channel, or a hypothetical equivalent channel, etc.

[0013] Since the network device can determine the precoding matrix used to precode the downlink data based on the precoding matrix fed back by the terminal device, the precoding matrix used by the network device to precode the downlink data can be the same as or similar to the precoding matrix fed back by the terminal device. Therefore, the equivalent channel guessed by the terminal device based on the above assumption can be the same as or similar to the real equivalent channel after precoding in the subsequent downlink data transmission process.

[0014] In combination with the first aspect, in some implementations of the first aspect, the channel information of the first subband includes R×2J channel estimation values, and a value c among the R×2J channel estimation values ​​is r，j It is the channel estimation value corresponding to the first subband obtained by measuring the precoded reference signal of the jth reference signal port on the rth receiving antenna port; wherein 2J represents the number of reference signal ports, R represents the number of receiving antenna ports, J≥1, R≥1, 0≤j≤2J-1, 0≤r≤R-1, and J, R, j, r are all integers.

[0015] The R×2J channel estimation values ​​correspond to R receiving antenna ports and 2J reference signal ports. Each of the channel estimation values ​​may be a value measured by a terminal device on a first subband based on a precoded reference signal of a certain reference signal port received on a receiving antenna port. The R×2J channel estimation values ​​may be used to construct a channel matrix, such as constructing an R×2J-dimensional channel matrix.

[0016] In combination with the first aspect, in some implementations of the first aspect, the broadband precoding information is determined by R×2J values, and the value α in the R×2J values ​​is r，j is the sum of channel estimation values ​​corresponding to the multiple subbands determined on the rth receiving antenna port based on the precoding reference signal of the jth reference signal port.

[0017] That is, each of the R×2J values ​​can be obtained by accumulating and summing the channel estimation values ​​corresponding to one receiving antenna port and one reference signal port and multiple subbands. Since there is a conjugate relationship between the channel and the precoding, in the embodiment of the present application, the terminal device can determine the precoding matrix based on the above relationship by the matrix constructed by the R×2J values.

[0018] In combination with the first aspect, in some implementations of the first aspect, the equivalent channel H of the first sub-band eff Satisfaction: H eff =CP; C represents the channel of the first subband determined based on channel measurement, and P represents the wideband precoding matrix determined based on channel measurement.

[0019] Here, C can specifically be the channel matrix of the first subband determined based on channel measurement. The elements in the channel matrix can be the above-mentioned R×2J channel estimation values. However, it should be understood that the representation of the channel is not limited to a matrix, for example, it can also be represented by a vector, an ordered array, etc. This application does not limit this. The calculation formula for the equivalent channel shown above is only an example shown for ease of understanding.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: correcting the power of the equivalent channel of the first subband based on port power difference information, wherein the port power difference information is used to indicate the difference in transmission power of each reference signal port relative to the data port.

[0021] The port power difference information may be indicated, for example, by the multiplexing degree of the reference signal port or the energy per resource element (EPRE), etc. Each reference signal port may correspond to a multiplexing degree or an EPRE, and the multiplexing degree or EPRE corresponding to each reference signal port may be used to determine the difference in the transmit power of the reference signal port relative to the transmit power of the data port.

[0022] In order to save pilot overhead, in some cases, the network equipment may reuse some reference signal ports, for example, reuse one or more reference signal ports to correspond to multiple terminal devices. Due to the reference signal port multiplexing, the transmit power of the multiplexed reference signal port measured by the terminal device may be reduced, and may not be equal to the transmit power of other non-multiplexed reference signal ports. However, during data transmission, there is no reference signal port multiplexing. When determining the power of the equivalent channel, the terminal device needs to assume that the power of each reference signal port is equal. Therefore, the terminal device can correct the multiplexed reference signal port based on the port power difference information to make the transmit power of each reference signal port equal. The CQI determined in this way is more accurate, which can facilitate the network device to make reasonable decisions for downlink data transmission, thereby helping to improve downlink transmission performance.

[0023] In combination with the first aspect, in certain implementations of the first aspect, the port power information is used to determine a correction coefficient corresponding to each reference signal port, and the correction coefficient of each reference signal port is used to correct the transmit power of the corresponding reference signal port.

[0024] That is, the terminal device can correct the transmit power of the reference signal measured by the terminal device based on the correction coefficient of each reference signal port, thereby making the transmit power of each reference signal port equal.

[0025] In combination with the first aspect, in certain implementations of the first aspect, each precoded reference signal is obtained by precoding a reference signal based on an angle vector and a delay vector.

[0026] The network device can precode the reference signal based on the angle vector and the delay vector, that is, precode it in the spatial domain and the frequency domain respectively. Therefore, each reference signal port can correspond to an angle vector and a delay vector. Each precoded reference signal can be obtained by precoding the reference signal based on an angle vector and a delay vector. However, it should be understood that whether the reference signal is precoded based on the angle vector does not affect the use of the channel measurement method provided in this application. As long as the network device precodes the reference signal based on the delay vector, the terminal device can obtain a more accurate sub-band CQI according to the above method.

[0027] In a second aspect, a communication device is provided, which may be a terminal device or a component in a terminal device. The communication device may include various modules or units for executing the method in the first aspect and any possible implementation manner of the first aspect.

[0028] In a third aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and can be used to execute instructions in the memory to implement the method in the first aspect and any possible implementation of the first aspect. Optionally, the communication device also includes a memory. Optionally, the communication device also includes a communication interface, and the processor is coupled to the communication interface.

[0029] In one implementation, the communication device is a receiving device. When the communication device is a terminal device, the communication interface may be a transceiver, or an input / output interface. In addition, the communication device may be configured with one or more receiving antenna ports.

[0030] Optionally, the transceiver may be a transceiver circuit.

[0031] Optionally, the input / output interface may be an input / output circuit.

[0032] In another implementation, the communication device is a chip configured in a sub-band device. When the communication device is a chip configured in a terminal device, the communication interface may be an input / output interface. In addition, the terminal device configured with the communication device may be configured with one or more receiving antenna ports.

[0033] Optionally, the input / output interface may be an input / output circuit.

[0034] In a fourth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is used to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method in the first aspect and any possible implementation of the first aspect.

[0035] In the specific implementation process, the processor can be one or more chips, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, a gate circuit, a trigger, and various logic circuits. The input signal received by the input circuit can be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit can be the same circuit, which is used as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation methods of the processor and various circuits.

[0036] In a fifth aspect, a processing device is provided, comprising a processor and a memory. The processor is used to read instructions stored in the memory, and can receive signals through a receiver and transmit signals through a transmitter to execute the method in the first aspect and any possible implementation of the first aspect.

[0037] Optionally, the number of the processors is one or more, and the number of the memories is one or more.

[0038] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0039] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips respectively. The embodiments of the present application do not limit the type of memory and the setting method of the memory and the processor.

[0040] It should be understood that the related data interaction process, such as sending indication information, can be a process of outputting indication information from the processor, and receiving reference channel state information and port difference information can be a process of inputting reference channel state information and port difference information to the processor. Specifically, the data output by the processor can be output to the transmitter, and the input data received by the processor can come from the receiver. Among them, the transmitter and the receiver can be collectively referred to as a transceiver.

[0041] The processing device in the fifth aspect may be one or more chips. The processor in the processing device may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor may be one or more general-purpose processors, which are implemented by reading software codes stored in a memory, and the memory may be integrated in the processor or located outside the processor and exist independently.

[0042] In a sixth aspect, a computer program product is provided, comprising: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute the method in the above-mentioned first aspect and any possible implementation manner of the first aspect.

[0043] In the seventh aspect, a computer-readable storage medium is provided, in which a computer program (also referred to as code, or instruction) is stored. When the computer-readable storage medium is run on a computer, the computer executes the method in the above-mentioned first aspect and any possible implementation manner of the first aspect.

[0044] In an eighth aspect, a communication system is provided, comprising the aforementioned receiving device and sending device. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic diagram of a communication system applicable to a channel measurement method according to an embodiment of the present application;

[0046] Figure 2 is a schematic diagram of precoding a reference signal based on a delay vector provided in an embodiment of the present application;

[0047] Figure 3 is a schematic flow chart of a channel measurement method provided in an embodiment of the present application;

[0048] Figure 4 It is a schematic diagram of multiple ports being multiplexed provided in an embodiment of the present application;

[0049] Figure 5 is a schematic block diagram of a communication device provided in an embodiment of the present application;

[0050] Figure 6 is another schematic block diagram of a communication device provided in an embodiment of the present application;

[0051] Figure 7 It is a schematic structural diagram of the terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0053] The technical solution provided in this application can be applied to various communication systems, such as: 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, future fifth generation (5G) mobile communication system or new radio access technology (NR). Among them, the 5G mobile communication system can include non-standalone (NSA) and / or standalone (SA).

[0054] The technical solution provided in the present application can also be applied to machine type communication (MTC), long term evolution technology for machine-to-machine communication (LTE-M), device-to-device (D2D) network, machine-to-machine (M2M) network, Internet of Things (IoT) network or other networks. Among them, the IoT network can include, for example, the Internet of Vehicles. Among them, the communication methods in the Internet of Vehicles system are collectively referred to as vehicle to other devices (vehicle to X, V2X, X can represent anything), for example, the V2X can include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication or vehicle to network (V2N) communication, etc.

[0055] The technical solution provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, etc. This application does not limit this.

[0056] In the embodiment of the present application, the network device may be any device with wireless transceiver function. The device includes but is not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or homeNode B, HNB), baseband unit (BBU), access point (AP) in wireless fidelity (WiFi) system, wireless relay node, wireless backhaul node, transmission point (TP) or transmission and reception point (TRP), etc., and can also be a gNB in ​​5G, such as NR, system, or a transmission point (TRP or TP), one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a distributed unit (DU), etc.

[0057] In some deployments, the gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB, for example, the CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer. The AAU implements some physical layer processing functions, radio frequency processing, and related functions of active antennas. Since the information of the RRC layer will eventually become the information of the PHY layer, or be converted from the information of the PHY layer, therefore, under this architecture, high-level signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or, sent by the DU+AAU. It can be understood that the network device can be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU may be classified as a network device in an access network (radio access network, RAN), or the CU may be classified as a network device in a core network (core network, CN), which is not limited in the present application.

[0058] The network equipment provides services for the cell, and the terminal equipment communicates with the cell through the transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the network equipment. The cell can belong to a macro base station (for example, macro eNB or macro gNB, etc.), or it can belong to a base station corresponding to a small cell. The small cell here may include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0059] In an embodiment of the present application, the terminal device may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device.

[0060] The terminal device can be a device that provides voice / data connectivity to users, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals can be: mobile phones, tablet computers (pad), computers with wireless transceiver functions (such as laptops, PDAs, etc.), mobile Internet devices (mobile internet devices, MIDs), virtual reality (virtual reality, VR) devices, augmented reality (augmented reality, AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (session initiation protocol, SIP) phones, wireless local loop (wireless local loop, WLL) stations, personal digital assistants (personal digital assistants) assistant, PDA), handheld devices with wireless communication function, computing devices or other processing devices connected to a wireless modem, vehicle-mounted devices, wearable devices, terminal devices in 5G networks or terminal devices in future evolved public land mobile communication networks (public land mobile network, PLMN), etc.

[0061] Among them, wearable devices can also be called wearable smart devices, which are a general term for the intelligent design and development of wearable devices for daily wear using wearable technology, such as glasses, gloves, watches, clothing and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also realize powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include full-featured, large-sized, and independent of smartphones to achieve complete or partial functions, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0062] In addition, the terminal device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection. IoT technology can achieve massive connections, deep coverage, and terminal power saving through narrowband (NB) technology, for example.

[0063] In addition, terminal devices can also include sensors such as smart printers, train detectors, and gas stations. Their main functions include collecting data (part of the terminal equipment), receiving control information and downlink data from network devices, and sending electromagnetic waves to transmit uplink data to network devices.

[0064] To facilitate understanding of the embodiments of the present application, first Figure 1 A communication system applicable to the channel measurement method provided in an embodiment of the present application is described in detail. Figure 1 FIG. 1 is a schematic diagram of a communication system 100 applicable to the method provided in an embodiment of the present application. As shown in the figure, the communication system 100 may include at least one network device, such as Figure 1 The network device 101 in the 5G system shown in FIG. 1 ; the communication system 100 may also include at least one terminal device, such as Figure 1 The terminal devices 102 to 107 shown in the figure. The terminal devices 102 to 107 can be mobile or fixed. The network device 101 and one or more of the terminal devices 102 to 107 can communicate via wireless links. Each network device can provide communication coverage for a specific geographical area and can communicate with terminal devices located in the coverage area. For example, the network device can send configuration information to the terminal device, and the terminal device can send uplink data to the network device based on the configuration information; for another example, the network device can send downlink data to the terminal device. Therefore, Figure 1 The network device 101 and terminal devices 102 to 107 constitute a communication system.

[0065] Optionally, the terminal devices may communicate directly with each other. For example, direct communication between the terminal devices may be achieved using D2D technology. As shown in the figure, the terminal devices 105 and 106, and the terminal devices 105 and 107 may communicate directly using D2D technology. The terminal devices 106 and 107 may communicate with the terminal device 105 individually or simultaneously.

[0066] Terminal devices 105 to 107 may also communicate with network device 101 respectively. For example, they may communicate directly with network device 101, such as terminal devices 105 and 106 in the figure may communicate directly with network device 101; or they may communicate indirectly with network device 101, such as terminal device 107 in the figure communicates with network device 101 via terminal device 106.

[0067] It should be understood that Figure 1 A network device and multiple terminal devices, as well as communication links between the communication devices are exemplarily shown. Optionally, the communication system 100 may include multiple network devices, and each network device may include other number of terminal devices within its coverage, such as more or fewer terminal devices. This application does not limit this.

[0068] The above-mentioned communication equipment, such as Figure 1 The network device 101 and the terminal devices 102 to 107 in the embodiment may be configured with multiple antennas. The multiple antennas may include at least one transmitting antenna for sending signals and at least one receiving antenna for receiving signals. In addition, each communication device also additionally includes a transmitter chain and a receiver chain. It can be understood by those skilled in the art that they may include multiple components related to signal transmission and reception (such as processors, modulators, multiplexers, demodulators, demultiplexers or antennas, etc.). Therefore, the network device and the terminal device may communicate via multi-antenna technology.

[0069] Optionally, the wireless communication system 100 may also include other network entities such as a network controller and a mobility management entity, but the embodiments of the present application are not limited thereto.

[0070] In order to better understand the embodiments of the present application, the following points are first explained.

[0071] First, for ease of understanding, here is a brief introduction to the meanings of the several letters involved below.

[0072] N: The number of frequency domain units, N is a positive integer.

[0073] N s : Number of subbands, N s is a positive integer. In one possible design, the frequency domain unit is a subband. In this case, N=N s It should be understood that the frequency domain unit being a subband is only a possible design and should not constitute any limitation to the present application.

[0074] n: represents the nth subband, 0≤n≤N s -1, n is an integer.

[0075] R: number of receiving antenna ports, R is a positive integer.

[0076] r: represents the rth receiving antenna port, 0≤r≤R-1, and r is an integer.

[0077] T: the number of transmit antenna ports in one polarization direction, T is a positive integer. If the network device is configured with dual-polarization transmit antennas, that is, the number of polarization directions of the transmit antenna is 2, then the number of transmit antenna ports in the two polarization directions is 2T.

[0078] K: The number of angle vectors, K is a positive integer.

[0079] L: the number of delay vectors, L is a positive integer.

[0080] J: the number of angle delay pairs determined by K angle vectors and L delay vectors, or the number of combinations of angle vectors and delay vectors determined by K angle vectors and L delay vectors, J is a positive integer. Since the precoded reference signal of each reference signal port is obtained by precoding the reference signal based on an angle vector and a delay vector, each reference signal port can correspond to a combination of an angle vector and a delay vector. Therefore, the number of reference signal ports can be J (corresponding to a single-polarized transmit antenna) or 2J (corresponding to a dual-polarized transmit antenna).

[0081] j: represents the j-th reference signal port, 0≤j≤J-1, or 0≤j≤2J-1, where j is an integer.

[0082] C: The channel measured based on the received reference signal, which can be used to represent channel information. In the embodiment of the present application, for the convenience of distinction, the channel corresponding to the nth subband is recorded as C n , C n Can be used to represent the channel information of the nth subband. Where 0≤n≤N s -1, n is an integer. In the embodiment of the present application, the channel C may be a real channel or a precoded channel, that is, a precoded channel.

[0083] It should be understood that in this application, for the sake of distinction and explanation, different names are defined for real channels and precoded channels. However, this should not constitute any limitation to this application. Both real channels and precoded channels can be called channels, and this application does not limit this.

[0084] c r，j，n : The channel estimation value corresponding to the j-th reference signal port, the r-th receive antenna port, and the n-th subband.

[0085] α r，j : With the jth reference signal port, the rth receiving antenna port, N s The sum of the channel estimation values ​​corresponding to the subbands. That is, α r，jCan satisfy

[0086] a(θ k ): The kth angle vector among K angle vectors, 0≤k≤K-1, k is an integer.

[0087] b(τ l ): the lth delay vector among the L delay vectors, 0≤l≤L-1, l is an integer.

[0088] V: The real downlink channel, which can be represented as a matrix with the dimension of the number of receiving antenna ports × the number of transmitting antenna ports. For example, V can be a matrix with the dimension of R×T (corresponding to a single-polarized transmitting antenna) or a matrix of R×2T (corresponding to a dual-polarized transmitting antenna). In the embodiment of the present application, for the convenience of distinction, the real channel corresponding to the nth subband is recorded as V n .

[0089] P: precoding matrix determined based on channel measurement.

[0090] H: A space-frequency matrix determined based on one receive antenna port, or in other words, a space-frequency matrix corresponding to one receive antenna port. H can be represented as a matrix with the dimension of the number of frequency domain elements × the number of transmit antenna ports. For example, H can be a matrix with the dimension of N×T (corresponding to a single-polarized transmit antenna) or N×2T (corresponding to a dual-polarized transmit antenna).

[0091] p j : Power correction value corresponding to the jth reference signal port, p j >0.

[0092] Second, in the embodiments of the present application, for the convenience of description, when numbering is involved, the numbers can be numbered consecutively starting from 0. For example, N s The subbands may include the 0th subband to the Nth subband. s -1 subband, the K angle vectors may include the 0th angle vector to the K-1th angle vector, the L delay vectors may include the 0th delay vector to the L-1th delay vector, etc. Of course, the specific implementation is not limited to this. For example, the numbering may also start from 1. For example, N s The subbands may include the 1st to the Nth subbands. s subbands, the K angle vectors may include the 1st angle vector to the Kth angle vector, the L delay vectors may include the 1st delay vector to the Lth delay vector, etc. For the sake of brevity, they are not listed here one by one.

[0093] It should be understood that the above descriptions are all arrangements made to facilitate the description of the technical solutions provided in the embodiments of the present application, and are not intended to limit the scope of the present application.

[0094] Third, in this application, there are many places involving matrix and vector transformations. For ease of understanding, a unified explanation is given here. The superscript T represents transposition, such as A T Represents the transpose of the matrix (or vector) A; the superscript H represents the conjugate transpose, such as A H Represents the conjugate transpose of the matrix (or vector) A. The superscript * indicates conjugation, such as A * represents the conjugate of the matrix (or vector) A. In addition, the superscript * can also be used to represent the conjugate of a complex number. In the following text, for the sake of brevity, the description of the same or similar cases is omitted.

[0095] Fourth, in the embodiments shown below, the embodiments provided by the present application are described by taking the angle vector and the delay vector as column vectors as an example, but this shall not constitute any limitation to the present application. Based on the same concept, those skilled in the art can also think of other possible expressions.

[0096] Fifth, in this application, "used for indication" may include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used for indicating A, it may include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must carry A.

[0097] The information indicated by the indication information is called the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as but not limited to, the information to be indicated can be directly indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, wherein there is an association between the other information and the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, the indication of specific information can also be achieved with the help of the arrangement order of each information agreed in advance (such as protocol regulations), thereby reducing the indication overhead to a certain extent. At the same time, the common parts of each information can also be identified and uniformly indicated to reduce the indication overhead caused by indicating the same information separately. For example, those skilled in the art should understand that the precoding matrix is ​​composed of precoding vectors, and each precoding vector in the precoding matrix may have the same parts in terms of composition or other attributes.

[0098] In addition, the specific indication method may also be various existing indication methods, such as but not limited to the above-mentioned indication methods and various combinations thereof. The specific details of the various indication methods can refer to the prior art and will not be repeated herein. As can be seen from the above, for example, when it is necessary to indicate multiple information of the same type, different indication methods may be used for different information. In the specific implementation process, the desired indication method can be selected according to specific needs. The embodiment of the present application does not limit the selected indication method. In this way, the indication method involved in the embodiment of the present application should be understood to cover various methods that can enable the party to be indicated to obtain the information to be indicated.

[0099] In addition, the information to be indicated may exist in other equivalent forms, for example, a row vector can be expressed as a column vector, a matrix can be expressed by the transposed matrix of the matrix, a matrix can also be expressed in the form of a vector or an array, and the vector or array can be formed by connecting the row vectors or column vectors of the matrix, etc. The technical solutions provided in the embodiments of the present application should be understood to cover various forms. For example, some or all of the features involved in the embodiments of the present application should be understood to cover various forms of expression of the features.

[0100] The information to be indicated can be sent as a whole, or divided into multiple sub-information and sent separately, and the sending period and / or sending time of these sub-information can be the same or different. The specific sending method is not limited in this application. Among them, the sending period and / or sending time of these sub-information can be pre-defined, for example, pre-defined according to the protocol, or configured by the transmitting device by sending configuration information to the receiving device. Among them, the configuration information can include, for example but not limited to, one or a combination of at least two of radio resource control signaling, medium access control (MAC) layer signaling and physical layer signaling. Among them, radio resource control signaling, for example, radio resource control (RRC) signaling; MAC layer signaling, for example, includes MAC control element (CE); physical layer signaling, for example, includes downlink control information (DCI).

[0101] Sixth, the definitions of many characteristics (such as channel quality indicator (CQI), SINR, channel, subband, angle and delay, etc.) listed in this application are only used to explain the functions of the characteristics by way of example, and the details thereof can be referred to the prior art.

[0102] Seventh, the first, second and various digital numbers in the embodiments shown below are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application. For example, to distinguish different indication information.

[0103] Eighth, "pre-definition" or "pre-configuration" can be implemented by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in a device (for example, including a terminal device and a network device), and the present application does not limit its specific implementation method. Among them, "saving" can mean saving in one or more memories. The one or more memories can be set separately or integrated in an encoder or decoder, a processor, or a communication device. The one or more memories can also be partially set separately and partially integrated in a decoder, a processor, or a communication device. The type of memory can be any form of storage medium, which is not limited by the present application.

[0104] Ninth, the "protocol" involved in the embodiments of the present application may refer to a standard protocol in the communication field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0105] Tenth, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c. Where a, b and c can be single or multiple, respectively.

[0106] Eleventh, in the embodiments of the present application, descriptions such as "when...", "in the case of...", "if" and "if" all mean that under certain objective circumstances, the device (such as a terminal device or a network device) will make corresponding processing, which does not limit the time, and does not require the device (such as a terminal device or a network device) to have a judgment action when implementing it, nor does it mean that there are other limitations.

[0107] Twelfth, in the embodiments of the present application, antenna ports (referred to as ports) are mentioned in many places. Antenna ports may include transmitting antenna ports (or transmitting antenna ports) and receiving antenna ports. To avoid ambiguity, the following explanation is made: a transmitting antenna port may refer to an antenna port for transmitting a reference signal (such as a precoding reference signal, etc.). Therefore, a transmitting antenna port may also be referred to as a reference signal port. A receiving antenna port may refer to an antenna port for receiving a reference signal.

[0108] In an embodiment of the present application, the transmitting antenna port may be a port on the network device side, and the receiving antenna port may be a port on the terminal device side.

[0109] Thirteenth, for ease of understanding, the following embodiments take the interaction process between a network device and a terminal device as an example to illustrate the channel measurement method provided in the embodiment of the present application for measuring a downlink channel. However, it should be understood that this should not constitute any limitation to the present application. The channel measurement method provided in the present application can also be used to measure an uplink channel. In this case, for example, a reference signal can be sent by a terminal device, and a channel measurement can be performed by a network device based on the received reference signal to determine a precoding matrix, and then determine a CQI.

[0110] To facilitate understanding of the embodiments of the present application, several terms involved in the embodiments of the present application are briefly introduced below.

[0111] 1. CQI: used to indicate the quality of the channel. CQI mainly corresponds to the signal-to-noise ratio of the channel, for example, to the signal to interference plus noise ratio (SINR). Taking the measurement of the downlink channel as an example, the CQI selection criteria can be defined in the protocol, and the terminal device can report the corresponding CQI value to the network device based on the SINR measurement result. The network device can select the MCS suitable for the downlink channel based on the reported CQI value.

[0112] 2. SINR: It can be referred to as signal-to-interference-and-noise ratio. SINR refers to the ratio of the strength of the received useful signal to the strength of the received interference signal (noise and interference).

[0113] In one implementation, the SINR may satisfy the following formula: Where C represents the channel obtained based on channel measurement; P represents the precoding matrix determined based on channel measurement; CP can be called an equivalent channel; I represents interference (inference); N represents noise (noise). |||| represents the norm, |||| 2 It represents the square of the norm and can be used to calculate the power of the equivalent channel CP.

[0114] In the embodiment of the present application, since the CQI of the subband needs to be determined, the above C is used to represent the channel of the subband obtained based on the channel measurement. For example, the channel of the nth subband is recorded as C n ; P is used to represent the broadband precoding matrix obtained based on channel measurement; CP represents the equivalent channel of the subband.

[0115] Since the channel C, precoding matrix P and equivalent channel CP involved in the formula will be described in detail below, they are not described in detail here.

[0116] 3. Channel reciprocity: In some communication modes, such as TDD, uplink and downlink channels transmit signals on the same frequency domain resources but different time domain resources. Within a relatively short time (such as the coherence time of channel propagation), it can be considered that the channel fading experienced by the signals on the uplink and downlink channels is the same. This is the reciprocity of the uplink and downlink channels. Based on the reciprocity of the uplink and downlink channels, network equipment can measure the uplink channel based on the uplink reference signal, such as the sounding reference signal (SRS). And the downlink channel can be estimated based on the uplink channel, so as to determine the CQI of the downlink channel, the precoding matrix adapted to the downlink channel, etc.

[0117] However, in other communication modes, such as FDD, since the frequency band interval of the uplink and downlink channels is much larger than the coherence bandwidth, the uplink and downlink channels do not have complete reciprocity, and the precoding matrix used to determine the downlink transmission using the uplink channel may not be able to adapt to the downlink channel. However, the uplink and downlink channels in the FDD mode still have partial reciprocity, for example, the reciprocity of angles and the reciprocity of delays. Therefore, angles and delays can also be called reciprocity parameters.

[0118] When a signal is transmitted through a wireless channel, it can reach the receiving antenna through multiple paths from the transmitting antenna. Multipath delay causes frequency selective fading, which is the change of the frequency domain channel. Delay is the transmission time of a wireless signal on different transmission paths, which is determined by distance and speed and has nothing to do with the frequency domain of the wireless signal. When a signal is transmitted on different transmission paths, there are different transmission delays due to different distances. Since the physical position between the network device and the terminal device is fixed, the multipath distribution of the uplink and downlink channels is the same in terms of delay. Therefore, the delay in the uplink and downlink channels in FDD mode can be considered to be the same, or reciprocal.

[0119] In addition, the angle may refer to the angle of arrival (angle of arrival, AOA) of the signal arriving at the receiving antenna via the wireless channel, or the angle of departure (angle of departure, AOD) of the signal transmitted by the transmitting antenna. In an embodiment of the present application, the angle may refer to the angle of arrival of the uplink signal arriving at the network device, or the angle of departure of the downlink signal transmitted by the network device. Due to the reciprocity of the transmission paths of the uplink and downlink channels at different frequencies, the angle of arrival of the uplink reference signal and the angle of departure of the downlink reference signal can be considered to be reciprocal.

[0120] In the embodiment of the present application, each angle can be represented by an angle vector. Each delay can be represented by a delay vector. Therefore, in the embodiment of the present application, an angle vector can represent an angle, and a delay vector can represent a delay.

[0121] 4. Angle vector: It can also be called spatial vector, beam vector, etc. Angle vector can be understood as a precoding vector used to beamform the reference signal. Through beamforming, the reference signal transmitted by the transmitting device (such as a network device) can have a certain spatial directivity. Therefore, the process of precoding the reference signal based on the angle vector can also be regarded as the process of spatial domain (or simply, spatial domain) precoding.

[0122] If the actual downlink channel is denoted as V, V can be expressed as a matrix of dimension R×T or R×2T. Where R is the number of receiving antenna ports, T is the number of transmitting antenna ports in one polarization direction, and 2T is the number of transmitting antenna ports in two polarization directions; R and T are both positive integers. In downlink transmission, since the reference signal loaded with the angle vector can be transmitted to the terminal device through the downlink channel, the channel measured by the terminal device based on the received precoding reference signal is equivalent to the channel loaded with the angle vector. For example, the angle vector a(θ k ) is loaded into the downlink channel V, which can be expressed as Va(θ k ).

[0123] The number of ports of the precoded reference signal obtained after precoding the reference signal based on one or more angle vectors can be the same as the number of angle vectors. Therefore, if the reference signal corresponding to the transmitting antenna port in each polarization direction is precoded based on K angle vectors, the total number of ports of the precoded reference signal can be 2K, where 2 corresponds to the two polarization directions. The channel measured in this way is a precoded channel and can be expressed as a matrix of dimension R×2K, where K is a positive integer. It can be understood that if the number of angle vectors K is less than the number of transmitting antenna ports T in each polarization direction, the dimensionality reduction of the antenna port can be achieved through spatial domain precoding, thereby reducing the pilot overhead.

[0124] In the embodiment of the present application, the angle vector may be a vector with a length of T.

[0125] Optionally, the angle vector is a discrete Fourier transform (DFT) vector. The DFT vector may refer to a vector in a DFT matrix.

[0126] Optionally, the angle vector is a conjugate transposed vector of the DFT vector. The DFT conjugate transposed vector may refer to a column vector in a conjugate transposed matrix of the DFT matrix.

[0127] Optionally, the angle vector is an oversampled DFT vector.The oversampled DFT vector may refer to a vector in an oversampled DFT matrix.

[0128] In one possible design, the angle vector may be, for example, a two-dimensional (2D)-DFT vector v defined in a type II codebook in NR protocol TS 38.214 version 15 (release 15, R15). l，m In other words, the angle vector can be a 2D-DFT vector or an oversampled 2D-DFT vector.

[0129] It should be understood that the angle vector is a form of representing angles proposed in this application. The angle vector is named only for the convenience of distinguishing it from the delay vector and should not constitute any limitation to this application. This application does not exclude the possibility of defining other names in future protocols to represent the same or similar meanings.

[0130] 5. Delay vector: It can also be called frequency domain vector. The delay vector can be used to represent the change law of the channel in the frequency domain. As mentioned above, multipath delay leads to frequency selective fading. From the Fourier transform, it can be seen that the time delay of the signal in the time domain can be equivalent to the phase gradient in the frequency domain.

[0131] Since the phase change of the channel in each frequency domain unit is related to the delay, the change law of the phase of the channel in each frequency domain unit can be represented by the delay vector. In other words, the delay vector can be used to represent the delay characteristics of the channel.

[0132] Precoding the reference signal based on the delay vector may essentially refer to performing phase rotation on each frequency domain unit in the frequency domain based on the elements in the delay vector, so as to pre-compensate the frequency selective characteristics caused by the multipath delay by precoding the reference signal. Therefore, the process of precoding the reference signal based on the delay vector may be regarded as the process of frequency domain precoding.

[0133] Precoding the reference signal based on different delay vectors is equivalent to performing phase rotation on each subband of the channel based on different delay vectors. Moreover, the phase rotation angles of the reference signals corresponding to different ports on the same subband can be different. In order to distinguish different delays, the network device can precode the reference signal based on each delay vector in the L delay vectors.

[0134] Optionally, the length of the delay vector is N. As mentioned above, N may refer to the number of frequency domain units in the bandwidth of the reference signal resource. Here, the bandwidth of the reference signal resource may be understood as the frequency bandwidth occupied by the reference signal resource in the frequency domain.

[0135] For example, the lth delay vector b(τ l ) can be expressed as: Where, l = 0, 1, ..., L-1; L can represent the number of delay vectors; f0, f1, ..., f N-1 Respectively represent the carrier frequencies of the 0th, 1st to N-1th frequency domain units.

[0136] It should be understood that the above examples of specific forms of the delay vector are only examples and should not constitute any limitation to the present application. For example, the delay vector can also be taken from the DFT matrix. The present application does not limit the specific form of the delay vector.

[0137] For the convenience of explanation, the delay vector is denoted as b(τ l ). Each element in the delay vector may correspond to a delay. A delay vector of length N includes elements corresponding to N delays.

[0138] In an embodiment of the present application, if the delay vector is loaded onto a channel, the N elements in the delay vector may be loaded onto N frequency domain units, that is, each element is loaded onto a frequency domain unit. A frequency domain unit may be, for example, a subband, a resource block (RB), a resource block group (RBG), a precoding resource block group (PRG), etc. This application does not limit this.

[0139] Optionally, each frequency domain unit is an RB. Each element in the delay vector can be loaded on an RB. In this case, the length N of the delay vector can be equal to the number of RBs in the broadband. For a delay vector, each element thereof corresponds to an RB.

[0140] Optionally, each frequency domain unit is a subband. Each element in the delay vector can be loaded on a subband. In this case, the length N of the delay vector can be equal to the number of subbands in the broadband. For a delay vector, each element thereof corresponds to a subband.

[0141] It should be understood that the above is only for ease of understanding, taking a delay vector as an example to illustrate the correspondence between the elements in the delay vector and the frequency domain units. However, this should not constitute any limitation to this application. The network device can load one or more delay vectors onto the channel, and each RB can, for example, contain one or more resource elements (RE) that can be used to carry reference signals.

[0142] In downlink transmission, since the reference signal loaded with the delay vector can be transmitted to the terminal device through the downlink channel, the channel measured by the terminal device based on the received precoded reference signal is equivalent to the channel loaded with the delay vector. Taking the frequency domain unit as RB as an example, if the reference signal is frequency-domain precoded based on a delay vector of length N, the N elements in the delay vector can be loaded onto the reference signal carried by N RBs, that is, the N elements in the delay vector are loaded onto N RBs. Load the nth element in the delay vector onto the channel V on the nth RB n For example, it can be expressed as

[0143] It should be understood that precoding the reference signal based on the delay vector is similar to the processing method of spatial precoding, except that the spatial vector (or angle vector) is replaced by a delay vector.

[0144] It should be noted that the frequency domain precoding of the reference signal based on the delay vector can be performed before resource mapping or after resource mapping, and this application does not limit this.

[0145] For ease of understanding, the following Figure 2 Detailed description based on the delay vector b(τ l ) is the process of precoding a reference signal.

[0146] Figure 2An example of frequency domain precoding of a reference signal carried on N RBs based on a delay vector b(τ1) is shown. The N RBs may include RB#0, RB#1 to RB#N-1. Each of the N RBs may include one or more REs for carrying the reference signal. For example, the RE used to carry the reference signal may be the RE on the first time domain symbol and the first subcarrier in each RB. As shown in the shaded squares in the figure. In this case, the time domain vector b(τ1) may be loaded on the RE on the first time domain symbol and the first subcarrier in each RB. The reference signal carried on the RE on the first time domain symbol and the first subcarrier in each RB of the N RBs may correspond to the same reference signal port.

[0147] Assuming the delay vector If the delay vector b(τ1) is loaded onto N RBs, the corresponding phase rotation can be performed on the N RBs. The N elements in the delay vector can correspond to the N RBs one by one. For example, the elements in the frequency domain vector b(τ1) are can be loaded on RB#0, the element in the frequency domain vector b(τ1) Can be loaded on RB#1, the elements in the delay vector b(τ1) can be loaded on RB#N-1. Similarly, the nth element in the delay vector b(τ1) Can be loaded on RB#n. For the sake of brevity, they are not listed here one by one.

[0148] It should be understood that Figure 2 This is just an example, showing an example of loading the delay vector b(τ1) into N RBs, but this shall not constitute any limitation to the present application. Figure 2 The N RBs used to carry reference signals may be continuous N RBs or discontinuous N RBs, which is not limited in this application. Although not shown in the figure, it can be understood that Figure 2 RB#0 to RB#N-1 in the RB may respectively include one or more REs that can be used to carry reference signals.

[0149] It should also be understood that the delay vector is a form of representing the delay proposed by the present application. The delay vector is named only for the convenience of distinguishing it from the angle vector and should not constitute any limitation to the present application. The present application does not exclude the possibility of defining other names in future protocols to represent the same or similar meanings.

[0150] 6. Precoded reference signal: may refer to a reference signal obtained after precoding a reference signal. Precoding may specifically include beamforming and / or phase rotation. Beamforming may be achieved, for example, by precoding a downlink reference signal based on one or more angle vectors, that is, by spatial domain precoding. Phase rotation may be achieved, for example, by precoding a downlink reference signal by using one or more delay vectors, that is, by frequency domain precoding.

[0151] In an embodiment of the present application, precoding a downlink reference signal based on one or more angle vectors may also be referred to as loading one or more angle vectors onto a downlink reference signal to achieve beamforming. Precoding a downlink reference signal based on one or more delay vectors may also be referred to as loading one or more delay vectors onto a downlink reference signal to achieve phase rotation.

[0152] The precoded reference signals involved in the embodiments of the present application may specifically include reference signals that have been precoded in the frequency domain, and reference signals that have been precoded in the spatial domain and in the frequency domain. In other words, reference signals loaded with a delay vector, and reference signals loaded with an angle vector and a delay vector.

[0153] In the embodiment of the present application, based on an angle vector a(θ k ) and a time delay vector b(τ l ) is used to precode the reference signal, the precoding matrix used to precode the reference signal can be expressed as the product of the conjugate transpose of an angle vector and a delay vector, for example, it can be expressed as a(θ k )×b(τ l ) H , whose dimension may be T×N. Alternatively, the precoding matrix used to precode the reference signal may also be expressed as a Kronecker product of an angle vector and a delay vector, for example, as Its dimension may be T×N.

[0154] It should be understood that the various mathematical expressions listed above for an angle delay pair are only examples and should not constitute any limitation to the present application. For example, the precoding matrix used to precode the reference signal can also be expressed as the product of a delay vector and a conjugate transpose of an angle vector, or the Kronecker product of a delay vector and an angle vector, and its dimension can be N×T. Alternatively, the precoding matrix used to precode the reference signal can also be expressed as a mathematical transformation of the above various expressions. For the sake of brevity, they are not listed here one by one.

[0155] 7. Channel: A channel is a path for data transmission. The channel in the embodiments of the present application may specifically refer to a physical channel, which may be composed of a transmission medium and a communication device.

[0156] Channel information may refer to information used to characterize a channel. For example, in an embodiment of the present application, a channel may be represented in the form of a matrix. In other words, a channel matrix is ​​a form of channel information. Of course, the method used to characterize a channel is not limited to a matrix. In the present application, the channel is shown in the form of a matrix only for ease of understanding and explanation. The present application does not limit the specific form of the channel information.

[0157] The channel can be represented by a matrix. As mentioned above, the channel can be represented as a matrix of dimension R×T or a matrix of dimension R×2T.

[0158] In one possible implementation, the network device may send a reference signal to obtain a channel measurement result. The terminal device may perform channel measurement based on the received reference signal to estimate the downlink channel. The reference signal for channel measurement may be, for example, a channel state information reference signal (CSI-RS). This application does not limit this.

[0159] It should be noted that the reference signal sent by the network device for measuring the channel may be a reference signal that has not been precoded, or a reference signal that has been precoded. Correspondingly, the channel measured by the terminal device based on the received reference signal may be a real channel or a channel that has been precoded. This application does not limit this.

[0160] The terminal device can determine the precoding matrix adapted to the downlink channel based on the channel measurement. In an embodiment of the present application, in order to obtain the SINR of the downlink channel, the terminal device can guess the precoding matrix that the network device may use to precode the downlink data based on the channel measurement. Those skilled in the art can understand that the precoding matrix guessed by the terminal device for precoding the downlink data can be the above-mentioned precoding matrix adapted to the downlink channel. For example, the precoding matrix P can be the precoding matrix indicated by the terminal device to the network device through the precoding matrix indicator (PMI), or it can be close to it. However, it should be understood that this does not mean that the network device will definitely use the precoding matrix P to precode the downlink data.

[0161] As mentioned above, the actual downlink channel is denoted as V. If the reference signal sent by the network device for measuring the channel is not precoded, the channel obtained by the terminal device based on the channel measurement may be V, or close to V; if the reference signal sent by the network device for measuring the channel is a reference signal precoded based on the precoding matrix W, the channel obtained by the terminal device based on the channel measurement may be VW, or close to VW.

[0162] It can be seen that if the channel is not precoded, or in other words, if the reference signal sent by the network device is not precoded, the CP used by the terminal device when determining SINR can be the product of the channel V and the precoding matrix P, that is, VP. If the channel is precoded, or in other words, if the reference signal sent by the network device is precoded, the CP used by the terminal device when determining SINR can be the product of the precoded channel VW and the precoding matrix P, that is, VWP.

[0163] 8. Precoding matrix: In the embodiments of the present application, the precoding matrix is ​​involved in many places and can be divided into two categories according to its function.

[0164] A type of precoding matrix is ​​a precoding matrix used by a network device to precode a reference signal, and may be constructed, for example, by the K angle vectors and L delay vectors described above.

[0165] Another type of precoding matrix is ​​a precoding matrix determined by the terminal device based on the received precoding reference signal for channel measurement. The precoding matrix may be a precoding matrix fed back by the terminal device to the network device. The precoding matrix is ​​adapted to the downlink channel. The network device can further determine the precoding matrix for downlink data transmission based on the precoding matrix fed back by the terminal device. For example, the precoding matrix fed back by the terminal device is directly used as the precoding matrix for downlink data transmission, or, after some beamforming methods, such as zero forcing (ZF), minimum mean-squared error (MMSE), maximization of signal-to-leakage-and-noise (SLNR), etc., a precoding matrix for downlink data transmission is obtained. This application does not limit this.

[0166] The description of the precoding matrix involved in many places in the embodiments of the present application can be understood by those skilled in the art in combination with the context.

[0167] 9. Equivalent channel: In the embodiment of the present application, assuming that the precoding matrix P determined by the terminal device based on the channel measurement is loaded onto the channel, the obtained channel can be called an equivalent channel. The equivalent channel can be, for example, the above-mentioned VP or the above-mentioned VWP.

[0168] It should be noted that the precoding matrix P is determined by the terminal device based on channel measurement, and does not mean that the network device will definitely precode the downlink data based on the precoding matrix P. In other words, the precoding matrix used by the network device to precode the downlink data is not necessarily the precoding matrix P. Since the precoding matrix P is determined based on channel measurement, it is adapted to the downlink channel. Therefore, the terminal device can guess that the network device may use the precoding matrix P to precode the downlink data based on the result of the channel measurement, thereby determining the equivalent channel. Therefore, it can be understood that the equivalent channel is not a real channel. As mentioned above, the equivalent channel is determined by assuming that the precoding matrix is ​​loaded on the channel, rather than actually loading the precoding matrix on the channel. Therefore, the equivalent channel can be understood as a hypothetical equivalent channel, or a virtual equivalent channel, etc. However, it can be understood that since the network device determines the precoding matrix for downlink data transmission based on the precoding matrix fed back by the terminal device, the hypothetical equivalent channel is the same or similar to the equivalent channel measured after the precoding matrix is ​​loaded on the downlink channel. In the embodiments of the present application, the equivalent channel is named only for the convenience of distinguishing from the channel obtained based on the channel measurement described above, and shall not constitute any limitation to the present application. Those skilled in the art can understand its technical essence. In the following text, for the sake of brevity, the description of the same or similar situations is omitted.

[0169] As mentioned above, if you want to feed back CQI, you can first determine SINR. SINR is related to the power of the equivalent channel. Therefore, the terminal device first needs to determine the equivalent channel.

[0170] In FDD mode, since the delay and angle satisfy the reciprocity of the uplink and downlink channels, the network equipment usually pre-loads the delay and angle determined by the uplink channel measurement on the reference signal to measure the downlink channel, and then reconstructs the downlink channel according to the results of the channel measurement and determines the precoding matrix that matches it.

[0171] In one implementation, a precoding matrix adapted to the downlink channel may be determined according to a space-frequency matrix corresponding to the downlink channel. Here, the space-frequency matrix may be understood as a channel matrix in the frequency domain, which may be used to determine the precoding matrix.

[0172] Assume that the space-frequency matrix is ​​denoted as H. From the perspective of each receiving antenna port, the space-frequency matrix H can be expressed as [h0 h1... h N-1 ] TAmong them, h0 to h N-1 There are N vectors corresponding to N subbands, and each vector can be a channel corresponding to each subband measured based on a reference signal received by a receiving antenna port. If the network device is configured with a transmit antenna in one polarization direction, the dimensions of the N vectors are 1×T; if the network device is configured with transmit antennas in two polarization directions, the dimensions of the N vectors are 1×2T.

[0173] It can be seen that the space-frequency matrix can be regarded as a joint matrix composed of the channel combinations corresponding to the N sub-bands, and its dimension is N×T or N×2T.

[0174] It should be understood that the space-frequency matrix is ​​only an intermediate quantity introduced for ease of understanding and should not constitute any limitation to the present application. Based on the same concept, those skilled in the art can determine the precoding matrix by performing equivalent transformations or other algorithms. In other words, during the process of the terminal device performing channel measurement, the terminal device does not necessarily generate the space-frequency matrix. The present application does not limit this.

[0175] At present, a feedback method is known, which projects the channels corresponding to multiple sub-bands into the spatial domain and the frequency domain to obtain one or more angle vectors with stronger spatial domain and one or more delay vectors with stronger frequency domain, and then characterizes the channels corresponding to the multiple sub-bands by the linear superposition of the combination of the one or more angle vectors and the one or more delay vectors. For example, the angle delay pair mentioned above can be expressed as a(θ k )×b(τ l ) H , then the linear superposition and multiple combinations of K angle vectors and L time delay vectors can be expressed as The above formula can be obtained by the mathematical formula SXF H where S represents a matrix constructed by one or more (for example, K) angle vectors. For example, if the network device is equipped with a transmitting antenna with a polarization direction, then S = [a(θ0) a(θ1) ... a(θ K-1 )] T×K ; If the network device is equipped with transmitting antennas with two polarization directions, then F represents a matrix constructed by one or more (eg, L) time delay vectors, for example, F = [b(τ0) b(τ1) ... b(τ L-1 )] N×F , X represents a coefficient matrix composed of linear superposition coefficients corresponding to each angle vector in the K angle vectors and each delay vector in the L delay vectors (or, corresponding to each angle delay pair). Each element in X can represent the linear superposition coefficient of a corresponding angle delay pair.

[0176] The matrix dimension determined by the weighted summation formula shown above is T×N (corresponding to the transmitting antenna in one polarization direction), which is exactly the transposed relationship with the dimension of the space-frequency matrix H above. That is, the space-frequency matrix H can satisfy: H T =SXF H However, it should be understood that the above definition of the dimension of the space-frequency matrix should not constitute any limitation to the present application. For example, the space-frequency matrix H can also be defined as: H = SXF H To avoid ambiguity, the space-frequency matrix is ​​uniformly defined as H T =SXF H .

[0177] As mentioned above, the CQI of a subband is related to the power of the equivalent channel of the subband. In the FDD channel reciprocity scenario, since the network device precodes the reference signal at least based on the delay vector, the channel measured by the terminal device on each subband is different, and the precoding matrix obtained by directly performing SVD on the channel measured on each subband is different from the precoding matrix fed back by the terminal device based on the channel measurement. In other words, there may be a large difference between the precoding matrix actually used by the network device in downlink transmission and the precoding matrix determined by the terminal device based on the direct SVD of the subband channel. Therefore, if the precoding matrix is ​​determined directly based on the channel information of the first subband, and then the CQI of the first subband is determined, the obtained CQI may not be accurate. Therefore, it is not conducive to the network device to select a reasonable MCS, which in turn affects the downlink transmission performance.

[0178] In view of this, the present application provides a channel measurement method in order to obtain more accurate CQI feedback.

[0179] It should be understood that the following is only for the convenience of understanding and explanation, and the method provided by the embodiment of the present application is described in detail by taking the interaction between the terminal device and the network device as an example. However, this should not constitute any limitation on the execution subject of the method provided by the present application. For example, the terminal device shown in the embodiment below can be replaced by a component (such as a circuit, a chip, or a chip system) configured in the terminal device. The network device shown in the embodiment below can also be replaced by a component (such as a circuit, a chip, or a chip system) configured in the network device.

[0180] The embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided in the embodiments of the present application. As long as it is possible to communicate according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application, for example, the execution subject of the method provided in the embodiments of the present application may be a terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute the program.

[0181] The channel measurement method provided by the present application is described in detail below with reference to the accompanying drawings. Figure 3 3 is a schematic flow chart of a channel measurement method 300 provided in an embodiment of the present application. Figure 3 As shown, the method 300 may include steps 310 to 340. Each step in the method 300 is described in detail below.

[0182] In step 310, the terminal device receives a precoding reference signal. Accordingly, in step 310, the network device sends a precoding reference signal.

[0183] Exemplarily, the network device may precode the reference signal based on K angle vectors and L delay vectors. A variety of angle vector and delay vector combinations may be obtained from the K angle vectors and L delay vectors. The angle vectors and / or delay vectors in any two combinations are different. The angle vector and delay vector in each combination may be used to precode the reference signal to obtain a precoded reference signal corresponding to a reference signal port. Therefore, the precoded reference signal obtained by the network device based on the precoding of K angle vectors and L delay vectors may correspond to one or more reference signal ports, and the precoded reference signal of each reference signal port may be obtained by precoding the reference signal based on an angle vector among the K angle vectors and a delay vector among the L delay vectors. In other words, the precoded reference signal of each port may be obtained by precoding the reference signal based on a combination of an angle vector and a delay vector. In an embodiment of the present application, each precoded reference signal may correspond to a reference signal port.

[0184] In a possible implementation, the network device may combine each angle vector in the K angle vectors with each delay vector in the L delay vectors in pairs to obtain K×L combinations of angle vectors and delay vectors, or obtain K×L angle delay pairs. That is, the network device may precode the reference signal based on each angle vector in the K angle vectors and each delay vector in the L delay vectors. When the network device precodes the reference signal based on the kth (0≤k≤K-1, k is an integer) angle vector in the K angle vectors, it may traverse each delay vector in the L delay vectors to precode the reference signal; or, when the network device precodes the reference signal based on the lth (0≤l≤L-1, l is an integer) delay vector in the L delay vectors, it may traverse each angle vector in the K angle vectors to precode the reference signal. In other words, the K angle vectors can be considered to be common to each delay vector, and the L delay vectors can also be considered to be common to each angle vector. In other words, the K angle vectors and the L time delay vectors are shared with each other.

[0185] In another possible implementation, when the network device precodes the reference signal based on the kth angle vector among the K angle vectors, the network device may traverse the L corresponding to the kth angle vector. k (0≤L k ≤L-1,L k Each of the delay vectors (where L is an integer) precodes the reference signal. L of the above L delay vectors can satisfy: In this implementation, the delay vectors corresponding to at least two angle vectors are different.

[0186] Here, the delay vectors corresponding to at least two angle vectors are different, which may mean that, among the K angle vectors, the delay vectors corresponding to at least two angle vectors are different, and the delay vectors corresponding to the other angle vectors may be the same or different, which is not limited in this application. In other words, the delay vectors corresponding to the angle vectors are partially or completely different.

[0187] Among them, the delay vectors corresponding to the two angle vectors are different, which may mean that the delay vectors corresponding to the two angle vectors are completely different, that is, the delay vectors corresponding to the two angle vectors are not repeated, or have no intersection. For example, the delay vector corresponding to the angle vector a(θ1) includes b(τ2), and the delay vector corresponding to the angle vector a(θ2) includes b(τ1) and b(τ3). The delay vectors corresponding to the two angle vectors are different, which may also mean that the delay vectors corresponding to the two angle vectors are partially different, that is, the delay vectors corresponding to the two angle vectors are partially repeated but not completely the same, or the delay vectors corresponding to the two angle vectors have an intersection but are not completely the same. For example, the delay vector corresponding to a(θ1) includes b(τ2) and b(τ3), and the delay vector corresponding to the angle vector a(θ2) includes b(τ1) and b(τ3).

[0188] When the delay vectors corresponding to any two angle vectors among the K angle vectors do not overlap, When the delay vectors corresponding to two or more angle vectors among the K angle vectors are partially repeated, Therefore, the network device can obtain the K angle vectors and L delay vectors mentioned above: A combination of an angle vector and a delay vector.

[0189] In another possible implementation, when the network device precodes the reference signal based on the lth delay vector among the L delay vectors, the network device may traverse the K corresponding to the lth delay vector. l (0≤K l ≤K-1, K l Each angle vector in the K angle vectors (where (K) is an integer) precodes the reference signal. The K in the above K angle vectors can satisfy: In this implementation, the angle vectors corresponding to at least two time delay vectors are different.

[0190] Here, at least two delay vectors correspond to different angle vectors, which may mean that, among the L delay vectors, at least two delay vectors correspond to different angle vectors, and the angle vectors corresponding to the other delay vectors may be the same or different, which is not limited in this application. In other words, the angle vectors corresponding to the delay vectors are partially or completely different.

[0191] Among them, the different angular vectors corresponding to the two delay vectors may mean that the angular vectors corresponding to the two delay vectors are completely different, that is, the angular vectors corresponding to the two delay vectors do not repeat, or have no intersection. For example, the angular vector corresponding to the delay vector b(τ1) includes a(θ2), and the angular vector corresponding to the delay vector b(τ2) includes a(θ1). The different angular vectors corresponding to the two delay vectors may also mean that the angular vectors corresponding to the two delay vectors are partially different, that is, the angular vectors corresponding to the two delay vectors are partially repeated but not completely the same, or the angular vectors corresponding to the two delay vectors have an intersection but are not completely the same. For example, the angular vector corresponding to the delay vector b(τ1) includes a(θ2), and the angular vector corresponding to the delay vector b(τ2) includes a(θ1) and a(θ2). When the angular vectors corresponding to any two delay vectors among the L delay vectors do not repeat each other, When the angle vectors corresponding to two or more delay vectors among the L delay vectors are partially repeated, Therefore, the network device can obtain the K angle vectors and L delay vectors mentioned above: A combination of an angle vector and a delay vector.

[0192] It should be understood that the above is only for the sake of understanding, and the corresponding relationship between the angle vector and the delay vector is listed, but this should not constitute any limitation on the present application. The present application does not limit the corresponding relationship between the angle vector and the delay vector.

[0193] It can be understood that if the network device precodes the reference signal based on K angle vectors and L delay vectors, the number of ports of the transmitted precoded reference signal can be the number of combinations determined by the K angle vectors and the L delay vectors. That is, the number of reference signal ports J can be determined by the number of combinations determined by the K angle vectors and the L delay vectors. In the above-mentioned different implementations, the value of J is different, for example, J = K × L, or, or,

[0194] For ease of understanding and explanation, it is assumed that J = K × L below, that is, K angle vectors and L delay vectors are combined in pairs to obtain K × L angle delay pairs. Therefore, the precoded reference signal received by the terminal device corresponds to 2K × L reference signal ports, that is, 2J reference signal ports.

[0195] As mentioned above, K angle vectors and L time delay vectors are loaded onto the reference signal, that is, K angle vectors and L time delay vectors are loaded onto the channel. This process can be achieved by formula F T HS * In other words, a channel C loaded with K angle vectors and L delay vectors can satisfy: C T =F T HS * .

[0196] Among them, S and F have been described in detail above and will not be repeated here for the sake of brevity.

[0197] Taking a dual-polarized transmitting antenna as an example, the channel loaded with K angle vectors and L delay vectors can be expressed as:

[0198]

[0199] Assuming that the kth angle vector and the lth delay vector correspond to the jth reference signal port among the J reference signal ports, the channel of the jth reference signal port can be expressed as: b(τ l )Ha(θ k ) * . Further, the channel corresponding to the nth subband can be expressed as: b(τ l ) n H(n)a(θ k ) * . Among them, b(τ l ) n Denotes the delay vector b(τ l ) is loaded onto the nth subband, that is, the delay vector b(τ l ) represents the nth element in the space-frequency matrix H; H(n) represents the vector corresponding to the nth subband in the space-frequency matrix H, that is, the nth row in the space-frequency matrix H.

[0200] Since there is a corresponding relationship between the J reference signal ports and the above-mentioned K angle vectors and L delay vectors, the angle vector and delay vector corresponding to each reference signal port can be represented by a mapping function. For example, μ(j) represents the angle vector corresponding to the j-th reference signal port, and η(j) represents the delay vector corresponding to the j-th reference signal port. It can be further obtained that the channel corresponding to the n-th subband and the J reference signal ports can be represented as:

[0201]

[0202] Optionally, the K angle vectors and the L delay vectors may be determined based on uplink channel measurement.

[0203] Specifically, since the angle and the time delay have uplink and downlink channel reciprocity, the network device can determine K angle vectors and L time delay vectors according to the pre-estimated uplink channel matrix.

[0204] The network device can, for example, use the methods in the prior art to estimate the K angle vectors and the L time delay vectors. For example, the K angle vectors and the L time delay vectors are determined by performing DFT on the space-frequency matrix, or by a joint angle and delay estimation (JADE) algorithm. Specifically, the estimation algorithm can be, for example, a multiple signal classification algorithm (MUSIC), a Bartlett algorithm, or an estimation of signal parameters via rotation invariant technique algorithm (ESPRIT), etc. This application does not limit the specific method for the network device to determine the K angle vectors and the L time delay vectors.

[0205] From the above description, it can be seen that the channel measured by the terminal device based on the received precoding reference signal is not a real channel, but a channel loaded with an angle vector and a delay vector, or in other words, a channel after precoding.

[0206] It should be understood that the precoded reference signal is not necessarily obtained by precoding the reference signal based on K angle vectors and L delay vectors. In another possible implementation, the network device can perform frequency domain precoding on the reference signal based on the delay vector, and the number of reference signal ports corresponding to the precoded reference signal received by the terminal device can be equal to the number of delay vectors, such as J=L, or can also be twice the number of delay vectors, such as J=2L.

[0207] It should also be understood that regardless of whether the precoded reference signal received by the terminal device is obtained by precoding the reference signal based on the angle vector and the delay vector, or by precoding the reference signal based on the delay vector, the terminal device can determine the CQI of the first subband according to the process described below.

[0208] In step 320, the terminal device determines the channel information of the first subband and the precoding information of the wideband; and in step 330, determines the CQI of the first subband according to the channel information of the first subband and the precoding information of the wideband.

[0209] Among them, broadband may refer to a continuous bandwidth. For example, broadband may refer to the total bandwidth of frequency domain resources occupied by the reference signal resources allocated by the network device to the terminal device. Broadband may also refer to the bandwidth part (bandwidth part, BWP) allocated by the network device to the terminal device. This application does not limit this. Among them, the reference signal resources or BWP may be pre-configured by the network device through signaling (such as high-level signaling, etc.), for example. This application does not limit this. The subband may also be pre-configured by the network device through signaling (such as high-level signaling, etc.), for example. In one possible implementation, the subband may be, for example, a CQI subband.

[0210] Broadband is relative to subband. Broadband has a larger frequency bandwidth than subband. Broadband may include multiple subbands. The first subband may be one of the multiple subbands. In one implementation, the protocol may predefine the measurement and reporting of CQI for one or more subbands in the broadband. In another implementation, the network device may pre-indicate, for example, through high-layer signaling, that CQI is measured and reported for one or more subbands in the broadband. The first subband may be any one of the one or more subbands for which CQI measurement and reporting are required.

[0211] Without loss of generality, the following text takes the first sub-band as an example to explain in detail the specific process of the terminal device determining the CQI of the sub-band.

[0212] In the embodiment of the present application, the CQI of the first subband is not only related to the channel information of the first subband, but also related to the precoding information of the broadband. As described above, the relationship between the CQI of the first subband and the channel information of the first subband and the precoding information of the broadband is described below through a detailed description of step 320 and step 330.

[0213] As mentioned above, if the precoding matrix is ​​determined directly based on the channel of the first subband, and then the CQI of the first subband is determined, the obtained CQI may not be accurate. In an embodiment of the present application, the broadband precoding matrix can be applied to each subband therein, or in other words, the broadband precoding matrix can be used to determine the precoding matrix of each subband in the broadband, or in other words, the precoding matrix applicable to each subband in the broadband can be the same. In one implementation, the broadband precoding matrix can be used as the precoding matrix of each subband in the broadband. Therefore, the broadband precoding matrix and the channel of the first subband can be used to determine the equivalent channel of the first subband. In order to determine the CQI of the first subband, the terminal device can first determine the channel of the first subband and the broadband precoding matrix.

[0214] The terminal device can determine the channel of the first subband based on the received precoded reference signal. As mentioned above, since the reference signal is a precoded reference signal, the channel of the first subband obtained by the terminal device based on channel measurement is a precoded channel, not a real channel.

[0215] As described in step 310 above, if the network device loads K angle vectors and L delay vectors onto the reference signal, the channel corresponding to the nth subband and J reference signal ports can be expressed as:

[0216]

[0217] Therefore, the terminal device can obtain R×2J channel estimation values ​​by measuring based on the received precoding reference signal. The R×2J channel estimation values ​​are the R×2J elements obtained by the above calculation. Among them, the terminal device can obtain 2J channel estimation values ​​by measuring based on the precoding reference signal received by each receiving antenna port. In other words, among the above R×2J channel estimation values, each 2J channel estimation values ​​correspond to one receiving antenna port.

[0218] The R×2J elements may be represented, for example, as a matrix with a dimension of R×2J, or as a vector with a length of R×2J, etc. This application does not limit this.

[0219] For example, if the R×2J elements are represented as a matrix with a dimension of R×2J, the channel matrix C corresponding to the nth subband can be obtained: n as follows:

[0220] Each element in the matrix can represent a channel estimation value corresponding to a reference signal port, a receiving antenna port, and a subband. j，r，n represents the channel estimation value corresponding to the j-th reference signal port, the r-th receiving antenna port, and the n-th subband.

[0221] The nth subband mentioned above can be regarded as an example of the first subband. Thus, the terminal device can determine the channel information of the first subband.

[0222] It should be noted that the determination of the above channel estimation value is based on the assumption that each subband is a frequency domain unit. If each frequency domain unit is an RB, and each subband includes multiple RBs, in this case, the channel estimation values ​​corresponding to one receiving antenna port and one reference signal port on each subband are also multiple. For example, the terminal device can determine the channel estimation value corresponding to the subband by averaging, summing, etc., multiple channel estimation values ​​corresponding to the same receiving antenna port and the same reference signal port on the same subband. The specific method can refer to the prior art, and this application is not limited to this.

[0223] The terminal device can be based on the corresponding N s The channels of the sub-bands further determine the precoding information of the wideband.

[0224] In the uplink and downlink reciprocity scheme of FDD channels, the terminal equipment corresponds to N s The channel estimation values ​​corresponding to the same receiving antenna port and the same reference signal port in the channels of the sub-bands are cumulatively summed to determine the linear superposition coefficient corresponding to the receiving antenna port and the reference signal port. For example, for the rth receiving antenna port and the jth reference signal port, the terminal device can add N s The channel estimation value c of the subband r，j，0 to c r，j，N-1 Sum to obtain the linear superposition coefficient corresponding to the rth receive antenna port and the jth reference signal port The linear superposition coefficient α r，j Corresponding to the rth receiving antenna port and the jth reference signal port. The terminal device iterates over the values ​​of j from 0 to 2J-1 and iterates over the values ​​of r from 0 to R-1. Based on each value of j and each value of r, the terminal device performs N s The channel estimation values ​​of the subbands are accumulated and summed to obtain R×2J linear superposition coefficients corresponding to the 2J reference signal ports and the R receiving antenna ports. The R×2J linear superposition coefficients can be used to reconstruct the downlink channel.

[0225] In a possible implementation, the terminal device may reconstruct the downlink channel D based on the R×2J linear superposition coefficients as follows:

[0226]

[0227] The matrix D can be understood as a channel corresponding to the broadband. It should be understood that the matrix D is only an example for ease of understanding and explanation, and the terminal device does not necessarily need to generate the above matrix D in the process of determining the precoding information of the broadband.

[0228] There may be multiple ways for the terminal device to determine the broadband precoding information based on the above R×2J linear superposition coefficients, which is not limited in this application.

[0229] In one implementation, the terminal device may construct a matrix D based on the above R×2J linear superposition coefficients as follows:

[0230]

[0231] By performing SVD on the above matrix D, a precoding matrix adapted to the downlink channel can be determined. Exemplarily, the process of performing SVD on the matrix D can be expressed as follows: D = UΛA H . Those skilled in the art can understand that the right unitary matrix A obtained by performing SVD on the matrix D can be used to determine the precoding matrix adapted to the matrix D. Therefore, the right unitary matrix A can be understood as an example of precoding information. The precoding matrix determined by the matrix A is the broadband precoding matrix determined by the terminal device based on channel measurement.

[0232] It can be understood that since the dimension of the precoding matrix is ​​related to the rank of the channel, the precoding matrix determined by the terminal device can be, for example, one or more eigenvectors in the matrix A, corresponding to one or more transmission layers. For example, if the rank is 1, then P = A (:, 1). A (:, 1) represents the first column in the matrix A. For the sake of brevity, examples are not given here one by one. It can be understood that in some cases, P = A.

[0233] In another implementation, the terminal device can conjugate the above R×2J linear superposition coefficients to construct an R×2J dimensional matrix, and then perform SVD on the matrix. For example, the following matrix can be obtained by conjugating the above R×2J linear superposition coefficients:

[0234]

[0235] The above matrix is ​​also the conjugate of matrix D, D * . For the matrix D * By performing SVD, a precoding matrix P adapted to the downlink channel can also be obtained. For example, the matrix D * The process of performing SVD can be expressed as follows: * =U * Λ(A * ) H It can be understood that for the matrix D *The right unitary matrix obtained by performing SVD is the conjugate of the matrix A mentioned above. * It can be used to determine the precoding matrix adapted to the channel. Therefore, the right unitary matrix A * It can be understood as another example of precoding information. * The determined precoding matrix is ​​a broadband precoding matrix determined by the terminal device based on channel measurement.

[0236] In yet another implementation, the terminal device may construct a 2J×R dimensional matrix from the R×2J linear superposition coefficients in the above matrix D as follows:

[0237]

[0238] The above matrix is ​​the transpose of matrix D. T . For the matrix D T By performing SVD, a precoding matrix P adapted to the downlink channel can also be obtained. For example, the matrix D T The process of performing SVD can be expressed as follows: T =(UΛA H ) T =A * ΛU T It can be understood that since the channel D is transposed, T The left unitary matrix A for SVD * It can be used to determine the precoding matrix adapted to the channel. Therefore, the left unitary matrix A * It can be understood as another example of precoding information. * The determined precoding matrix is ​​a broadband precoding matrix determined by the terminal device based on channel measurement.

[0239] In another implementation, the terminal device may also conjugate the above R×2J linear superposition coefficients to construct a 2J×R dimensional matrix as follows:

[0240]

[0241] The above matrix is ​​the conjugate transpose of matrix D, D H . For the matrix D H By performing SVD, a channel-adaptive precoding matrix P can also be obtained. For example, the matrix D H The process of performing SVD can be expressed as follows: H =(UΛA H ) H =AΛ T U H It can be understood that since the channel D is conjugate transposed, HThe left unitary matrix A after SVD can be used to determine the precoding matrix adapted to the channel. Therefore, the left unitary matrix A can be understood as another example of precoding information. The precoding matrix determined by the matrix A is also the broadband precoding matrix determined by the terminal device based on channel measurement.

[0242] In the various possible implementations shown above, due to different operations on the R×2J linear superposition coefficients and different dimensions of the constructed matrices, the determined precoding information is expressed in different forms, such as A, A * . However, this should not constitute any limitation to the present application. Those skilled in the art will understand that there is a conjugate relationship between the channel and precoding. Specifically, in order to obtain a narrower transmission beam, the transmitting end (such as the above-mentioned network device) can achieve this through precoding. Precoding is to obtain the in-phase superposition of beams transmitted by multiple transmitting ports of the channel on the receiving side (such as the above-mentioned terminal device), and to make up the phase difference between the beams transmitted by each transmitting port by taking the conjugate of the channel.

[0243] Therefore, regardless of whether the precoding information in the above example is conjugated to matrix A, the conjugate relationship between the channel and the precoding exists, which has nothing to do with SVD. For example, when the terminal device is configured with only one receiving antenna port, performing SVD on the channel can obtain that the channel is equal to the conjugate transpose of the right unitary matrix, that is, the precoding matrix is ​​the conjugate transpose of the channel. The above examples are just different forms of expression of the precoding information obtained in different implementation methods, and their essence is the same.

[0244] It should be understood that the above is only for ease of understanding, and the determination method of the broadband precoding matrix is ​​explained by making different mathematical transformations on the channel D. However, this should not constitute any limitation to the present application. The specific process of the terminal device determining the broadband precoding matrix is ​​related to its pre-set algorithm and should not be limited by the above example.

[0245] It should also be understood that in the process of determining the broadband precoding information by the terminal device described above, for ease of understanding and explanation, it is assumed that the dimension of the space-frequency matrix H is N×T, and the space-frequency matrix H satisfies H T =SXF H However, this shall not constitute any limitation to the present application. For example, it can also be assumed that the space-frequency matrix has a transposed relationship with the above assumption. In this case, the space-frequency matrix H satisfies H T =SXF H Alternatively, we can assume that the space-frequency matrix has a conjugate relationship with the above assumptions. In this case, the space-frequency matrix H satisfies H * =SXF HHowever, it can be understood that no matter what mathematical transformation is performed on the space-frequency matrix, the terminal device can determine the precoding information of the broadband based on the principles and processes described above. For the sake of brevity, examples are not given one by one in this article. Based on the channel of the nth subband and the precoding matrix of the broadband, the terminal device can determine the equivalent channel H corresponding to the nth subband eff Satisfaction: H eff =C n P.

[0246] Since the nth sub-band mentioned above is an example of the first sub-band, the terminal device can determine the equivalent channel of the first sub-band.

[0247] Thereafter, the terminal device may further determine the power of the equivalent channel of the first sub-band.

[0248] In some cases, in order to save pilot overhead, some ports are reused. For example, some ports can correspond to multiple terminal devices. It should be understood that the port mentioned here specifically refers to the antenna port of the network device end, such as the reference signal port mentioned above. Since the receiving antenna port is not involved in the following, the antenna port of the network device end is referred to as a port.

[0249] For ease of understanding, here we combine Figure 4 To explain. Figure 4 Schematic diagram of multiple ports being reused provided in an embodiment of the present application. Figure 4 As shown, Figure 4 A total of 16 ports are shown, namely port 0 to port 15. Take 4 terminal devices as an example, which are respectively recorded as: UE 1, UE 2, UE 3 and UE 4. The 4 terminal devices can correspond to 4 ports respectively, and the ports are multiplexed.

[0250] As shown in the figure, the four ports corresponding to UE 1 are port 1, port 4, port 9, and port 13; the four ports corresponding to UE 2 are port 1, port 4, port 7, and port 11; the four ports corresponding to UE 3 are port 1, port 7, port 11, and port 13; the four ports corresponding to UE 4 are port 1, port 9, port 11, and port 13. It can be seen that multiplexing is performed on the four ports of port 1, port 4, port 9, and port 13. For example, on port 1, UE1, UE2, UE3, and UE4 are multiplexed, and the multiplexing degree can be called 4. For another example, on port 4, UE1 and UE2 are multiplexed, and the multiplexing degree can be called 2. For another example, on port 9, UE1 and UE4 are multiplexed, and the multiplexing degree can be called 2. For another example, on port 13, UE1, UE3, and UE4 are multiplexed, and the multiplexing degree can be called 3.

[0251] It should be understood that the above Figure 4 The description of port multiplexing is only an example and should not constitute any limitation to the present application. The present application does not limit the port multiplexing degree and the terminal device corresponding to each multiplexed port. When there are beams with high isolation between multiple terminal devices, that is, when the beam isolation for serving multiple terminal devices is high, the multiple terminal devices can reuse the same port.

[0252] Generally, if the ports are multiplexed, the channel obtained by the terminal device based on the received precoding reference signal has actually integrated the difference in port power. In other words, the channel corresponding to the nth subband in the above example It can be understood as the channel measured when the transmit power of each reference signal port is equal. If the transmit power of each reference signal port is different, the measured channel can satisfy:

[0253]

[0254] in, is a 2J×2J dimensional diagonal matrix, each element of which corresponds to One column in , that is, can correspond to a reference signal port. This is like performing a power calibration on each reference signal port when the transmission power of each reference signal port is different. The element p j It can be understood as the power correction value corresponding to the jth reference signal port. In order to distinguish it from the power correction in the following text, it is recorded as a primary power correction. It should be understood that the primary power correction is named for the convenience of understanding and explanation, and the terminal device does not necessarily perform this step.

[0255] However, since there is no reference signal port multiplexing when the channel is used to transmit data, that is, the power of each reference signal port is equal in theory. Therefore, when calculating the power of the equivalent channel, the terminal device can remove the power difference caused by port multiplexing to obtain equal transmission power of each reference signal port.

[0256] Therefore, when determining the power of the equivalent channel, the terminal device may first correct the transmit power of each reference signal port according to the port power difference information to obtain equal transmit power for each reference signal port and then calculate the power of the equivalent channel.

[0257] In one implementation, the channel C n The inverse transformation of the above power correction can be performed. Specifically, Right multiplication This is like the channel C obtained by measuring the above channel. n The power calibration was performed again, and the corrected channel Cn ′ can be expressed as:

[0258]

[0259] In order to distinguish it from the primary power correction mentioned above, it is recorded as secondary power correction. It can be understood that the secondary power correction is a step that the terminal device actually needs to perform.

[0260] In one possible design, the power correction value may be determined by the port power difference information. Optionally, the port power difference information may be, for example, the port multiplexing. Assuming the port multiplexing is M, the power correction value may be: 10lg(1 / M). The 1 / M may represent the power ratio of the reference signal port to the data port, that is, the energy per resource element (EPRE) in the prior art. Optionally, the port power difference information may also be, for example, EPRE. The network device may indicate the power difference between the reference signal port and the data port to the terminal device by indicating the multiplexing M or indicating the EPRE. The indication of the port power difference information may be a newly added signaling, such as indicating the multiplexing M; or it may be an existing signaling, such as indicating the EPRE. The present application does not limit the specific manner in which the network device indicates the port power difference information.

[0261] The terminal device may calculate the equivalent channel based on the second-corrected channel. For example, the terminal device may multiply the second-corrected channel with the above-mentioned broadband precoding matrix to obtain the equivalent channel C n 'P. Thereafter, the terminal device may determine the power of the equivalent channel, thereby determining the SINR of the first sub-band, and further determining the CQI of the first sub-band.

[0262] In step 340, the terminal device sends the CQI of the first sub-band. Correspondingly, in step 340, the network device receives the CQI of the first sub-band.

[0263] Exemplarily, the CQI of the first subband may be carried in a CSI report, for example, it may be part of the information element in the CSI report. The CSI report may also include CQIs of one or more subbands other than the first subband. In addition, the CSI report may also include a wideband CQI, etc. The present application does not limit the specific information contained in the CSI report. Of course, the CQI of the first subband may also be carried in other signaling, and the other signaling mentioned here may be, for example, existing signaling in the prior art, or may also be a newly designed signaling. The present application does not limit this.

[0264] The terminal device can, for example, send the CQI of the first subband to the network device through physical uplink resources, such as a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH), so that the network device can determine the MCS applicable to the first subband based on the CQI of the first subband.

[0265] The specific method in which the terminal device sends the CQI of the first subband to the network device through the physical uplink resource may be the same as that in the prior art. For the sake of brevity, a detailed description of the specific process is omitted here.

[0266] In the embodiment of the present application, the terminal device determines the equivalent channel by applying the precoding matrix of the broadband to each sub-band in the broadband, and then combining the channel information of the sub-band. Thus, the terminal device can feedback a more accurate CQI to the network device. The network device can determine a reasonable MCS for downlink transmission based on the more accurate CQI. This is conducive to improving the downlink transmission performance.

[0267] It should be understood that in each of the above embodiments, the terminal device and / or the network device can perform some or all of the steps in each embodiment. These steps or operations are only examples, and the embodiments of the present application can also perform other operations or deformations of various operations. In addition, each step can be performed in the different orders presented in each embodiment, and it is possible not to perform all the operations in the embodiments of the present application. Moreover, the size of the sequence number of each step does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0268] Figure 5 is a schematic block diagram of a communication device provided in an embodiment of the present application. Figure 5 As shown, the communication device 1000 may include a processing unit 1100 and a transceiver unit 1200 .

[0269] In one possible design, the communication device 1000 may correspond to the terminal device in the above method embodiment, for example, it may be a terminal device, or a component configured in the terminal device (such as a circuit, a chip or a chip system, etc.).

[0270] It should be understood that the communication device 1000 may correspond to the terminal device in the method 300 according to the embodiment of the present application, and the communication device 1000 may include a method for executing Figure 3 The units of the method performed by the terminal device in the method 300 in the communication device 1000 are respectively for implementing Figure 3The corresponding process of method 300 in FIG.

[0271] Wherein, when the communication device 1000 is used to perform Figure 3 When the method 300 in the embodiment is used, the processing unit 1100 can be used to execute step 320 in the method 300, and the transceiver unit 1200 can be used to execute steps 310 and 330 in the method 300. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0272] It should also be understood that when the communication device 1000 is a terminal device, the transceiver unit 1200 in the communication device 1000 can be implemented by a transceiver, for example, corresponding to Figure 6 The transceiver 2020 or the transceiver 2020 in the terminal device 2000 shown in FIG. Figure 7 The transceiver 3030 in the terminal device 3000 shown in FIG. 1 , the processing unit 1100 in the communication device 1000 may be implemented by at least one processor, for example, corresponding to Figure 6 The processor 2010 in the terminal device 2000 shown in FIG. Figure 7 The processor 3010 in the terminal device 3000 is shown.

[0273] It should also be understood that when the communication device 1000 is a chip or a chip system configured in a terminal device, the transceiver unit 1200 in the communication device 1000 can be implemented through an input / output interface, and the processing unit 1100 in the communication device 1000 can be implemented through a processor, microprocessor or integrated circuit integrated on the chip or chip system.

[0274] Figure 6 2 is another schematic block diagram of a communication device 2000 provided in an embodiment of the present application. Figure 6 As shown, the communication device 2000 includes a processor 2010, a transceiver 2020 and a memory 2030. The processor 2010, the transceiver 2020 and the memory 2030 communicate with each other through an internal connection path, the memory 2030 is used to store instructions, and the processor 2010 is used to execute the instructions stored in the memory 2030 to control the transceiver 2020 to send signals and / or receive signals.

[0275] It should be understood that the communication device 2000 may correspond to the terminal device in the above method embodiment, and may be used to execute the various steps and / or processes executed by the network device or the terminal device in the above method embodiment. Optionally, the memory 2030 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. The memory 2030 may be a separate device or may be integrated in the processor 2010. The processor 2010 may be used to execute the instructions stored in the memory 2030, and when the processor 2010 executes the instructions stored in the memory, the processor 2010 is used to execute the various steps and / or processes of the above method embodiment corresponding to the network device or the terminal device.

[0276] Optionally, the communication device 2000 may be the terminal device in the foregoing embodiment.

[0277] The transceiver 2020 may include a transmitter and a receiver. The transceiver 2020 may further include an antenna, and the number of antennas may be one or more. The processor 2010 and the memory 2030 and the transceiver 2020 may be devices integrated on different chips. For example, the processor 2010 and the memory 2030 may be integrated in a baseband chip, and the transceiver 2020 may be integrated in a radio frequency chip. The processor 2010 and the memory 2030 and the transceiver 2020 may also be devices integrated on the same chip. This application does not limit this.

[0278] Optionally, the communication device 2000 may be a component configured in a terminal device, such as a chip, a chip system, etc.

[0279] The transceiver 2020 may also be a communication interface, such as an input / output interface. The transceiver 2020, the processor 2010, and the memory 2020 may all be integrated into the same chip, such as a baseband chip.

[0280] Figure 7 3000 is a schematic diagram of the structure of the terminal device 3000 provided in the embodiment of the present application. The terminal device 3000 can be applied to Figure 1In the system shown, the functions of the terminal device in the above method embodiment are performed. As shown in the figure, the terminal device 3000 includes a processor 3010 and a transceiver 3030. Optionally, the terminal device 3000 also includes a memory 3020. Among them, the processor 3010, the transceiver 3030 and the memory 3020 can communicate with each other through an internal connection path to transmit control and / or data signals, and the memory 3020 is used to store a computer program, and the processor 3010 is used to call and run the computer program from the memory 3020 to control the transceiver 3030 to send and receive signals. Optionally, the terminal device 3000 may also include an antenna 3040 for sending the uplink data or uplink control signaling output by the transceiver 3030 through a wireless signal.

[0281] The processor 3010 and the memory 3020 may be combined into a processing device, and the processor 3010 is used to execute the program code stored in the memory 3020 to implement the above functions. In specific implementation, the memory 3020 may also be integrated into the processor 3010, or independent of the processor 3010. Figure 5 The processing unit 1100 or Figure 6 Corresponding to processor 2010 in.

[0282] The transceiver 3030 can be used with Figure 5 The transceiver unit 1200 or Figure 6 The transceiver 3030 may include a receiver (or receiver, receiving circuit) and a transmitter (or transmitter, transmitting circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0283] It should be understood that Figure 7 The terminal device 3000 shown can realize Figure 3 The method embodiment shown involves various processes of the terminal device. The operations and / or functions of each module in the terminal device 3000 are respectively to implement the corresponding processes in the above method embodiment. For details, please refer to the description in the above method embodiment. To avoid repetition, the detailed description is appropriately omitted here.

[0284] The processor 3010 can be used to execute the actions implemented by the terminal device in the previous method embodiment, and the transceiver 3030 can be used to execute the actions of the terminal device sending to or receiving from the network device described in the previous method embodiment. Please refer to the description in the previous method embodiment for details, which will not be repeated here.

[0285] Optionally, the terminal device 3000 may further include a power supply 3050 for providing power to various devices or circuits in the terminal device.

[0286] In addition, in order to make the functions of the terminal device more complete, the terminal device 3000 may also include one or more of an input unit 3060, a display unit 3070, an audio circuit 3080, a camera 3090 and a sensor 3100, and the audio circuit may also include a speaker 3082, a microphone 3084, etc.

[0287] An embodiment of the present application also provides a processing device, including a processor and an interface; the processor is used to execute the method executed by the terminal device or the network device in any of the above method embodiments.

[0288] It should be understood that the above-mentioned processing device can be one or more chips. For example, the processing device can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0289] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0290] It should be noted that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. 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 gates or transistor logic devices, discrete hardware components. The 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 the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor can be combined and performed. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0291] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0292] According to the method provided in the embodiment of the present application, the present application also provides a computer program product, which includes: a computer program code, when the computer program code is run on a computer, the computer executes Figure 3 The method in the illustrated embodiment.

[0293] According to the method provided in the embodiment of the present application, the present application also provides a computer-readable storage medium, which stores a program code, and when the program code is run on a computer, the computer executes Figure 3 The method in the illustrated embodiment.

[0294] According to the method provided in the embodiment of the present application, the present application also provides a system, which includes one or more terminal devices and one or more network devices mentioned above.

[0295] The network devices in the above-mentioned various device embodiments completely correspond to the network devices or terminal devices in the terminal devices and method embodiments, and the corresponding modules or units perform the corresponding steps. For example, the communication unit (transceiver) performs the steps of receiving or sending in the method embodiment, and other steps except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can refer to the corresponding method embodiments. Among them, the processor can be one or more.

[0296] In the above embodiments, the terminal device can be used as an example of a receiving device, and the network device can be used as an example of a sending device. However, this should not constitute any limitation to the present application. For example, the sending device and the receiving device can also be terminal devices, etc. The present application does not limit the specific types of the sending device and the receiving device.

[0297] The terms "component", "module", "system", etc. used in this specification are used to represent 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 and / 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 may reside in a process and / or an execution thread, and a component may be located on a computer and / or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may, for example, communicate through local and / or remote processes according to signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems through signals).

[0298] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0299] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0300] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0301] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0302] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0303] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0304] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A channel measurement method, characterized in that: include: Determine a channel quality indicator CQI of the first subband according to channel information of the first subband and precoding information of the broadband; wherein the broadband includes multiple subbands, and the first subband is one of the multiple subbands; the precoding information of the broadband is determined based on the channel information of the multiple subbands; the channel information of the first subband is obtained by performing channel measurement based on multiple precoding reference signals, wherein each precoding reference signal is obtained by precoding a reference signal based on at least one delay vector; Sending a CQI of the first subband.

2. The method according to claim 1, characterized in that The determining, according to the channel information of the first subband and the precoding information of the broadband, the CQI of the first subband includes: Determine, according to the channel information of the first subband and the precoding information of the wideband, the power of an equivalent channel of the first subband, wherein the equivalent channel of the first subband is an equivalent channel determined based on the channel information of the first subband determined by the channel measurement and the precoding information of the wideband; The CQI of the first subband is determined according to the power of the equivalent channel of the first subband.

3. The method according to claim 2, characterized in that The equivalent channel H of the first sub-band eff Satisfaction: H eff =CP; C represents the channel of the first subband determined based on the channel measurement, and P represents the precoding matrix of the wideband determined based on the channel measurement.

4. The method according to any one of claims 1 to 3, characterized in that The channel information of the first subband includes R×2J channel estimation values, and a value c among the R×2J channel estimation values ​​is r,j It is the channel estimation value corresponding to the first subband obtained by measuring the precoded reference signal of the jth reference signal port on the rth receiving antenna port; wherein 2J represents the number of reference signal ports, R represents the number of receiving antenna ports, J≥1, R≥1, 0≤j≤2J-1, 0≤r≤R-1, and J, R, j, r are all integers.

5. The method according to claim 4, characterized in that The broadband precoding information is determined by R×2J values, and the value α in the R×2J values ​​is r,j is the sum of channel estimation values ​​corresponding to the multiple subbands determined on the rth receiving antenna port based on the precoding reference signal of the jth reference signal port.

6. The method according to claim 2 or 3, characterized in that: The method further comprises: The power of the equivalent channel of the first subband is corrected based on the port power difference information, where the port power difference information is used to indicate the difference in transmit power of each reference signal port relative to the data port.

7. The method according to claim 6, characterized in that The port power difference information is used to determine a correction coefficient corresponding to each reference signal port, and the correction coefficient of each reference signal port is used to correct the transmit power of the corresponding reference signal port.

8. The method according to any one of claims 1 to 3, characterized in that Each precoded reference signal is obtained by precoding a reference signal based on an angle vector and a time delay vector.

9. A communication device, characterized in that: include: A processing unit, configured to determine a channel quality indicator CQI of the first subband according to channel information of the first subband and precoding information of the broadband; wherein the broadband includes multiple subbands, and the first subband is one of the multiple subbands; the precoding information of the broadband is determined based on the channel information of the multiple subbands; the channel information of the first subband is obtained by performing channel measurement based on multiple precoding reference signals, wherein each precoding reference signal is obtained by precoding a reference signal based on at least one delay vector; A transceiver unit is configured to send the CQI of the first subband.

10. The device according to claim 9, characterized in that The processing unit is specifically used to determine the power of the equivalent channel of the first subband according to the channel information of the first subband and the precoding information of the broadband, wherein the equivalent channel of the first subband is an equivalent channel determined based on the channel information of the first subband determined by the channel measurement and the precoding information of the broadband; and is used to determine the CQI of the first subband according to the power of the equivalent channel of the first subband.

11. The device according to claim 10, characterized in that The equivalent channel H of the first sub-band eff Satisfaction: H eff =CP; C represents the channel of the first subband determined based on the channel measurement, and d represents the precoding matrix of the wideband determined based on the channel measurement.

12. The device according to any one of claims 9 to 11, characterized in that The channel information of the first subband includes 2J×R channel estimation values, and a value c among the 2J×R channel estimation values ​​is r,j It is the channel estimation value corresponding to the first subband obtained by measuring the precoded reference signal of the jth reference signal port on the rth receiving antenna port; wherein 2J represents the number of reference signal ports, R represents the number of receiving antenna ports, J≥1, R≥1, 0≤j≤2J-1, 0≤r≤R-1, and J, R, j, r are all integers.

13. The device according to claim 12, characterized in that The broadband precoding information is determined by R×2J values, and the value α in the R×2J values ​​is r,j is the sum of channel estimation values ​​corresponding to the multiple subbands determined on the rth receiving antenna port based on the precoding reference signal of the jth reference signal port.

14. The device according to claim 10 or 11, characterized in that The processing unit is further configured to correct the power of the equivalent channel of the first subband based on port power difference information, wherein the port power difference information is used to indicate a difference in transmit power of each reference signal port relative to a data port.

15. The device according to claim 14, characterized in that The port power difference information is used to determine a correction coefficient corresponding to each reference signal port, and the correction coefficient of each reference signal port is used to correct the transmit power of the corresponding reference signal port.

16. The device according to any one of claims 9 to 11, characterized in that Each precoded reference signal is obtained by precoding a reference signal based on an angle vector and a time delay vector.

17. A communication device, characterized in that: The communication device comprises at least one processor, wherein the at least one processor is configured to execute a computer program stored in a memory, so that the communication device implements the method according to any one of claims 1 to 8.

18. A computer-readable storage medium, characterized in that: The invention comprises a computer program, which, when being run on a computer, causes the computer to execute the method according to any one of claims 1 to 8.

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