CN114204970A

CN114204970A - Method and device for channel measurement

Info

Publication number: CN114204970A
Application number: CN202010908771.6A
Authority: CN
Inventors: 范利; 葛士斌; 汪洁; 袁一凌; 种稚萌; 毕晓艳
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2022-03-18
Also published as: WO2022048593A1

Abstract

The application provides a method and a device for channel measurement, wherein a terminal side can receive a precoding reference signal from a network side, the precoding reference signal corresponds to one or more ports, the terminal side performs channel measurement based on the precoding reference signal and a first time delay specific to a terminal device to obtain a superposition coefficient corresponding to each port, wherein the first time delay can be indicated by the network side or can be determined by the terminal side; in order to enable the network side to determine the adopted codebook, the terminal side sends first indication information, and the first indication information is used for indicating the superposition coefficient. According to the method and the device, the specific first time delay aiming at each terminal device is considered during channel measurement, so that the influence of time delay deviation caused by uplink and downlink timing errors can be reduced, the interference among multi-user CSI-RSs is reduced, the CSI-RS multiplexing rate is improved, and the CSI-RS overhead is reduced.

Description

Method and device for channel measurement

Technical Field

The present application relates to the field of communications, and more particularly, to a method and a communication apparatus for channel measurement.

Background

In a large-scale multiple-input multiple-output (Massive MIMO) technology, a network device sends data to a terminal device, and Channel State Information (CSI) fed back to the network device by the terminal device is required, and the CSI fed back by the terminal device has a great effect on the performance of a system.

In some systems, such as Frequency Division Duplex (FDD) systems, the uplink and downlink physical channels have some reciprocity, such as reciprocity in multipath angles and reciprocity in time delay. Therefore, the design of the CSI acquisition scheme may be based on partial reciprocity.

Based on a partial reciprocity idea, partial prior information including angle and delay information of an uplink channel can be estimated by using uplink channel information, then the network equipment loads the obtained angle or delay on a downlink pilot frequency, and informs the terminal equipment to measure and feed back the supplementary information which needs to be obtained by the network equipment. And finally, the network equipment reconstructs a downlink channel or precodes according to the information measured by the uplink pilot frequency and the supplementary information fed back by the terminal equipment.

However, how to perform delay offset when the multi-user network device loads the delay to the downlink pilot frequency does not cause interference between multi-user channel state information-reference signals (CSI-RS), does not reduce the CSI-RS multiplexing rate, and does not increase CSI-RS overhead, which is a problem that needs to be solved urgently.

Disclosure of Invention

The application provides a channel measurement method and a communication device, so that when channel estimation is carried out based on a partial reciprocity thought, the influence of delay deviation caused by uplink and downlink timing errors can be reduced, meanwhile, the interference among multi-user CSI-RSs is reduced, the CSI-RS reuse rate is improved, and the CSI-RS overhead is reduced.

In a first aspect, a method for channel measurement is provided. The method may be performed by a first apparatus, which may be a terminal device, or may also be performed by a chip or a chip system or a circuit configured in the terminal device, and this application is not limited thereto.

The method can comprise the following steps: receiving a precoding reference signal, wherein the precoding reference signal corresponds to one or more ports; performing channel measurement based on the pre-coding reference signal and a first time delay specific to the terminal equipment to obtain a superposition coefficient corresponding to each port; and sending first indication information, wherein the first indication information is used for indicating the superposition coefficient.

Based on the technical scheme, the specific first time delay aiming at each terminal device is considered during channel measurement, so that the influence of time delay deviation caused by uplink and downlink timing errors can be reduced, the interference among multi-user CSI-RSs can be reduced, the CSI-RS multiplexing rate is improved, and the CSI-RS overhead is reduced.

With reference to the first aspect, in some possible implementation manners, the method further includes receiving second indication information, where the second indication information is used to indicate a second time delay specific to the terminal device. It is understood that the terminal device specific first delay may be obtained according to the second delay indicated by the network side.

With reference to the first aspect, in some possible implementation manners, the method further includes sending fourth indication information, where the fourth indication information is used to indicate the first time delay. It is to be understood that the terminal side may indicate the terminal device specific first time delay to the network side, so that in case the first time delay is determined by the terminal side, alignment of the network side and the terminal side is achieved.

With reference to the first aspect, in some possible implementation manners, the method further includes sending third indication information, where the third indication information is used to indicate a port selection matrix of the port.

In a second aspect, a method of channel measurement is provided. The method may be performed by a second apparatus, which may be a network device, or may also be performed by a chip or a chip system or a circuit configured in the network device, and this application is not limited thereto.

The method can comprise the following steps: generating a pre-coding reference signal, wherein the pre-coding reference signal corresponds to one or more ports; transmitting the precoded reference signal; receiving first indication information, wherein the first indication information is used for indicating superposition coefficients corresponding to the ports, and the superposition coefficients are associated with first time delays specific to terminal equipment.

With reference to the second aspect, in some possible implementations, the method further includes sending second indication information, where the second indication information is used to indicate a second time delay specific to the terminal device. It is understood that the terminal device specific first delay may be obtained according to the second delay indicated by the network side.

With reference to the second aspect, in some possible implementation manners, the method further includes receiving fourth indication information, where the fourth indication information is used to indicate the first time delay. It is to be understood that the terminal side may indicate the terminal device specific first time delay to the network side, so that in case the first time delay is determined by the terminal side, alignment of the network side and the terminal side is achieved.

With reference to the second aspect, in some possible implementations, the method further includes receiving third indication information, where the third indication information is used to indicate a port selection matrix of the port.

With reference to the first aspect or the second aspect, in some possible implementation manners, the superposition coefficient corresponding to each port is used to determine a first codebook, where the first codebook satisfies the requirement

Wherein W₁Selecting a matrix for a port of said port, W₂A superposition coefficient matrix W of superposition coefficients corresponding to the ports_fIs a matrix of frequency components and is,

represents W_fQ is a diagonal matrix related to said first time delay, Q^HRepresenting the conjugate transpose of Q. It can be understood that the novel codebook structure can improve the calculation precision of the codebook.

Wherein W₂A superposition coefficient matrix of superposition coefficients corresponding to the respective ports, or W₂A superposition coefficient matrix of the selected superposition coefficient corresponding to the port in the superposition coefficients corresponding to the ports; w_fIs a matrix of frequency components and is,

With reference to the first aspect or the second aspect, in some possible implementations, Q is:

wherein the diagonal elements are

f_kDenotes the frequency of the kth subband, K is 1,2, … …, K is the number of subbands, τ^*Is the first time delay; or

Wherein O is 0, 1, …, O-1, and the elements on the diagonal are

K, K being the number of subbands, OFor the number of columns of the oversampled discrete fourier transform, DFT, codebook, O is associated with the first time delay; or

Wherein the diagonal elements are

f_kDenotes the frequency of the kth subband, K is 1,2, … …, K is the number of subbands, (τ)^*+τ_TA) For said first time delay, τ^*For uplink time delay, τ_TAIs the uplink and downlink timing deviation; or

Wherein O is 0, 1, …, O-1, O 'is 0, 1, …, O' -1, and the diagonal elements are

K is the number of sub-bands, O is the number of columns of the first oversampled Discrete Fourier Transform (DFT) codebook, O 'is the number of columns of the second oversampled DFT codebook, and O' are associated with the first time delay.

It is to be understood that the first oversampled discrete fourier transform DFT codebook may be determined by the network device, the second oversampled discrete fourier transform DFT codebook may be determined by the terminal device, that is, O is determined by the network device and O' is determined by the terminal device.

With reference to the first aspect or the second aspect, in some possible implementations, the second indication information includes information of the second time delay, or the second indication information includes an index of an oversampled discrete fourier transform, DFT, codebook. It is to be understood that the second indication information may directly or indirectly indicate said second time delay.

With reference to the first aspect or the second aspect, in some possible implementations, the second delay is the first delay. It can be understood that the second time delay indicated by the network side is the first time delay, and the terminal side directly uses the time delay indicated by the network side to perform channel measurement, thereby reducing the computational complexity.

With reference to the first aspect or the second aspect, in some possible implementations, the first delay is a delay determined within a predetermined delay range corresponding to the second delay. It can be understood that the second time delay indicated by the network side is only used as a reference, the terminal side needs to further determine the first time delay, which avoids channel measurement inaccuracy when timing deviation exists between uplink and downlink, improves accuracy of channel measurement, and determines the first time delay within a certain range based on the time delay indicated by the reference network side, thereby reducing computation and processing complexity.

With reference to the first aspect or the second aspect, in some possible implementations, the first delay is a delay obtained by performing delay adjustment estimation. It can be understood that the network side may not perform delay skew, and the terminal side directly determines the first delay, thereby improving the accuracy of channel measurement.

With reference to the first aspect or the second aspect, in some possible implementations, the fourth indication information includes information of the first delay, or the fourth indication information includes information of a delay adjustment amount used to obtain the first delay. It is to be understood that the fourth indication information may directly or indirectly indicate said first time delay.

In a third aspect, an apparatus for channel measurement is provided, where the apparatus may be a communication apparatus, and is configured to perform the communication method provided in the first aspect. In particular, the apparatus may comprise means and/or modules, such as a processing means and/or a communication means, for performing the communication method provided by the first aspect.

In one implementation, the apparatus is a terminal device. When the device is a terminal device, the communication unit may be a transceiver, or an input/output interface; the processing unit may be a processor.

In another implementation, the apparatus is a chip or a system of chips configured in a terminal device. When the device is a chip or a chip system configured in a terminal device, the communication unit may be an input/output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip or the chip system; the processing unit may be a processor, a processing circuit, a logic circuit, or the like.

Alternatively, the transceiver may be a transmit-receive circuit. Alternatively, the input/output interface may be an input/output circuit.

In a fourth aspect, an apparatus for channel measurement is provided, where the apparatus may be a communication apparatus, and is configured to perform the communication method provided in the second aspect. In particular, the apparatus may comprise a unit and/or a module, such as a processing unit and/or a communication unit, for performing the communication method provided by the second aspect.

In one implementation, the apparatus is a network device. When the apparatus is a network device, the communication unit may be a transceiver, or an input/output interface; the processing unit may be a processor.

In another implementation, the apparatus is a chip or a system of chips configured in a network device. When the apparatus is a chip or a system of chips configured in a network device, the communication unit may be an input/output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip or the system of chips; the processing unit may be a processor, a processing circuit, a logic circuit, or the like.

In a fifth aspect, a processing apparatus is provided that includes a processor. The processor is coupled to the memory and is operable to execute instructions in the memory to implement the communication method of the first aspect described above in any of the possible implementations of the first aspect. Optionally, the processing device further comprises a memory. Optionally, the processing device further comprises a communication interface, the processor being coupled to the communication interface for inputting and/or outputting information. The information includes at least one of instructions and data.

In one implementation, the processing device is a terminal device. When the processing device is a terminal device, the communication interface may be a transceiver, or an input/output interface.

In another implementation, the processing device is a chip or a system of chips. When the processing device is a chip or a system of chips, the communication interface may be an input/output interface, an interface circuit, an output circuit, an input circuit, a pin or related circuit on the chip or the system of chips, and the like. The processor may also be embodied as a processing circuit or a logic circuit.

In another implementation, the processing device is a chip or a system of chips configured in the terminal device.

In a sixth aspect, a processing apparatus is provided that includes a processor. The processor is coupled to the memory and is operable to execute the instructions in the memory to implement the communication method of any of the above-mentioned second aspect and possible implementations of the second aspect. Optionally, the processing device further comprises a memory. Optionally, the processing device further comprises a communication interface, the processor being coupled to the communication interface for inputting and/or outputting information. The information includes at least one of instructions and data.

In one implementation, the processing device is a network device. When the processing device is a network device, the communication interface may be a transceiver, or an input/output interface.

In another implementation, the processing device is a chip or a system of chips configured in a network device.

In a seventh aspect, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a communication apparatus, causes the communication apparatus to implement the communication method in the first aspect and any possible implementation manner of the first aspect.

In an eighth aspect, there is provided a computer-readable storage medium having stored thereon a computer program which, when executed by a communication apparatus, causes the communication apparatus to implement the second aspect and the communication method in any possible implementation manner of the second aspect.

In a ninth aspect, a computer program product containing instructions is provided, which when executed by a computer causes the communication apparatus to implement the communication method provided in the first aspect.

In a tenth aspect, a computer program product containing instructions that, when executed by a computer, cause a communication apparatus to implement the communication method provided by the second aspect is provided.

In an eleventh aspect, a communication system is provided, which includes the foregoing network device and terminal device.

Drawings

Fig. 1a and 1b are schematic diagrams of a communication system suitable for use in embodiments of the present application;

FIG. 2 is a schematic diagram of uniform offset to the delay 0 point for all users;

FIG. 3 is a diagram of a method of channel measurement according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a method of channel measurement according to another embodiment of the present application;

FIG. 5 is a schematic diagram of a method of channel measurement according to yet another embodiment of the present application;

fig. 6 is a schematic block diagram of a communication device provided by an embodiment of the present application;

fig. 7 is a schematic structural diagram of a terminal device provided in an embodiment of the present application;

fig. 8 is a schematic structural diagram of a network device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a Long Term Evolution (LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications System (UMTS), a fifth generation (5th generation, 5G) mobile communications system, a New Radio (NR), or the like. The 5G mobile communication system may include a non-independent Network (NSA) and/or an independent network (SA), among others.

The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system. The communication system may also be a PLMN network, a device-to-device (D2D) network, a machine-to-machine (M2M) network, an internet of things (IoT) network, or other network. The IoT network may comprise, for example, a car networking network. The communication modes in the car networking system are collectively referred to as V2X (X represents anything), for example, the V2X communication includes: vehicle to vehicle (V2V), vehicle to roadside infrastructure (V2I), vehicle to pedestrian (V2P) or vehicle to network (V2N), etc.

The terminal device in the embodiment of the present application may also be referred to as: user Equipment (UE), Mobile Station (MS), Mobile Terminal (MT), access terminal, subscriber unit, subscriber station, mobile station, remote terminal, mobile device, user terminal, terminal device, wireless communication device, user agent, or user equipment, etc.

The terminal device may be a device providing voice/data connectivity to a user, e.g. a handheld device, a vehicle mounted device, etc. with wireless connection capability. Currently, some examples of terminals are: a mobile phone (mobile phone), a tablet computer, a notebook computer, a palm computer, a Mobile Internet Device (MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote operation (remote local supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation security (transportation safety), a wireless terminal in city (city), a wireless terminal in smart home (smart home), a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (wireless local) phone, a personal digital assistant (WLL) station, a handheld personal communication device with wireless communication function, a wireless terminal in industrial control (industrial control), a wireless terminal in transportation security (personal control), a wireless terminal in city (smart home), a wireless terminal in smart home (smart home), a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (personal digital assistant (PDA) phone, a wireless local communication device with wireless communication function, a wireless communication device, a, A computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a Public Land Mobile Network (PLMN) for future evolution, and the like, which are not limited in this embodiment of the present application.

By way of example and not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable equipment can also be called wearable intelligent equipment, is the general term of applying wearable technique to carry out intelligent design, develop the equipment that can dress to daily wearing, like glasses, gloves, wrist-watch, dress and shoes etc.. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device includes full functionality, large size, and can implement full or partial functionality without relying on a smart phone, such as: smart watches or smart glasses and the like, and only focus on a certain type of application functions, and need to be used in cooperation with other devices such as smart phones, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

In addition, in the embodiment of the application, the terminal device may also be a terminal device in an IoT system, where IoT is an important component of future information technology development, and the main technical feature of the IoT system is to connect an article with a network through a communication technology, so as to implement an intelligent network with interconnected human-computer and interconnected articles. In the embodiment of the present application, the IoT technology can achieve massive connection, deep coverage, and power saving for the terminal through, for example, a Narrowband (NB) technology.

In addition, in this embodiment of the application, the terminal device may further include sensors such as an intelligent printer, a train detector, and a gas station, and the main functions include collecting data (part of the terminal device), receiving control information and downlink data of the network device, and sending electromagnetic waves to transmit uplink data to the network device.

In addition, the network device in this embodiment may be a device for communicating with a terminal device, where the network device may be an evolved NodeB (eNB) or an eNodeB in an LTE system, and may also be a wireless controller in a Cloud Radio Access Network (CRAN) scenario, or the network device may be a relay station, an access point, a vehicle-mounted device, a wearable device, a network device in a future 5G network, a network device in a future evolved PLMN network, or the like, and the embodiment of the present application is not limited.

The network device in this embodiment may be a device in a wireless network, for example, a Radio Access Network (RAN) node that accesses a terminal to the wireless network. Currently, some examples of RAN nodes are: next generation base station gNB, Transmission Reception Point (TRP), evolved Node B (eNB), home base station, baseband unit (BBU), Access Point (AP) in WiFi system, or the like.

In one network configuration, a network device may include a Centralized Unit (CU) node, or a Distributed Unit (DU) node, or a RAN device including a CU node and a DU node, or a control plane CU node (CU-CP node) and a user plane CU node (CU-UP node), and a RAN device of a DU node.

In the embodiment of the application, the terminal device or the network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a Central Processing Unit (CPU), a Memory Management Unit (MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that implement business processing through processes (processes), such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer comprises applications such as a browser, an address list, word processing software, instant messaging software and the like. Furthermore, the embodiment of the present application does not particularly limit the specific structure of the execution main body of the method provided by the embodiment of the present application, as long as the communication can be performed according to the method provided by the embodiment of the present application by running the program recorded with the code of the method provided by the embodiment of the present application, for example, the execution main body of the method provided by the embodiment of the present application may be a terminal device or a network device, or a functional module capable of calling the program and executing the program in the terminal device or the network device.

In addition, various aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROM), card, stick, or key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

For the understanding of the embodiments of the present application, a communication system suitable for the embodiments of the present application will be described in detail with reference to fig. 1a and 1 b.

Fig. 1a is a diagram of a wireless communication system 100 suitable for use in embodiments of the present application. As shown in fig. 1, the wireless communication system 100 may include at least one network device, such as the network device 111 shown in fig. 1a, and the wireless communication system 100 may further include at least one terminal device, such as the terminal devices 121 to 123 shown in fig. 1 a. The network equipment and the terminal equipment can be both provided with a plurality of antennas, and the network equipment and the terminal equipment can communicate by using a multi-antenna technology.

When the network device communicates with the terminal device, the network device may manage one or more cells, and an integer number of terminal devices may be in one cell. Optionally, the network device 111 and the terminal devices 121 to 123 form a single-cell communication system, and without loss of generality, a cell is denoted as cell # 1. Network device 111 may be a network device in cell #1, or network device 111 may serve a terminal device (e.g., terminal device 121) in cell # 1.

It should be noted that a cell may be understood as an area within the wireless signal coverage of a network device.

Fig. 1b is another schematic diagram of a wireless communication system 200 suitable for use in embodiments of the present application. As shown in fig. 2, the technical solution of the embodiment of the present application may also be applied to D2D communication. The wireless communication system 200 comprises a plurality of terminal devices, e.g. terminal device 124 to terminal device 126 in fig. 1 b. Communication may be made directly between end device 124 to end device 126. For example, terminal device 124 and terminal device 125 may transmit data to terminal device 126 separately or simultaneously.

It should be understood that fig. 1a and 1b described above are merely exemplary illustrations, and the present application is not limited thereto. For example, the embodiments of the present application may be applied to any communication system, as long as at least two devices exist in the communication system, where one device needs to transmit a precoding reference signal; the other device receives the precoded reference signal, performs channel measurement and feeds back channel state information.

To facilitate understanding of the embodiments of the present application, a brief description of several terms referred to in the present application will be given below.

1. The precoding technology comprises the following steps: the network device can process the signal to be transmitted by means of the precoding matrix matched with the channel state under the condition of the known channel state, so that the signal to be transmitted after precoding is matched with the channel, and the complexity of eliminating the influence between the channels by the receiving device is reduced. Therefore, by precoding the signal to be transmitted, the received signal quality (e.g., signal to interference plus noise ratio (SINR)) is improved. Therefore, by using the precoding technique, the transmission between the sending device and the multiple receiving devices can be realized on the same time-frequency resource, that is, multi-user multiple input multiple output (MU-MIMO) is realized.

It should be understood that the related descriptions regarding precoding techniques herein are merely exemplary for ease of understanding and are not intended to limit the scope of the embodiments of the present application. In a specific implementation process, the sending device may also perform precoding in other manners. For example, when the channel information (for example, but not limited to, the channel matrix) cannot be obtained, precoding is performed using a preset precoding matrix or a weighting processing method. For brevity, the detailed contents thereof are not described herein again.

2. Channel reciprocity: in a Time Division Duplex (TDD) mode, uplink and downlink channels transmit signals on different time domain resources on the same frequency domain resource. The channel fading experienced by the signals on the uplink and downlink channels can be considered to be the same over a relatively short time (e.g., the coherence time of the channel propagation). This is the reciprocity of the uplink and downlink channels. Based on reciprocity of the uplink and downlink channels, the network device may measure the uplink channel according to an uplink reference signal, such as a Sounding Reference Signal (SRS), and may estimate the downlink channel according to the uplink channel, thereby determining a precoding matrix for downlink transmission.

The uplink and downlink channels in Frequency Division Duplex (FDD) mode have some reciprocity, such as angle reciprocity and delay reciprocity, in other words, delay and angle reciprocity in the FDD mode. Thus, the angle and the time delay may also be referred to as reciprocity parameters.

Since the signal may travel multiple paths from the transmit antenna to the receive antenna as it travels through the wireless channel. Multipath delay causes frequency selective fading, which is a change in the frequency domain channel. The delay is the transmission time of the radio signal on different transmission paths, is determined by the distance and the speed, and has no relation with the frequency domain of the radio signal. When signals are transmitted on different transmission paths, different transmission delays exist due to different distances. Therefore, the uplink and downlink channels with the same delay in FDD mode can be considered to be identical or reciprocal.

In addition, the angle may refer to an angle of arrival (AOA) at which a signal arrives at a receiving antenna via a wireless channel, and may also refer to an angle of departure (AOD) at which a signal is transmitted through a transmitting antenna. In this embodiment, the angle may refer to an arrival angle at which the uplink signal reaches the network device, or may refer to a departure angle at which the network device transmits the downlink signal. The angle of arrival of the uplink reference signal and the angle of departure of the downlink reference signal may be considered to be the same, or reciprocal. Therefore, the uplink and downlink channels of the angle in the FDD mode have reciprocity.

3. Reference Signal (RS): also referred to as pilots (pilots), reference sequences, etc. In the embodiment of the present application, the reference signal may be a reference signal for channel measurement. For example, the reference signal may be a channel state information reference signal (CSI-RS) for downlink channel measurement, or may be a Sounding Reference Signal (SRS) for uplink channel measurement. It should be understood that the above-listed reference signals are only examples and should not constitute any limitation to the present application. This application does not exclude the possibility of defining other reference signals in future protocols to achieve the same or similar functions.

The precoded reference signal may be a reference signal obtained by precoding the reference signal. The precoding may specifically include beamforming (beamforming) and/or phase rotation. Beamforming may be implemented by precoding the downlink reference signal based on one or more angle vectors, and phase rotation may be implemented by precoding the downlink reference signal with one or more delay vectors.

In the embodiment of the present application, for convenience of distinction and explanation, a reference signal obtained through precoding, such as beamforming and/or phase rotation, is referred to as a precoding reference signal; the reference signals that are not precoded are simply referred to as reference signals.

In the 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 the downlink reference signal to implement beamforming. Precoding the downlink reference signal based on one or more delay vectors, which may also be referred to as loading one or more delay vectors onto the downlink reference signal to implement phase rotation. Precoding the downlink reference signal based on one or more delay vectors, which may also be referred to as loading one or more relative delay vectors onto the downlink reference signal to implement phase rotation. With respect to the relative time delays, the following embodiments are described in detail.

4. Port (port): which may be understood as a virtual antenna identified by the receiving device. In this embodiment, a port may refer to a reference signal sending port and a transmitting antenna port, for example, a reference signal of each port may be a reference signal that is not precoded, or may be a precoded reference signal obtained by precoding a reference signal based on at least one delay vector; the port may also be a reference signal port after beamforming, for example, the reference signal corresponding to each port may be a precoded reference signal obtained by precoding the reference signal based on an angle vector, or may be a precoded reference signal obtained by precoding the reference signal based on an angle vector and a delay vector. The signal of each port may be transmitted through one or more Resource Blocks (RBs).

The transmit antenna port may refer to an actual transmit unit (TxRU). It can be appreciated that if the reference signal is spatially precoded, the number of ports can refer to the number of reference signal ports, which can be less than the number of transmit antenna ports.

In the embodiments illustrated below, when referring to transmit antenna ports, it may refer to the number of ports that are not spatially precoded. I.e. the actual number of independent transmission units. When referring to ports, in different embodiments, the ports may refer to transmit antenna ports or reference signal ports. The specific meaning expressed by a port may be determined according to a specific embodiment.

5. Angle vector: which may be understood as a precoding vector used for beamforming the reference signals. Through beam forming, the transmitted reference signal can have certain spatial directivity. Therefore, the process of precoding the reference signal based on the angle vector can also be regarded as a process of spatial domain (or, in short, spatial domain) precoding.

The number of ports of the precoded reference signal obtained by precoding the reference signal based on one or more angle vectors is the same as the number of angle vectors.

Optionally, the angle vector is taken from an (oversampled) Discrete Fourier Transform (DFT) matrix.

The reference signal loaded with the angle vector may be transmitted to the terminal device through a downlink channel, and therefore, a channel measured by the terminal device according to the received precoding reference signal is equivalent to the channel loaded with the angle vector.

It should be understood that an angle vector is one form proposed herein for representing an angle. The angle vector is named only for the convenience of distinguishing from the time delay and should not constitute any limitation to the present application. This application does not exclude the possibility of defining other names in future protocols to represent the same or similar meanings.

6. Frequency domain unit: the unit of the frequency domain resource can represent different frequency domain resource granularities. The frequency domain units may include, but are not limited to, subbands (subbands), Resource Blocks (RBs), Resource Block Groups (RBGs), precoding resource block groups (PRGs), and the like, for example.

In this embodiment, the network device may determine the precoding matrix corresponding to each frequency domain unit based on the feedback of the terminal device.

7. Terminal device specific (which may be referred to as UE specific) latency: the user-specific delay is a delay to which a network device shifts a delay observed by each port on a terminal side for a terminal device (the delay may be embodied as a certain delay tap in a delay domain, the delay is specific to the terminal device, and the delays of different terminal devices may be different or the same), which is equivalent to a specific delay component to which an equivalent channel of the terminal device is moved, and is a delay to which a path delay is shifted after the path delay is shifted, and the path delay is an angular delay pair (which may be a relative delay or an absolute delay) corresponding to a path, and the angular delay pair may be a combination of an angular vector and a delay vector. Each angular delay pair may include an angular vector and a delay vector. The angle vectors and/or delay vectors contained in any two angular delay pairs are different. In other words, each angular delay pair may be uniquely determined by an angular vector and a delay vector. It should be understood that an angular delay pair may be understood as a representation of a space-frequency fundamental unit defined by an angular vector and a delay vector, but it is not necessarily the only representation. For example, it may be expressed as a space-frequency component matrix, a space-frequency component vector, or the like.

A space-frequency component matrix can be determined by an angular delay pair. Alternatively, a space-frequency component matrix can be uniquely determined by an angle vector and a delay vector. A space-frequency component matrix and an angle delay pair are mutually converted. The space-frequency matrix may be an intermediate quantity for determining the precoding matrix.

For the space-frequency component matrix, the space-frequency component vector, and the like, reference may be made to the description of the prior art, which is not limited in this application.

8. Time delay offset: the delay offset mentioned in this application is the time delay (which can be recorded as tau' or tau) of original channel shifted to destination by network side^*) That is, after performing the delay offset, the equivalent channel delay observed at the terminal side is at τ' or τ^*。

9. Reference signal resource: the reference signal resource may be used to configure transmission attributes of the reference signal, such as time-frequency resource location, port mapping relationship, power factor, scrambling code, and the like, and refer to the prior art specifically. The transmitting end device may transmit the reference signal based on the reference signal resource, and the receiving end device may receive the reference signal based on the reference signal resource. One reference signal resource may include one or more RBs.

In the embodiment of the present application, the reference signal resource may be, for example, a CSI-RS resource.

10. FDD downlink channel reconstruction (also referred to as CSI acquisition based on FDD partial reciprocity):

the method for reconstructing the downlink channel based on the CSI of the FDD system comprises the following steps:

the method comprises the following steps: the network equipment receives the SRS sent by the terminal equipment, and estimates information (such as a direction angle, time delay and the like) with reciprocity of an uplink and a downlink by utilizing the uplink SRS;

step two: the network device sends a downlink reference signal to the terminal device, and specifically, the network device loads (may include offset performed on a delay component) the obtained information with reciprocity between uplink and downlink onto the downlink reference signal, and notifies the terminal device to measure and feed back the supplementary information that the network device needs to obtain;

step three: the terminal device re-estimates and feeds back the supplementary information by using the downlink reference signal (for example, the supplementary information may be full-band complex amplitude corresponding to each port, that is, a superposition coefficient corresponding to each port);

step four: and the network equipment reconstructs a downlink channel by using the information acquired in the first step and the third step, namely, a precoding matrix matched with the channel state is determined according to the acquired information and a preset codebook structure to process the signal to be transmitted, so that the signal to be transmitted after precoding is matched with the channel.

11. Subband (subband): also referred to as subcarriers, are used for carrying signals, occupy a certain bandwidth in a frequency domain, and may be embodied as Resource Elements (REs). The subbands referred to in this application are subbands used to transmit CSI-RS.

12. Port-corresponding superposition coefficient: the superposition coefficient corresponding to the port may be a path complex amplitude under a specific condition, and a projection coefficient of a channel on a precoding vector carried by the CSI-RS port is the superposition coefficient corresponding to the CSI-RS port. And the UE feeds back the superposition coefficient corresponding to each sending port to the network equipment. And the network equipment reconstructs a downlink channel by using the direction angle and the time delay of each path estimated by the uplink and the superposition coefficient of each sending port reestimated and fed back by the UE.

In addition, in order to facilitate understanding of the embodiments of the present application, the following description is made.

First, in the present application, "for indicating" may include for direct indication and for indirect indication. When a certain indication information is described for indicating a, the indication information may be included to directly indicate a or indirectly indicate a, and does not mean that a is necessarily carried in the indication information.

If the information indicated by the indication information is referred to as information to be indicated, in a specific implementation process, there are many ways of indicating the information to be indicated, for example, but not limited to, directly indicating the information to be indicated, such as the information to be indicated itself or an index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, wherein an association relationship exists 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 part of the information to be indicated is known or predetermined. For example, the indication of the specific information may be implemented by means of a predetermined arrangement order of the respective information (e.g., protocol specification), thereby reducing the indication overhead to some extent.

The information to be indicated may be sent together as a whole, or may be sent separately by dividing into a plurality of pieces of sub information, and the sending periods and/or sending timings of these pieces of sub information may be the same or different. Specific transmission method this application is not limited. The sending period and/or sending timing of the sub information may be predefined, for example, predefined according to a protocol, or may be configured by the transmitting end device by sending configuration information to the receiving end device. The configuration information may include, for example and without limitation, one or a combination of at least two of radio resource control (rrc) signaling, Medium Access Control (MAC) layer signaling, and physical layer signaling. Among them, radio resource control signaling such as packet Radio Resource Control (RRC) signaling; the MAC layer signaling includes, for example, a MAC Control Element (CE); the physical layer signaling includes, for example, Downlink Control Information (DCI).

Second, the first, second and various numerical numbers in the embodiments shown below are merely for convenience of description and are not intended to limit the scope of the embodiments of the present application. For example, the first and second may be distinguished as types in the embodiment of the present application, and not as object contents.

Third, the term "store" referred to in the embodiments of the present application may refer to storing in one or more memories. The one or more memories may be provided separately or integrated in the encoder or decoder, the processor, or the communication device. The one or more memories may also be provided separately, with a portion of the one or more memories being integrated into the decoder, the processor, or the communication device. The type of memory may be any form of storage medium and is not intended to be limiting of the present application.

Fourth, the "protocol" referred to in this embodiment of the present application may refer to a standard protocol in the communication field, and may include, for example, an LTE protocol, an NR protocol, a WLAN protocol, and other related protocols in the communication system, which is not limited in this application.

Fifth, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, and c, may represent: a, or, b, or, c, or, a and b, or, a and c, or, b and c, or, a, b and c. Wherein a, b and c may be single or plural respectively.

Sixth, the DFT involved in the embodiments of the present application may or may not be oversampled. Hereinafter, therefore, the term "oversampled discrete fourier transform DFT" or "oversampled DFT" is used collectively to mean either an oversampled DFT or a DFT without oversampling.

In a 5G communication system, a large-scale multi-antenna technology plays a crucial role in the spectral efficiency of the system. When the MIMO technology is adopted, modulation coding and signal precoding are required when the network device transmits data to the terminal device. How the network device sends data to the terminal device needs to depend on Channel State Information (CSI) fed back to the network device by the terminal device, which has a great effect on the performance of the system.

In the TDD system, since the uplink channel and the downlink channel use the same bandwidth and have reciprocity, the network device side can obtain CSI of the downlink channel through the uplink channel by using the reciprocity of the uplink channel and the downlink channel, and then perform signal precoding.

In an FDD system, the network device side may send information with reciprocity to the pilot frequency by using the partial reciprocity of FDD, and the terminal device only needs to feed back information without reciprocity (e.g. information other than angle and time delay). The network device can obtain the complete CSI of the downlink channel by combining the information with reciprocity obtained by the uplink channel and the information without reciprocity fed back by the terminal device.

The network device needs to estimate part of prior information including angle and delay information of the uplink channel by using the uplink channel information. And the network equipment projects on a certain spatial domain substrate (S) complete set or a frequency domain substrate (F) complete set to obtain a corresponding optimal angle and a time delay estimation value. H_ULRepresenting the space-frequency matrix resulting from the uplink channel measurements.

H_ULCan be expressed as: h_UL＝SC_ULF^H。

Wherein, S corresponds to airspace information and physically corresponds to an arrival angle/departure angle of the network device. S may represent a matrix of one or more angle vector constructions. F corresponds to the frequency domain information and physically corresponds to the multipath time delay of the multipath signal reaching the network equipment. F may represent a matrix of one or more delay vector constructions. C may represent a weighting coefficient corresponding to one angle vector and one delay vector. C_ULAnd representing a coefficient matrix corresponding to the uplink channel. The superscript H denotes a conjugate transpose, e.g., F^HRepresenting the conjugate transpose of a matrix (or vector) F.

The network equipment loads the angle time delay pair on the pilot frequency, and the terminal equipment carries out channel measurement according to the received pilot frequency signal to obtain the superposition coefficient of the corresponding angle time delay pair.

When the network device loads the angle delay pair on the pilot, a delay offset may be made, but if a unified delay offset is defaulted for multiple users, that is, an equivalent channel of different UEs is defaulted to be uniformly offset to a certain delay component, for example, as shown in fig. 2, a user-specific delay is not determined for different users, but all users are uniformly offset to a position where a delay tap is 0 in a delay domain, that is, a delay 0 point, interference between channel state information-reference signals (CSI-RS) of multiple users may be caused, and a problem of reducing CSI-RS multiplexing rate and CSI-RS overhead is too large may be caused.

In view of this, the present application provides a method, which may reduce the influence of delay skew caused by uplink and downlink timing errors, reduce interference among multi-user CSI-RS, improve CSI-RS reuse rate, and reduce CSI-RS overhead, by using a specific delay for each UE, that is, a specific first delay for the UE.

Various embodiments provided herein will be described in detail below with reference to the accompanying drawings. The following embodiments are described mainly by way of example, but not by way of limitation, with reference to the system shown in fig. 1 a.

Fig. 3 is a schematic interaction diagram of a method 300 for channel measurement according to an embodiment of the present application. The method 300 may include the following steps.

The terminal device receives 310 the precoded reference signal.

Correspondingly, the network device generates the precoding reference signal and transmits the precoding reference signal, where the precoding reference signal corresponds to one or more ports, and the ports may be regarded as transmission ports of the precoding reference signal.

The network device may precode the downlink reference signals based on information with reciprocity, which may be determined based on uplink channel measurements. For example, since the angle and the delay have reciprocity of the uplink and downlink channels, the network device may precode the downlink reference signal with an angle vector and/or a delay vector determined based on the uplink channel measurement, so that the terminal device performs channel estimation based on the precoded reference signal.

It should be understood that other information with reciprocity may be used in the embodiments of the present application. The following is mainly exemplified by angles and/or time delays.

Optionally, in this embodiment of the present application, the network device may perform precoding on the downlink reference signal based on the angle vector determined by the uplink channel measurement.

Take T delay vectors as an example. Wherein T is not less than 1 and is an integer. In the present embodiment, each angle may be characterized by an angle vector. Each delay can be characterized by a delay vector. Therefore, in the embodiment of the present application, one angle vector may represent one angle, and one delay vector may represent one delay. Hereinafter, the delay and the delay vector are sometimes used alternately, and the angle vector are sometimes used alternately.

The T delay vectors may be determined based on uplink channel measurements. Alternatively, the T delay vectors may not be determined based on uplink channel measurements. For example, the T delay vectors may be predefined, as defined by the protocol; alternatively, the T delay vectors may be determined based on one or more previous downlink channel measurement statistics. The present application does not limit the manner of obtaining the T delay vectors.

The number of delay vectors corresponding to one angle vector is not limited in the embodiments of the present application.

For example, in one possible design, T delay vectors correspond to each of the F angle vectors. Or, any two of the F angle vectors may correspond to the same T delay vectors.

As another example, in another possible design, one or more of the T delay vectors may correspond to one of the F angle vectors. Or, in the F angle vectors, the delay vectors corresponding to at least two angle vectors are different.

The following is an exemplary description of an F angle vector. Wherein F is not less than 1 and is an integer.

Optionally, the precoded reference signal is obtained by precoding the reference signal based on the F angular vectors.

The network device may precode reference signals, such as CSI-RS, based on each of the predetermined F angular vectors to obtain precoded reference signals corresponding to the F ports. The precoded reference signal for each port may be precoded based on one of the F angular vectors.

Since the angle has reciprocity between the uplink and downlink channels, the F angle vector can be determined based on uplink channel measurements. The network device may determine the stronger F angles according to the uplink channel matrix estimated in advance. The F angle may be characterized by an F angle vector.

The F angular vectors may be taken from a predefined set of angular vectors, for example. Optionally, each angular vector in the set of angular vectors is taken from an (oversampled) DFT matrix. Optionally, each angular vector in the set of angular vectors is a steering vector.

The network device may determine the F angle vector using, for example, a Joint Angle and Delay Estimation (JADE) algorithm in the prior art. Specifically, the estimation algorithm may be, for example, a multiple signal classification algorithm (MUSIC), a Bartlett (Bartlett) algorithm, or a rotation invariant subspace algorithm (ESPRIT). The network device may also determine the F angle vector by (oversampling) DFT on a space-frequency matrix determined based on the uplink channel measurements. The specific method for determining the F angle vector by the network device is not limited in this application.

It should be understood that the F angle vector is not necessarily determined based on uplink channel measurements. For example, the F angle vector may be predefined, as defined by the protocol; alternatively, the F angle vector may be statistically determined based on results fed back from one or more previous downlink channel measurements. The present application is not limited to the determination of the F angular vector.

The following description focuses on the processing of the delay vector in the present application, and the processing of the angle vector will not be described in detail in the present application.

And 320, the terminal equipment performs channel measurement based on the pre-coding reference signal and the specific first time delay of the terminal equipment to obtain the superposition coefficient corresponding to each port.

The specific first delay of the terminal device may be indicated to the terminal device by the network device, may be determined by the terminal device based on the indication of the network device within a predetermined delay range, may also be obtained by the terminal device performing delay adjustment estimation, and optionally may be obtained by the terminal device performing delay adjustment estimation in association with each port (so to speak, all ports) or in association with some ports. In any way, the first time delay is a time delay specific to the terminal device, and may also be referred to as a time delay specific to the terminal device. It should be understood that "the superposition coefficient corresponding to each of the ports" includes all or part of the superposition coefficients corresponding to each of the ports. If there are 8 ports and 4 superposition coefficients corresponding to each port, then there are 32 total superposition coefficients corresponding to each port (8 times 4), "the superposition coefficient corresponding to each port" may be all the 32 superposition coefficients, or may be some of the superposition coefficients (for example, the superposition coefficients selected by the terminal device according to a preset rule), for example, the same number of superposition coefficients are selected for each port, or the superposition coefficients are selected according to the preset rule for each port, 3 superposition coefficients meeting a predetermined condition are selected for port 1, 4 superposition coefficients meeting the predetermined condition are selected for port 2, 2 superposition coefficients meeting the predetermined condition are selected for port 3, 0 superposition coefficient meeting the predetermined condition is selected for port 4, and so on. It should also be understood that if the "superposition coefficient corresponding to each of the ports" is a partial superposition coefficient corresponding to each of the ports, it is not excluded that the terminal device also obtains all superposition coefficients corresponding to each of the ports, and it is understood that "obtaining" feedback information (content indicated by the first indication information described below) for the terminal device in 320 is not excluded that other information is obtained.

It is to be understood that the terminal device may be based on the terminal device specific first time delay, directly based on the first time delay, or indirectly based on the first time delay, for example, based on information associated with the first time delay (the associated information can be obtained by the first time delay), for example, an (oversampled) DFT frequency domain vector (such as w in the following) corresponding to the first time delay_qAnd/or w'_q)。

In the following embodiments, the channel measurements in the acquisition modes with different first time delays will be described separately.

And 330, the terminal equipment sends the first indication information.

And the corresponding network equipment receives the first indication information, wherein the first indication information is used for indicating the superposition coefficient.

The first indication information may directly carry the superposition coefficient, may also carry a parameter associated with the superposition coefficient, or a modified form of the superposition coefficient, or the like, and in short, the first indication information may directly or indirectly indicate the superposition coefficient. It can be understood that the first indication information may be issued through one or more signaling, and the application is not limited thereto.

The superposition coefficients corresponding to the respective ports are used for determining the first codebook, and it should be understood that all descriptions referring to "the respective ports" in this application are intended to emphasize that each port of all ports is to be considered, and the "superposition coefficient corresponding to each port" is to say that the superposition coefficient corresponding to each port is considered in all ports, that is, a collection of the superposition coefficients corresponding to the respective ports is considered. Then "the superposition coefficients corresponding to the respective ports are used for determining the first codebook" may be understood as "the superposition coefficients corresponding to each of all the ports are used together for determining the first codebook"; for example, if there are P ports and the superposition coefficients corresponding to each port (which may be all the superposition coefficients corresponding to each port, or corresponding partial superposition coefficients) are L ', then there are PL ' superposition coefficients for determining the first codebook, where P, L ' is an integer greater than or equal to 1 and PL ' represents P multiplied by L '.

The first codebook satisfies

That is to say the structure of the first codebook may be directly

Other forms are also possible as long as they satisfy

That is, the first codebook structure may be, for example

Wherein W'_f＝QW_fThat is, the first codebook satisfies

). Wherein W₁Selecting a matrix for a port of said port, W₂A superposition coefficient matrix (marked as case one) of the superposition coefficients corresponding to each port, or W₂A superposition coefficient matrix (denoted as case two), W, of superposition coefficients corresponding to the selected port_fIs a matrix of frequency components (which may also be referred to as a frequency domain basis vector matrix),

represents W_fQ is a diagonal matrix related to said first time delay, Q^HRepresenting the conjugate transpose of Q. In the following embodiments, the codebook structures will be described respectively according to the channel measurements in the acquisition modes with different first time delays.

The port selection matrix W₁Which may be any type of port selection matrix (including existing port selection matrix types and possible port selection matrix types in the future, which is not limited in this application) that can be used to indicate information for port selection. For example, for a dual polarized antenna, W₁The dimension can be P x 2L₀，W₁For selecting 2L from P CSI-RS ports₀A port, L₀Meaning the number of CSI-RS ports (space vector) selected for one polarization direction, and P meaning the number of CSI-RS ports. L is₀And the value of P can be configured by the network side through one or more of RCC, MAC CE and DCI signaling, and can also be agreed by the protocol. Furthermore, if the ports are divided into port groups, W can also be interpreted from the perspective of the port groups₁Enabling selection of corresponding ports, e.g. W for dual-polarized antennas₁The dimension can be expressed as

The number of CSI-RS port groups representing one polarization direction,

and the number of the CSI-RS port groups selected by one polarization direction is shown.Suppose that

If read from the port perspective, here W₁Each column of elements represents a port group, wherein an element with the value of 1 represents the selection of a corresponding CSI-RS port, and the corresponding CSI-RS port is selected according to the W₁Representing 2 CSI-RS port groups, a first CSI-RS port in the first group and a third CSI-RS port in the second group are selected. If read from the port group perspective, here W₁Each row element represents a port group, wherein the element with the value of 1 represents the selection of the corresponding CSI-RS port group, and the corresponding CSI-RS port group is selected according to the W₁Representing 4 CSI-RS port groups, a first CSI-RS port group and a third CSI-RS port group are selected.

W_fOr any type of frequency domain component matrix (including existing frequency domain component matrix types and future possible frequency domain component matrix types, which are not limited in this application), W_fMay comprise one or more specific column vectors (also referred to as basis vectors) which may be N in length for a column vector comprising one column vector_f×1，N_fThe number of frequency units may be equal to the number of RBs or subbands of the CSI-RS transmission bandwidth, may be a function of the number of RBs or subbands, and may be a network side notification or protocol convention. For example, the network side may restrict W by signaling_fFor a particular K columns of the (oversampled) DFT, the K columns represent K particular frequency component locations.

It will be appreciated that the port selection matrix W described above₁The selected port may not be indicated to the network device by the terminal device in other forms, for example, in the form of bitmap (bitmap), so that the first codebook may satisfy

Wherein,

and Q^HSee the above explanation, W₂As explained above, the stack of superposition coefficients corresponding to the portsAdding coefficient matrix (case one), i.e. combining the indication of bitmap and W₂The selected ports in all the ports and the superposition coefficients corresponding to the selected ports can be known; or W₂A superposition coefficient matrix of superposition coefficients corresponding to the selected port (case two), that is, combining the indication of bitmap and W₂It is possible to know which port is selected from all the ports and the superposition coefficient corresponding to the selected port.

Note that for case one, W₂The superposition coefficient matrix of the superposition coefficients corresponding to each port is only W₂Structural size of (or W)₂The number of matrix elements) takes into account the respective port (that is to say the number of ports of all ports), for example W₂The number of rows of (a) is the number of ports of all ports. But this does not mean that W₂Information content (W) of₂The content indicated by the matrix element) includes the superposition coefficient corresponding to each of all ports, e.g., some ports are not selected and their corresponding W₂May have a value of 0 on the matrix element, with only the selected port at W₂The corresponding matrix element in (1) has its corresponding superposition coefficient. Likewise, for case two, W₂The superposition coefficient matrix of the superposition coefficients corresponding to the selected port is only illustrated by W₂Structural size of (or W)₂Number of matrix elements) is selected taking into account (i.e. taking into account the number of ports selected), e.g. W₂The number of rows of (a) is the number of ports of the selected port. It can be seen that the matrix size may be smaller for case two versus case one.

340, the terminal equipment sends the third indication information.

340 is an optional step, where the corresponding network device receives third indication information, where the third indication information is used to indicate the port selection matrix W₁. Select matrix W to port₁The indication of (2) may be a direct indication or an indirect indication. Optionally, the third indication information may be sent through a message with the first indication information or through different messages respectively.

By the embodiment of the application, the channel measurement can be performed by using the specific time delay for each UE, so that the influence of time delay deviation caused by uplink and downlink timing errors can be reduced, the interference among multi-user CSI-RSs can be reduced, the CSI-RS multiplexing rate can be improved, and the CSI-RS overhead can be reduced.

Fig. 4 is a schematic interaction diagram of a method 400 for channel measurement according to another embodiment of the present application. The present embodiment is different from the embodiment shown in fig. 3 in that the obtaining manner of the first time delay in the present embodiment is indicated to the terminal device by the network device, and the method 400 may include the following steps.

The terminal device receives 410 the precoded reference signal.

410 is similar to 310 above, see description of 310, and will not be described further herein.

And 420, the terminal equipment receives the second indication information.

Accordingly, the network device generates the second indication information, and transmits the second indication information, where the second indication information is used to indicate a second time delay specific to the terminal device. In this embodiment, the second time delay is the first time delay.

Optionally, the second indication information may directly carry the second time delay, or may carry a parameter associated with the second time delay, or a variant of the second time delay, or the like, and in short, the second indication information may directly or indirectly indicate the second time delay. It can be understood that the second indication information may be issued through one or more signaling, which is not limited in this application. It should be understood that 410 and 420 are not necessarily in sequential order.

430, the terminal device determines a specific first time delay of the terminal device according to the second indication information, and performs channel measurement based on the precoding reference signal and the terminal first time delay to obtain a superposition coefficient corresponding to each port.

The direct or indirect indication means for the second indication information may specifically be:

means (1): the second indication information directly indicates the second time delay (note asτ^*)

Note that, here, τ^*Is the quantized delay information. The network device derives angular delay information (theta) for the ith path (or ith port) from the upstream channel estimate_i，τ_i)，θ_iFor angle information, τ_iFor time-delay information, and by pre-coding the angle and pre-bias post-delay (theta)_i，τ_i-τ^*) Loading the equivalent channel to a pilot, estimating the equivalent channel by using the pilot, assuming that the number of subbands is K (i.e. the number of subbands used for transmitting CSI-RS), the number of transmit antennas at the network device is M (UE may not sense the M), the number of receive antennas at the UE is N, the number of ports is P, where K, M, N, and P are integers, K and P may be indicated to the UE by the network device, and the equivalent channel on the nth (N is greater than or equal to 1 and less than or equal to N) UE antenna may be represented as:

wherein,

a complex field representing P rows and K columns,

indicating the downlink channel on the nth receive antenna and on the kth subband of the UE, where dl indicates downlink, N is 1,2, … …, N,

and representing the precoding weight vector of the p port and the k subband of the network equipment. Wherein K is 1,2, … …, K;

a complex field representing M rows and 1 columns;

of (2) element(s)

Denotes an equivalent channel estimated by the UE on the nth receiving antenna, the pth (P ═ 1,2, … …, P) port, and the kth subband, where eq denotes equivalence.

UE based on specific time delay tau^*Performing channel estimation to obtain equivalent channel, and recording as

(wherein

To consider tau not^*Resulting equivalent channel):

q is to utilize tau^*And carrying out a diagonal matrix of channel estimation, wherein the following form is satisfied:

wherein,

a plurality of fields representing K rows and K columns, the diagonal matrix having diagonal elements of

f_kThe frequency of the kth subband is represented, where K is 1,2, … …, and K is the number of subbands.

The UE calculates PL superposition coefficients corresponding to the nth receiving antenna of the UE (PL represents P multiplied by L, and the PL superposition coefficients are the sum of the superposition coefficients corresponding to the ports in the P ports, where the superposition coefficient corresponding to each port may be L):

wherein,

complex field representing PL row 1 column, vec (A) represents expanding matrix A into column vector by column, L is frequency domain component matrix W_fNumber of columns, W_fMay be indicated to the UE by the network equipment or predefined by the protocol. C is mentioned_nThat is, the superposition coefficient corresponding to each port corresponding to the nth receiving antenna of the UE.

Thereby obtaining the superposition coefficient c corresponding to each port of the nth receiving antenna of the UE_n。

Means (2): the second indication information indirectly indicates the second time delay by indicating other information

Suppose the number of sub-bands is K, the number of network equipment transmitting antennas is M, the number of UE receiving antennas is N, and the number of ports is P. The network equipment sends down signaling to indicate the UE to be in a specific frequency domain component w_q(with said τ)_*Correlation, corresponding to an indirect indication of τ^*) An upper feedback path coefficient (optionally, an index (index) of a (oversampled) DFT codebook may be indicated, which is equivalent to related information indicating O and O, optionally, O and O may be indicated to the UE together, or may be indicated to the UE through different messages, or may also indicate an O/O ratio; where O is the number of columns in the (oversampled) DFT codebook, O is 0, 1, …, O-1, it being understood that O is τ^*Associating;

wherein,

a complex field representing K rows and 1 columns, O ═ 0, 1, …, O-1, O being the number of columns in the (oversampled) DFT codebook, w_qThe column vector elements of

K is the number of sub-bands; the network device can phase O and OAnd transmitting the relevant information to the UE.

Network equipment obtains angle time delay information (theta) from uplink channel estimation_i，τ_i) After loading on the pilot, and proceed

Pre-offset of (2), wherein

Is w_qConjugation of (1).

The UE estimates an equivalent channel using the pilot, and the equivalent channel on the nth (N ═ 1,2, … …, N) antenna of the UE can be represented as:

wherein,

a complex field representing P rows and K columns,

indicating the downlink channel on the nth receive antenna, on the kth subband, where d1 indicates the downlink,

a complex field representing M rows and 1 columns;

of (2) element(s)

Denotes the equivalent estimated by the kth subband of the UE on the nth receiving antenna, the pth (P ═ 1,2, … …, P) port, and the kth subbandChannel, wherein eq represents equivalence.

UE is based on w_qAfter channel estimation, an equivalent channel is obtained and recorded as

(wherein

To consider w_qResulting equivalent channel):

is used to utilize w_qThe diagonal matrix for channel estimation is determined by the relevant information of O and O indicated by the network device, and satisfies the following form:

wherein, w_q(k) Denotes w_qThe k-th element of (2), the diagonal elements of the diagonal matrix are

K and K are the number of subbands, O is 0, 1, … and O-1.

wherein,

The terminal device sends 440 the first indication information.

Correspondingly, the network device receives the first indication information, where the first indication information is used to indicate the superposition coefficient corresponding to each port. 440 is similar to 330, and the same contents can be referred to the description of 330, and will not be described herein.

For a receiving antenna, the UE may report a feedback coefficient according to an indication of a network device or may select a part of coefficients from P × L coefficients to report by itself, and the coefficient selective reporting function may be implemented by reporting a bitmap (bitmap) or by other indication manners, which is described below for simplicity.

For all receiving antenna feedback modes of the UE:

if all receive antennas are for the UE, then there are N c_nFor feedback, it is assumed that, for each receiving antenna, the same number of P' coefficients are selected from the PL coefficients for feedback (of course, different numbers of coefficients may be selected for different receiving antennas for feedback), and coefficients corresponding to all receiving antennas are fed back

A complex field representing N rows and P' columns. Wherein, c_nFor the superposition coefficient corresponding to each port corresponding to the nth (N-1, 2, … …, N) UE antenna, [ c [₁ … c_N]^TIs represented by [ c₁ … c_N]The transposing of (1).

For Rank (Rank) feedback:

coefficient C for all receiving antennas₁ … c_N]^TSingular Value Decomposition (SVD) is carried out, equivalent coefficients of all the ranks corresponding to a feedback Rank Indicator (RI) are determined, and RP' equivalent coefficients are determined, wherein R is the Rank number and is less than or equal to N.

It can be understood that what feedback method the UE adopts is not limited, and may be a feedback method in the prior art.

Similar to the embodiment of fig. 3, the superposition coefficients corresponding to the ports are used to determine a first codebook, where the first codebook satisfies:

or,

for a detailed description, reference is made to the embodiment of fig. 3, which is not repeated herein.

It should be understood that the formula satisfied by the above first codebook is from the perspective of one receiving antenna, considering the set of superposition coefficients corresponding to each port in all ports corresponding to one receiving antenna, W₂1 is provided; if for multiple receive antennas, W₂There are N or may be N W₂Equivalent variations of (2).

Exemplary, optional, wherein

A matrix is selected for the ports (S is the number of ports selected for the UE,

positive integer field representing S rows and P columns, where P is the number of ports for the network device to transmit reference signals)

A complex field, W, representing P rows and L columns₂Is c_nThe quantization of (a) is performed,

is a matrix of frequency components specified by the network device,

representing a positive integer field of K rows and L columns.

For means (1) in 430, Q is a diagonal matrix of the form (see above for a detailed explanation, which is not repeated here):

for means (2) in 430, Q is a diagonal matrix of the form (see above for a detailed explanation, which is not repeated here):

450, the terminal equipment sends the third indication information.

450 is an optional step, the corresponding network device receives the third indication information, where the third indication information is used to indicate the port selection matrix W₁. Select matrix W to port₁The indication of (2) may be a direct indication or an indirect indication. Optionally, the third indication information may be sent through a message with the first indication information or through different messages respectively.

According to the embodiment of the application, the channel measurement can be performed by using the specific time delay for each UE based on the indication of the network equipment, so that the influence of time delay deviation caused by uplink and downlink timing errors can be reduced, the interference among multi-user CSI-RSs can be reduced, the CSI-RS multiplexing rate can be improved, and the CSI-RS overhead can be reduced.

Fig. 5 is a schematic interaction diagram of a method 500 for channel measurement provided by yet another embodiment of the present application. The difference between this embodiment and the embodiment shown in fig. 4 is that the first delay is obtained by the UE through delay estimation (the network device may apply the delay offset or may not apply the delay offset), and the method 500 may include the following steps.

The terminal device receives 510 a precoded reference signal.

510 is similar to 310, 410 described above, see description of 310, 410, and will not be described herein.

And 520, the terminal equipment receives the second indication information.

520 is an optional step in this embodiment, the UE may receive the second indication information indicating a second time delay specific to the terminal device. In this embodiment, the second delay is not the first delay, the second delay is a specific delay to which the network device is biased for the UE, and the first delay is a specific delay to be finally determined by the UE to be used for channel measurement (i.e., channel estimation). Optionally, the second indication information may directly carry the second time delay, or may carry a parameter associated with the second time delay, or a variant of the second time delay, or the like, and in short, the second indication information may directly or indirectly indicate the second time delay. It can be understood that the second indication information may be issued through one or more signaling, which is not limited in this application. It should be understood that 510 and 520 are not necessarily in sequential order.

530, the terminal device performs channel measurement based on the pre-coding reference signal and the specific first time delay of the terminal device, and obtains the superposition coefficient corresponding to each port.

Similar to 320 and 430, the same parts are not described herein again; the difference is that in this embodiment, the first delay is obtained by performing delay estimation by the UE, and may include:

in a first mode, the UE estimates the delay within a predetermined delay range corresponding to the second delay according to the indication of the second indication information, where the predetermined delay range may be a certain delay value range agreed by a protocol, and the UE may perform delay estimation within the predetermined delay range with the second delay as a reference based on the indication of the network device to obtain the first delay.

Taking the measure (1) in the embodiment of fig. 4 as an example, the same contents as the measure (1) in 430 are not repeated in this embodiment. UE based on specific time delay tau^*(i.e. the second time delay, or referred to as uplink time delay) to perform channel estimation, and then obtain an equivalent channel, i.e. the equivalent channel

Wherein

To consider tau not^*Resulting equivalent channel, Q_τ*Is used to utilize tau^*The diagonal matrix for channel estimation is of the form:

UE is based on time delay tau due to the existence of time deviation of uplink and downlink time delay^*After channel estimation, a correct time delay tap cannot be obtained, so that an equivalent channel needs to be obtained by additionally performing channel estimation based on uplink and downlink timing deviations, which can be calculated by the UE side and are recorded as τ_TAThen, the equivalent channel after channel estimation based on the uplink and downlink timing deviation is recorded as

Q_TAIs used to utilize tau_TAA diagonal matrix for channel estimation is performed, satisfying the following form

Alternatively, the two steps can be combined into one step, i.e. based on τ at the same time^*And τ_TAPerform channel estimation, i.e.

(τ^*+τ_TA) A first time delay specific to the terminal device.

The UE calculates P × L coefficients corresponding to the nth UE antenna as follows:

taking the measure (2) in the embodiment of fig. 4 as an example, the same contents as the measure (2) in 430 are not repeated in this embodiment. For with the said tau^*Related w_qUsing w_qThe diagonal matrix for channel estimation is determined by the relevant information of O and O indicated by the network device, and satisfies the following form:

for with the said tau_TACorrelated (oversampled) DFT frequency domain vector of w'_qThe relevant information of the index (index) of the corresponding (oversampled) DFT codebook is O 'and O'. From w'_qThe diagonal matrix for channel estimation is performed, satisfying the following form, and O' are decided by the UE:

and secondly, the network equipment does not send the second indication information, and even under the condition that the network equipment does not carry out time delay offset, the UE carries out time delay adjustment quantity estimation to obtain the second indication informationFirst delay (also equivalent to obtaining a corresponding (oversampled) DFT frequency domain vector), optionally, the UE may perform delay adjustment estimation jointly for each port (so to speak, jointly for all ports) or jointly for some ports. Unlike the first mode, the UE does not obtain τ separately in the second mode^*And τ_TATherefore, the second mode corresponds to the direct basis of (τ)^*+τ_TA) Performing channel estimation, or said UE performs channel estimation directly based on a specific τ ', where τ ' is a first time delay specific to the terminal device and τ ' is equivalent to (τ)^*+τ_TA). Or, in the second mode, the UE does not obtain w respectively_qAnd w'_qSo the second method is directly based on w_qAnd w'_qPerforming channel estimation, also called UE, directly on a specific basis

The channel estimation is carried out in such a way that,

is equivalent to w_qAnd w'_q，

The associated information of the index of the corresponding (oversampled) DFT codebook is o^*And O^*Determined by the UE.

The terminal device sends 540 the first indication information.

540 is similar to 440, and the same can be found in the description of 440, and will not be described herein. In contrast, the codebook structure in the present embodiment

Q in (1) for mode one is a diagonal matrix of the form:

wherein the diagonal elements are

f_kDenotes the frequency of the kth subband, K is 1,2, … …, K is the number of subbands, (τ)^*+τ_TA) For said first time delay, τ^*For uplink time delay, τ_TAIs the uplink and downlink timing offset.

For mode two, Q can be equivalently transformed as:

wherein the diagonal elements are

For approach one (2) Q is a diagonal matrix of the form:

wherein the diagonal elements of the diagonal matrix are

K is the number of subbands, where O is 0, 1, …, O-1, O 'is 0, 1, …, O' -1, O is the number of columns of the first (oversampled) DFT codebook, O 'is the number of columns of the second (oversampled) DFT codebook, and O' are associated with the first time delay. It is to be understood that the first (oversampled) DFT codebook may be determined by the network device, the second (oversampled) DFT codebook may be determined by the terminal device, that is, O is determined by the network device and O' is determined by the UE.

For mode two, Q can be equivalently transformed as:

wherein the diagonal elements of the diagonal matrix are

K is the number of subbands, where o^*＝0，1，…，O^*-1。

And 550, the terminal equipment sends third indication information.

550 is an optional step, where the corresponding network device receives third indication information indicating the port selection matrix W₁. Select matrix W to port₁The indication of (2) may be a direct indication or an indirect indication.

560, the terminal device sends the fourth indication information.

560 is an optional step, the corresponding network device receives fourth indication information, where the fourth indication information is used to indicate the first time delay. Optionally, the fourth indication information may directly or indirectly indicate the first time delay, for example, the fourth indication information includes information (e.g., τ) of the first time delay^*+τ_TAτ'), or the fourth indication includes a delay adjustment amount (e.g., τ) for obtaining the first delay_TA) Or include other information (e.g., O/O, O '/O', etc.) to indicate.

Optionally, the third indication information, the fourth indication information, and the first indication information may be sent through one message or sent through different messages, respectively.

According to the embodiment of the application, the UE is used for carrying out time delay estimation to determine that the channel measurement is carried out aiming at the specific time delay of the UE aiming at the possible uplink and downlink timing deviation, so that the influence of the time delay deviation caused by the uplink and downlink timing errors can be reduced, the interference among multi-user CSI-RSs is reduced, the CSI-RS multiplexing rate is improved, and the CSI-RS overhead is reduced.

It should be noted that, in the embodiments of fig. 3 to fig. 5, the first indication information, the third indication information, and the fourth indication information may be sent through the same signaling or through different signaling, which is not limited in this application.

For the above embodiments of fig. 3 to 5, the interference between users can be reduced when multiple users perform CSI-RS multiplexing in the time delay domain, and two users are taken as an example below. For simplicity of description, in this example, the angle domain information is ignored, and it is assumed that the network device and the UE are both configured with 1 antenna, the frequency domain has K subbands, each user only has one path, and when the precoding reference signal only corresponds to one port, the channels of the users are as follows:

wherein alpha is₁、α₂The superposition coefficients corresponding to users 1 and 2 (i.e. the superposition coefficient corresponding to the port, which may also be referred to as path complex coefficient), τ, respectively₁、τ₂Path delays for users 1,2, respectively (let τ be assumed)₁≠τ₂) UE1 multiplexes the same CSI-RS port with UE 2.

When the network side uniformly offsets UE1 and UE2 to a certain delay component (for example, delay 0 point), the network side issues CSI-RS weight precoding as w ═ (w ═ w)₁+w₂)^*，w₁And w₂Frequency domain phase change vectors (w) corresponding to path delays of users 1 and 2, respectively₁+w₂)^*Is (w)₁+w₂) The UE side estimates the path complex coefficients as follows:

can obtain

And

the signal-to-interference ratios of (a) and (b) are,

when the network device shifts to UE1 for UE1 to a first latency specific to UE1 (assuming a latency 0 point), the network device shifts to UE2 for UE2 to a first latency specific to UE2 (assuming τ^*) When the CSI-RS weight precoding is issued by the network side, the CSI-RS weight precoding is w ═ w (w)₁+Qw₂)^*Wherein Q is a diagonal matrix:

the UE side estimates the path coefficient as

Can obtain

And

respectively of

K is the number of subbands, denoted by γ₁And

γ₂and

as can be seen, the matrix Q can be designed such that

I.e. the estimated path complex coefficient signal-to-interference ratio improvement, especially when w₁And w₂When not orthogonal, Q may be selected such that Q is^Hw₁And w₂And (4) orthogonality is realized, the CSI-RS is multiplexed at the moment, and no interference exists among multiple users.

The method provided in the embodiments of the present application is described above in detail. Hereinafter, the communication device according to the embodiment of the present application will be described in detail with reference to fig. 6 to 8.

Fig. 6 is a schematic block diagram of a communication device provided in an embodiment of the present application. As shown, the communication device 1000 may include a communication unit 1100 and a processing unit 1200.

In one possible design, the communication apparatus 1000 may correspond to the terminal device in the above apparatus embodiment, and may be, for example, the terminal device or a chip configured in the terminal device.

Specifically, the communication apparatus 1000 may correspond to the terminal device in the method 300 according to the embodiment of the present application, and the communication apparatus 1000 may include a unit for executing the method executed by the terminal device in the method 300 in fig. 3. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flows of the method 300 in fig. 3.

Wherein, when the communication device 1000 is configured to execute the method 300 in fig. 3, the communication unit 1100 is configured to execute the step 310 in the method 300 relating to the terminal receiving step, to execute the steps 330,340 relating to the terminal transmitting step, and the processing unit 1200 is configured to execute the step 320 in the method 300.

Specifically, the communication apparatus 1000 may correspond to the terminal device in the method 400 according to the embodiment of the present application, and the communication apparatus 1000 may include a unit for executing the method executed by the terminal device in the method 400 in fig. 4. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flows of the method 400 in fig. 4.

Wherein, when the communication device 1000 is configured to perform the method 400 in fig. 4, the communication unit 1100 is configured to perform the steps 410,420 relating to the terminal receiving in the method 400, and to perform the steps 440,450 relating to the terminal transmitting in the method 400, and the processing unit 1200 is configured to perform the step 430 in the method 400.

Specifically, the communication apparatus 1000 may correspond to the terminal device in the method 500 according to the embodiment of the present application, and the communication apparatus 1000 may include a unit for executing the method executed by the terminal device in the method 500 in fig. 5. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flow of the method 500 in fig. 5.

Wherein, when the communication device 1000 is configured to perform the method 500 in fig. 5, the communication unit 1100 is configured to perform steps 510,520 in the method 500 relating to terminal reception, to perform steps 540,550,560 relating to terminal transmission, and the processing unit 1200 is configured to perform step 530 in the method 500.

It should be understood that the specific processes of the units for executing the corresponding steps are described in detail in the above device embodiments, and therefore, for brevity, are not described in detail herein.

It is further understood that when the communication apparatus 1000 is a terminal device, the communication unit 1100 in the communication apparatus 1000 may correspond to the transceiver 2020 in the terminal device 2000 shown in fig. 7, and the processing unit 1200 in the communication apparatus 1000 may correspond to the processor 2010 in the terminal device 2000 shown in fig. 7.

It should also be understood that when the communication device 1000 is a chip or a chip system configured in a terminal device, the communication unit 1100 in the communication device 1000 may be an input/output interface, an interface circuit, an output/input circuit, a pin or a related circuit, and the processing unit 1200 may be a processor, a processing circuit or a logic circuit.

Specifically, the communication apparatus 1000 may correspond to the network device in the method 300 according to the embodiment of the present application, and the communication apparatus 1000 may include a unit for executing the method executed by the network device in the method 300 of fig. 3. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flows of the method 300 in fig. 3.

Wherein, when the communication device 1000 is configured to perform the method 300 in fig. 3, the communication unit 1100 is configured to perform the step 310 in the method 300 involving the network device transmitting, to perform the steps 330,340 involving the network device receiving, and the processing unit 1200 is configured to perform the step of generating the precoded reference signal in the method 300.

Specifically, the communication apparatus 1000 may correspond to the network device in the method 400 according to the embodiment of the present application, and the communication apparatus 1000 may include a unit for executing the apparatus executed by the network device in the method 400 of fig. 4. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flows of the method 400 in fig. 4.

Wherein, when the communication device 1000 is configured to perform the method 400 in fig. 4, the communication unit 1100 is configured to perform the steps 410,420 of the method 400 relating to the step of network device transmission, to perform the steps 440,450 relating to the step of network device reception, and the processing unit 1200 is configured to perform the step of generating the precoded reference signal and the second indication information in the method 400.

Specifically, the communication apparatus 1000 may correspond to the network device in the method 500 according to the embodiment of the present application, and the communication apparatus 1000 may include a unit for executing the apparatus executed by the network device in the method 500 of fig. 5. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flow of the method 500 in fig. 5.

Wherein, when the communication device 1000 is configured to perform the method 500 in fig. 5, the communication unit 1100 is configured to perform steps 510,520 of the method 500 relating to the step of transmitting by the network device, to perform steps 540,550,560 relating to the step of receiving by the network device, and the processing unit 1200 is configured to perform the step of generating the precoded reference signal and/or the second indication information in the method 500.

It should also be understood that when the communication apparatus 1000 is a network device, the communication unit in the communication apparatus 1000 may correspond to the transceiver 3200 in the network device 3000 shown in fig. 8, and the processing unit 1200 in the communication apparatus 1000 may correspond to the processor 3100 in the network device 3000 shown in fig. 8.

It should also be understood that when the communication device 1000 is a chip or a system of chips configured in a network device, the communication unit 1100 in the communication device 1000 may be an input/output interface, an interface circuit, an output/input circuit, a pin or a related circuit, and the processing unit 1200 may be a processor, a processing circuit or a logic circuit.

Fig. 7 is a schematic structural diagram of a terminal device 2000 according to an embodiment of the present application. The terminal device 2000 can be applied in the system as shown in fig. 1a and 1b, and performs the functions of the terminal device in the above method embodiment.

As shown, the terminal device 2000 includes a processor 2010 and a transceiver 2020. Optionally, the terminal device 2000 further comprises a memory 2030. Wherein the processor 2010, the transceiver 2020, and the memory 2030 are interconnected via the interconnection path for communicating control and/or data signals, the memory 2030 is used for storing a computer program, and the processor 2010 is used for retrieving and executing the computer program from the memory 2030 to control the transceiver 2020 to transmit and receive signals. Optionally, the terminal device 2000 may further include an antenna 2040, configured to transmit uplink data or uplink control signaling output by the transceiver 2020 by using a wireless signal.

The processor 2010 and the memory 2030 may be combined into a processing device, and the processor 2010 is configured to execute the program codes stored in the memory 2030 to achieve the above functions. In particular, the memory 2030 may be integrated with the processor 2010 or may be separate from the processor 2010. The processor 2010 may correspond to the processing unit in fig. 6.

The transceiver 2020 may correspond to the communication unit in fig. 6, and may also be referred to as a transceiver unit. The transceiver 2020 may include a receiver (or receiver, receiving circuit) and a transmitter (or transmitter, transmitting circuit). Wherein the receiver is used for receiving signals, and the transmitter is used for transmitting signals.

It should be understood that terminal device 2000 shown in fig. 7 is capable of implementing various processes involving the terminal device in the method embodiments shown in fig. 3-4. The operations and/or functions of the modules in the terminal device 2000 are respectively to implement the corresponding flows in the above device embodiments. Reference is made specifically to the description of the embodiments of the apparatus described above, and the detailed description is omitted here as appropriate to avoid repetition.

The processor 2010 may be configured to perform the actions described in the previous apparatus embodiments as being implemented within the terminal device, and the transceiver 2020 may be configured to perform the actions described in the previous apparatus embodiments as being transmitted from the terminal device to the network device or received from the network device. Please refer to the description of the embodiment of the apparatus, which is not repeated herein.

Optionally, the terminal device 2000 may further include a power supply 2050 for supplying power to various devices or circuits in the terminal device.

In addition, in order to further improve the functions of the terminal device, the terminal device 2000 may further include one or more of an input unit 2060, a display unit 2070, an audio circuit 2080, a camera 2090, a sensor 2100, and the like, and the audio circuit may further include a speaker 2082, a microphone 2084, and the like.

Fig. 8 is a schematic structural diagram of a network device provided in the embodiment of the present application, where the network device 3000 may be applied to the system shown in fig. 1a, and performs the functions of the network device in the foregoing method embodiments.

In a 5G communication system, the network device 3000 may include CU, DU, and AAU in comparison to the network device in the LTE communication system, which is composed of one or more radio frequency units, such as a Remote Radio Unit (RRU) and one or more baseband units (BBUs):

the non-real-time part of the original BBU is divided and redefined as CU, which is responsible for processing non-real-time protocols and services, part of physical layer processing functions of the BBU, the original RRU and the passive antenna are combined into AAU, and the rest functions of the BBU are redefined as DU and are responsible for processing physical layer protocols and real-time services. In short, CU and DU are distinguished by real-time processing of content, and AAU is a combination of RRU and antenna.

The CU, DU, and AAU may be separately or jointly disposed, so that multiple network deployment forms may occur, one possible deployment form is consistent with the conventional 4G network device as shown in fig. 8, and the CU and DU are deployed in hardware. It should be understood that fig. 8 is only an example, and the scope of protection of the present application is not limited, for example, the deployment modality may also be that the DUs are deployed in the BBU room, the CU is deployed centrally or the DU is deployed centrally, the CU is deployed at a higher level, and the like.

The AAU3100 may implement a transceiving function called a transceiving unit 3100, corresponding to the communication unit 1100 in fig. 6. Alternatively, the transceiving unit 3100 may also be referred to as a transceiver, transceiving circuit, or transceiver, etc., which may comprise at least one antenna 3101 and a radio frequency unit 3102. Alternatively, the transceiving unit 3100 may include a receiving unit and a transmitting unit, the receiving unit may correspond to a receiver (or receiver, receiving circuit), and the transmitting unit may correspond to a transmitter (or transmitter, transmitting circuit). The CU and DU3200 may implement internal processing functions referred to as a processing unit 3200, corresponding to processing unit 1200 in fig. 6. Alternatively, the processing unit 3200 may control a network device, etc., and may be referred to as a controller. The AAU, CU and DU may be physically disposed together or may be physically disposed separately.

The network device is not limited to the embodiment shown in fig. 8, and may be in another embodiment: for example: the antenna comprises a BBU (baseband unit) and an Adaptive Radio Unit (ARU), or comprises a BBU and an Active Antenna Unit (AAU); the CPE may be a Customer Premise Equipment (CPE) or another type, and the present application is not limited thereto.

In an example, the processing unit 3200 may be formed by one or more boards, and the boards may jointly support a radio access network of a single access system (e.g., an LTE network), or may respectively support radio access networks of different access systems (e.g., an LTE network, a 5G network, or other networks). The BBU 3200 also includes a memory 3201 and a processor 3202. The memory 3201 is used to store necessary instructions and data. The processor 3202 is used for controlling the network device to perform necessary actions, for example, for controlling the network device to execute the operation flow related to the network device in the above method embodiment. The memory 3201 and processor 3202 may serve one or more boards. That is, the memory and processor may be provided separately on each board. Multiple boards may share the same memory and processor. In addition, each single board can be provided with necessary circuits.

It should be understood that the network device 3000 shown in fig. 8 is capable of implementing the network device functions involved in the method embodiments of fig. 3-5. The operations and/or functions of the units in the network device 3000 are respectively for implementing the corresponding processes executed by the network device in the method embodiment of the present application. To avoid repetition, detailed description is appropriately omitted herein. The structure of the network device illustrated in fig. 8 is only one possible form, and should not limit the embodiments of the present application in any way. This application does not exclude the possibility of other forms of network device architecture that may appear in the future.

The CU and DU3200 described above may be used to perform the actions described in the previous method embodiments that are implemented internally by the network device, while the AAU3100 may be used to perform the actions described in the previous method embodiments that the network device sends to or receives from the terminal device. Please refer to the description of the previous embodiment of the method, which is not repeated herein.

The embodiment of the application also provides a processing device, which comprises a processor and a communication interface; the processor is configured to execute a computer program, so that the processing apparatus implements the method in the above method embodiments.

It should be understood that the processing means described above may be one chip or a system of chips. For example, the processing device may be a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), a system on chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a digital signal processing circuit (DSP), a Microcontroller (MCU), a Programmable Logic Device (PLD), or other integrated chips. The communication interface may be an input/output interface, interface circuit, output circuit, input circuit, pin or related circuit on the chip or system of chips, etc. The processor may also be embodied as a processing circuit or a logic circuit.

In implementation, the steps of the above apparatus may be implemented by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of an apparatus disclosed in the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the device by combining the hardware. To avoid repetition, it is not described in detail here.

It should be noted that the processor in the embodiments of the present application may be an integrated circuit chip having signal processing capability. In implementation, the steps of the above device embodiments may be implemented by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor described above may 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 device, discrete gate or transistor logic, discrete hardware components. The various means, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the apparatus disclosed in this application can be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the device by combining the hardware.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and apparatus described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

According to an apparatus provided by an embodiment of the present application, the present application further provides a computer program product, including: computer program code which, when run on a computer, causes the computer to perform the method of any of the embodiments shown in figures 3-5.

According to the apparatus provided by the embodiment of the present application, a computer-readable medium is further provided, and the computer-readable medium stores program code, which when executed on a computer, causes the computer to execute the method of any one of the embodiments shown in fig. 3 to 5.

According to the apparatus provided in the embodiment of the present application, the present application further provides a system, which includes the foregoing one or more terminal devices and one or more network devices.

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

The network device in the above-mentioned various device embodiments completely corresponds to the terminal device and the network device or the terminal device in the device embodiments, and the corresponding module or unit executes the corresponding steps, for example, the communication unit (transceiver) executes the steps of receiving or transmitting in the device embodiments, and the steps other than transmitting and receiving may be executed by the processing unit (processor). The function of a particular element may be that of a corresponding device embodiment. The number of the processors may be one or more.

As used in this specification, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between 2 or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from two components interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal).

Those of ordinary skill in the art will appreciate that the various illustrative logical blocks and steps (step) described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing embodiments of the apparatuses, and are not described herein again.

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

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

In the above embodiments, the functions of the functional units may be fully or partially implemented by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). The procedures or functions described in accordance with the embodiments of the present application are generated in whole or in part when the computer program instructions (programs) are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the apparatus according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of channel measurement, the method comprising:

receiving a precoding reference signal, wherein the precoding reference signal corresponds to one or more ports;

performing channel measurement based on the pre-coding reference signal and a first time delay specific to the terminal equipment to obtain a superposition coefficient corresponding to each port;

and sending first indication information, wherein the first indication information is used for indicating the superposition coefficient.

2. The method of claim 1, wherein the superposition coefficients corresponding to the ports are used to determine a first codebook, and wherein the first codebook satisfies the requirement

represents W_fQ is a diagonal matrix related to said first time delay, Q^HRepresenting the conjugate transpose of Q.

3. According to claimThe method of claim 1, wherein the superposition coefficients corresponding to the ports are used to determine a first codebook, and the first codebook satisfies the requirement

4. The method of claim 2 or 3, wherein Q is:

wherein the diagonal elements are

Wherein O is 0, 1, …, O-1, and the elements on the diagonal are

K is 1,2, … …, K is the number of subbands, O is the number of columns of the oversampled DFT codebook, and O is associated with the first time delay; or

Wherein the diagonal elements are

K is 1,2, … …, K is the number of subbands, O is the number of columns in the first oversampled DFT codebook, O 'is the number of columns in the second oversampled DFT codebook, and O' are associated with the first time delay.

5. The method according to any one of claims 1-4, further comprising:

and receiving second indication information, wherein the second indication information is used for indicating a second time delay specific to the terminal equipment.

6. The method of claim 5,

the second indication information includes information of the second time delay, or

The second indication information includes an index of an oversampled DFT codebook.

7. The method of claim 5 or 6, wherein the second time delay is the first time delay.

8. The method of claim 5 or 6, wherein the first delay is a delay determined within a predetermined delay range corresponding to the second delay.

9. The method of any of claims 1-4, wherein the first delay is a delay obtained by performing a delay adjustment estimation.

10. The method according to claim 8 or 9, characterized in that the method further comprises:

and sending fourth indication information, wherein the fourth indication information is used for indicating the first time delay.

11. The method of claim 10,

the fourth indication information includes information of the first time delay, or

The fourth indication information includes information for obtaining a delay adjustment amount of the first delay.

12. The method according to any one of claims 1-11, further comprising:

and sending third indication information, wherein the third indication information is used for indicating a port selection matrix of the port.

13. A method of channel measurement, the method comprising:

generating a pre-coding reference signal, wherein the pre-coding reference signal corresponds to one or more ports;

transmitting the precoded reference signal;

receiving first indication information, wherein the first indication information is used for indicating superposition coefficients corresponding to the ports, and the superposition coefficients are associated with first time delays specific to terminal equipment.

14. The method of claim 13, wherein the superposition coefficients corresponding to the ports are used forDetermining a first codebook, the first codebook satisfying

15. The method of claim 13, wherein the superposition coefficients corresponding to the ports are used to determine a first codebook, and wherein the first codebook satisfies the requirement

16. The method of claim 14 or 15, wherein Q is:

wherein the diagonal elements are

Wherein O is 0, 1, …, O-1, and the elements on the diagonal are

Wherein the diagonal elements are

17. The method according to any one of claims 13-16, further comprising:

and sending second indication information, wherein the second indication information is used for indicating a second time delay specific to the terminal equipment.

18. The method of claim 17,

19. The method of claim 17 or 18, wherein the second time delay is the first time delay.

20. The method of claim 17 or 18, wherein the first delay is a delay determined within a predetermined delay range corresponding to the second delay.

21. The method according to any of claims 13-16, wherein the first delay is a delay obtained by estimating a delay adjustment amount by a terminal device.

22. The method according to claim 20 or 21, further comprising:

receiving fourth indication information, wherein the fourth indication information is used for indicating the first time delay.

23. The method of claim 22,

24. The method according to any one of claims 13-23, further comprising:

and receiving third indication information, wherein the third indication information is used for indicating a port selection matrix of the port.

25. An apparatus for channel measurement, the apparatus comprising:

a communication unit, configured to receive a precoded reference signal, where the precoded reference signal corresponds to one or more ports;

a processing unit, configured to perform channel measurement based on the precoding reference signal and a first time delay specific to a terminal device, and obtain a superposition coefficient corresponding to each port;

the communication unit is further configured to send first indication information, where the first indication information is used to indicate the superposition coefficient.

26. The apparatus of claim 25, wherein the superposition coefficients corresponding to the ports are used to determine a first codebook, and wherein the first codebook satisfies the requirement

27. The apparatus of claim 25, wherein the superposition coefficients corresponding to the ports are used to determine a first codebook, and wherein the first codebook satisfies the requirement

Wherein W₂A superposition coefficient matrix of superposition coefficients corresponding to the respective ports, or W₂The superposition coefficient of the superposition coefficient corresponding to the selected port in the superposition coefficients corresponding to the portsA matrix; w_fIs a matrix of frequency components and is,

28. The apparatus of claim 26 or 27, wherein Q is:

wherein the diagonal elements are

Wherein O is 0, 1, …, O-1, and the elements on the diagonal are

Wherein the diagonal elements are

f_kDenotes the frequency of the kth subband, K is 1,2, … …, K is the number of subbands, (τ)^*+τ_TA) For said first time delay, τ^*For uplink time delay, τ_TAIs up and down-row timing offset; or

29. The apparatus according to any of claims 25-28, wherein the communication unit is further configured to:

30. The apparatus of claim 29,

31. The apparatus of claim 29 or 30, wherein the second time delay is the first time delay.

32. The apparatus of claim 29 or 30, wherein the first delay is a delay determined within a predetermined delay range corresponding to the second delay.

33. The apparatus of any one of claims 25-28, wherein the first delay is a delay obtained by performing a delay adjustment estimation.

34. The apparatus of claim 32 or 33, wherein the communication unit is further configured to:

35. The apparatus of claim 34,

36. The apparatus according to any of claims 25-35, wherein the communication unit is further configured to:

37. The apparatus according to any of claims 25-36, wherein the apparatus is a terminal device, the communication unit is a transceiver, and the processing unit is a processor.

38. An apparatus for channel measurement, the apparatus comprising:

a processing unit, configured to generate a pre-coding reference signal, where the pre-coding reference signal corresponds to one or more ports;

a communication unit configured to transmit the precoded reference signal;

the communication unit is further configured to receive first indication information, where the first indication information is used to indicate a superposition coefficient corresponding to each port, and the superposition coefficient is associated with a first time delay specific to a terminal device.

39. The apparatus of claim 38, wherein the superposition coefficients corresponding to the ports are used to determine a first codebook, and wherein the first codebook satisfies the requirement

40. The apparatus of claim 38, wherein the superposition coefficients corresponding to the ports are used to determine a first codebook, and wherein the first codebook satisfies the requirement

41. The apparatus of claim 39 or 40, wherein Q is:

wherein the diagonal elements are

f_kDenotes the frequency of the kth subband, K is 1,2, … …, K is the number of subbands, τ^*Is the first time delay;or

Wherein O is 0, 1, …, O-1, and the elements on the diagonal are

Wherein the diagonal elements are

42. The apparatus of any of claims 38-41, wherein the communication unit is further configured to:

43. The apparatus of claim 42,

44. The apparatus of claim 42 or 43, wherein the second time delay is the first time delay.

45. The apparatus of claim 42 or 43, wherein the first delay is a delay determined within a predetermined delay range corresponding to the second delay.

46. The apparatus of any one of claims 38-41, wherein the first delay is a delay obtained by estimating a delay adjustment amount by a terminal device.

47. The apparatus according to claim 45 or 46, wherein the communication unit is further configured to:

48. The apparatus of claim 47,

49. The apparatus of any of claims 38-48, wherein the communication unit is further configured to:

50. The apparatus according to any of claims 38-49, wherein the apparatus is a network device, the communication unit is a transceiver, and the processing unit is a processor.

51. A processing apparatus, comprising at least one processor and a communication interface;

the communication interface is used for inputting and/or outputting information;

the processor is adapted to execute a computer program such that the method according to any of claims 1-24 is implemented.

52. The processing apparatus according to claim 51, wherein the processing apparatus is a chip or a system of chips.

53. A computer-readable storage medium, comprising a computer program which, when run on a computer, causes the method of any of claims 1-24 to be implemented.