CN114600384A

CN114600384A - Channel measurement method and communication device

Info

Publication number: CN114600384A
Application number: CN201980101549.0A
Authority: CN
Inventors: 刘永; 葛士斌; 金黄平; 毕晓艳
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2022-06-07
Anticipated expiration: 2039-10-30
Also published as: WO2021081847A1; CN114600384B

Abstract

The application provides a channel measurement method and a communication device. The method comprises the following steps: the terminal equipment generates and sends first indication information, wherein the first indication information is used for indicating P groups of weighting coefficients corresponding to P transmitting ports, reference signals of each transmitting port in the P transmitting ports are obtained by precoding the reference signals based on a time delay vector and/or an angle vector, and the weighting coefficient corresponding to each transmitting port in the P transmitting ports and the time delay vector and/or the angle vector corresponding to each transmitting port are used for constructing a precoding matrix; wherein, the P-th group of weighting coefficients corresponding to the P-th transmitting port in the P transmitting ports are obtained by performing time domain transformation on the channel information between the P-th transmitting port and the R receiving ports of the terminal equipment. By utilizing the partial reciprocity between the uplink channel and the downlink channel, the CSI of the downlink channel is obtained. And more accurate feedback can be obtained through time domain transformation, which is beneficial to providing the transmission performance of the system.

Description

Channel measurement method and communication device

Technical Field

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

Background

In a large-scale multiple-input multiple-output (Massive MIMO) technology, a network device can reduce interference among multiple users and interference among multiple signal streams of the same user through precoding, which is beneficial to improving signal quality, realizing space division multiplexing and improving spectrum utilization rate.

The terminal device may determine a precoding matrix based on downlink channel measurement, for example, and hopefully, through feedback, the network device obtains a precoding matrix that is the same as or similar to the precoding matrix determined by the terminal device. Specifically, the terminal device may instruct to construct the precoding matrix by feeding back one or more spatial vectors, one or more frequency domain vectors, and one or more weighting coefficients, for example. However, this feedback approach incurs a large feedback overhead.

In some communication technologies, such as Time Division Duplex (TDD) technology, there is reciprocity between the uplink channel and the downlink channel, and the network device may estimate the uplink channel based on measurements of the uplink channel. However, in some communication technologies, such as Frequency Division Duplex (FDD) technology, the uplink and downlink channels are not completely reciprocal. Therefore, how to obtain an accurate channel state of the downlink channel by using the partial reciprocity between the uplink channel and the downlink channel is a technical problem to be solved urgently.

Disclosure of Invention

The present application provides a channel measurement method and a communication apparatus, which are intended to utilize partial reciprocity between an uplink channel and a downlink channel to obtain Channel State Information (CSI) of the downlink channel, and provide system transmission performance.

In a first aspect, a channel measurement method is provided. The method may be performed by the terminal device, or may be performed by a component (e.g., a chip or a system of chips) configured in the terminal device.

Specifically, the method comprises the following steps: generating first indication information, wherein the first indication information is used for indicating P groups of weighting coefficients corresponding to P transmitting ports, reference signals of each transmitting port in the P transmitting ports are obtained by precoding the reference signals based on a time delay vector and/or an angle vector, and the weighting coefficient corresponding to each transmitting port in the P transmitting ports and the time delay vector and/or the angle vector corresponding to each transmitting port are used for constructing a precoding matrix; the P-th group of weighting coefficients corresponding to the P-th transmitting port in the P transmitting ports are obtained by carrying out time domain transformation on channel information between the P-th transmitting port and R receiving ports of the terminal equipment, the P-th transmitting port is any one of the P transmitting ports, P is more than or equal to 0 and less than or equal to P-1, P is more than or equal to 1, R is more than or equal to 1, and P, P and R are integers; and sending the first indication information.

It should be understood that the reference signal may be obtained by precoding based on one of an angle vector and a delay vector, or may be obtained by precoding based on the angle vector and the delay vector. This is not a limitation of the present application. The terminal device may perform channel measurement based on the received reference signal to feed back a weighting coefficient corresponding to each transmission port. It is to be understood that the weighting coefficients corresponding to each transmit port may also refer to the weighting coefficients corresponding to the angle vector and the delay vector.

Based on the above technical solution, the network device may perform precoding on the downlink reference signal based on the angle and the time delay determined by the uplink channel measurement, for example, so that the terminal device performs downlink channel measurement according to the precoded reference signal. Because the network device precodes the reference signal based on the reciprocal angle and/or time delay of the uplink and downlink channels, the terminal device does not need to feed back the space domain and/or frequency domain vector (such as the angle vector and/or the time delay vector), thereby greatly reducing the feedback overhead of the terminal device.

In addition, when the terminal device performs channel measurement based on the received precoding reference signal, the measured channel in the frequency domain is converted into the time domain, and a value obtained by time domain conversion is fed back as a weighting coefficient of an angle delay pair. Therefore, the problem that a channel recovered by a weighting coefficient obtained by accumulating and summing a plurality of discontinuous equivalent channels is inaccurate can be avoided, and higher feedback precision is obtained, so that the network equipment is facilitated to determine a precoding matrix adaptive to a downlink channel based on feedback, and the transmission performance of the system is facilitated to be improved.

With reference to the first aspect, in some possible implementations of the first aspect, each of the P sets of weighting coefficients includes R' weighting coefficients, and the P-th set of weighting coefficients is obtained by performing time-domain transformation on channel information between the P-th transmitting port and one or more receiving ports of the R receiving ports; r is more than or equal to R 'and more than or equal to 1, and R' is an integer.

That is, each set of weighting coefficients may correspond to one transmitting port, and the weighting coefficients in each set of weighting coefficients may be obtained by performing time domain transformation on channel information between one transmitting port and one receiving port, or may be obtained by performing time domain transformation on channel information between one transmitting port and a plurality of receiving ports. This is not a limitation of the present application.

Further, each of the P sets of weighting coefficients includes R weighting coefficients corresponding to the R receiving ports, and an R-th weighting coefficient of the P-th set of weighting coefficients is obtained by performing time domain transformation on channel information between the P-th transmitting port and an R-th receiving port of the R receiving ports.

That is, each weighting coefficient in each set of weighting coefficients may be obtained by performing time domain transformation on channel information between one transmitting port and one receiving port.

With reference to the first aspect, in some possible implementations of the first aspect, the method further includes: performing time domain transformation on the vector determined by the channel information between the p-th transmitting port and the r-th receiving port to obtain a transformed vector, wherein the r-th weighting coefficient in the p-th group of weighting coefficients is the n-th weighting coefficient in the vector obtained by the time domain transformation_p,rA value; wherein the vector determined by the channel information between the p-th transmitting port and the r-th receiving port includes N values, the N values include channel information corresponding to N frequency domain units for carrying reference signals of the p-th transmitting port, and N is greater than or equal to 0 and greater than or equal to N_p,r≤N-1，N≥1，n _p,rAnd N are integers.

Optionally, the time domain transformation comprises: an Inverse Fast Fourier Transform (IFFT) or an Inverse Discrete Fourier Transform (IDFT).

The above provides a way to obtain weighting coefficients by a time-domain transform. It should be understood that the above list is only an example, and should not constitute any limitation to the present application. The present application does not limit the specific implementation of the time domain transform.

Alternatively, n_p,rIs a predefined value. As an example, n _p,r＝0。

Because the first time domain transform value (i.e., the dc component) of the N time domain transform values obtained after performing the IFFT on the N channel estimation values is exactly equal to the sum of the N channel estimation values, the N channel estimation values are estimated based on the reference signals of the same transmit port received on the N frequency domain units. Thus, n may be substituted_p,rIs defined as 0.

It should be understood that n is described in detail herein using an IFFT as an example only for ease of understanding_p,rThe reason is defined as 0. This should not be construed as an admission that the invention is not so limitedAny limitation is imposed. Since the manner of time domain transformation is not limited to the above list, in different implementations, n is used_p,rThe definition of (c) may also be different. This is not a limitation of the present application.

Optionally, the first indication information is further used to indicate n corresponding to a channel between the p-th transmitting port and the r-th receiving port_p,rThe value of (c).

That is, the terminal device may decide on its own which of the N time-domain transform values to determine as the weighting factor, i.e., the terminal device may determine on its own N_p,rAnd reporting the value to the network equipment.

With reference to the first aspect, in some possible implementations of the first aspect, the method further includes: based on a predetermined filter coefficient, carrying out filter processing on the transformed vector to obtain an r weighting coefficient in the p weighting coefficient group; wherein the filter coefficient comprises N elements including a non-zero element and N-1 zero elements, and the non-zero element is the N-th element of the N elements _p,rAnd (4) each element.

As described above, the terminal device may select one value from the vectors obtained by the time domain transform as the weighting coefficient. The specific process that the terminal device takes one of the N time domain transform values as a weighting coefficient can be realized by filtering. The foregoing provides a filtering method for performing filtering processing on a vector obtained by the time-domain transform by using a predetermined filter coefficient, so that a terminal device can obtain a value that can be used as a weighting coefficient from the vector.

Exemplarily based on n enumerated above_p,rThe filter coefficient may be expressed, for example, as [ 10 … 0 ] when equal to 0] _1×N。

It should be understood that the above listed methods and filter coefficients are only examples and should not constitute any limitation to the present application. The present application is not limited to a specific manner of filtering and a specific form of filter coefficients.

In a second aspect, a channel measurement method is provided. The method may be performed by the terminal device, or may be performed by a component (e.g., a chip or a system of chips) configured in the terminal device.

Specifically, the method comprises the following steps: generating second indication information, wherein the second indication information is used for indicating P groups of weighting coefficients corresponding to P transmitting ports, reference signals of each transmitting port in the P transmitting ports are obtained by precoding the reference signals at least based on a time delay vector, and the weighting coefficient corresponding to each transmitting port in the P transmitting ports and the time delay vector corresponding to each transmitting port are used for constructing a precoding matrix; wherein, the P-th group weighting coefficient corresponding to the P-th transmitting port of the P transmitting ports is the sum of a plurality of values obtained by respectively filtering the channel information of one or a plurality of frequency domain unit groups, each frequency domain unit group of the one or a plurality of frequency domain unit groups comprises a plurality of frequency domain units, the total number of the frequency domain units comprised by the one or a plurality of frequency domain unit groups is the number of the frequency domain units used for bearing the reference signal of the P-th transmitting port, the P-th transmitting port is any one of the P transmitting ports, P is greater than or equal to 0 and less than or equal to P-1, P is greater than or equal to 1, and P are integers; and sending the second indication information.

It should be understood that the reference signal corresponding to each transmit port may be obtained by precoding based on a delay vector, or may be obtained by precoding based on an angle vector and a delay vector. This is not a limitation of the present application. The terminal device may perform channel measurement based on the received reference signal to feed back a weighting coefficient corresponding to each transmission port. It is to be understood that the weighting coefficients corresponding to each transmit port may also refer to the weighting coefficients corresponding to the angle vector and the delay vector.

Based on the above technical solution, the network device may perform precoding on the downlink reference signal based on the time delay determined by the uplink channel measurement, for example, so that the terminal device performs downlink channel measurement according to the precoded reference signal. Because the network device precodes the reference signal based on the time delay of the reciprocity of the uplink and downlink channels, the terminal device does not need to feed back the relevant information of the frequency domain (such as the time delay vector), thereby greatly reducing the feedback overhead of the terminal device.

In addition, by performing filtering processing on the channel information estimated on the plurality of frequency domain units, noise can be reduced, so that the channel information corresponding to each frequency domain unit obtained by filtering is more accurate. Therefore, the accuracy of channel measurement and feedback can be improved, the network equipment can determine the precoding matrix adaptive to the downlink channel based on the feedback, and the transmission performance of the system can be improved.

With reference to the second aspect, in some possible implementations of the second aspect, the method further includes: respectively filtering the channel information of the one or more frequency domain unit groups based on a predetermined filtering coefficient corresponding to the p-th transmitting port to obtain a filtered value; summing the filtered values of the one or more groups of frequency domain units to obtain a weighting coefficient corresponding to the p-th transmit port.

That is, the terminal device may filter the channel information corresponding to each transmission port based on the filter coefficient corresponding to the transmission port. The channel information corresponding to the transmitting port may be obtained by the terminal device through channel estimation based on the reception of a reference signal by the transmitting port.

With reference to the second aspect, in some possible implementations of the second aspect, the method further includes: based on the time delay tau corresponding to the p-th transmitting port_pOr time delay τ_pDetermines the filter coefficients, wherein each delay corresponds to a delay vector.

It can be seen that the filter coefficient is related to the delay corresponding to the transmit port. That is, the filter coefficient used by the terminal device to filter the channel information corresponding to a certain transmitting port is related to the delay corresponding to the transmitting port.

Optionally, the filter coefficients are:

wherein the content of the first and second substances,

wherein, the first and the second end of the pipe are connected with each other,

a correlation matrix, which represents the correlation between the frequency domain units in a frequency domain unit group for carrying the reference signal of the p-th transmitting port;

as a correction value for

The correction is carried out so that the correction is carried out,

for a time delay tau corresponding to the p-th transmitting port_pOr with time delay τ_pN represents the number of frequency domain units for carrying the reference signal of the p-th transmitting port, N > 1 and is an integer;

is a pair of

Correcting to obtain a correlation matrix; SNR is signal to noise ratio; i denotes a unit matrix.

An example of wiener filter coefficients is given above. In the embodiment of the application, the correction value related to the time delay is introduced into the wiener filter coefficient, so that the compensation of the wiener filter coefficient in the prior art can be realized. It can be seen that the correction value is related to the time delay corresponding to the transmitting port, and the correlation among the pilot frequencies on a plurality of frequency domain units of the same port is fully utilized, so that the channel information corresponding to each frequency domain unit obtained by filtering is more accurate, and the originally discontinuous equivalent channel can be subjected to combined filtering to a greater extent. Therefore, the problem of channel estimation inaccuracy caused by the fact that frequency domain resources cannot be bound in the prior art can be solved.

It should be understood that the above listed wiener filter coefficients are only examples and should not limit the present application in any way. The present application is not limited to a specific form of the filter coefficient.

With reference to the second aspect, in some possible implementations of the second aspect, the method further includes: and receiving third indication information, wherein the third indication information is used for indicating the time delay or the relevant parameters of the time delay corresponding to each of the P transmitting ports, and each time delay corresponds to a time delay vector.

The terminal equipment is convenient to determine the filter coefficient by indicating the time delay corresponding to each transmitting port or the related coefficient of the time delay to the terminal equipment, thereby realizing the filtering of the estimated channel information.

Optionally, the third indication information indicates, as the latency corresponding to each transmit port, the latency corresponding to each transmit port in the P transmit ports.

Optionally, the indication of the third indication information on the relevant parameter of the time delay corresponding to each of the P transmit ports is: the time delay tau corresponding to the first transmitting port in the P ports₀And the difference value delta tau between the time delay corresponding to the other ports except the first transmitting port in the P transmitting ports and the time delay corresponding to the first transmitting port.

The above provides two possible implementations for indicating latency. It should be understood that the above list is only an example, and should not constitute any limitation to the present application. The present application is not limited to the specific implementation manner of indicating the time delay corresponding to the transmitting port.

In a third aspect, a communication device is provided, which comprises various means or units for performing the method of any one of the possible implementations of the first aspect.

In a fourth aspect, a communications 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 method of any one of the possible implementations of the first aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

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

In another implementation, the communication device is a chip configured in the terminal equipment. When the communication device is a chip configured in a terminal device, the communication interface may be an input/output interface.

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

In a fifth aspect, a communication device is provided, which comprises various modules or units for performing the method of any one of the possible implementations of the second aspect.

In a sixth aspect, a communications 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 method of any one of the possible implementations of the second aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

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

In another implementation, the communication device is a chip configured in the access network equipment. When the communication device is a chip configured in an access network device, the communication interface may be an input/output interface.

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

In a seventh aspect, a processor is provided, including: input circuit, output circuit and processing circuit. The processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor performs the method in any one of the possible implementations of the first and second aspects.

In a specific implementation process, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a flip-flop, various logic circuits, and the like. The input signal received by the input circuit may be received and input by, for example and without limitation, a receiver, the signal output by the output circuit may be output to and transmitted by a transmitter, for example and without limitation, and the input circuit and the output circuit may be the same circuit that functions as the input circuit and the output circuit, respectively, at different times. The embodiment of the present application does not limit the specific implementation manner of the processor and various circuits.

In an eighth aspect, a processing apparatus is provided that includes a processor and a memory. The processor is configured to read instructions stored in the memory and to receive signals via the receiver and transmit signals via the transmitter to perform the method of any of the possible implementations of the first and second aspects.

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

Alternatively, the memory may be integral to the processor or provided separately from the processor.

In a specific implementation process, the memory may be a non-transient memory, such as a Read Only Memory (ROM), which may be integrated on the same chip as the processor, or may be separately disposed on different chips.

It will be appreciated that the associated data interaction process, for example, sending the indication information, may be a process of outputting the indication information from the processor, and receiving the capability information may be a process of receiving the input capability information from the processor. In particular, the data output by the processor may be output to a transmitter and the input data received by the processor may be from a receiver. The transmitter and receiver may be collectively referred to as a transceiver, among others.

The apparatus in the above eighth aspect may be a chip, the processor may be implemented by hardware or may be implemented by software, and when implemented by hardware, the processor may be a logic circuit, an integrated circuit, or the like; when implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory, which may be integrated with the processor, located external to the processor, or stand-alone.

In a ninth aspect, there is provided a computer program product, the computer program product comprising: a computer program (which may also be referred to as code, or instructions), which when executed, causes a computer to perform the method of any one of the possible implementations of the first and second aspects described above.

In a tenth aspect, a computer-readable medium is provided, which stores a computer program (which may also be referred to as code, or instructions) that, when executed on a computer, causes the computer to perform the method of any one of the possible implementations of the first and second aspects described above.

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

Drawings

Fig. 1 is a schematic architecture diagram of a communication system suitable for a channel measurement method provided in an embodiment of the present application;

fig. 2 is a schematic diagram of precoding a reference signal based on a delay vector according to an embodiment of the present application;

fig. 3 is a schematic flow chart of a channel measurement method provided by an embodiment of the present application;

fig. 4 is a schematic flow chart of a channel measurement method provided in another embodiment of the present application;

fig. 5 is a schematic flow chart of a channel measurement method provided by another embodiment of the present application;

Fig. 6 is a schematic flow chart of a channel measurement method according to still another embodiment of the present application;

fig. 7 is a schematic block diagram of a communication device provided by an embodiment of the present application;

fig. 8 is a schematic structural diagram of a terminal device provided in an embodiment of the present application;

fig. 9 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 Worldwide Interoperability for Microwave Access (WiMAX) communication system, a future fifth Generation (5th Generation, 5G) mobile communication system, or a new radio Access Technology (NR). 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 Machine Type Communication (MTC), Long Term Evolution-machine (LTE-M) communication between machines, device-to-device (D2D) network, machine-to-machine (M2M) network, internet of things (IoT) network, or other networks. The IoT network may comprise, for example, a car networking network. The communication modes in the car networking system are collectively referred to as car to other devices (V2X, X may represent anything), for example, the V2X may include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) or vehicle to network (V2N) communication, etc.

The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system and the like. This is not a limitation of the present application.

In the embodiment of the present application, the network device may be any device having a wireless transceiving function. Such devices include, but are not limited to: evolved Node B (eNB), Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), home base station (e.g., home evolved Node B or home Node B, HNB), baseband unit (BBU), Access Point (AP) in wireless fidelity (WiFi) system, wireless relay Node, wireless backhaul Node, Transmission Point (TP) or Transmission and Reception Point (TRP), etc., and may also be 5G, such as NR, gbb in the system, or transmission point (TRP or TP), one or a group of base stations in the 5G system may also include multiple antennas, or panels, and may also be configured as network panels or NB, such as a baseband unit (BBU), or a Distributed Unit (DU), etc.

In some deployments, the gNB may include Centralized Units (CUs) and DUs. The gNB may also include an Active Antenna Unit (AAU). The CU implements part of the function of the gNB, and the DU implements part of the function of the gNB, for example, the CU is responsible for processing non-real-time protocols and services, and implementing functions of a Radio Resource Control (RRC) layer and a packet data convergence layer (PDCP) layer. The DU is responsible for processing a physical layer protocol and a real-time service, and implements functions of a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. The AAU implements part of the physical layer processing functions, radio frequency processing and active antenna related functions. Since the information of the RRC layer eventually becomes or is converted from the information of the PHY layer, the higher layer signaling, such as the RRC layer signaling, may also be considered to be transmitted by the DU or by the DU + AAU under this architecture. It is to be understood that the network device may be a device comprising one or more of a CU node, a DU node, an AAU node. In addition, the CU may be divided into network devices in an access network (RAN), or may be divided into network devices in a Core Network (CN), which is not limited in this application.

The network device provides a service for a cell, and a terminal device communicates with the cell through a transmission resource (e.g., a frequency domain resource, or a spectrum resource) allocated by the network device, where the cell may belong to a macro base station (e.g., a macro eNB or a macro gNB), or may belong to a base station corresponding to a small cell (small cell), where the small cell may include: urban cell (metro cell), micro cell (microcell), pico cell (pico cell), femto cell (femto cell), etc., and these small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-rate data transmission service.

In the embodiments of the present application, a terminal device may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment.

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 may be: a mobile phone (mobile phone), a tablet computer (pad), a computer with wireless transceiving function (e.g., a laptop, a palmtop, etc.), a Mobile Internet Device (MID), 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 medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation security, a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol), a PDA, a wireless local loop phone (SIP), a wireless personal digital assistant (personal digital assistant, etc.) A handheld device with wireless communication capabilities, 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, etc.

Wherein, wearable equipment also can be called as wearing formula smart machine, is the general term of using wearing formula technique to carry out intelligent design, developing 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, the terminal device may also be a terminal device in an internet of things (IoT) system. The IoT is an important component of future information technology development, and is mainly technically characterized in that articles are connected with a network through a communication technology, so that an intelligent network with man-machine interconnection and object interconnection is realized. The IoT technology can achieve massive connection, deep coverage, and power saving of the terminal through, for example, Narrowband (NB) technology.

In addition, the terminal equipment can also comprise sensors such as an intelligent printer, a train detector, a gas station and the like, and the main functions of the terminal equipment comprise data collection (part of the terminal equipment), control information and downlink data receiving of the network equipment, electromagnetic wave sending and uplink data transmission to the network equipment.

For the understanding of the embodiments of the present application, a communication system suitable for the method provided in the embodiments of the present application will be first described in detail with reference to fig. 1. Fig. 1 shows a schematic diagram of a communication system 100 suitable for the method provided by the embodiment of the present application. As shown, the communication system 100 may include at least one network device, such as the network device 101 in the 5G system shown in fig. 1; the communication system 100 may further comprise at least one terminal device, such as the terminal devices 102 to 107 shown in fig. 1. The terminal devices 102 to 107 may be mobile or stationary. Network device 101 and one or more of terminal devices 102-107 may each communicate over a wireless link. Each network device may provide communication coverage for a particular geographic area and may communicate with terminal devices located within that coverage area. For example, the network device may send configuration information to the terminal device, and the terminal device may send uplink data to the network device based on the configuration information; for another example, the network device may send downlink data to the terminal device. Thus, the network device 101 and the terminal devices 102 to 107 in fig. 1 constitute one communication system.

Alternatively, the terminal devices may communicate directly with each other. Direct communication between terminal devices may be achieved, for example, using D2D technology or the like. As shown in the figure, direct communication between

terminal devices

105 and 106, and between

terminal devices

105 and 107 may be performed using D2D technology. Terminal device 106 and terminal device 107 may communicate with terminal device 105 separately or simultaneously.

The terminal apparatuses 105 to 107 can also communicate with the network apparatus 101, respectively. For example, it may communicate directly with network device 101, such as

terminal devices

105 and 106 in the figure may communicate directly with network device 101; it may also communicate with network device 101 indirectly, such as terminal device 107 communicating with network device 101 via terminal device 106.

It should be understood that fig. 1 exemplarily shows one network device and a plurality of terminal devices, and communication links between the respective communication devices. Alternatively, the communication system 100 may include a plurality of network devices, and each network device may include other numbers of terminal devices within its coverage area, such as more or fewer terminal devices. This is not limited in this application.

The above-described respective communication devices, such as the network device 101 and the terminal devices 102 to 107 in fig. 1, may be configured with a plurality of antennas. The plurality of antennas may include at least one transmit antenna for transmitting signals and at least one receive antenna for receiving signals. Additionally, each communication device can additionally include a transmitter chain and a receiver chain, each of which can comprise a plurality of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.), as will be appreciated by one skilled in the art. Therefore, the network equipment and the terminal equipment can communicate through the multi-antenna technology.

Optionally, the wireless communication system 100 may further include other network entities such as a network controller, a mobility management entity, and the like, which is not limited thereto.

In order to facilitate understanding of the embodiments of the present application, the following is a brief description of the processing procedure of the downlink signal at the physical layer before transmission. It should be understood that the processing of the downstream signal described below may be performed by the network device, or may be performed by a chip configured in the network device. For convenience of description, hereinafter, collectively referred to as network devices.

The network device may process a codeword (code word) on a physical channel. Where the codeword may be coded bits that are encoded (e.g., including channel coding). The codeword is scrambled (scrambling) to generate scrambled bits. The scrambled bits are modulation mapped (modulation mapping) to obtain modulation symbols. The modulation symbols are mapped to a plurality of layers (layers), or transport layers, through layer mapping. The modulated symbols after layer mapping are precoded (precoding) to obtain precoded signals. The precoded signal is mapped to a plurality of Resource Elements (REs) after mapping the precoded signal to the REs. These REs are then modulated by Orthogonal Frequency Division Multiplexing (OFDM) and transmitted through an antenna port (antenna port).

It should be understood that the above-described processing procedure for the downlink signal is only an exemplary description, and should not limit the present application in any way. For the processing procedure of the downlink signal, reference may be made to the prior art, and a detailed description of the specific procedure is omitted here for brevity.

For the convenience of understanding the embodiments of the present application, the terms referred to in the embodiments of the present application will be briefly described 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 some communication modes, such as TDD, the 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 the downlink channel can be estimated according to the uplink channel, so that a precoding matrix for downlink transmission can be determined.

However, in other communication modes, such as FDD, the uplink and downlink channels do not have complete reciprocity because the frequency band spacing of the uplink and downlink channels is much larger than the coherence bandwidth, and the precoding matrix determined by using the uplink channel for downlink transmission may not be able to be adapted to the downlink channel. However, the uplink and downlink channels in FDD mode still have some reciprocity, such as angular reciprocity and time delay reciprocity. Thus, the angle and the time delay may also be referred to as reciprocity parameters.

When transmitted over a wireless channel, a signal may travel multiple paths from a transmitting antenna to a receiving antenna. 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. Since the physical location between the network device and the terminal device is fixed, the multipath profiles of the uplink and downlink channels are the same in time delay. 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 reaches a receiving antenna via a radio 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. Due to reciprocity of transmission paths of uplink and downlink channels on different frequencies, the arrival angle of the uplink reference signal and the departure angle of the downlink reference signal can be considered as reciprocity.

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.

3. Reference Signal (RS) and precoding reference signal: the reference signal may also be referred to as a pilot (pilot), reference sequence, 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 an 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.

4. Port (port): may include a transmit port and a receive port.

Wherein a transmitting port may be understood as a virtual antenna recognized by a receiving device.

Alternatively, the port may refer to a transmit antenna port. For example, the reference signal for each transmit antenna port may be a reference signal that is not precoded. The transmit antenna port may refer to an actual transmit unit (TxRU).

Alternatively, the port may also refer to a beamformed port. For example, the reference signal of each port may be a precoded reference signal obtained by precoding the reference signal based on one angle vector. It can be understood that if beamforming is performed on the reference signal, the port number may refer to the port number of the precoded reference signal. The number of ports of the precoded reference signal may be smaller than the number of transmit antenna ports.

Alternatively, the ports may also refer to ports subjected to phase rotation, for example, the reference signal of each port may be a precoded reference signal that is precoded based on one delay vector and is transmitted through one transmit antenna port. This port may also be referred to as a port of a precoded reference signal.

Alternatively, the port may refer to a port subjected to beamforming and phase rotation. For example, the reference signal of each port may be a precoded reference signal obtained by precoding the reference signal based on an angle vector and a delay vector. This port may also be referred to as a port of a precoded reference signal.

The reference signal for each port may be transmitted through one or more frequency domain units.

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, and may also refer to ports for precoding reference signals. The specific meaning expressed by a port may be determined according to a specific embodiment. For convenience of distinction, a port of the precoded reference signal is referred to as a reference signal port hereinafter.

The receiving port may be understood as a receiving antenna of the receiving device. For example, in downlink transmission, a receiving port may refer to a receiving antenna of a terminal device.

5. Angle vector: which may be understood as a precoding vector used for beamforming the reference signals. Through beamforming, a reference signal transmitted by the transmitting device 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 angle vector may also be referred to as a spatial vector, a beam (beam) vector, etc.

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. When the number K of the angle vectors is less than the number T of the transmitting antenna ports in one polarization direction, the dimension reduction of the antenna ports can be realized through space domain precoding, so that the pilot frequency overhead is reduced. Wherein K is more than or equal to 1, T is more than or equal to 1, and K, T are integers.

The angle vector may be a length T vector.

Optionally, the angle vector is a Discrete Fourier Transform (DFT) vector. The DFT vector may refer to a vector in a DFT matrix.

Optionally, the angle vector is a conjugate transpose vector of the DFT vector. The DFT conjugate transpose vector may refer to a column vector in a conjugate transpose matrix of the DFT matrix.

Optionally, the angle vector is an oversampled DFT vector. The oversampled DFT vectors may refer to vectors in an oversampled DFT matrix.

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

Such as

Wherein, I₁Number of antenna ports of the same polarization direction contained in each column (or row) of the antenna array, I₂The number of antenna ports of the same polarization direction included in each row (or column) of the antenna array. In the present embodiment, T ═ I₁×I ₂。O ₁And O₂Is an oversampling factor. i.e. i₁And i₂Satisfies 0 ≤ i₁≤(O ₁×I ₁-1)，0≤i ₂≤(O ₂×I ₂-1)。

Optionally, the angular vector is a steering vector of a Uniform Linear Array (ULA). Such as, for example,

wherein, theta_kIs an angle, K ═ 1, 2, … …, K. K represents the number of angle vectors; λ is the wavelength and d is the antenna spacing.

Wherein the steering vector may represent a phase difference in the arrival angle of a path between the responses of different antennas. Guide vector a (θ) _k) With vectors in DFT matrix

Satisfies the following conditions:

optionally, the angle vector is a steering vector of a Uniform Plane Array (UPA). The steering vector may be, for example, a steering vector containing horizontal and pitch angle information. Such as, for example,

wherein, theta _kIs a horizontal angle, and the angle is a horizontal angle,

is a pitch angle; rho_tIs the three-dimensional coordinate of the tth transmit antenna port, T is 1, 2, … …, T; u. of_kThe unit sphere base vector corresponding to the k-th angle:

hereinafter, for convenience of explanation, the angle vector will be referred to as a (θ)_k)。

In downlink transmission, since the reference signal loaded with the angle vector can be transmitted to the terminal device through a downlink channel, a channel measured by the terminal device according to the received precoding reference signal is equivalent to the channel loaded with the angle vector. For example, the angle vector a (θ)_k) Is loaded to a downlink channel V, which can be represented as Va (theta)_k)。

Assuming that the sending equipment is configured with a single-polarization antenna, and the number of transmitting antenna ports is T; the number of frequency domain units is N, N is more than or equal to 1, and N is an integer. The channel estimated based on the received reference signal may be a matrix of dimension N x T for one receive port of the receiving device. If the reference signals are spatially precoded based on one angle vector, the angle vectors may be loaded onto the reference signals, respectively. Since the dimension of the angle vector is T × 1, the dimension of the channel estimated based on the precoded reference signal may be N × 1 for one receiving port of the receiving device. And the dimension of the channel estimated by the terminal device based on the received precoded reference signal can be 1 × 1 per frequency domain unit per receive port.

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. And (3) time delay vector: which may also be referred to as frequency domain vectors. The delay vector may be used as a vector representing the variation law of the channel in the frequency domain. As previously mentioned, multipath delay results in frequency selective fading. As known from fourier transform, the time delay of the signal in the time domain is equivalent to the phase gradient in the frequency domain.

For example, for signal g (t), the signal may be transformed onto the frequency domain by a fourier transform:

for signal g (t-t)₀) The signal can be transformed onto the frequency domain by a fourier transform:

wherein, omega is a frequency variable, and the corresponding phase rotations of different frequencies are different; t and t-t₀Representing the time delay.

The two time-delayed signals may be denoted as x (t) ═ g (t) + g (t-t)₀) From which a function of the frequency variation can be derived

Let g (. omega.) 1 be obtained

Thus, the two differently delayed signals cause frequency domain selective fading.

Since the phase change of the channel in each frequency domain unit is related to the time delay, the change rule of the phase of the channel in each frequency domain unit can be represented by a time delay vector. In other words, the delay vector may be used to represent the delay characteristics of the channel.

The precoding of the reference signal based on the delay vector may essentially refer to performing phase rotation on each frequency domain unit in the frequency domain based on elements in the delay vector, so as to pre-compensate the frequency selection characteristic caused by multipath delay by precoding the reference signal. Therefore, the process of precoding the reference signal based on the delay vector can be regarded as a process of frequency domain precoding.

Precoding the reference signal based on different delay vectors is equivalent to performing phase rotation on each frequency domain unit of the channel based on different delay vectors. Moreover, due to different loaded delay vectors, different resources (e.g., Resource Elements (REs)) in the same frequency domain unit may have different phase rotation angles. To distinguish between different delays, the network device may precode the reference signal separately based on each of the L delay vectors.

Optionally, the length of the delay vector is N, N may refer to the number of frequency domain units used for carrying a reference signal (e.g., a non-precoded reference signal or a precoded reference signal), N ≧ 1, and N is an integer.

Alternatively, the L-th delay vector of the L delay vectors may be represented as b (τ) _l)，

Wherein L is 1, 2, … …, L; l may represent the number of delay vectors; f. of₀，f ₁，……，f _N-1Respectively representing the carrier frequencies of the 1 st, 2 nd to nth frequency domain units.

Optionally, the delay vector is taken from the DFT matrix. Such as

Each vector in the DFT matrix may be referred to as a DFT vector.

Wherein, O_fAs an oversampling factor, O_fNot less than 1; k is index of DFT vector and satisfies k is more than or equal to 0 and less than or equal to O_fX N-1 or 1-O_f×N≤k≤0。

For example, when k < 0, b (τ)_l) With the vector u in the DFT matrix_kCan satisfy the following conditions:

wherein

Δf＝f _n-f _n+1，1≤n≤N-1。

For convenience of explanation, the delay vector is denoted as b (τ)_l)。

In the embodiments of the present application, for convenience of understanding, a specific process of performing frequency domain precoding on a reference signal is described with a Resource Block (RB) as an example of a frequency domain unit. When an RB is taken as an example of a frequency domain unit, each frequency domain unit may be considered to include only one RB for carrying a reference signal. In fact, each frequency domain unit may include one or more RBs for carrying reference signals. When multiple RBs for carrying reference signals are included in each frequency domain unit, the network device may load the delay vector onto the multiple RBs for carrying reference signals in each frequency domain unit.

In downlink transmission, since the reference signal loaded with the delay vector can be transmitted to the terminal device through a downlink channel, a channel measured by the terminal device according to the received precoding reference signal is equivalent to the channel loaded with the delay vector. If the frequency domain precoding is performed on the reference signal based on the delay vector with the length of N, N elements in the delay vector may be loaded on the reference signal loaded on N RBs, respectively. Channel V loading the nth element of the delay vector onto the nth RB⁽ⁿ⁾Above may be represented, for example, as

It should be noted that, performing frequency domain precoding on the reference signal based on the delay vector may be performed before resource mapping or may be performed after resource mapping, which is not limited in this application.

For the sake of understanding, the following detailed description is based on the delay vector b (τ) in conjunction with FIG. 2_l) And precoding the reference signal.

FIG. 2 shows a vector b (τ) based on time delays₁) An example of frequency domain precoding is performed on reference signals carried on N RBs. The N RBs may include RB #0, RB #1, and RB # N-1. One or more REs for carrying the reference signal are included on each of the N RBs. For example, the RE used to carry the reference signal may be the first time domain symbol, the RE on the first subcarrier in each RB. As shown by the shaded squares in the figure. In this case, the time domain vector b (τ) may be loaded on the first time domain symbol, RE on the first subcarrier in each RB ₁). The first time domain symbol in each RB of the N RBs, the reference signal carried on the RE on the first subcarrier, may be a reference signal corresponding to the same port.

Hypothesis delay vector

If the delay vector b (tau) is to be measured₁) And the N frequency domain units can be subjected to phase rotation when loaded on the N frequency domain units. The N elements in the delay vector may correspond one-to-one to the N frequency domain units. For example, the frequency domain vector b (τ)₁) 0 th element of (1)

Can be loaded on RB #0, the frequency domain vector b (tau)₁) 1 st element of (1)

Can be loaded on RB #1 with time delayVector b (τ)₁) N-1 elements of

May be loaded on RB # N-1. By analogy, the delay vector b (tau)₁) The nth element of (1)

May be loaded on RB # n. For the sake of brevity, this is not to be enumerated here.

It should be understood that the RB is only an example of a frequency domain unit and should not limit the present application in any way. The present application is not limited to the specific definition of frequency domain units.

It should also be understood that the delay vector is one form proposed herein for representing delay. The delay vectors are named only for convenience of distinguishing from angles 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.

In addition, assuming that the network device is configured with a single-polarized antenna, the number of transmitting antenna ports is T, and the number of frequency domain units is N. Then for one receive port of the terminal device, the channel estimated based on the received reference signal can be represented as a matrix of dimension N × T. If the reference signal is frequency-domain precoded based on L delay vectors, for a receiving port of the terminal device, a channel estimated based on the received precoded reference signal may be represented as a matrix with dimension N × L. And the dimension of the channel estimated by the terminal device based on the received precoded reference signal may be 1 × L per frequency domain unit per receive port.

7. 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.

8. Angle delay is as follows: also referred to as a space-frequency vector pair. An 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. At least one item of the angle vector and the time delay vector contained in any two angle time delay pairs is different. In other words, each angular delay pair may be uniquely determined by an angular vector and a delay vector.

In the embodiment of the application, the angle vector a (theta) is based on_k) And a delay vector b (tau)_l) When precoding a reference signal, a precoding matrix for precoding the reference signal may be expressed as a product of a conjugate transpose of an angle vector and a delay vector, for example, may be expressed as a (θ)_k)×b(τ _l) ^HIts dimension may be T × N. Alternatively, the precoding matrix for precoding the reference signal can also be expressed as a Kronecker product of an angle vector and a delay vector, for example, as

Its dimension may be T × N.

It should be understood that the various mathematical expressions listed above are only examples and should not constitute any limitation to the present application. For example, the precoding matrix used to precode the reference signal may also be expressed as the product of a delay vector and the conjugate transpose of an angle vector, or as the kronecker product of a delay vector and an angle vector, which may be N × T in dimension. Alternatively, the precoding matrix used to precode the reference signals may also be represented as a mathematical transformation of the various expressions described above. For the sake of brevity, this is not to be enumerated here.

In embodiments of the application, a weighted sum of one or more angular delay pairs may be used For determining the space-frequency matrix. A matrix of dimension T × N determined based on an angular delay pair may be referred to as a component of the space-frequency matrix, or simply a space-frequency component matrix. In the following embodiments, for convenience of explanation, it is assumed that a matrix of dimension T × N determined by an angular delay pair is represented by a (θ)_k)×b(τ _l) ^HThus obtaining the product.

9. Space-frequency matrix: in the embodiment of the present application, the space-frequency matrix is an intermediate quantity for determining the precoding matrix.

In the embodiment of the present application, the space-frequency matrix may be determined based on the receiving port, and may also be determined based on the transmission layer. As mentioned above, the space-frequency matrix may be determined by a weighted sum of one or more angular delay pairs, and the dimension of the space-frequency matrix may also be N × T.

If the space-frequency matrix is determined based on the receiving port, the space-frequency matrix may be referred to as a space-frequency matrix corresponding to the receiving port. The space-frequency matrix corresponding to the receiving port can be used for constructing a downlink channel matrix of each frequency domain unit, and then a precoding matrix corresponding to each frequency domain unit can be determined. The channel matrix corresponding to a certain frequency domain unit may be, for example, a conjugate transpose of a matrix constructed from column vectors corresponding to the same frequency domain unit in the space-frequency matrix corresponding to each receiving port. For example, the nth column vector in the space-frequency matrix corresponding to each receiving port is extracted, and the matrix with dimension of T multiplied by R can be obtained by arranging the n column vectors from left to right according to the sequence of the receiving ports, wherein R represents the number of the receiving ports, and R is not less than 1 and is an integer. The channel matrix V of the nth frequency domain unit can be obtained after the matrix is subjected to conjugate transpose ⁽ⁿ⁾. The relationship between the channel matrix and the space-frequency matrix will be described in detail below, and the detailed description of the relationship will be omitted here for the moment.

If the space-frequency matrix is determined based on the transport layer, the space-frequency matrix may be referred to as a space-frequency matrix corresponding to the transport layer. The space-frequency matrix corresponding to the transmission layer may be directly used to determine the precoding matrix corresponding to each frequency domain element. The precoding matrix corresponding to a certain frequency domain unit may be, for example, a column direction corresponding to the same frequency domain unit in a space-frequency matrix corresponding to each transmission layerThe quantity is constructed. For example, the nth column vector in the space-frequency matrix corresponding to each transmission layer is extracted, and the matrix with the dimension of T multiplied by Z can be obtained by arranging from left to right according to the sequence of the transmission layers, wherein Z represents the number of transmission layers, and Z is an integer larger than or equal to 1. The matrix can be used as the precoding matrix W of the nth frequency domain unit⁽ⁿ⁾。

It should be noted that the precoding matrix determined by the channel measurement method provided in the embodiment of the present application may be a precoding matrix directly used for downlink data transmission; the precoding matrix finally used for downlink data transmission may also be obtained through some beamforming methods, for example, including Zero Forcing (ZF), minimum mean-squared error (MMSE), signal-to-leakage-noise (SLNR), and the like. This is not a limitation of the present application. The precoding matrices referred to in the following may refer to precoding matrices determined based on the channel measurement method provided in the present application.

The relation between the space frequency matrix and the downlink channel matrix and the precoding matrix is simply explained.

The space-frequency matrix is an intermediate quantity that can be used to construct a precoding matrix, which is proposed based on the frequency domain continuity of the channel. The space-frequency matrix H may satisfy: H-SCF^H. Where S represents a matrix constructed of one or more (e.g., K being a positive integer) angle vectors, e.g., S ═ a (θ)₁) a(θ ₂) … a(θ _K)]F denotes a matrix constructed from one or more (e.g., L being a positive integer) delay vectors, e.g., F ═ b (τ)₁) b(τ ₂) … b(τ _L)]And C denotes a coefficient matrix constituted by weighting coefficients corresponding to each of the K angle vectors and each of the L delay vectors. Each element in C may represent a weighting coefficient of a corresponding one of the angle vector pairs.

In FDD mode, due to reciprocity of uplink and downlink channels of time delay and angle, a space-frequency matrix H obtained by measuring uplink channel_ULCan be represented as H_UL＝SC _ULF ^HSpace-frequency matrix H obtained by downlink channel measurement_DLCan be represented as H_DL＝SC _DLF ^H. Therefore, in the embodiment of the present application, the coefficient matrix C corresponding to the downlink channel is determined and fed back through downlink channel measurement_DLA precoding matrix adapted to the downlink channel can be determined.

As mentioned previously, the space-frequency component matrix is defined by a (θ)_k)×b(τ _l) ^HDetermining, thereby determining, a space-frequency matrix H_DLThe dimensions of (A) are as follows: the number of transmit antenna ports x the number of frequency domain elements. For example, the dimension of the space-frequency matrix corresponding to the downlink channel is T × N. In the following embodiments, the space-frequency matrix refers to the matrix H with dimension T × N as described above without specific description_DL。

However, this is not necessarily a space-frequency matrix determined by the real channel. In the general case, the dimensions of the channel matrix are defined as: the number of receive ports x the number of transmit ports, e.g., the dimension of the downlink channel is R × T. The dimension of the space-frequency matrix determined by the channel matrix is NxT and the space-frequency matrix H_DLThe dimension of (T) N is exactly the opposite. Therefore, in the embodiment of the present application, the real channel may be represented by the space-frequency matrix H_DLA conjugate transpose of the determined channel matrix. In other words, by the space-frequency matrix H_DLThe determined downlink channel matrix may be a conjugate transpose of the true channel.

Further, the space-frequency matrix H_DLA precoding matrix may be determined. The precoding matrix of the nth frequency domain unit may be constructed by the nth column vector in the space-frequency matrix corresponding to each transmission layer.

Taking Singular Value Decomposition (SVD) of the channel matrix as an example, the conjugate transpose of the precoding matrix can be obtained by SVD of the channel matrix V. If the channel matrix is subjected to conjugate transformation and then SVD is carried out, namely V is measured^HAnd performing SVD, so that a precoding matrix can be obtained. Therefore, the space frequency determined by the conjugate transpose of the real channel in the embodiment of the present applicationMatrix H_DLThe precoding matrix corresponding to each frequency domain unit can be directly determined and obtained.

In combination with formula H above_UL＝SC _ULF ^HTo understand the relation between the space-frequency matrix and the downlink channel matrix.

To H_DL＝SC _DLF ^HDeformation may result in S^HH _DL＝C _DLF ^HFurther modification can give (H)_DL ^HS) ^H＝C _DLF ^HFrom which a coefficient matrix C can be derived_DL＝(H _DL ^HS) ^HF. Wherein H_DL ^HIs a space-frequency matrix determined by the real channel; h_DL ^HAnd S is a real channel subjected to space-domain precoding. In the coefficient matrix C_DLEach element of (A) may be represented by (H)_DL ^HS) ^HOne row in F multiplied by one column in F. In other words, the matrix coefficient C_DLCan be determined by the real channel H_DL ^HConjugate transpose of S (H)_DL ^HS) ^HIs multiplied by a column of F, or, is derived from the real channel H_DL ^HThe conjugate transpose of one column of S is multiplied by one column of F.

Therefore, in the embodiment of the present application, the space-frequency matrix H is determined based on the weighting coefficients of the angle delay pairs fed back by the terminal device _DLMay be derived from the conjugate transpose of the real channel. Conversely, the space-frequency matrix in the embodiment of the present application may also be a conjugate transpose of the true channel V (i.e., V;)^H) Thus obtaining the product.

It should be understood that the true channel and space-frequency matrix H_DLIs not fixed. Different definitions of the space-frequency matrix and the space-frequency component matrix may result in the true channel and the space-frequency matrix H_DLThe relationship between them changes. For example, the space-frequency matrix H _DLIt can be obtained by conjugate transposing of the real channel, and also by transposing of the real channel.

When the definitions of the space-frequency matrix and the space-frequency component matrix are different, the operations performed by the network device are also different when the time delay and the angle are loaded, and the operations performed by the terminal device when channel measurement and feedback are performed are also correspondingly changed. However, this is only the implementation behavior of the terminal device and the network device, and should not be construed as limiting the present application in any way. The embodiments of the present application are only for ease of understanding, and show a case where the space-frequency matrix is obtained by conjugate transpose of a real channel. The definition of the channel matrix, the dimension of the space-frequency matrix and its definition, and the conversion relationship between the two are not limited in the present application. Similarly, the present application does not limit the conversion relationship between the space-frequency matrix and the precoding matrix.

10. Antenna delay is to: which may be a combination of one transmit antenna port and one delay vector. Each antenna delay pair may include one transmit antenna port and one delay vector. The transmit antenna ports and/or delay vectors contained in any two antenna delay pairs are different. In other words, each antenna delay pair may be uniquely determined by one transmit antenna port and one delay vector. It should be understood that the antenna delay pair may be understood as a representation of a space-frequency basic unit determined by one transmit antenna port and one delay vector, but is not necessarily the only representation, and the present application does not limit the representation of the combination of the transmit antenna port and the delay vector.

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

First, for the sake of easy understanding, the following is a brief description of the main parameters involved in the present application:

t: the number of transmitting antenna ports in one polarization direction, T being a positive integer;

p: the number of transmitting ports in one polarization direction, and P is a positive integer;

r: receiving port number, wherein R is a positive integer;

z: the number of transmission layers, Z is a positive integer;

n: the number of frequency domain units used for bearing reference signals, wherein N is a positive integer;

K: the number of angle vectors, K is a positive integer;

l: a delay vector number, L being a positive integer;

j: the number of polarization directions of the transmitting antenna, J is a positive integer;

second, in the embodiments of the present application, for convenience of description, when numbering is referred to, numbering may be continued from 0. For example, the K angle vectors may include a 0 th angle vector to a K-1 st angle vector, the L delay vectors may include a 0 th delay vector to an L-1 th delay vector, and so on, which are not listed here for brevity. Of course, the specific implementation is not limited thereto. For example, the numbers may be consecutively numbered from 1. For example, the K angle vectors may include a 1 st angle vector through a K angle vector, the L delay vectors may include a 1 st delay vector through an L delay vector, and so on.

It should be understood that the above descriptions are provided for convenience of describing the technical solutions provided by the embodiments of the present application, and are not intended to limit the scope of the present application.

Third, in the present application, multiple places refer to the transformation of matrices and vectors. For ease of understanding, the same description is made here. The superscript T denoting transposition, e.g. A^TRepresents a transpose of a matrix (or vector) a; the upper corner marks represent conjugation, e.g. A ^*Represents the conjugate of matrix (or vector) a; the superscript H denotes a conjugate transpose, e.g., A^HRepresenting the conjugate transpose of matrix (or vector) a. Hereinafter, for the sake of brevity, the description of the same or similar cases is omitted.

Fourth, in the embodiments shown below, the embodiments provided in the present application are described by taking an example in which the angle vector and the delay vector are both column vectors, but this should not limit the present application in any way. Other more possible manifestations will occur to those skilled in the art based on the same idea.

Fifth, 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. Meanwhile, the universal parts of all information can be identified and indicated in a unified mode, so that the indicating overhead caused by independently indicating the same information is reduced. For example, it will be understood by those skilled in the art that the precoding matrix is composed of precoding vectors, and that each precoding vector in the precoding matrix may have the same components in terms of composition or other attributes.

The specific indication method may be any of various existing indication methods, such as, but not limited to, the above indication methods, various combinations thereof, and the like. The specific details of various indication modes can refer to the prior art, and are not described in detail herein. As can be seen from the above description, when a plurality of information of the same type are required to be indicated, for example, different information may be indicated differently. In a specific implementation process, a required indication manner may be selected according to a specific need, and the indication manner selected in the embodiment of the present application is not limited, so that the indication manner related to the embodiment of the present application should be understood to cover various methods that enable a party to be indicated to obtain information to be indicated.

In addition, other equivalent forms of the information to be indicated may exist, for example, a row vector may be represented by a column vector, a matrix may be represented by a transpose matrix of the matrix, a matrix may also be represented by a vector or an array, the vector or the array may be formed by connecting each row vector or each column vector of the matrix, and the like. The technical solutions provided in the embodiments of the present application should be understood to cover various forms. By way of example, reference to some or all of the features of the embodiments of the present application should be understood to encompass various manifestations of such features.

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).

Sixth, the definitions listed in the present application for many characteristics (e.g. kronecker product, Channel State Information (CSI), RB, angle, and delay, etc.) are only used to explain the functions of the characteristics by way of example, and the details thereof can refer to the prior art.

Seventh, the first, second and various numerical numbering 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, different indication information is distinguished, and the like.

Eighth, "predefining" or "preconfiguration" may be implemented by pre-saving corresponding codes, tables or other manners that may be used to indicate related information in devices (e.g., including terminal devices and network devices), and the specific implementation manner of the present application is not limited thereto. Wherein "saving" may refer to saving in one or more memories. The one or more memories may be separate devices or may be integrated in the encoder or decoder, the processor, or the communication device. The one or more memories may also be provided as a portion of a stand-alone device, a portion of which is integrated into a decoder, a processor, or a communication device. The type of memory may be any form of storage medium and is not intended to be limiting of the present application.

Ninth, the "protocol" referred to in the embodiments 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, and a related protocol applied in a future communication system, which is not limited in the present application.

Tenth, "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.

Eleventh, in the embodiment of the present application, the descriptions "when … …", "in … …", "if" and "if" all refer to that a device (e.g., a terminal device or a network device) performs corresponding processing under a certain objective condition, and do not limit the time, and do not require a certain judgment action when the device (e.g., a terminal device or a network device) is implemented, and do not mean that there are other limitations.

Twelfth, in the embodiments of the present application, a transmitting port and a receiving port are mentioned in many places. To avoid ambiguity, the following explanation is made: a transmit port may refer to a port that transmits a reference signal (e.g., a precoded reference signal, etc.). A receive port may refer to a port that receives a reference signal (e.g., a precoded reference signal, etc.). In this embodiment, the transmitting port may be a port on the network device side, and the receiving port may be a port on the terminal device side.

The channel measurement method provided by the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

It should be understood that the following is only for convenience of understanding and explanation, and the method provided by the embodiment of the present application is described in detail by taking the interaction between the terminal device and the network device as an example. This should not constitute any limitation on the subject matter of the implementations of the methods provided herein. For example, the terminal device shown in the following embodiments may be replaced with a component (such as a chip or a chip system) or the like configured in the terminal device. The network devices shown in the following embodiments may also be replaced by components (such as chips or systems of chips) configured in the network devices.

The embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided by the embodiments of the present application, as long as the communication can be performed according to the method provided by the embodiments of the present application by running the program recorded with the code of the method provided by the embodiments of the present application, for example, the execution subject of the method provided by the embodiments 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.

For ease of understanding, a brief description of several embodiments is presented herein below:

the application provides a channel measurement method based on time domain transformation. On each receive port, the terminal device may receive precoded reference signals from one or more transmit ports. The terminal device may perform channel estimation based on the received precoded reference signal of each transmit port, and perform time domain transformation on channel information estimated in multiple frequency domain units corresponding to the same transmit port. I.e. the variation of the channel in the frequency domain is converted into the time domain to obtain a strongest value. And the terminal equipment feeds back the strongest signal obtained by time domain transformation to the network equipment. The value fed back to the network device by the terminal device is the weighting coefficient corresponding to the same transmission port. The embodiments described below in conjunction with fig. 3 and 4 illustrate the above-described channel measurement method based on time domain transform in detail.

The application also provides a channel measurement method based on frequency domain filtering. On each receive port, the terminal device may receive precoded reference signals from one or more transmit ports. The terminal device may perform channel estimation based on the received precoded reference signal of each transmit port, and perform frequency domain filtering on the estimated channel information. The terminal device may filter channel information on frequency domain units in the same frequency domain unit group by using the frequency domain unit group as a unit. When the precoding reference signal of the same transmission port is carried by the frequency domain units in the plurality of frequency domain unit groups, the terminal device may accumulate the results of filtering the channel information on the frequency domain units in the plurality of frequency domain unit groups. The terminal device may feed back the result of the accumulation to the network device. The value fed back to the network device by the terminal device is the weighting coefficient corresponding to the same transmission port. The embodiments described below in conjunction with fig. 5 and 6 illustrate the above-described channel measurement method based on frequency domain filtering in detail.

In the following embodiment, the network device may perform precoding on the reference signal based on the delay vector and the angle vector, or may perform precoding on the reference signal based on the delay vector or the angle vector, which is not limited in this application.

Next, the channel measurement method based on time domain transform will be described in detail with reference to fig. 3. Fig. 3 is a schematic flow chart of a channel measurement method 300 provided by the embodiment of the present application, which is shown from the perspective of device interaction. The method 300 shown in fig. 3 may include steps 310 through 340. The steps in method 300 are described in detail below.

For the convenience of understanding, the following describes the channel measurement and feedback process performed by the terminal device in detail by taking the precoded reference signal sent by the transmitting antenna in one polarization direction as an example. The one polarization direction transmitting antenna may be any one of J polarization direction transmitting antennas configured by the network device. The number J of polarization directions of the transmitting antennas configured for the network device is not limited in the present application.

In step 310, the terminal device receives a precoded reference signal. Correspondingly, the network device transmits the precoded reference signal.

In this embodiment, the network device may precode the reference signal based on the K angle vectors and the L delay vectors. From the K angle vectors and the L delay vectors, various combinations of angle vectors and delay vectors can be obtained. The angle vectors and/or the delay vectors in any two combinations are different. The angle vector and the delay vector in each combination may be used to precode the reference signal to obtain a precoded reference signal corresponding to one port. Therefore, the precoded reference signal precoded by the network device based on the K angular vectors and the L delay vectors may correspond to one or more ports, and the precoded reference signal of each port may be obtained by precoding the reference signal based on one of the K angular vectors and one of the L delay vectors. Alternatively, the precoded reference signal for each port may be obtained by precoding the reference signal based on a combination of an angle vector and a delay vector.

In a possible implementation manner, the network device may combine each of the K angle vectors and each of the L delay vectors two by two to obtain a K × L combination of the angle vectors and the delay vectors, or obtain a K × L angle delay pair. That is, the network device may precode the reference signal based on each of the K angle vectors and each of the L delay vectors. When the network equipment precodes the reference signal based on the kth angle vector (K is more than or equal to 1 and less than or equal to K, and K is an integer) in the K angle vectors, each delay vector in the L delay vectors can be traversed to precode the reference signal; or, when the network device precodes the reference signal based on the ith (L is greater than or equal to 1 and less than or equal to L, and L is an integer) delay vector in the L delay vectors, the network device may traverse each angle vector in the K angle vectors to precode the reference signal. In other words, the K angle vectors may be considered common for each delay vector, and the L delay vectors may also be considered common for each angle vector. Alternatively, the K angle vectors and the L delay vectors are common to each other.

In another possible implementation manner, when the network device precodes the reference signal based on the kth angle vector of the K angle vectors, the network device may traverse L corresponding to the kth angle vector_k(1≤L _k≤L，L _kInteger) each of the delay vectors precodes a reference signal. L of the L delay vectors may satisfy:

in this implementation, the delay vectors for at least two angle vectors are different.

Here, the different delay vectors corresponding to at least two angle vectors may mean that, among the K angle vectors, at least two angle vectors are different from each other, and the delay vectors corresponding to other angle vectors may be the same or different from each other, which is not limited in the present application. In other words, the delay vectors corresponding to the angle vectors are partially or entirely different.

The two angle vectors may correspond to different delay vectors, which means that the two angle vectors correspond to different delay vectors, that is, the two angle vectors correspond to delay vectors that are not repeated, or do not intersect with each other. For example, the angle vector a (θ)₁) The corresponding delay vector includes b (τ)₂) Angle vector a (θ) ₂) The corresponding delay vector includes b (τ)₁) And b (τ)₃). The delay vectors corresponding to the two angle vectors are different, which may also mean that the delay vectors corresponding to the two angle vectors are partially different, that is, the delay vectors corresponding to the two angle vectors are partially repeated but not completely identicalOr, the delay vectors corresponding to the two angle vectors intersect with each other, but are not completely the same. For example, a (θ)₁) The corresponding delay vector includes b (τ)₂) And b (τ)₃) Angle vector a (θ)₂) The corresponding delay vector includes b (τ)₁) And b (τ)₃)。

When the delay vectors corresponding to any two of the K angle vectors are not repeated,

when there is a partial repetition in the delay vectors corresponding to two or more of the K angle vectors,

therefore, the network device can obtain the K angle vectors and the L time delay vectors

A combination of angle vectors and delay vectors.

In another possible implementation manner, when the network device precodes the reference signal based on the ith delay vector of the L delay vectors, the network device may traverse K corresponding to the ith delay vector_l(1≤K _l≤K，K _lInteger) each of the angle vectors precodes a reference signal. K in the K angular vectors may satisfy:

In this implementation, the angle vectors corresponding to at least two delay vectors are different.

Here, the different angle vectors corresponding to at least two delay vectors may mean that, of the L delay vectors, at least two delay vectors have different angle vectors, and the angle vectors corresponding to other delay vectors may be the same or different, which is not limited in the present application. In other words, the angle vectors corresponding to the delay vectors are partially or entirely different.

The two delay vectors have different corresponding angle vectors, which may mean that the two delay vectors have completely different corresponding angle vectors, that is, the two delay vectors have no repetition or intersection. E.g. delay vector b (τ)₁) The corresponding angle vector includes a (theta)₂) Time delay vector b (tau)₂) The corresponding angle vector includes a (theta)₁). The angle vectors corresponding to the two delay vectors are different, which may also mean that the angle vectors corresponding to the two delay vectors are partially different, that is, the angle vectors corresponding to the two delay vectors are partially repeated but not completely identical, or the angle vectors corresponding to the two delay vectors are intersected but not completely identical. E.g. delay vector b (tau) ₁) The corresponding angle vector includes a (theta)₂) Time delay vector b (tau)₂) The corresponding angle vector includes a (theta)₁) And a (theta)₂). When the angle vectors corresponding to any two of the L delay vectors are not repeated,

when the angle vectors corresponding to two or more delay vectors in the L delay vectors are partially repeated,

A combination of angle vectors and delay vectors.

It should be understood that the above list of the corresponding relationship between the angle vector and the delay vector is only for the convenience of understanding, but this should not limit the present application in any way. The present application does not limit the correspondence between the angle vector and the delay vector.

It can be understood that, if the network device precodes the reference signal based on the K angular vectors and the L delay vectors, the number of ports of the precoded reference signal to be transmitted may be the number of combinations determined by the K angular vectors and the L delay vectors. That is, the number of transmit ports P may be determined by the number of combinations determined by the K angle vectors and the L delay vectors. In several different implementations described above, P has different values, e.g., P ═ K × L, or,

Alternatively, the first and second electrodes may be,

since the angle and the delay have reciprocity between an uplink channel and a downlink channel, optionally, the K angle vectors and the L delay vectors may both be determined based on uplink channel measurement.

Specifically, the network device may determine K angles and L delays according to an uplink channel matrix estimated in advance. The K angles may be characterized by K angle vectors. The L delays may be characterized by L delay vectors. The uplink channel matrix may be a weighted sum of several space-frequency component matrices determined by the K angle vectors and the L delay vectors.

The K angle vectors may be, for example, stronger K angle vectors determined from a predefined set of angle vectors. The K angle vectors may be determined for the L delay vectors collectively, or may be determined for each of the L delay vectors separately. This is not a limitation of the present application. Optionally, each angle vector in the set of angle vectors is taken from a DFT matrix. The K angle vectors may be determined, for example, by performing a DFT on the uplink channel matrix. Optionally, each angular vector in the set of angular vectors is a steering vector.

The L delay vectors may be, for example, stronger L delay vectors determined from a predefined set of delay vectors. The L delay vectors may be determined for the K angle vectors together, or may be determined for each of the K angle vectors. This is not a limitation of the present application. Optionally, each delay vector in the set of delay vectors is taken from a DFT matrix. The L delay vectors may be determined, for example, by DFT on the uplink channel matrix.

The network device may determine the K angle vectors and the stronger one or more delay vectors corresponding to each angle vector, for example, using 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 K angle vectors and L delay vectors by performing a DFT on the space-frequency matrix determined based on the uplink channel measurements. The specific method for determining the K angle vectors and the L delay vectors by the network device is not limited in this application.

Taking DFT for the space-frequency matrix as an example, it is assumed that the angle vector and the delay vector are both taken from the DFT matrix. The predefined set of angular vectors may be, for example, a set of vectors consisting of a plurality of vectors in a spatial DFT matrix. For the sake of distinction, this set of vectors is referred to as a set of angular vectors U_s，U _s＝[u _s,1 u _s,2 … u _s,T]. The predefined set of delay vectors may be, for example, a set of vectors consisting of a plurality of vectors in a frequency domain DFT matrix. For the sake of distinction, this set of vectors is referred to as a set of delay vectors U _f，U _f＝[u _f，1 u _f，2 … u _f,N]。

The network equipment canDetermining an uplink channel through channel estimation, and further determining a space-frequency matrix H of the uplink channel_UL. The network equipment can estimate the uplink channel to obtain a space-frequency matrix H_ULDFT conversion of space domain and frequency domain is carried out to obtain a coefficient matrix C_ULThe following were used: c_UL＝U _s ^HH _ULU _f. For the sake of easy understanding, the space-frequency matrix H of the uplink channel will be referred to herein_ULDimension of (d) and dimension H of space-frequency matrix of downlink channel_DLAnd the consistency is maintained. The dimensions of the space-frequency matrix of the downlink channel and its relation to the downlink channel, the space-frequency matrix H determined by the uplink channel have been described above_ULMay be N x T.

It should be understood that the space-frequency matrix H for the uplink channel is shown here_ULAnd for determining the coefficient matrix C_ULThe calculation formula (b) is merely an example, and should not be construed as limiting the present application in any way. For space-frequency matrix H_ULDefining different dimensions for determining the coefficient matrix C_ULThe calculation formula (2) is also different.

The network device can derive the coefficient matrix C from_ULThe stronger K rows are determined. The stronger K rows may be used to determine K angular vectors. For example, if P ═ K × L, the network device may be based on the coefficient matrix C_ULThe size of the square sum of the modulus of the elements of each row in the middle determines the square sum of the modulus of the larger K rows. The square of the modulus and the larger K rows may be used to determine the K angular vectors. The K row-by-row coefficient matrix C _ULCan be used to determine the position of the K angular vectors in the set of angular vectors. E.g., the K rows in coefficient matrix C_ULThe row number in (1) may be the column number of the K angle vectors in the angle vector set. From this K angle vectors can be determined. The K angle vectors are selected from the set of angle vectors to precode the downlink reference signal.

The network device can derive the coefficient matrix C from_ULThe stronger L columns are determined. Each of the stronger L columns may be used to determine L timesA delay vector. For example, the network device may be based on the coefficient matrix C_ULThe size of the square sum of the squares of the column elements in (a) determines the L columns of the larger square sum of the squares of the columns. The larger L columns of the sum of squares of the modes may be used to determine L delay vectors. The L rows are arranged in a coefficient matrix C_ULMay be used for the positions of the L delay vectors in the set of delay vectors. E.g., the L columns are in the coefficient matrix C_ULThe column index number in (b) may be a column index number of the L delay vectors in the delay vector set. From which L delay vectors can be determined. The L delay vectors are delay vectors selected from the delay vector set to precode the downlink reference signal.

The network device may also be based on the coefficient matrix C_ULEach of the stronger K rows in the sequence determines the stronger one or more delay vectors. For example, if

For the K-th row of the K rows, the network device may determine one or more elements whose squares are greater than a preset value, e.g., L, according to the squares of the moduli of the elements_kAnd (4) respectively. The preset value may be a predefined value, for example. E.g. 80% of the sum of the squares of the modes of the elements of this column. Square of the modulus is greater than L of the predetermined value_kEach element can be used to determine L_kA delay vector. For example, L where the square of the modulus is greater than a preset value_kElement-by-element coefficient matrix C_ULThe column in (a) can be used to determine L_kThe position of each delay vector in a predefined set of delay vectors. Such as, the L_kElement-by-element coefficient matrix C_ULThe column number in (1) may be L_kThe column number of each delay vector in the delay vector set. For K angle vectors, the total number of delay vectors may be L. The L delay vectors are selected delay vectors in the delay vector set.

The network device may also be based on the coefficient matrix C_ULEach of the stronger L columns of (a) to (b)And determining one or more stronger angle vectors. For example, if

For the L-th row of the L rows, the network device may determine one or more elements having a square of a modulus greater than a preset value, e.g., K, according to the square of the modulus of each element_lAnd (4) respectively. The process of determining the corresponding angle vector for each delay vector by the network device is similar to the process of determining the corresponding delay vector based on each angle vector, and is not described herein again for brevity.

It should be understood that the above lists several possible methods that may be used by a network device to determine the K angle vectors and the L delay vectors, for ease of understanding only. This should not be construed as limiting the application in any way. The specific implementation manner of determining the K angle vectors and the L delay vectors by the network device is not limited in this application.

In addition, the uplink channel matrix may be estimated by the network device according to a previously received uplink reference signal, such as an SRS, or obtained according to a data signal after correct decoding, which is not limited in this application. The specific method for the network device to estimate the uplink channel matrix according to the uplink reference signal may refer to the prior art, and a detailed description of the specific method is omitted here for brevity. Since the angles and the time delays of the uplink and downlink channels are reciprocal in the FDD mode, K angle vectors and L time delay vectors obtained by measuring the uplink channel can be loaded to the downlink reference signal, so that the terminal device can perform downlink channel measurement based on the received precoding reference signal. Of course, K angle vectors obtained by uplink channel measurement may also be loaded to the downlink reference signal, or L delay vectors obtained by uplink channel measurement may also be loaded to the downlink reference signal. This embodiment mainly describes in detail a case where K angle vectors and L delay vectors are loaded to a downlink reference signal.

It should be understood that determining the K angle vectors and the L delay vectors described above based on uplink channel measurements is not the only implementation. The K angle vectors and the L delay vectors may be, for example, predefined, such as protocol definitions; alternatively, the network device may determine the downlink channel measurement statistics based on one or more previous downlink channel measurement statistics. The present application does not limit the manner of obtaining the K angle vectors and the L delay vectors.

It should also be understood that the K angle vectors and the L delay vectors are not necessarily determined based on uplink channel measurements. For example, the K angle vectors and the L delay vectors may be predefined, as defined by the protocol; alternatively, the K angle vectors and the L delay vectors may be statistically determined based on results fed back from one or more previous downlink channel measurements. The present application does not limit the determination method of the K angle vectors and the L delay vectors.

The network device precodes the downlink reference signals based on the K angular vectors and the L delay vectors to obtain precoded reference signals, which can be transmitted through preconfigured reference signal resources. Optionally, the downlink reference signal is a CSI-RS, and the reference signal resource is a CSI-RS resource. The reference signal resource may include a plurality of frequency domain units, such as N frequency domain units. That is, the precoded reference signal for each transmit port may be carried over N frequency domain elements. When the N frequency domain units are used to carry the precoded reference signals of the P transmit ports, different transmit ports may be distinguished by frequency division multiplexing (FDD), time division multiplexing (TDD), code division multiplexing (CDD), and the like. This is not a limitation of the present application.

In step 320, the terminal device generates first indication information indicating P groups of weighting coefficients corresponding to the P transmit ports.

The terminal device may perform channel estimation based on the received precoded reference signal, and generate the first indication information based on the estimated channel information. The first indication information may be used to indicate P sets of weighting coefficients corresponding to the P transmit ports. Wherein each set of weighting coefficients may comprise one or more weighting coefficients.

In the embodiment of the present application, the terminal device may feed back P groups of weighting coefficients corresponding to P transmission ports based on the reception port. In the P sets of weighting coefficients corresponding to the P transmit ports indicated by the first indication information, each set of weighting coefficients may include one or more weighting coefficients. For example, each set of weighting coefficients may include R' weighting coefficients. R 'is more than or equal to 1 and less than or equal to R, and R' is an integer.

Optionally, R' is 1. That is, each set of weighting coefficients includes one weighting coefficient. The weighting coefficient may be obtained by performing time domain transformation and then weighting on channel information obtained by performing channel estimation on the basis of the precoding reference signals received at the R receiving ports, or by performing time domain transformation after weighting; or the channel information obtained by performing channel estimation based on a pre-coding reference signal received at one of the R receiving ports is obtained after time domain transformation; channel information obtained by performing channel estimation based on a precoded reference signal received at one receiving port (i.e., R ═ 1) may also be obtained by time domain transformation.

Alternatively, R' ═ R. That is, each set of weighting coefficients may also include R weighting coefficients. For example, the R weighting coefficients correspond to R receiving ports, and each weighting coefficient is obtained by performing time domain transformation on channel information obtained by performing channel estimation on a precoding reference signal received at one receiving port.

Alternatively, R' < R. That is, each set of weighting coefficients includes less than R weighting coefficients. For example, the number of receiving ports is multiple (i.e., R > 1), and one or more of the R' weighting coefficients may be obtained by performing time domain transform on channel information obtained by performing channel estimation based on precoded reference signals received on part of the receiving ports and then weighting the channel information, or performing time domain transform on the channel information after weighting the channel information.

The terminal device may also feed back P sets of weighting coefficients corresponding to the P transmit ports based on the transport layer. Each set of weighting coefficients may include Z weighting coefficients, corresponding to Z transport layers. It should be noted that the weighting coefficients corresponding to the Z transmission layers may also be determined based on the result of performing time domain transformation on channel information obtained by performing channel estimation on the precoding reference signal received by each receiving port. The detailed procedure of how to determine the P groups of weighting coefficients based on the transport layer will be described in detail later, and will be omitted here for the moment.

For any one of the P transmitting ports, for example, the P-th transmitting port, P may take any integer value from 0 to P-1, and the terminal device may determine the weighting coefficient corresponding to the P-th transmitting port by performing the following procedure.

Traversing R within the range of 0 to R-1, and repeatedly executing the following steps i and ii to determine the weighting coefficients corresponding to the p-th transmitting port and the R-th receiving port:

i, performing channel estimation based on a precoding reference signal of a p-th transmitting port received on an r-th receiving port to obtain channel information respectively corresponding to N frequency domain units;

step ii, performing time domain transformation on the channel information respectively corresponding to the N frequency domain units determined in the step i, and performing time domain transformation on the nth value of the N values obtained by the time domain transformation_p,rThe values are determined as weighting coefficients corresponding to the pth transmit port and the mth receive port.

And traversing and taking values of P in the range from 0 to P-1, and repeatedly executing the processes to obtain P groups of weighting coefficients corresponding to the P transmitting ports.

The following describes in detail a process of determining P groups of weighting coefficients corresponding to P transmitting ports when the terminal device feeds back the weighting coefficients based on the receiving ports.

For ease of understanding, it is first assumed that R is 1, i.e., each set of weighting coefficients may include one weighting coefficient. The precoded reference signal for each transmit port may be carried over N RBs (i.e., an instance of a frequency domain unit). In this case, the set of weighting coefficients corresponding to each transmit port may include one weighting coefficient. The first indication information may be used to indicate P weighting coefficients corresponding to P transmit ports.

Since the transmission port that the terminal device can identify is a port corresponding to the precoding reference signal, the terminal device can perform channel estimation based on the received precoding reference signal of each transmission port.

If precoding of the reference signal is not considered, for each receiving port, the dimension of the downlink channel estimated by the terminal device based on the received precoded reference signal may be nxt. The dimension of the downlink channel received on each RB may be 1 × T. Since the network device precodes the reference signal based on the angle vector and the delay vector, the dimension of each angle vector may be T × 1, and after precoding the reference signal by the angle vector and the delay vector, the dimension of the downlink channel received by the terminal device on each receiving port and each RB may be 1 × 1. The downlink channel with the dimension of 1 × 1 is channel information obtained by performing channel estimation based on the precoded reference signal on one RB. Alternatively, the channel information may specifically be a channel estimation value obtained by performing channel estimation based on the received precoding reference signal. It is to be understood that the channel estimation value may specifically be equivalent channel information, i.e., channel information loaded with precoding.

Since the network device precodes the reference signal based on the K angle vectors and the L delay vectors, the precoded reference signal carried by each RB may correspond to one or more transmit ports, such as the P transmit ports described above. The P transmit ports may have a one-to-one correspondence with P angular delay pairs. The precoded reference signal corresponding to the P-th transmission port of the P transmission ports may be obtained by precoding the reference signal based on the kth angular vector of the K angular vectors and the L-th delay vector of the L delay vectors, for example. I.e. the p-th transmit port corresponds to the k-th angle vector and the l-th delay vector. In other words, the precoded reference signal corresponding to the p-th transmission port may be used to determine the weighting coefficient of the angle vector formed by the k-th angle vector and the l-th delay vector, that is, may be used to determine the weighting coefficient of the p-th angle delay pair. Therefore, the weighting coefficient corresponding to the pth transmission port, i.e., the weighting coefficient of the pth angular delay pair, is described above.

Hereinafter, without loss of generality, a process of the terminal device determining the weighting coefficient corresponding to the p-th transmission port is described in detail.

For the precoded reference signal of the p-th transmit port, the terminal device may determine the weighting coefficient of the p-th angle delay pair based on a channel estimation value obtained by performing channel estimation on the precoded reference signal received on one receive port and N RBs. The weighting factor of the pth angle delay pair may be determined by the N channel estimates over the N RBs.

Suppose that the channel estimation value obtained by the terminal device performing channel estimation based on the precoding reference signal of the p-th transmitting port received on the nth RB is recorded as

Then, a channel estimation value obtained by the terminal device performing channel estimation based on the precoding reference signal of the p-th transmission port may be recorded as:

n channel estimates. It can be seen that the N channel estimates correspond to N RBs, i.e., to N frequency domain units. The N channel estimates may characterize the channel variation in the frequency domain. Since the N channel estimation values are determined by channel estimation based on the precoded reference signal of the p-th transmission port, the N channel estimation values are channel estimation values corresponding to the p-th angle delay pair.

As previously mentioned, the space-frequency matrix H_DLSatisfy H_DL＝SC _DLF ^H. In the examples of the present application, H _DLMay be T N; the number of angle vectors may be K, the length of each angle vector may be T, and the dimension of S may be T × K; each delay vector may be L, each delay vector may be N in length, and then the dimension of F may be N × L. A variation on the above equation can result: s^HH _DL＝C _DLF ^HFurther, can obtain (H)_DL ^HS) ^H＝C _DLF ^H. To (H)_DL ^HS) ^H＝C _DLF ^HFurther modified, coefficient matrix C can be obtained_DL＝(H _DL ^HS) ^HF。

When the network equipment performs space domain pre-coding on the reference signal based on the K angle vectors, namely, the real channel is multiplied by S to obtain H_DL ^HS。H _DL ^HAnd S is a real channel subjected to space-domain precoding. In the embodiment of the present application, the dimension thereof may be N × K. When the network device performs frequency domain precoding on the reference signal after space domain precoding based on the L time delay vectors, the reference signal can be subjected to (H)_DL ^HS) ^HAnd F. In the embodiment of the present application, the dimension thereof may be K × L.

In the coefficient matrix, C_DLEach element of (A) may be represented by (H)_DL ^HS) ^HOne row in F multiplied by one column in F. In other words, the matrix coefficient C_DLCan be determined by the real channel H_DL ^HAnd multiplying one row of the conjugate transpose of S by one column in F.

E.g. coefficient matrix C_DLThe element of the first row and the k column in (1) is^H _DL ^HS) ^HThe ith row in (1) and the kth column in (F). Coefficient matrix C _DLI.e. the weighting coefficients corresponding to the kth angle vector and the ith delay vector.

As can be seen from the matrix multiplication operation, (H)_DL ^HS) ^HEach row vector in (F) includes the same number of elements as each column vector in (F). In the present embodiment, (H)_DL ^HS) ^HEach row vector in (b) and each column vector in (F) may include N elements. When the row vector and the column vector are multiplied, each element (e.g., the nth element, N is traversed from 1 to N) in the row vector and the column vector need to be multiplied respectivelyThe corresponding elements (e.g. the nth element, N is traversed from 1 to N) are multiplied and then summed, and (H)_DL ^HS) ^HThe N elements in each row in (a) correspond to N frequency domain units (e.g., RBs, subbands, etc.). However, the network device cannot know the correlation between the downlink channels in each frequency domain unit (e.g. RB) in advance, and therefore cannot complete (H) at the network device side_DL ^HS) ^HF, and only loading the elements in each delay vector to each RB of the downlink channel.

For ease of understanding, it is assumed here that both the K angle vectors and the L delay vectors are loaded on each of the N RBs. Will be described in the above by C_DL＝(H _DL ^HS) ^HFurther modifications of F can result in: c _DL＝(F ^HH _DL ^HS) ^H＝(F ^HH _DL'S) ^H. Wherein H_DL' denotes a space-frequency matrix determined by a real downlink channel, which has dimension of R x T, H_DLThe dimension of' is N T. H is made of_DL' may comprise N row vectors of dimension 1 × T, e.g. comprising h₀，h ₁To h_N-1Corresponding to the 0 th to the N-1 st RBs among the N RBs, respectively.

It can be understood that the space-frequency matrix H defined in the embodiments of the present application_DLAnd the space-frequency matrix H determined by the real channel in the above_DL' Internally satisfies H_DL'＝H _DL ^H. This is due to the space-frequency matrix H defined in this application_DLIs determined by the conjugate transpose of the real channel.

After loading L angle vectors and K delay vectors, the channel estimated by the terminal device based on the precoded reference signal received at one receiving port can be represented as:

wherein, b (τ)₀) To b (τ)_L-1) L delay vectors in F can be represented; b (τ)₀) _nCan represent b (τ)₀) N of the N elements, b (τ)_L-1) _nCan represent b (τ)_L-1) N is 0, 1, … …, N-1; s may represent a matrix of dimensions T × K constructed from K angular vectors. Thus, b (τ)_l) _n ^Hh _nS (N-0, 1, … …, N-1; L-0, 1, … …, L-1) may be a row vector of dimension 1 × K.

That is, a matrix

The nth row in (1) may represent a channel estimation value obtained by performing channel estimation based on precoding reference signals of a plurality of ports received on the nth RB. Matrix array

May comprise K × L elements, which may correspond to K × L ports, respectively, or K × L angular delay pairs.

Since the precoding reference signal received by the terminal device experiences the downlink channel, the correlation of the downlink channel between RBs can be known, and the above summation operation can be completed. I.e. the matrix

Each column element in (a) is summed separately. That is, will

Corresponding to the same delay vector and the same angle vectorCan get: (b (τ)₀) ^HH _DL'S … b(τ _L-1) ^HH _DL'S) ^H. The above operation can be understood as summing the channel estimates over N RBs for each delay vector and each angle vector, or, alternatively, for each transmit port.

Wherein, b (τ)_l) ^HH _DL' S (L ═ 1, 2, … …, L) may be a row vector of dimension 1 × K, corresponding to the L-th delay vector of the L delay vectors. The kth element in the row vector may correspond to the kth angle vector in the K angle vectors. Thus, b (τ)_l) ^HH _DLThe kth element in' S may correspond to the estimated value y of the downlink channel obtained by channel estimation based on the precoded reference signal of the p-th port as described above _n ^p。

Will be (b (tau)₁) ^HH _DL'S … b(τ _L) ^HH _DL'S) ^HAfter rearrangement, a coefficient matrix C with dimension of K multiplied by L can be obtained_DL，

The coefficient matrix C_DLThe elements of the kth row and the l column in (a) correspond to the kth angle vector and the l delay vector, i.e. to the weighting coefficients of the angle delay pair formed by the kth angle vector and the l delay vector.

Therefore, the terminal device may determine the weighting coefficient corresponding to each angle delay pair obtained by combining each angle vector and the delay vector by summing the channel estimation values of N RBs. Where N RBs are N frequency domain units in the reference signal resource, since they are distributed over the frequency domain resource of the reference signal resource, they can also be understood as being the full band of the reference signal resource.

Based on the above description, the weighting coefficient corresponding to the pth angle delay pair may be obtained by cumulatively summing N channel estimation values corresponding to the pth angle delay pair. However, when the network device precodes the reference signal based on the delay vector, N different elements in the delay vector are loaded on N RBs corresponding to the same transmit port, respectively. The channel estimation value estimated by the terminal device on each RB may be discontinuous. If the value obtained by directly accumulating and summing the N channel estimation values is used as the weighting coefficient of the p-th angle delay pair for feedback, the recovered downlink channel may have a large difference from the real channel, and the determined precoding matrix for downlink data transmission may not be well matched with the real channel, thereby affecting the transmission performance of the system.

In this embodiment of the present application, the terminal device may perform time domain transformation on the N channel estimation values, convert a channel in a frequency domain into a time domain, and represent the weighting coefficient of the p-th angle delay pair by using a value obtained through the time domain transformation.

In one implementation, the terminal device may perform time domain transformation on the vector constructed by the N channel estimation values. N values (for convenience of explanation, hereinafter referred to as time domain transform values) can be obtained by time domain transform. The terminal device may convert one of the N time-domain transform values (e.g., the nth value)_pValue) is fed back as a weighting factor corresponding to this p-th angular delay pair.

One of the N time domain transform values can be fed back as a weighting factor corresponding to the angle delay pair because if the N channel estimation values are time domain transformed, such as by IFFT, if there is no delay variation in the uplink and downlink, the dc component (i.e., 0 th value of the N time domain transform values) of the N obtained time domain transform values is exactly equal to the sum of the N channel estimation values accumulated based on the precoding reference signal estimates received in the N frequency domain units. Since the N channel estimation values are estimated based on the reference signals received in the N frequency domain units, respectively, the sum of the N channel estimation values can be understood as the sum of the frequency domain accumulations of the N frequency domain units.

For example, if based on the delay vector b (τ)₁) And b (τ)₂) The reference signal is precoded, one port of which the terminal device is directed (e.g., and b (τ))₁) Corresponding port) may be expressed as:

wherein h is_nAnd the channel estimation value of the nth frequency domain unit is shown, and l is 1 and 2.

In the formula, each superposition term is respectively:

substituting the above equation can result in:

since the substrates are orthogonal, the multiplication is 0. Thus, in the above formula, c ═ N α₁。

As can be seen from the above derivation, the 0 th value (i.e., the DC component) N α of the IFFT-derived N time-domain transform values₁Exactly equal to the cumulative sum based on the N channel estimates.

The specific process of determining the weighting coefficient of the p-th angle delay pair by the terminal device through performing time domain transformation on the N channel estimation values is described in detail below.

If the N channel estimation values are recorded as a vector, the vector may represent the estimation of the precoded reference signal of the p-th transmission portThe channel vector of (2). The vector may be represented, for example, as:

or the like, or, alternatively,

in this embodiment, for convenience of explanation, a channel vector formed by the N channel estimation values is described as

Optionally, the time domain transform comprises an IFFT or an IDFT. Taking IFFT as an example, the above and channel vectors are combined

Performing IFFT can obtain N time-domain transform values. The terminal device may determine one of the N time domain transform values as a weighting coefficient corresponding to the pth angle delay pair.

Suppose that the terminal device can convert the nth of the N time delay transformation values_pThe values are determined as weighting coefficients corresponding to the pth angular delay pair. Weighting coefficient c corresponding to the p-th angular delay pair, e.g. obtained by IFFT_pCan be expressed as:

i.e. the weighting coefficients c corresponding to the kth angle vector and the l-th delay vector_k,lCan be expressed as:

n is above_pThe value of (A) may be, for example, pre-The definition, such as the protocol is predefined, may also be determined by the terminal device, and may also be indicated by the network device, which is not limited in this application. It can be appreciated that 0 ≦ n_pN is not more than N-1, and N_pAre integers.

Alternatively, n_pIs a predefined value. Exemplarily, n_pIs 0. In other words, the terminal device may use the 0 th value of the N time domain transform values as the weighting coefficient corresponding to the p-th angular delay pair.

It is to be understood that n _p0 is merely one possible implementation and should not be construed as limiting the present application in any way. For example, in the case where there is a deviation in uplink and downlink timings, n_pOther values are also possible, for example, they may be determined empirically in advance, or predefined in a protocol, etc. This is not a limitation of the present application.

Alternatively, n_pDetermined by the terminal device. Optionally, the first indication information indicates n_pThe value of (c).

For example, the terminal device may select a maximum value from the N time domain transform values as a weighting coefficient corresponding to the p-th angular delay pair.

Alternatively, n_pIs determined for the network device. Optionally, before step 320, the method further comprises: the terminal equipment receives fourth indication information, and the fourth indication information is used for indicating n_pThe value of (c). Correspondingly, the network device transmits the fourth indication information.

It is to be understood that the above-listed pairs of n_pThe determination or indication of values of (b) is merely an example and should not constitute any limitation of the present application.

The specific process of the terminal device using one of the N time domain transformation values as the weighting coefficient of the pth angle delay pair may be implemented by filtering, for example. For example, a vector formed by the N time-domain transform values is multiplied by a filter coefficient to obtain a weighting coefficient of the p-th angular delay pair. The filter coefficients may comprise N elements, which may be denoted as vectors of dimension 1 × N, or vectors of dimension N × 1, for example. For the sake of distinction, a vector of N elements in the filter coefficient is referred to as a filter coefficient vector. The N elements included in the filter coefficient may include N-1 zero elements and 1 non-zero element, and the non-zero element may be the nth element of the N elements (or the filter coefficient vector with dimension 1 × N or the filter coefficient vector with dimension N × 1) _pAnd (4) each element.

The N time domain transform values may constitute, for example, a vector having a dimension of N × 1 or a vector having a dimension of 1 × N. For ease of distinction, it is referred to as a time-domain transform vector, for example.

The terminal device may multiply the time domain transform vector with the dimension of N × 1 to the left of the filter coefficient vector with the dimension of 1 × N, or may multiply the time domain transform vector with the dimension of 1 × N to the right of the filter coefficient vector with the dimension of N × 1, so as to obtain the weighting coefficient corresponding to the pth angle delay pair.

For example, the N time-domain transform values may form a time-domain transform vector with dimension N × 1. Suppose n above_pIs 0, the filter coefficient vector formed by the filter coefficients can be recorded as [ 10 … 0 ]] _1×N. The N time-domain transform vectors may be filtered by left-multiplying the time-domain transform vector of dimension N × 1 by the filter coefficient vector [ 10 … 0 ]] _1×NTo be implemented. Thus, the 0 th value of the N time-domain transform values can be obtained.

It should be understood that the filter coefficients listed here are only one possible form and should not be construed as limiting the application in any way. Since the specific process of filtering can refer to the prior art, it is not illustrated here for the sake of brevity. It should also be understood that filtering is only one possible implementation and should not constitute any limitation to the present application. The specific implementation manner of selecting a certain value from the N time domain transform values by the terminal device is not limited in the present application.

It should also be understood that the above-mentioned nomenclature for each vector is merely for convenience of distinction and description, and should not be construed as limiting the present application in any way.

In the above, for convenience of understanding only, a specific process of determining the weighting coefficient corresponding to the pth transmission port by the terminal device is described in detail by taking R ═ 1 as an example. This should not be construed as limiting the application in any way. The number R of receiving ports may be 1 or greater than 1. When R > 1, the terminal device may determine a set of weighting coefficients corresponding to the p-th transmit port based on the precoded reference signal of the p-th transmit port received on each RB per receive port.

Assuming that the set of weighting coefficients corresponding to the pth transmit port includes R weighting coefficients, the R weighting coefficients may correspond to R receive ports. Wherein the r-th weighting coefficient may be determined based on the p-th transmit port's precoded reference signal received on the r-th receive port and the N RBs. R may take any integer value from 0 to R-1. For any value of r, the terminal device may determine a weighting factor according to the method described above. Thereby R weighting coefficients corresponding to the p-th transmitting port and R receiving ports can be obtained.

Illustratively, the terminal device may convert the nth of the N time domain transform values for the r-th receive port, the p-th transmit port_p,rThe values are determined as the weighting coefficients corresponding to the r-th receiving port and the p-th transmitting port, i.e. the r-th coefficient of the weighting coefficients corresponding to the p-th angular delay pair.

Optionally, the method further comprises: performing time domain transformation on a vector determined by channel information between the p-th transmitting port and the r-th receiving port to obtain a transformed vector, wherein the n-th vector in the transformed vector_p,rThe value is the r-th weighting factor in the p-th set of weighting factors.

As described above, the specific implementation of the terminal device using one of the N time domain transform values as the weighting coefficient of the p-th angular delay pair may be implemented by filtering, for example. When R > 1, for any value of R, the terminal device may multiply a vector formed by N time domain transform values corresponding to an R-th receiving port and a p-th transmitting port by a filter coefficient to obtain a weighting coefficient of the p-th angular delay pair, where the weighting coefficient may correspond to the R-th receiving port.

Wherein the filter coefficient mayTo include N elements, for example, can be written as a vector of dimension 1 × N, or a vector of dimension N × 1. This vector may be referred to as a filter coefficient vector, corresponding to that described above. The N elements included in the filter coefficient may include N-1 zero elements and 1 non-zero element, and the non-zero element may be an nth element of the N elements (or a filter coefficient vector with a dimension of 1 × N or a filter coefficient vector with a dimension of N × 1) _p,rAnd (4) each element.

After determining the filter coefficient vector, the terminal device may determine the weighting coefficients corresponding to the r-th receive port and the p-th transmit port based on the same manner as described above. Traversing R in the range of 0 to R-1 to obtain R weighting coefficients corresponding to R receiving ports and the p-th transmitting port, namely, a group of weighting coefficients corresponding to the p-th transmitting port.

It should be understood that filtering is only one possible implementation and should not constitute any limitation to the present application. The specific implementation manner of selecting a certain value from the N time domain transform values by the terminal device is not limited in the present application.

It will also be appreciated that for different values of r, n_p,rThe values of (A) may be the same or different. This is not a limitation of the present application. For example, in one implementation, n is chosen for any value of r_p,rAre all 0. That is, the 0 th value among the N time-domain transform values corresponding to the r-th receive port and the p-th transmit port is used as a weighting coefficient corresponding to the r-th receive port and the p-th transmit port.

With respect to n_p,rReference may be made to the above description of n_pThe description thereof is not repeated here for the sake of brevity.

In fact, the number of weighting coefficients corresponding to each transmit port is not necessarily the same as the number of receive ports. As mentioned above, R ≧ 1, the weighting coefficient corresponding to each transmit port can be R ', R' is 1 ≦ R. That is, when R > 1, the weighting coefficients corresponding to each transmit port may be R or less than R.

In some implementations, the terminal device may perform channel estimation on only the precoded reference signals received on a portion of the receive ports to determine the weighting coefficients corresponding to the portion of the receive ports.

For example, the terminal device is configured with 2 receiving ports. The terminal equipment performs channel estimation on the precoded reference signals received on only one of the receiving ports. The terminal device may estimate N channel estimation values based on the precoded reference signal of each (e.g., p-th) transmitting port received at the receiving port, where the N channel estimation values may obtain a weighting coefficient corresponding to the p-th transmitting port after time domain transformation.

The protocol may define some rules in advance so that the terminal device decides to determine the reported weighting coefficients based on the precoded reference signals received on which receiving port. Alternatively, the protocol may also predefine the terminal device or the network device may signal the terminal device to determine the weighting coefficients in advance based on the precoding reference signals received on which receiving port. Still alternatively, the terminal device may decide on its own to determine the weighting coefficients based on the precoded signals received on which receive port. This is not a limitation of the present application.

In some implementations, the terminal device may also perform weighting on a channel estimation value obtained by performing channel estimation based on precoded reference signals received on multiple receiving ports, and perform time domain transformation on the weighted value; or, a value weighted sum obtained by performing time domain transformation on a channel estimation value obtained by performing channel estimation on a precoding reference signal received at each of a plurality of receiving ports may be performed, so that weighting coefficients corresponding to one transmitting port and a plurality of receiving ports are weighted, and the number of the obtained weighting coefficients corresponding to each transmitting port is smaller than the number R of the receiving ports.

For example, the terminal device is configured with 4 receiving ports. The terminal device may perform weighting on a channel estimation value obtained by performing channel estimation based on a precoding reference signal received on each 2 receiving ports, and perform time domain transformation on the weighted value, thereby obtaining 2 weighting coefficients corresponding to one (e.g., the p-th) transmitting port; alternatively, the terminal device may also perform time domain transformation on a channel estimation value obtained by performing channel estimation on a precoding reference signal received at each of the 4 receiving ports to obtain values corresponding to the 4 receiving ports, and then perform weighted summation on the values corresponding to each of the 2 receiving ports, so as to obtain 2 weighting coefficients corresponding to one (e.g., the p-th) transmitting port.

It should be understood that the above lists some receiving ports and the corresponding relations of the weighting coefficients for easy understanding, but these examples are only for easy understanding and should not constitute any limitation to the present application. The present application does not limit the correspondence between the receiving ports and the weighting coefficients.

It should also be understood that the above-mentioned manner of weighting the receiving ports is only an example, and the application is not limited to the weighting of each receiving port.

Based on the method described above, the terminal device may determine a set of weighting coefficients corresponding to each of the P transmit ports. The terminal device may generate the first indication information based on the determined weighting coefficient corresponding to each transmission port.

The first indication information, when used to indicate P groups of weighting coefficients corresponding to the P transmit ports, may construct a matrix with dimension P × R', for example. For the sake of distinction and explanation, the matrix constructed by the P sets of weighting coefficients is referred to as a coefficient matrix. Each row in the coefficient matrix may correspond to a transmit port. The number of weighting coefficients included in each row is the number of weighting coefficients corresponding to one transmit port. It is to be understood that when R' ═ R, the weighting coefficients corresponding to each transmit port correspond to R receive ports.

An example of a coefficient matrix of dimension P × R constructed from P sets of weighting coefficients corresponding to P transmit ports is shown below.

Coefficient c in the coefficient matrix_p,rA weighting factor corresponding to the p-th transmit port (or p-th angle delay pair, corresponding to the k-th angle vector and the l-th delay vector) and the r-th receive port may be expressed.

The value of the P groups of weighting coefficients by the terminal device may be indicated by a quantized value, an index of quantized values, or other forms, for example. In one implementation, the terminal device may perform normalization processing on the P groups of weighting coefficients, and generate the first indication information based on a result of the normalization processing. The normalization process is a process of controlling the amplitude values of all the weighting coefficients within a range not exceeding 1 in the range of the normalization unit.

Illustratively, the terminal device may determine a weighting coefficient having the largest magnitude from the P sets of weighting coefficients (for convenience of distinction and explanation, for example, the magnitude of the weighting coefficient is referred to as the largest magnitude). The terminal device may divide the magnitudes of the remaining weighting coefficients except for the weighting coefficient by the maximum magnitude, respectively, to obtain a ratio corresponding to each weighting coefficient. After the terminal device normalizes the P groups of weighting coefficients, the maximum amplitude is normalized to 1, and the other weighting coefficients are respectively corresponding ratios. After being normalized, the terminal device may generate the first indication information based on a quantized value or a non-quantized value of each result after normalization.

It should be understood that the above normalization process is processed over a range of P transmit ports, i.e., the normalization unit is P transmit ports. This is merely illustrated for ease of understanding. The normalization unit may also be a transmit port, that is, each row in the coefficient matrix is normalized separately. The normalization unit is not limited in the present application.

It should also be understood that the above-mentioned normalization process is only an example, and should not limit the present application in any way. Since the specific implementation of the normalization process is the prior art, for the sake of brevity, it will not be described in detail here.

As previously described, a network device may be configured with J polarization directions, J ≧ 1. The terminal device may perform channel estimation based on the precoded reference signal of the transmitting port in each polarization direction according to the method described above, to obtain the weighting coefficient corresponding to each transmitting port in each polarization direction.

Assuming that the number of polarization directions J is 2, P sets of weighting coefficients may be determined based on the precoded reference signals of P transmit ports for each of the 2 polarization directions. A coefficient matrix of dimension 2P × R (assuming R' ═ R) can be constructed from the weighting coefficients corresponding to 2P transmit ports in 2 polarization directions as follows:

The first P rows in the coefficient matrix correspond to P transmit ports in the first polarization direction. The weighting coefficients in the first P rows are P sets of weighting coefficients corresponding to the P transmit ports in the first polarization direction. The last P rows in the coefficient matrix correspond to P transmit ports in the second polarization direction. The weighting coefficients in the next P rows are P sets of weighting coefficients corresponding to P transmit ports in the second polarization direction.

It should be understood that the weighting coefficients corresponding to the P transmit ports determined by the terminal device are shown in the form of a matrix for ease of understanding only above. This should not be construed as limiting the application in any way. The terminal device does not necessarily generate the coefficient matrix in the process of generating the first indication information.

It should also be understood that, when indicating the weighting coefficients corresponding to the transmitting ports in multiple polarization directions, the terminal device may indicate the weighting coefficients sequentially according to a predetermined order, for example.

For example, the terminal device may perform normalization processing on the weighting coefficient corresponding to each transmission port in the first polarization direction and the weighting coefficient corresponding to each transmission port in the second polarization direction, respectively, and generate the first indication information based on a result of the normalization processing. The first indication information may include information indicating a weighting coefficient corresponding to each transmission port in the first polarization direction and information indicating a weighting coefficient corresponding to each transmission port in the second polarization direction. In this case, the normalization unit may be P transmission ports in one polarization direction.

For another example, the terminal device may perform normalization processing on the weighting coefficients corresponding to the transmission ports in the two polarization directions, and generate the first indication information based on the result of the normalization processing. In this case, the normalization unit may be 2P transmission ports in two polarization directions.

It should be understood that the present application is not limited to the order in which the terminal device indicates the weighting coefficients. As long as the network device can recover the weighting coefficients corresponding to the transmitting ports in the J polarization directions according to the first indication information.

It should also be understood that when the terminal device indicates the weighting coefficients corresponding to the respective transmission ports in the respective polarization directions by the first indication information, it does not necessarily mean that the first indication information includes an indication of all the weighting coefficients. As long as the network device can determine all the weighting coefficients according to the first indication information, the first indication information can be considered to indicate all the weighting coefficients.

For example, when the terminal device indicates, through the first indication information, the weighting coefficients corresponding to P transmission ports in one polarization direction, such as the P × R 'weighting coefficients described above, it does not necessarily indicate that the first indication information includes an indication of each of the P × R' weighting coefficients. After normalizing the P × R' weighting coefficients, the terminal device may indicate the position corresponding to the maximum amplitude value (e.g., corresponding transmit port and receive port or row and column in the coefficient matrix), the ratio of the amplitude value of other weighting coefficients to the maximum amplitude value, and the like. That is, as long as the network device can recover the P × R 'weighting coefficients according to the first indication information, the first indication information can be considered to indicate the P × R' weighting coefficients.

In addition, since each transmitting port corresponds to one angle vector and one delay vector, or corresponds to one angle delay pair, each of the weighting coefficients is a weighting coefficient corresponding to the angle delay pair. The network device may determine the angle delay pair corresponding to each weighting coefficient according to the correspondence between each transmitting port and the angle vector and the delay vector.

In step 330, the terminal device transmits the first indication information. Accordingly, in step 330, the network device receives the first indication information.

Specifically, the first indication information may be, for example, CSI, or a part of cells in the CSI, or other information. Illustratively, the first indication information is a Precoding Matrix Indicator (PMI). This is not a limitation of the present application. The first indication information may be carried in one or more messages in the prior art and sent by the terminal device to the network device, or may be carried in one or more newly designed messages and sent by the terminal device to the network device. The terminal device may send the first indication information to the network device through a physical uplink resource, such as a Physical Uplink Shared Channel (PUSCH) or a Physical Uplink Control Channel (PUCCH), for example, so that the network device determines the precoding matrix based on the first indication information.

The specific method for the terminal device to send the first indication information to the network device through the physical uplink resource may be the same as that in the prior art, and a detailed description of a specific process of the terminal device is omitted here for brevity.

In the above implementation, since the terminal device feeds back P sets of weighting coefficients corresponding to P transmit ports based on the receive port, each set of weighting coefficients may include weighting coefficients corresponding to one or more, and each weighting coefficient may correspond to one or more receive ports.

Optionally, the method further comprises: and the terminal equipment sends fifth indication information, wherein the fifth indication information is used for indicating the receiving port number R. Accordingly, the network device receives the fifth indication information.

The network device determines the number of the weighting coefficients indicated by the first indication information according to the number of the receiving ports by indicating the number of the receiving ports to the network device.

The fifth indication information and the first indication information may be carried in the same signaling or may be carried in different signaling, which is not limited in this application.

It should be appreciated that the terminal device feeding back P sets of weighting coefficients corresponding to P transmit ports based on the receive ports is only one possible implementation. And should not be construed as limiting the application in any way.

In another implementation, the terminal device may also feed back P groups of weighting coefficients corresponding to the P transmit ports based on the transport layer. In this implementation, in the P groups of weighting coefficients corresponding to the P transmission ports indicated by the first indication information, each group of weighting coefficients may include Z weighting coefficients corresponding to Z transmission layers.

For ease of understanding, the process of determining the weighting coefficients based on the transport layer feedback by the terminal device is described here by taking as an example the weighting coefficients corresponding to each transmit port in both polarization directions.

It is assumed that the set of weighting coefficients corresponding to each transmit port determined by the terminal device is R, corresponding to R receive ports. The weighting coefficient determined by the terminal device based on the receiving port can be expressed by a matrix as:

the terminal device may perform SVD on the coefficient matrix to obtain a weighting coefficient based on the transport layer feedback. The weighting coefficients determined by the terminal device based on the transport layer may be represented by a matrix as:

each weighting coefficient in the coefficient matrix is denoted by d to be distinguished from the weighting coefficient c based on the receive port feedback. The first P rows in the coefficient matrix may correspond to a first polarization direction and the last P rows may correspond to a second polarization direction. The Z columns correspond to Z transport layers. Each row in the coefficient matrix may thus represent a set of weighting coefficients corresponding to one transmit port in one polarization direction. Each set of weighting coefficients may include Z weighting coefficients, corresponding to Z transmission layers. Wherein, the weighting coefficients of the P-th row and the z-th column in the previous P rows represent the weighting coefficients corresponding to the P-th transmitting port and the z-th transmission layer in the first polarization direction; the weighting coefficients of the pth row and the pth column in the next pth row represent the weighting coefficients corresponding to the pth transmitting port and the pth transmission layer in the second polarization direction.

It can be seen that the terminal device may determine P groups of weighting coefficients corresponding to P transmission ports based on the P groups of weighting coefficients corresponding to P transmission ports determined by the receiving port, and based on the transport layer feedback. It has been explained hereinbefore that the P sets of weighting coefficients corresponding to the P transmit ports determined based on the receive ports are obtained based on the time domain transform approach described hereinbefore. Therefore, in the embodiment of the present application, whether the P-group weighting coefficients are fed back by the receiving ports or the P-group weighting coefficients are fed back by the transmission layer. The determination of each weighting factor by the terminal device may be obtained by means of the time domain transformation described above.

The terminal device may generate first indication information based on the above-mentioned P groups of weighting coefficients corresponding to the P transmission ports in each polarization direction, so as to indicate the P groups of weighting coefficients corresponding to the P transmission ports in each polarization direction by the first indication information. The specific method for the terminal device to indicate the weighting coefficients based on the transmission layer feedback through the first indication information is similar to the specific method for indicating the P groups of weighting coefficients corresponding to the P transmitting ports based on the receiving port feedback through the first indication information, for example, the weighting coefficients may be normalized, and the like. Since the specific process that the terminal device indicates the weighting coefficient based on the receive port feedback through the first indication information has been described in detail above, for brevity, no further description is given here.

It should be understood that the above exemplary process of determining the weighting coefficients based on the transport layer feedback by the terminal device is only an example, and should not limit the present application in any way. The present application does not limit the specific method for determining the weighting coefficient based on the transmission layer feedback by the terminal device.

Optionally, the method further comprises: and the terminal equipment sends sixth indication information, wherein the sixth indication information is used for indicating the number Z of the transmission layers. Correspondingly, the network device receives the sixth indication information.

The sixth indication information may be carried in the same signaling as the first indication information or may be carried in a different signaling. Illustratively, the fifth indication information is Rank Indication (RI). It should be understood that the present application is not limited to the specific signaling for carrying the sixth indication information.

In step 340, the network device determines a precoding matrix according to the first indication information.

As described above, the terminal device may feed back P groups of weighting coefficients corresponding to P transmitting ports based on the receiving port, and may also feed back P groups of weighting coefficients corresponding to P transmitting ports based on the transmission layer. The network device may determine the precoding matrix from the first indication information based on different feedback granularities.

The following respectively describes a specific process of determining a precoding matrix by the network device according to the first indication information under the two situations.

If the terminal device feeds back P groups of weighting coefficients corresponding to P transmitting ports based on the receiving ports, the weighting coefficients indicated by the first indication information may include weighting coefficients corresponding to one or more receiving ports. The network device may reconstruct the downlink channel based on the weighting coefficients indicated by the first indication information and the angle delay pair corresponding to each weighting coefficient, so as to determine the precoding matrix of each frequency domain unit.

For ease of understanding, it is assumed here that each of the P sets of weighting coefficients fed back by the terminal device includes R weighting coefficients corresponding to R receiving ports. Then, the P weighting coefficients corresponding to each receiving port may correspond to the P angle delays one-to-one, respectively. The network device may be based on P weights corresponding to each receive port of the terminal deviceAnd constructing a space-frequency matrix corresponding to each receiving port by using the coefficients and the angle vector and the delay vector contained in each angle delay pair of the P angle delay pairs. For the sake of distinction and explanation, in the embodiments of the present application, the space-frequency matrix corresponding to the receiving port is denoted as H _DL,R。

And represents a space-frequency matrix corresponding to the R-th receiving port, wherein R can take any integer value from 0 to R-1.

In this embodiment, the space-frequency matrix corresponding to the r-th receiving port may be determined by P angular delay pairs and P weighting coefficients corresponding to the r-th receiving port. Wherein P angular delay pairs may be used to construct P space-frequency component matrices. As previously mentioned, the K-th angle vector a (θ) of the K angle vectors_k) And the L-th delay vector b (tau) of the L delay vectors_l) A space-frequency component matrix a (θ) may be constructed_k)×b(τ _l) ^H. Space-frequency matrix corresponding to the r-th receiving port

May be a weighted sum of P matrices of space-frequency components. That is to say that the first and second electrodes,

representing weighting coefficients corresponding to the kth angle vector and the l-th delay vector based on the feedback from the r-th receiving port. The dimension of the space-frequency matrix may be T × N.

Space-frequency matrix shown above

The formula (2) assumes that the K angle vectors and the L delay vectors are common to each other. When the time delay vectors corresponding to at least two angle vectors are different, the above formulaCan be modified into:

alternatively, when the angle vectors corresponding to at least two delay vectors are different, the above formula can be modified to

For convenience of explanation, the following descriptions are provided

For illustration purposes. It can be understood that whether the delay vectors corresponding to the angle vectors are the same or not, or whether the angle vectors corresponding to the delay vectors are the same or not, has no influence on the determination method of the pre-coding matrix.

It should be noted that, for convenience of understanding, the specific process of determining the space-frequency matrix corresponding to the receiving port is described by taking one polarization direction of the transmitting antenna as an example. This should not be construed as limiting the application in any way. When the number of polarization directions of the transmitting antennas is greater than 1, the network device may still determine the space-frequency matrix corresponding to each receiving port based on the method described above.

For example, the number of polarization directions is 2, and the space-frequency matrix corresponding to the r-th receiving port can be determined by the following calculation formula:

wherein the content of the first and second substances,

representing weighting coefficients corresponding to a k-th angle vector and an l-th time delay vector in a first polarization direction based on feedback of an r-th receiving port;

representing weighting coefficients corresponding to the kth angle vector and the l-th delay vector in a second polarization direction based on the feedback from the r-th receiving port.

It is to be understood that the space-frequency matrix defined above for 2 polarization directions

The calculation formula (b) is merely an example, and should not be construed as limiting the present application in any way. For example, the number of delay vectors and/or angle vectors loaded in different polarization directions may be the same or different, and the delay vectors and/or angle vectors loaded in different polarization directions may be the same or different.

For R receiving ports, the network device may determine the space-frequency matrix based on P weighting coefficients corresponding to each receiving port respectively

To

Thus, the network device can determine the downlink channel matrix corresponding to each frequency domain unit.

RB is an example of a frequency domain unit. For an nth RB of the N RBs, the network device may determine a conjugate transpose of a downlink channel matrix (V) corresponding to the nth RB⁽ⁿ⁾) ^H. Wherein, the matrix (V)⁽ⁿ⁾) ^HMay be R space-frequency matrices respectively determined based on the R receiving ports

To

The nth column vector in each space-frequency matrix is determined. For example, will

The nth column of (1) as a matrix (V)⁽ⁿ⁾) ^H Column 0 of (1), will

The nth column of (1) as a matrix (V)⁽ⁿ⁾) ^H Column 1; by analogy, can be

The nth column of (1) as a matrix (V)⁽ⁿ⁾) ^HColumn R-1. From this, a matrix (V) can be obtained⁽ⁿ⁾) ^HAnd further, a downlink channel matrix V corresponding to the nth RB can be determined⁽ⁿ⁾。

Based on the method, the downlink channel matrixes respectively corresponding to the RBs can be determined.

The network device may further determine a precoding matrix of each RB according to the downlink channel matrix of each RB. For example, the network device may determine the precoding matrix by performing SVD on the downlink channel matrix or the covariance matrix of the channel matrix, or may also determine the precoding matrix by performing eigenvalue decomposition (EVD) on the covariance matrix of the downlink channel matrix.

It should be understood that, the specific way of determining the precoding matrix by the network device according to the channel matrix may refer to the prior art, and the determination way of the precoding matrix is not limited in the present application.

It should also be understood that the above only illustrates a specific process of determining a downlink channel matrix and then determining a precoding matrix based on a space-frequency matrix for the convenience of understanding. This should not be construed as limiting the application in any way. The network device may also determine the precoding matrix directly from the space-frequency matrix.

It should be noted that the above shows the case where the terminal device corresponds to one receiving port based on each of the P groups of weighting coefficients for ease of understanding only. As described above, when the terminal device feeds back the weighting coefficients based on the receiving ports, the number of the weighting coefficients in each group is not necessarily equal to the number of the receiving ports. For example, the number of receiving ports is greater than 1, but the terminal device performs channel estimation and feedback only based on the precoding reference signal received at one of the receiving ports. Each set of weighting coefficients may comprise only one weighting coefficient. In this case, the network device may use the weighting coefficient fed back by the receiving port as the weighting coefficient of each receiving port, and further determine the precoding matrix according to the method described above. For another example, if the number of receiving ports is greater than 1, the terminal device performs time domain transform after weighting the channel estimation values of the multiple receiving ports, and feeds back the channel estimation values. Each set of weighting coefficients includes a number of weighting coefficients less than the number of receive ports. In this case, the network device may use the weighting coefficients fed back by the multiple receiving ports as the weighting coefficients of the multiple receiving ports, and further determine the precoding matrix according to the method described above. The specific manner in which the network device determines the precoding matrix based on the received weighting coefficients is not limited in the present application.

If the terminal device feeds back P groups of weighting coefficients corresponding to P transmission ports based on the transmission layer, the weighting coefficients indicated by the first indication information may include weighting coefficients of one or more transmission layers. The network device may determine, based on the weighting coefficient corresponding to each transmission layer and the angle delay pair corresponding to each weighting coefficient, the space-frequency matrix corresponding to the transmission layer, and further determine the precoding matrix of each frequency domain unit.

Specifically, since the P weighting coefficients corresponding to each transmission layer may respectively correspond to the P angular delays in a one-to-one manner. The network device may construct the P weighting coefficients corresponding to each transmission layer, and the angle vector and the delay vector included in each angle delay pair of the P angle delay pairsA space-frequency matrix corresponding to the transport layer is created. For the sake of distinction and explanation, in the embodiments of the present application, the space-frequency matrix corresponding to the receiving port is denoted as H_DL,Z。

Represents a space-frequency matrix corresponding to the Z-th transport layer, and Z may take any integer value from 0 to Z-1.

In the present embodiment, a space-frequency matrix corresponding to the z-th transmission layer

May be determined by P angular delay pairs and P weighting coefficients corresponding to the z-th transmission layer. Wherein P angular delay pairs may be used to construct P space-frequency component matrices. The precoding vector corresponding to the z-th transmission layer may be a weighted sum of the P space-frequency component matrices. That is to say that the first and second electrodes,

Space-frequency matrix shown above

The formula (2) assumes that the K angle vectors and the L delay vectors are common to each other. When the delay vectors corresponding to at least two angle vectors are different, the above equation can be modified as follows:

alternatively, when the angle vectors corresponding to at least two delay vectors are different, the above expression can be modified to

For convenience of explanation, the following descriptions are provided

For illustration purposes. It can be understood that whether the delay vectors corresponding to the angle vectors are the same or not, or whether the angle vectors corresponding to the delay vectors are the same, has no influence on the determination of the precoding matrix.

Wherein the content of the first and second substances,

representing weighting coefficients corresponding to a k-th angle vector and an l-th time delay vector in a first polarization direction based on the z-th transmission layer feedback;

representing weighting coefficients corresponding to the kth angle vector and the l-th delay vector in a second polarization direction based on the z-th transport layer feedback.

It should be understood that the above is for 2 polarization partiesTo a defined space-frequency matrix

For Z transmission layers, the network device may determine the space-frequency matrix corresponding to each transmission layer based on P weighting coefficients corresponding to each transmission layer respectively

To

Thus, the network device can determine the precoding matrix W corresponding to each RB⁽ⁿ⁾。

To

The nth column vector in each space-frequency matrix.

Precoding matrix W corresponding to nth RB⁽ⁿ⁾May be Z space-frequency matrices respectively determined based on the Z transmission layers as described above

To

The nth column vector in each space-frequency matrix is constructed. For example, will

The nth column in (1) is taken as a downlink channel matrix W⁽ⁿ⁾Column 0 of (1), will

The nth column in (1) is taken as a downlink channel matrix W⁽ⁿ⁾Column 1; by analogy, can be with

The nth column in (1) is taken as a downlink channel matrix W⁽ⁿ⁾Column Z-1. Based on the above method, precoding matrices respectively corresponding to RBs can be determined.

It should be understood that the specific process of the network device determining the precoding matrix is described in detail above by taking the space-frequency component matrix as an example for understanding only. This should not be construed as limiting the application in any way. The network device may also determine P space-frequency component vectors based on the P angular delay pairs, thereby determining a precoding matrix. Those skilled in the art can construct P space-frequency basic units in different forms based on P angular delay pairs, and further determine a precoding matrix. The P space-frequency basic units of different forms constructed based on the P angle delay pairs, and the way of determining the precoding matrix based on the weighted sum of the P space-frequency basic units all fall within the protection scope claimed in the present application.

It should also be understood that the above is only an example, and illustrates a possible implementation manner of the network device determining the precoding matrix according to the first indication information, but this should not constitute any limitation to the present application. The specific implementation manner of determining the precoding matrix by the network device according to the first indication information is not limited in the present application. The method for determining the precoding matrix by transforming the above listed matrix operations or equivalent substitution based on the same concept by those skilled in the art shall fall within the scope of the present application.

It should also be understood that the determination process of the precoding matrix corresponding to each frequency domain unit described above is described with RB as an example of the frequency domain unit. Therefore, the determined downlink channel is a downlink channel corresponding to an RB, and the determined precoding matrix is a precoding matrix corresponding to an RB. The precoding matrix corresponding to the RB may be a precoding matrix determined based on a channel matrix corresponding to the RB with the RB as a granularity, or a precoding matrix determined based on a precoding reference signal received on the RB, and may be used to precode data transmitted through the RB. The downlink channel corresponding to the RB may be a downlink channel determined based on a precoding reference signal received on the RB, and may be used to determine a precoding matrix corresponding to the RB.

When the granularity of the frequency domain unit is larger, for example, the frequency domain unit is a subband, a PRG, or a PRB, the network device may determine the precoding matrix corresponding to the frequency domain unit according to the precoding matrix corresponding to each RB in each frequency domain unit.

If each frequency domain unit includes an RB for carrying a reference signal, the network device may use the precoding matrix corresponding to the RB as the precoding matrix corresponding to the frequency domain unit to which the network device belongs. If each frequency domain unit includes a plurality of RBs for carrying reference signals, the network device may, for example, average correlation matrices of precoding matrices corresponding to the plurality of RBs in the same frequency domain unit and then perform SVD to determine the precoding matrix corresponding to the frequency domain unit; the network device may further take, for example, an average of precoding matrices corresponding to multiple RBs in the same frequency domain unit as a precoding matrix corresponding to the frequency domain unit, and so on.

It should be understood that, the specific method for the network device to determine the precoding matrix of the frequency domain unit according to the precoding matrix corresponding to the plurality of RBs in the frequency domain unit may refer to the technology, and is not limited to the above list. The specific method for determining the precoding matrix of the frequency domain unit by the precoding matrices corresponding to the plurality of RBs in the frequency domain unit of the network device is not limited in the present application.

It should also be understood that the above references to a weighting coefficient corresponding to a certain angle vector and a certain delay vector in the description, that is, a weighting coefficient corresponding to a pair of an angle delay composed of a certain angle vector and a certain delay vector. For example, the weighting coefficients corresponding to the kth angle vector and the l-th delay vector, that is, the weighting coefficient corresponding to the angle delay pair formed by the kth angle vector and the l-th delay vector. For brevity, they are not illustrated one by one here.

In this embodiment, for example, the network device may perform precoding on the downlink reference signal based on the angle and the time delay determined by the uplink channel measurement, so that the terminal device performs downlink channel measurement according to the precoded reference signal. Because the network equipment carries out precoding on the reference signal based on the angle and time delay of reciprocity of the uplink and downlink channels, the information of the downlink channel detected by the terminal equipment is information without reciprocity. Therefore, the terminal equipment does not need to feed back space-domain and frequency-domain vectors (such as the angle vector and the time delay vector), and the feedback overhead of the terminal equipment is greatly reduced. In addition, by converting the frequency domain channel into the time domain and feeding back the value obtained by time domain transformation as a weighting coefficient, the problem of inaccurate channel recovery based on the weighting coefficient obtained by frequency domain accumulation and summation of a plurality of discontinuous equivalent channels can be avoided, which is beneficial to improving the transmission performance of the system. Therefore, the feedback overhead is reduced, and simultaneously, higher feedback precision can be still ensured. Furthermore, by performing spatial pre-coding on the downlink reference signal, the number of ports of the reference signal can be reduced, thereby reducing the pilot overhead.

It should be understood that, for convenience of understanding only in the embodiments of the present application, a specific process of measuring and determining a precoding matrix for a downlink channel in a case where a space-frequency matrix is obtained by conjugate transpose of a real channel is shown in the embodimentThe process. This should not be construed as limiting the application in any way. True channel and space-frequency matrix H_DLIs not fixed. Different definitions of the space-frequency matrix and the space-frequency component matrix may result in the true channel and the space-frequency matrix H_DLThe relationship between them changes. For example, the space-frequency matrix H_DLIt can be obtained by conjugate transposing of the real channel, and also by transposing of the real channel.

When the definition of the relationship between the frequency matrix and the channel matrix is different, the operation performed by the network device is also different when the delay and the angle are loaded, and the operation performed by the terminal device when the channel measurement and feedback are performed is also changed correspondingly. However, this is only the implementation behavior of the terminal device and the network device, and should not be construed as limiting the present application in any way. The definition of the channel matrix, the dimension of the space-frequency matrix and its definition, and the conversion relationship between the two are not limited in the present application. Similarly, the present application does not limit the conversion relationship between the space-frequency matrix and the precoding matrix.

In the above embodiment of the method, the channel measurement method provided in the present application is described in detail by taking precoding of the reference signal based on the angle vector and the delay vector as an example. This should not be construed as limiting the application in any way. The network device may also precode the reference signal based on only the delay vector or the angle vector, so that the terminal device can perform downlink channel measurement based on the precoded reference signal. The following embodiments take precoding a reference signal based on a delay vector as an example, and describe the channel measurement method provided in this application in detail.

Fig. 4 is a schematic flow chart diagram of a channel measurement method 400 provided by another embodiment of the present application, shown from the perspective of device interaction. The method 400 shown in fig. 4 may include steps 410 through 440. The steps in method 400 are described in detail below.

For ease of understanding, the following describes the procedure of channel measurement and feedback by the terminal device in detail, with the precoded reference signals still being transmitted by the transmitting antennas in one polarization direction. The one polarization direction transmitting antenna may be any one of J polarization direction transmitting antennas configured by the network device. The number of polarization directions J of the transmitting antennas configured for the network device is not limited in the present application.

In step 410, the terminal device receives a precoded reference signal. Correspondingly, the network device transmits the precoded reference signal.

In this embodiment, the network device may perform precoding on the reference signal based on the L delay vectors, which may specifically be frequency domain precoding. Since the reference signal is not spatially precoded, the reference signal may correspond to T transmit antenna ports before precoding the reference signal based on the delay vector.

And precoding the reference signal based on the L time delay vectors, wherein the obtained precoded reference signal can correspond to the L groups of ports. Each group of ports may correspond to a precoded reference signal obtained by precoding reference signals of T transmit antenna ports based on the same delay vector. Each group of ports may include up to T ports, which may correspond to the T transmit antenna ports described above. Thus, the precoded reference signal for each port may correspond to one delay vector and one transmit antenna port. In other words, each port may be a combination of one delay vector and one transmit antenna port.

In one possible implementation, the network device may perform precoding on the reference signal on each transmit antenna port by traversing L delay vectors. Thus, T × L different combinations, or T × L antenna delay pairs, can be obtained. Since no angular vectors are involved for spatial precoding, each combination may correspond to a delay vector. In other words, by loading the L delay vectors on the reference signals of different transmit antenna ports, T × L combinations of the delay vectors and different transmit antenna ports can be obtained.

In another possible implementation manner, the network device may traverse the L delay vectors, precode the reference signals carried in part of the N frequency domain units based on one or more of the L delay vectors, and send the precoded reference signals through the T transmit antenna ports. The resulting precoded reference signals precoded based on different delay vectors may be mapped onto different frequency domain elements. The precoded reference signal carried on each frequency domain unit may be obtained based on precoding of a part of the L delay vectors. In a plurality of RBs, precoding reference signals carried by at least two frequency domain units are obtained based on different time delay vector precoding. In other words, by loading the L delay vectors on different frequency domain units and transmitting through the T transmit antenna ports, T × L ' different combinations of delay vectors and transmit antenna ports can be obtained, where L ' is greater than or equal to 1 and less than L, and L ' is an integer.

It should be understood that the correspondence between the transmit antenna ports and the delay vectors is listed above for ease of understanding only, but this should not limit the present application in any way. The present application does not limit the correspondence between the transmit antenna ports and the delay vectors.

It can be understood that, if the network device precodes the reference signal based on the L delay vectors, the number of ports of the transmitted precoded reference signal may be the number of combinations determined by the T transmit antenna ports and the L delay vectors. In this embodiment, for convenience of description, the number of the transmitting ports is denoted as L groups, and each group of the transmitting ports may include a delay vector and one or more transmitting antenna ports corresponding to the delay vector. For ease of understanding and explanation hereinafter, it is assumed that each set of transmit ports includes T transmit ports. That is, the L delay vectors are common to each transmit antenna port.

Because the time delay has reciprocity of an uplink channel and a downlink channel, the L time delay vectors can be determined based on uplink channel measurement. Since the specific method for determining L stronger delays by the network device based on the uplink channel measurement has been described in detail in the method 300 above, details are not repeated here for brevity.

It should be understood that determining L delay vectors based on uplink channel measurements is not the only implementation, and the L delay vectors may be, for example, predefined, such as protocol definition; alternatively, it may be determined statistically based on the results fed back from one or more previous downlink channel measurements. This is not a limitation of the present application.

Since the time delays of the uplink and downlink channels are reciprocal in the FDD mode, L time delay vectors obtained by measuring the uplink channel can be loaded to the downlink reference signal, so that the terminal device can perform downlink channel measurement based on the received precoding reference signal.

The network device may precode a downlink reference signal, such as CSI-RS, based on the L delay vectors, to obtain a precoded reference signal. The network device may transmit the precoded reference signal through the preconfigured reference signal resources. Since the process of precoding the reference signal based on the delay vector has been described in detail above with reference to fig. 2, and a manner for distinguishing different transmitting ports when the network device transmits the precoded reference signal through the reference signal resource is described in detail in the method 300, for brevity, details are not repeated here.

In step 420, the terminal device generates seventh indication information indicating P groups of weighting coefficients corresponding to the P angular delay pairs.

The terminal device may perform channel estimation based on the received precoded reference signal, and generate seventh indication information based on the estimated channel information. The seventh indication information may be used to indicate P groups of weighting coefficients corresponding to P angular delay pairs. Wherein each set of weighting coefficients may comprise one or more weighting coefficients.

Wherein the P angle delay pairs may be obtained by combining the L delay vectors and the K angle vectors. The K angle vectors may be combined with the L delay vectors to obtain P angle delay pairs, and the weights of the P angle delay pairs may be used to construct a precoding matrix. The K angle vectors may be, for example, signaled to the terminal device by the network device in advance, or may be determined by the terminal device itself.

In one implementation, the network device may indicate the relevant information of the angle to the terminal device in advance through signaling. There are many possible ways in which the network device may indicate the information about the angle. For example, the network device may indicate, to the terminal device, an angle vector corresponding to each of the L delay vectors through signaling according to the measurement result of the uplink channel; for another example, the network device may indicate, through signaling, an angle corresponding to each delay vector in the L delay vectors, so that the terminal device may determine the angle vector corresponding to each delay vector by itself; also for example, the network device may signal an angle (referred to as a reference angle for convenience of distinction and explanation) corresponding to each of the L delay vectors and a difference or ratio between the other angle and the reference angle. For the sake of brevity, this is not illustrated individually.

It should be noted that, if the angle vectors corresponding to any two of the L delay vectors are the same, it may be considered that the L delay vectors correspond to the same K angle vectors, or that the K angle vectors may be considered to be common for each delay vector.

In another implementation, the terminal device may perform channel measurement based on the received other downlink reference signals (e.g., demodulation reference signals (DMRSs)), so as to obtain a stronger K angle vectors of the downlink channel.

In yet another implementation, the terminal device may determine the K angle vectors based on one or more previous downlink channel measurement statistics.

It should be understood that the specific ways for the terminal device to obtain the K angle vectors listed above are only a few possible implementations, and should not limit the present application in any way. The specific way for the terminal device to obtain the K angle vectors is not limited in the present application.

In this embodiment of the present application, the terminal device may feed back, based on the receiving port, P groups of weighting coefficients corresponding to the P angle delay pairs. In the P groups of weighting coefficients corresponding to the P angular delay pairs indicated by the seventh indication information, each group of weighting coefficients may include one or more weighting coefficients. For example, each set of weighting coefficients may include R' weighting coefficients. R 'is more than or equal to 1 and less than or equal to R, and R' is an integer. In the above method 300, the detailed description has been given on the relationship between each group of weighting coefficients in the P groups of weighting coefficients and the R receiving ports under different values of R', and for brevity, the detailed description is omitted here.

The following first describes a process of determining P groups of weighting coefficients corresponding to the P angular delay pairs when the terminal device determines the weighting coefficients based on the receiving port.

For ease of understanding, it is first assumed that R is 1, i.e., each set of weighting coefficients may include one weighting coefficient. The precoded reference signals for each group of transmit ports may be carried over N RBs (i.e., one instance of a frequency domain element). In this case, the set of weighting coefficients corresponding to each set of transmit ports may include one weighting coefficient. The seventh indication information may be used to indicate L weighting coefficients corresponding to L groups of transmit ports.

Since the transmission ports that the terminal device can identify are ports of the precoded reference signal, the terminal device can perform channel estimation on a per-group transmission port basis.

As described above, in the case that the number of receiving ports is 1, if the network device precodes the reference signal based on the angle vector and the delay vector, the weighting coefficient corresponding to each transmitting port may be obtained by cumulatively summing up the channel estimation values of N RBs.

The terminal device may perform channel estimation on each RB after receiving the precoded reference signal from the network device. And the estimated channel information may be processed according to predetermined angle vectors corresponding to the respective delay vectors to determine a set of weighting coefficients corresponding to each angle delay pair.

As described above, if the network device precodes the reference signal based on L delay vectors, the real channel received by the terminal device may be represented as F^HH _DL ^HIts dimension may be L × T. Coefficient matrix C_DLCan be calculated by formula C_DL＝S ^H(F ^HH _DL ^H) ^HAnd (4) determining. The coefficient matrix C_DLEach element in (1) can be respectively formed by a real channel F after being subjected to frequency domain precoding^HH _DL ^HConjugate transpose of (F) ^HH _DL ^H) ^HLeft multiplication S^HThus obtaining the compound.

As known from matrix multiplication, will (F)^HH _DL ^H) ^HLeft multiplication S^HWhen (F)^HH _DL ^H) ^HEach column vector in (2) includes the number of elements and S^HEach row vector in the array includes the same number of elements. In the present embodiment, (F)^HH _DL ^H) ^HEach column vector in (1) includes the number of elements and S^HThe number of elements included in each row vector may be T. When the row vector and the column vector are multiplied, each element (e.g., the T-th element, T is traversed in 1 to T) in the row vector needs to be multiplied by the corresponding element (e.g., the T-th element, T is traversed in 1 to T) in the column vector, and then the sum is obtained. Therefore, after loading the angle vector to the channel estimation values of the RBs, the terminal device sums the channel estimation values of the N RBs obtained by loading the same angle vector, so as to obtain a weighting coefficient corresponding to one angle vector and one delay vector (i.e., one angle delay pair).

It should be understood that the space-frequency matrix H shown herein_DLThe relationship with the channel matrix is merely an example. Different definitions may cause a change in the relationship between the two. However, no matter how defined, the method only affects the internal implementation of the network device and the terminal device, and therefore, the method should not be limited in any way in this application. The internal implementation behaviors of the network device and the terminal device are not limited in the present application.

In this embodiment, if the network device precodes the reference signal carried on the same RB based on each delay vector of the L delay vectors, the precoded reference signal carried on the RB may correspond to L × T transmit ports, or L groups of transmit ports. Each group of ports includes T transmit ports. Each set of transmit ports corresponds to one of the L delay vectors.

In one implementation, the terminal device may determine the weighting coefficient corresponding to each angular delay pair based on channel information estimated from the pre-coded reference signals received at one receiving port for each group of transmitting ports.

The terminal device may determine channel information corresponding to each group of transmission ports on an nth RB according to a precoding reference signal corresponding to the same group of transmission ports received on the nth RB among the N RBs. For example, based on the precoded reference signals of the ith group of transmit ports, the estimated channel information may be a vector with dimension of 1 × T, for example, which is denoted as

Assuming that the K angle vectors are angle vectors common to the L delay vectors, for the K-th angle vector a (θ) of the K angle vectors_k) Then, the channel information of the angle delay pair formed by the kth angle vector and the l delay vector on the nth RB can be represented as

Assume that one or more of the K angular vectors correspond to one of L delay vectors, e.g., the L-th one of the L delay vectors corresponds to K of the K angular vectors_lThe angle vector, K in the K angle vectors corresponding to the ith delay vector_lAn angle vector. Then, on the nth RB, the ith delay vector and K_lKth in angular vector_lThe channel information of the angle delay pairs formed by the angle vectors can be represented as

Based on the same method, the terminal device may determine channel information corresponding to one delay vector and one angle vector, or channel information corresponding to one angle delay pair, on each RB of the N RBs.

It should be understood that the above-listed methods and calculation formulas for determining the weighting coefficients of the angle delay pairs are only examples, and should not limit the present application in any way. The present application does not limit the specific method for determining the weighting coefficients of the angle delay pairs. In addition, the calculation formula may be changed due to different definitions of the angle vector. In the present application, the specific form of each vector is not limited, and therefore the operation method between vectors is not limited.

As described above, since the precoded reference signal received by the terminal device is a reference signal precoded based on the time domain vector, the equivalent channel received by the terminal device is not continuous in the frequency domain. Therefore, the channel information corresponding to the same angle delay pair on each RB determined based on the above method is not accurate, and if the channel information corresponding to the same angle delay pair on N RBs is directly accumulated and summed, the result is not accurate. In this embodiment, a time domain transformation method may still be used to obtain more accurate weighting coefficients.

The terminal device may perform time domain transformation on the channel information on the N RBs corresponding to the same angle delay pair to obtain N transformed values. N-th of the N values_pThe values may be used as weighting coefficients corresponding to the pth angular delay pair.

In one implementation, the terminal device may obtain the weighting coefficient corresponding to each angle delay pair by means of time-domain filtering. The specific process of the temporal filtering has already been described in detail in step 320 of the method 300, and is not described herein again for brevity.

Based on the above-described method, the terminal device may determine P groups of weighting coefficients corresponding to P angle delay pairs in which the L delay vectors and the K angle vectors are combined. Each set of weighting coefficients can include R ' weighting coefficients, R ' is greater than or equal to 1 and less than or equal to R, and R ' is an integer. The weighting coefficients within each group may correspond to one or more of the R receive ports. It should be understood that, for the determination process of each weighting coefficient in the R' weighting coefficients by the terminal device, reference may be made to the method described above, and details are not described herein for brevity.

In another implementation, the terminal device may further feed back, based on the transmission layer, P groups of weighting coefficients corresponding to the P angle delay pairs. The specific implementation procedure of the terminal device determining the P groups of weighting coefficients corresponding to the P transmission ports based on the transmission layer feedback according to the P groups of weighting coefficients corresponding to the P transmission ports determined based on the receiving antennas can refer to the above description in step 320 of the method 300. Since this particular process is described in detail above in step 320 of method 300, it is not repeated here for brevity.

It should be understood that the above shows the channel measurement and feedback process based on the precoded reference signals transmitted by P transmission ports in one polarization direction for ease of understanding only. This should not be construed as limiting the application in any way. For multiple polarization directions, the terminal device may determine P sets of weighting coefficients corresponding to P transmit ports in each polarization direction based on the same method described above.

It should also be understood that the specific process of the terminal device generating the seventh indication information based on the determined weighting factor may refer to the specific process of the terminal device generating the first indication information in step 330 in the above method 300. For brevity, no further description is provided herein.

In step 430, the terminal device transmits the seventh indication information. Accordingly, the network device receives the seventh indication information.

In step 440, the network device determines a precoding matrix according to the seventh indication information.

It should be understood that the specific process of steps 430-440 may be the same as the specific process of steps 330-340 in method 300 above. The relevant description of steps 430 to 440 may refer to the relevant description of steps 330 to 340 in method 300 above, and for the sake of brevity, will not be repeated here.

In the embodiment of the application, the network device performs precoding on the downlink reference signal based on the angle and the time delay determined by the uplink channel measurement, so that the terminal device performs downlink channel measurement according to the precoded reference signal. Because the network device precodes the reference signal based on the time delay of reciprocity of the uplink and downlink channels, the information of the downlink channel detected by the terminal device is the information without reciprocity. Therefore, the terminal equipment does not need to feed back space-domain and frequency-domain vectors (such as the angle vector and the time delay vector), and the feedback overhead of the terminal equipment is greatly reduced. In addition, by converting the frequency domain channel into the time domain and feeding back the value obtained by time domain transformation as a weighting coefficient, the problem of inaccurate channel recovery based on the weighting coefficient obtained by accumulating and summing a plurality of discontinuous equivalent channels can be avoided, which is beneficial to improving the transmission performance. Therefore, the feedback overhead is reduced, and simultaneously, higher feedback precision can be still ensured.

It should be understood that the above is only for convenience of understanding, and shows an example that the network device precodes the reference signal based on the delay vector only, and the terminal device performs channel measurement and feedback based on the precoded reference signal. This should not be construed as limiting the application in any way. The network device may also precode the reference signal based on the angle vector only, and the terminal device may also perform time domain transformation on channel information estimated based on the precoded reference signal based on the similar method described above, so as to obtain P groups of weighting coefficients corresponding to P angle delay pairs. Since the specific process is similar to that described above, it will not be described in detail here for the sake of brevity.

Fig. 5 is a schematic flow chart of a channel measurement method 500 provided by the embodiment of the present application, which is shown from the perspective of device interaction. The method 500 shown in fig. 5 may include steps 510 through 550. The steps in method 500 are described in detail below.

In step 510, the terminal device receives a precoded reference signal. Correspondingly, the network device transmits the precoded reference signal.

It should be appreciated that the specific process of step 510 may be the same as the specific process of step 310 in method 300 above. The relevant description of step 510 may refer to the relevant description of step 310 in method 300 above and will not be repeated here for the sake of brevity.

In step 520, the terminal device generates second indication information indicating P groups of weighting coefficients corresponding to the P transmit ports.

In the embodiment of the present application, the terminal device may feed back P groups of weighting coefficients corresponding to P transmission ports based on the reception port. In the P groups of weighting coefficients corresponding to the P transmission ports indicated by the first indication information, each group of weighting coefficients may include one or more weighting coefficients. For example, each set of weighting coefficients may include R' weighting coefficients. R 'is more than or equal to 1 and less than or equal to R, and R' is an integer. In the above method 300, the detailed description has been given on the relationship between each group of weighting coefficients in the P groups of weighting coefficients and the R receiving ports under different values of R', and for brevity, the detailed description is omitted here.

As mentioned above, the terminal device may also feed back P groups of weighting coefficients corresponding to P transmit ports based on the transport layer. Each set of weighting coefficients may include Z weighting coefficients, corresponding to Z transmission layers. The detailed procedure of how to determine the P groups of weighting coefficients based on the transport layer will be described in detail later, and will be omitted here for the moment.

and i, performing channel estimation based on the precoding reference signal of the p transmitting port received on the r receiving port to obtain channel information respectively corresponding to the N frequency domain units. The N frequency domain units may be divided into one or more frequency domain unit groups, each frequency domain unit group including one or more of the N frequency domain units;

step ii, respectively performing frequency domain filtering on the channel information which is determined in the step i and corresponds to the frequency domain units in the one or more frequency domain unit groups to obtain N filtered values;

and step iii, accumulating and summing the N filtered values determined in the step ii, wherein the obtained value is the weighting coefficient corresponding to the p-th transmitting port and the r-th receiving port.

Since the transmission port that the terminal device can identify is a port corresponding to the precoding reference signal, the terminal device may perform channel estimation based on the received precoding reference signal of each transmission port to obtain channel information. Alternatively, the channel information may specifically be a channel estimation value obtained by performing channel estimation based on the received precoded reference signal. It will be appreciated that the channel estimate may specifically be an equivalent channel, i.e. a channel loaded with precoding.

As previously described, the P transmit ports may have a one-to-one correspondence with the P angular delay pairs. The precoded reference signal corresponding to the P-th transmission port of the P transmission ports may be obtained by precoding the reference signal based on the kth angular vector of the K angular vectors and the L-th delay vector of the L delay vectors, for example. Therefore, the weighting coefficient corresponding to the pth transmission port, i.e., the weighting coefficient of the pth angular delay pair, is described above.

For the precoded reference signal of the p-th transmission port, the terminal device may determine the weighting coefficient of the p-th angle delay pair based on a channel estimation value obtained by performing channel estimation on the precoded reference signals received on one reception port and N RBs. The weighting factor of the pth angle delay pair may be determined by the N channel estimates over the N RBs. Suppose that the channel estimation value obtained by the terminal device performing channel estimation based on the precoding reference signal of the p-th transmitting port received on the nth RB is recorded as

n channel estimates. It can be seen that the N channel estimates correspond to N RBs, i.e., to N frequency domain units.

The process of the terminal device performing channel estimation based on the precoding reference signals received on one receiving port and N RBs to obtain N channel estimation values is the same as the process described in step 320 of the method 300, and for brevity, the specific process may refer to the related description in step 320 of the method 300, and is not repeated here.

As described above, the weighting factor corresponding to the pth transmission port may be the cumulative sum of the channel estimation values over N RBs. However, when the network device precodes the reference signal based on the delay vector, the N elements in the delay vector are loaded on the N RBs corresponding to the same transmit port, respectively. The channel estimation value estimated by the terminal device on each RB is discontinuous. If the value obtained by directly accumulating and summing the N channel estimation values is used as the weighting coefficient of the p-th angle delay pair for feedback, the recovered downlink channel may have a large difference from the real channel, and the determined precoding matrix for downlink data transmission may not be well matched with the real channel, thereby affecting the transmission performance of the system.

In this embodiment, the terminal device may perform filtering processing on the N channel estimation values before performing cumulative summation on the N channel estimation values. Illustratively, the terminal device may divide the N RBs into one or more RB groups, each RB group may include a plurality of RBs, and the RBs in the RB groups do not repeat each other. And filtering the channel estimation value corresponding to each RB in each RB group to obtain a filtered value. The filtered values (it is understood that the filtered values are still N) are summed up to obtain the weighting coefficient corresponding to the pth transmitting port.

For example, assume that N-20, each 4 RBs are divided into one RB group. For example, RB #0 to RB #3 are one RB group, RB #4 to RB #7 are one RB group, RB #8 to RB #11 are one RB group, RB #12 to RB #15 are one RB group, and RB #16 to RB #19 are one RB group. The terminal device may filter the 5 RB groups, respectively, to obtain filtered values. It will be appreciated that the filtered values are still 20 values. And accumulating and summing the filtered values to obtain a weighting coefficient corresponding to the p-th transmitting port.

One or more RBs divided into one RB group for filtering may be referred to as bundled RBs (or RB Bundle).

It should be understood that the number of RBs included in each RB group is not limited in the present application. Meanwhile, the present application does not limit the specific rule for dividing the RB group. In other words, the number of frequency domain units included in each frequency domain unit group is not limited in the present application. Meanwhile, the specific rule for dividing the frequency domain unit group is not limited in the application.

Alternatively, the terminal device performs frequency domain filtering on the channel estimation value estimated at each RB group based on the wiener filter coefficient.

Since the network device precodes the reference signal based on the delay vector, the embodiment of the application corrects the wiener filter coefficient. Corrected filter coefficient W _pCan be expressed as:

wherein, W_pRepresenting the filter coefficients corresponding to the p-th transmit port.

A modified correlation matrix is represented that is then,

this can be corrected, for example, by:

wherein the content of the first and second substances,

the correlation matrix represents the correlation between RBs in one RB group for carrying the reference signal of the p-th transmission port (it is understood that the reference signal is a precoding reference signal), or, in the case where the pilot density is greater than 1, may also represent the correlation between reference signals REs in one RB group for carrying the reference signal of the p-th transmission port. With respect to correlation matrix

Can be referred to the related art of wiener filtering in the prior art, in order toFor brevity, this will not be described in detail here.

Is a correction value. In the embodiment of the application, the correction value can be used for correcting

And (6) correcting. In the embodiment of the present application, the correction value may be an M × M matrix, where M represents the number of RBs included in each RB group. For convenience of explanation, hereinafter, the following description,

SNR is the signal to noise ratio, abbreviated signal to noise ratio. And I is a unit array.

In one possible design, the number of frequency domain units included in any two of the one or more frequency domain unit groups is the same. For example, the frequency domain elements are divided into t frequency domain element groups, each frequency domain element group including M frequency domain elements. Then N is t × M.

It can be seen that the correlation matrix is used for the correlation matrix

Correction value beta for correction_pAssociated with a time delay. Wherein

The ith time delay tau corresponding to the pth transmitting port_lAnd (4) correlating. For example, it may be a time delay τ_pOr may be a time delay tau_pThe mathematical transformation of (2). This is not a limitation of the present application. Such as, for example,

or the like, or, alternatively,

and so on. For the sake of brevity, this is not illustrated individually. Here, the delay τ will be determined by_pIs obtained by mathematical transformation of_pThe relevant parameter is called the time delay tau_pThe relevant parameters of (1). It should be understood that the present application is not limited to the particular manner of mathematical transformation.

Since the correction value is related to the time delay, the terminal device needs to obtain the weighting coefficient corresponding to the pth transmission port in advance when determining the weighting coefficient corresponding to the pth transmission port

Or, in other words, the time delay τ_lOr time delay τ_lThe relevant parameters of (1).

In a possible implementation manner, the network device may indicate, in advance, the time delay or the relevant parameter of the time delay corresponding to each transmission port to the terminal device through signaling.

Optionally, the method 500 further comprises: in step 530, the network device sends third indication information, where the third indication information is used to indicate a delay or a parameter related to the delay corresponding to each of the P transmit ports. Accordingly, the terminal device receives the third indication information.

Each delay may correspond to a delay vector used when the network device precodes the reference signal.

Optionally, the indication of the delay by the network device may be, for example, the delay, or an index of a corresponding delay vector. For example, the network device may be paired with a delay τ_lMay be, for example, τ_lMay also be τ_lCorresponding delay vector b (tau)_l) Is used to determine the index of (1).

Optionally, the indication of the relevant parameters of the time delay by the network device may be: the P endsTime delay tau corresponding to a first transmitting port in a port₀And the time delay corresponding to the rest of the P transmitting ports except the first transmitting port is different from the time delay corresponding to the first transmitting port by the difference delta tau.

Wherein the first transmit port may be a certain transmit port predefined by the protocol, for example. For example, the first transmit port may be the 0 th transmit port of the P transmit ports, or the P-1 st transmit port of the P transmit ports, or any designated transmit port τ₀. Taking the first transmit port as the 0 th transmit port of the P transmit ports as an example, the corresponding delay is recorded as "l". The indication of the terminal device on the relevant parameter of the time delay may be, for example, the time delay corresponding to each transmitting port from the 1 st transmitting port to the P-1 st transmitting port and the time delay τ corresponding to the 0 th transmitting port ₀The difference of (a).

Of course, indicating the time delay corresponding to each transmitting port by indicating the difference is only one possible implementation, for example, the time delay τ corresponding to the first transmitting port may also be indicated₀And the time delay corresponding to the rest of the P transmitting ports except the first transmitting port is equal to the time delay tau corresponding to the first transmitting port₀The ratio of the delay values to the delay values indicates the delay corresponding to each transmitting port. The present application does not limit the specific manner of indicating the relevant parameter of the time delay.

It should be noted that the above description shows a case where each frequency domain unit group includes a relevant number of frequency domain units for easy understanding only. In fact, the present application does not limit the number of frequency domain units included in each frequency domain unit group. The number of frequency domain elements included in each frequency domain element group may be the same or different. When the number of frequency domain cells included in each frequency domain cell group is different, the correction value β is set to be smaller than the number of frequency domain cells included in each frequency domain cell group_pMay be of dimension M_max×M _maxOf the matrix of (a). Wherein M is_maxIndicating the maximum number of frequency domain elements contained in each group of frequency domain elements. That is, the number of frequency domain units contained in each group of frequency domain units is less than or equal to M_max. That is, the correction value β _pThe dimension of (d) may be a maximum value M of the number of frequency domain units included in each frequency domain unit group_max. It is understood that if the above-mentioned N frequency domain units are regarded as one frequency domain unit group, then M is_max＝N。

It should be understood that the filtering process of the channel estimation values on each frequency domain unit by using wiener filtering is only one possible implementation manner, and should not limit the present application in any way. The terminal device may also perform filtering processing on the channel estimation value by using other possible filtering manners, for example, filtering based on other criteria (such as non-MMSE), first-order or higher-order interpolation, kalman filtering, and the like. For the sake of brevity, this is not to be enumerated here.

Based on the frequency domain filtering process described above, the terminal device may obtain P sets of weighting coefficients corresponding to the P transmit ports. Each set of weighting coefficients may comprise a weighting coefficient.

It should be understood that, for convenience of understanding only, the terminal device obtains the weighting coefficient corresponding to each transmit port through the frequency domain filtering process by taking R ═ 1 as an example. This should not be construed as limiting the application in any way. As mentioned above, in the embodiment of the present application, R ≧ 1, the weighting coefficient corresponding to each transmit port may include R 'weighting coefficients, where R ≧ R' ≧ 1.

For different values of R ', the specific process of the terminal device determining R' weighting coefficients corresponding to each transmit port has been described in detail in step 320 of the method 300. In this embodiment, the specific process of the terminal device determining the R 'weighting coefficients corresponding to each transmitting port is similar to the specific process of the terminal device determining the R' weighting coefficients corresponding to each transmitting port in the method 300. In contrast, in the method 300, the weighting coefficient corresponding to each transmit port is determined based on a time domain transform, and in the embodiment, the weighting coefficient corresponding to each transmit port is determined based on a frequency domain filtering. In addition, the processing performed by the terminal device is the same for different values of R'. For the sake of brevity, the different values of R' are not described in detail herein.

In addition, as described above, the terminal device may also feed back P groups of weighting coefficients corresponding to the P transmit ports based on the transport layer. The terminal device may determine P groups of weighting coefficients corresponding to the P transmit ports based on the transport layer feedback according to the P groups of weighting coefficients corresponding to the P transmit ports determined based on the receive antennas. The specific implementation process thereof can refer to the related description in step 320 of the method 300 above. Since this particular process is described in detail above in step 320 of method 300, it is not repeated here for brevity.

It should also be understood that the specific process of the terminal device generating the second indication information based on the determined weighting coefficient may refer to the specific process of the terminal device generating the first indication information in step 330 in the above method 300. For brevity, no further description is provided herein.

In step 540, the terminal device transmits the second indication information. Accordingly, in step 530, the network device receives the second indication information.

In step 550, the network device determines a precoding matrix according to the second indication information.

It should be understood that the specific process of steps 540-550 may be the same as the specific process of steps 330-340 in method 300 above. The relevant description of steps 540 to 550 may refer to the relevant description of steps 330 to 340 in method 300 above, and for the sake of brevity, will not be repeated here.

In the embodiment of the present application, the network device performs precoding on the downlink reference signal based on, for example, the angle and the time delay determined by the uplink channel measurement, so that the terminal device performs downlink channel measurement according to the precoded reference signal. Because the network equipment carries out precoding on the reference signal based on the angle and time delay of reciprocity of the uplink and downlink channels, the information of the downlink channel detected by the terminal equipment is information without reciprocity. Therefore, the terminal device does not need to feed back the related information of the space domain and the frequency domain (such as the angle vector and the time delay vector), and the feedback overhead of the terminal device is greatly reduced. In addition, the channel information obtained by estimation in the multiple frequency domain units is filtered by the filter coefficient determined based on the time delay corresponding to each transmitting port, so that noise can be reduced, and the correlation among the pilots in the multiple frequency domain units is fully utilized to further ensure that the channel information corresponding to each frequency domain unit obtained by filtering is more accurate. In addition, through compensation of the filter coefficient, the originally discontinuous equivalent channel can be subjected to combined filtering to a greater extent, the problem of inaccurate channel estimation caused by the fact that frequency domain binding cannot be carried out in the prior art is solved, and the transmission performance is improved. Therefore, the feedback overhead is reduced, and simultaneously, higher feedback precision can be still ensured, thereby being beneficial to improving the transmission performance of the system. Furthermore, by performing spatial pre-coding on the downlink reference signal, the number of ports of the reference signal can be reduced, thereby reducing the pilot overhead.

The above embodiment describes the channel measurement method provided in the present application in detail by taking precoding the reference signal based on the angle vector and the delay vector as an example. This should not be construed as limiting the application in any way. The network device may also precode the reference signal based on only the delay vector or the angle vector, so that the terminal device can perform downlink channel measurement based on the precoded reference signal. The following embodiments take precoding a reference signal based on a delay vector as an example, and describe in detail the channel measurement method provided by the present application.

Fig. 6 is a schematic flow chart diagram of a channel measurement method 600 provided by yet another embodiment of the present application, shown from the perspective of device interaction. The method 600 shown in fig. 6 may include steps 610 through 650. The steps in method 600 are described in detail below.

For ease of understanding, the following describes the procedure of channel measurement and feedback by the terminal device in detail, with the precoded reference signals still being transmitted by the transmitting antennas in one polarization direction. The one polarization direction transmitting antenna may be any one of J polarization direction transmitting antennas configured by the network device. The number J of polarization directions of the transmitting antennas configured for the network device is not limited in the present application.

In step 610, the terminal device receives a precoded reference signal. Correspondingly, the network device transmits the precoded reference signal.

In this embodiment, the network device may perform precoding on the reference signal based on the L delay vectors, which may specifically be frequency domain precoding. The specific process of the network device precoding the reference signal based on the L delay vectors and the relationship between the number of transmit ports and L are detailed in step 410 of the method 400 above. The specific process of step 610 in this embodiment may refer to the related description in step 410 in method 400 above, and is not repeated here for brevity.

In step 620, the terminal device generates eighth indication information, where the eighth indication information is used to indicate P groups of weighting coefficients corresponding to P angular delay pairs.

First, the terminal device may perform channel estimation based on the precoded reference signal for each transmit port received on each RB to obtain channel information corresponding to each transmit port on N RBs. And the terminal equipment processes each channel estimation value based on the angle vector corresponding to each time delay vector acquired in advance to obtain the channel information corresponding to each angle time delay pair on the N RBs.

Thereafter, the terminal device may perform frequency domain filtering on the N channel information corresponding to the same angle delay pair based on the above-described frequency domain filtering method. For example, the N RBs are divided into one or more RB groups, and each RB group may include one or more RBs. The terminal device may perform frequency domain filtering in units of one RB group corresponding to one angular delay pair. The specific process of the terminal device performing the frequency domain filtering may refer to the related description in step 520 of the method 500 above. For brevity, no further description is provided herein.

Since the filter coefficients used for frequency domain filtering are related to the time delay, the terminal device may also obtain L time delays or related parameters of the time delays in advance before performing step 620.

Optionally, the method 600 further comprises: in step 630, the network device sends ninth indication information, where the ninth indication information is used to indicate L latencies or relevant parameters of latencies. Accordingly, the terminal device receives the ninth indication information.

The specific manner in which the network device indicates the L delays or the relevant parameters of the delays through the signaling has been described in detail in step 530 of the method 500 above, and for brevity, no further description is given here.

It should be understood that the above description shows the channel measurement and feedback process based on the precoded reference signals transmitted by P transmission ports in one polarization direction for ease of understanding only. This should not be construed as limiting the application in any way. For multiple polarization directions, the terminal device may determine P sets of weighting coefficients corresponding to P transmit ports in each polarization direction based on the same method described above.

It should also be understood that the specific process of the terminal device generating the eighth indication information based on the determined weighting coefficient may refer to the specific process of the terminal device generating the first indication information in step 330 in the above method 300. For brevity, no further description is provided herein.

In step 640, the terminal device transmits the eighth indication information. Accordingly, the network device receives the eighth indication information.

In step 650, the network device determines a precoding matrix according to the eighth indication information.

It should be understood that the specific process of steps 640-650 may be the same as the specific process of steps 330-340 in method 300 above. The relevant description of steps 640 to 650 may refer to the relevant description of steps 330 to 340 in method 300 above, and for the sake of brevity, will not be repeated here.

In the embodiment of the application, the network device performs precoding on the downlink reference signal based on the time delay determined by the uplink channel measurement, so that the terminal device performs downlink channel measurement according to the precoded reference signal. Because the network device precodes the reference signal based on the time delay of the reciprocity of the uplink and downlink channels, the terminal device does not need to feed back the relevant information of the frequency domain (such as the time delay vector), and the feedback overhead of the terminal device is greatly reduced. In addition, the channel information estimated and obtained on the plurality of frequency domain units is filtered by the filter coefficient determined based on the time delay corresponding to each transmitting port, so that the noise can be reduced, and the channel information corresponding to each frequency domain unit and obtained by filtering is more accurate by fully utilizing the correlation among the pilot frequencies on the plurality of frequency domain units. In addition, through compensation of the filter coefficient, the originally discontinuous equivalent channel can be subjected to combined filtering to a greater extent, the problem of inaccurate channel estimation caused by the fact that frequency domain binding cannot be carried out in the prior art is solved, and the transmission performance is improved. Therefore, the feedback overhead is reduced, and simultaneously, higher feedback precision can be still ensured, thereby being beneficial to improving the transmission performance of the system.

It should be understood that the above is only for convenience of understanding, and shows an example that the network device precodes the reference signal based on the delay vector only, and the terminal device performs channel measurement and feedback based on the precoded reference signal. This should not be construed as limiting the application in any way. The network device may also precode the reference signal based on the angle vector only, and the terminal device may also perform frequency domain filtering on channel information estimated based on the precoded reference signal based on the similar method described above, so as to obtain P groups of weighting coefficients corresponding to P angle delay pairs. Since the specific process is similar to that described above, it will not be described in detail here for the sake of brevity.

It is also to be understood that in the above embodiments, the terminal device and/or the network device may perform some or all of the steps in the embodiments. These steps or operations are merely examples, and other operations or variations of various operations may be performed by embodiments of the present application. Further, the various steps may be performed in a different order presented in the embodiments, and not all of the operations in the embodiments of the application may be performed. The sequence number of each step does not mean the execution sequence, and the execution sequence of each process should be determined by the function and the inherent logic of the process, and should not be limited in any way to the implementation process of the embodiment of the present application.

Fig. 7 is a schematic block diagram of a communication device provided in an embodiment of the present application. As shown in fig. 7, the communication device 1000 may include a processing unit 1100 and a transceiving unit 1200.

In a possible design, the communication apparatus 1000 may correspond to the terminal device in the above method embodiment, and for example, may be the terminal device, or a component (such as a chip or a chip system, etc.) configured in the terminal device.

It should be understood that the communication apparatus 1000 may correspond to a terminal device in the methods 300 to 600 according to the embodiments of the present application, and the communication apparatus 1000 may include a unit for performing the methods performed by the terminal device in the methods 300 to 600 in fig. 3 to 6. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flows of any one of the methods 300 in fig. 3 to 600 in fig. 6.

When the communication device 1000 is used to execute the method 300 in fig. 3, the processing unit 1100 may be used to execute step 320 in the method 300, and the transceiver unit 1200 may be used to execute step 310 and step 330 in the method 300. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

When the communication device 1000 is configured to perform the method 400 in fig. 4, the processing unit 1100 may be configured to perform step 420 in the method 400, and the transceiver unit 1200 may be configured to perform step 410 and step 430 in the method 400. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

When the communication device 1000 is configured to perform the method 500 in fig. 5, the processing unit 1100 may be configured to perform step 520 in the method 500, and the transceiver unit 1200 may be configured to perform step 510, step 530, and step 540 in the method 500. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

When the communication device 1000 is configured to perform the method 600 in fig. 6, the processing unit 1100 may be configured to perform step 620 in the method 600, and the transceiver unit 1200 may be configured to perform step 610, step 630 and step 640 in the method 600. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

It should also be understood that when the communication apparatus 1000 is a terminal device, the transceiver unit 1200 in the communication apparatus 1000 may be implemented by a transceiver, for example, may correspond to the transceiver 2020 in the terminal device 2000 shown in fig. 8, and the processing unit 1100 in the communication apparatus 1000 may be implemented by at least one processor, for example, may correspond to the processor 2010 in the terminal device 2000 shown in fig. 8.

It should also be understood that, when the communication device 1000 is a chip configured in a terminal device, the transceiver unit 1200 in the communication device 1000 may be implemented by an input/output interface, and the processing unit 1100 in the communication device 1000 may be implemented by a processor, a microprocessor, an integrated circuit, or the like integrated on the chip or a system of chips.

In another possible design, the communication apparatus 1000 may correspond to the network device in the above method embodiment, and may be, for example, a network device or a component (e.g., a chip or a system-on-chip, etc.) configured in a network device.

It should be understood that the communication apparatus 1000 may correspond to the network device in the methods 300 to 600 according to the embodiments of the present application, and the communication apparatus 1000 may include units for performing the methods performed by the network device in the methods 300 to 600 in fig. 3 to 6. Also, the units and other operations and/or functions described above in the communication apparatus 1000 are respectively for implementing the corresponding flows of any one of the methods 300 in fig. 3 to 600 in fig. 6.

When the communication device 1000 is used to execute the method 300 in fig. 3, the processing unit 1100 may be used to execute step 340 in the method 300, and the transceiver unit 1200 may be used to execute step 310 and step 330 in the method 300. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

When the communication device 1000 is configured to perform the method 400 in fig. 4, the processing unit 1100 may be configured to perform step 440 in the method 400, and the transceiver unit 1200 may be configured to perform step 410 and step 430 in the method 400. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

When the communication device 1000 is configured to perform the method 500 in fig. 5, the processing unit 1100 may be configured to perform step 550 in the method 500, and the transceiver unit 1200 may be configured to perform steps 510, 530 and 540 in the method 500. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

When the communication device 1000 is configured to perform the method 600 in fig. 6, the processing unit 1100 may be configured to perform step 650 in the method 600, and the transceiver unit 1200 may be configured to perform step 610, step 630 and step 640 in the method 600. It should be understood that the specific processes of the units for performing the above corresponding steps have been described in detail in the above method embodiments, and are not described herein again for the sake of brevity.

It should also be understood that when the communication apparatus 1000 is a network device, the transceiving unit in the communication apparatus 1000 may be implemented by a transceiver, for example, may correspond to the transceiver 3200 in the network device 3000 shown in fig. 9, and the processing unit 1100 in the communication apparatus 1000 may be implemented by at least one processor, for example, may correspond to the processor 3100 in the network device 3000 shown in fig. 9.

It should also be understood that when the communication device 1000 is a chip configured in a network device, the transceiver unit 1200 in the communication device 1000 may be implemented by an input/output interface, and the processing unit 1100 in the communication device 1000 may be implemented by a processor, a microprocessor, an integrated circuit, or the like integrated on the chip or a system of chips.

Fig. 8 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 to the system shown in fig. 1, 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. The processor 2010, the transceiver 2002 and the memory 2030 may be in communication with each other via the interconnection path to transfer control and/or data signals, the memory 2030 may be used for storing a computer program, and the processor 2010 may be 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. 7.

The transceiver 2020 may correspond to the transceiver unit in fig. 7, 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. 8 is capable of implementing various processes involving the terminal device in the method embodiments shown in fig. 3-6. The operations and/or functions of the modules in the terminal device 2000 are respectively to implement the corresponding flows in the above-described method embodiments. Reference may be made specifically to the description of the above method embodiments, and a detailed description is omitted here where appropriate to avoid repetition.

The processor 2010 may be configured to perform the actions described in the foregoing method embodiments as being implemented internally by the terminal device, and the transceiver 2020 may be configured to perform the actions described in the foregoing method embodiments as being transmitted by the terminal device to the network device or received by the terminal device from the network device. Please refer to the description of the previous embodiment of the method, 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. 9 is a schematic structural diagram of a network device provided in the embodiment of the present application, which may be a schematic structural diagram of a base station, for example. The base station 3000 can be applied to the system shown in fig. 1, and performs the functions of the network device in the method embodiments described above. As shown, the base station 3000 may include one or more radio frequency units, such as a Remote Radio Unit (RRU) 3100 and one or more baseband units (BBUs) (which may also be referred to as Distributed Units (DUs)) 3200. The RRU 3100 may be referred to as a transceiver unit, and corresponds to the transceiver unit 1100 in fig. 9. Alternatively, the transceiving unit 3100 may also be referred to as a transceiver, transceiving circuit, or transceiver, etc., which may include 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 RRU 3100 part is mainly used for transceiving and converting radio frequency signals to baseband signals, for example, for sending indication information to a terminal device. The BBU 3200 section is mainly used for performing baseband processing, controlling a base station, and the like. The RRU 3100 and the BBU 3200 may be physically disposed together or may be physically disposed separately, i.e. distributed base stations.

The BBU 3200 is a control center of the base station, and may also be referred to as a processing unit, and may correspond to the processing unit 1200 in fig. 9, and is mainly used for completing baseband processing functions, such as channel coding, multiplexing, modulating, spreading, and the like. For example, the BBU (processing unit) may be configured to control the base station to perform an operation procedure related to the network device in the foregoing method embodiment, for example, to generate the foregoing indication information.

In an example, the BBU 3200 may be formed by one or more boards, and the boards may collectively 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 base station to perform necessary actions, for example, for controlling the base station 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 base station 3000 shown in fig. 9 can implement the processes related to the network device in the method embodiments shown in fig. 3 to 6. The operations and/or functions of the respective modules in the base station 3000 are respectively for implementing the corresponding flows in the above-described method embodiments. Reference may be made specifically to the description of the above method embodiments, and a detailed description is appropriately omitted herein to avoid redundancy.

BBU 3200 as described above can be used to perform actions described in previous method embodiments as being implemented internally by a network device, while RRU 3100 can be used to perform actions described in previous method embodiments as being sent by or received from a terminal device by a network device. Please refer to the description of the previous embodiment of the method, which is not repeated herein.

It should be understood that the base station 3000 shown in fig. 9 is only one possible form of network device, and should not limit the present application in any way. The method provided by the application can be applied to network equipment in other forms. For example, including AAUs, and may also include CUs and/or DUs, or including BBUs and Adaptive Radio Units (ARUs), or BBUs; the network device may also be a Customer Premise Equipment (CPE) or other forms, and the present application is not limited to a specific form of the network device.

Wherein the CU and/or DU may be configured to perform the actions described in the foregoing method embodiments that are implemented inside the network device, and the AAU may be configured to perform the actions described in the foregoing 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 an interface; the processor is configured to perform the method of any of the above method embodiments.

It is to be understood that the processing means described above may be one or more 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.

In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in a 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 a memory, and a processor reads information in the memory and combines hardware thereof to complete the steps of the method. 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 method embodiments may be performed 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 methods, 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 method disclosed in connection with the embodiments of the present application may 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 a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

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 methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

According to the method provided by the embodiment of the present application, the present application further provides a computer program product, which includes: computer program code which, when run on a computer, causes the computer to perform the methods performed by the terminal device and the network device, respectively, in the embodiments shown in fig. 3 to 6.

According to the method provided by the embodiment of the present application, the present application further provides a computer-readable medium, which stores program codes, and when the program codes are run on a computer, the computer is caused to execute the methods respectively executed by the terminal device and the network device in the embodiments shown in fig. 3 to 6.

According to the method provided by 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.

The network device in the foregoing device embodiments completely corresponds to the terminal device and the network device or the terminal device in the method 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 method embodiments, and other steps besides transmitting and receiving may be executed by the processing unit (processor). The functions of specific elements may be referred to corresponding method embodiments. 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 method embodiments, 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 method 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 wholly 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 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 includes one or more 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 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 method 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 think 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

A method of channel measurement, comprising:

generating first indication information, where the first indication information is used to indicate P groups of weighting coefficients corresponding to P transmission ports, where a reference signal of each of the P transmission ports is obtained by precoding the reference signal based on a delay vector and/or an angle vector, and the weighting coefficient corresponding to each of the P transmission ports and the delay vector and/or the angle vector corresponding to each of the transmission ports are used to construct a precoding matrix; the P-th group of weighting coefficients corresponding to the P-th transmitting port of the P transmitting ports are obtained by carrying out time domain transformation on channel information between the P-th transmitting port and R receiving ports of the terminal equipment, wherein the P-th transmitting port is any one of the P transmitting ports, P is more than or equal to 0 and less than or equal to P-1, P is more than or equal to 1, R is more than or equal to 1, and P, P and R are integers;

and sending the first indication information.
The method of claim 1, wherein each of the P sets of weighting coefficients comprises R' weighting coefficients, the P-th set of weighting coefficients being obtained by time-domain transforming channel information between the P-th transmit port and one or more of the R receive ports; r is more than or equal to R 'and more than or equal to 1, and R' is an integer.
The method of claim 2, wherein each of the P sets of weighting coefficients comprises R weighting coefficients corresponding to the R receive ports, and wherein an R-th weighting coefficient of the P-th set of weighting coefficients is obtained by time-domain transforming channel information between the P-th transmit port and an R-th receive port of the R receive ports.
The method of claim 3, wherein the method further comprises:

performing time domain transformation on the vector determined by the channel information between the p-th transmitting port and the r-th receiving port to obtain a transformed vector, wherein the r-th weighting coefficient in the p-th group of weighting coefficients is the n-th weighting coefficient in the vector obtained by the time domain transformation_p,rA value; wherein the vector determined by the channel information between the p-th transmitting port and the r-th receiving port includes N values, the N values include channel information corresponding to N frequency domain units for carrying reference signals of the p-th transmitting port, and N is greater than or equal to 0 and greater than or equal to N_p,r≤N-1，N≥1，n _p,rAnd N are integers.
The method of claim 4, wherein n is_p,rIs a predefined value.
The method of claim 5, wherein n is _p,r＝0。
The method of claim 4, wherein the first indication information is further used for indicating n corresponding to a channel between the p-th transmitting port and the r-th receiving port_p,rThe value of (c).
The method of any of claims 4 to 7, further comprising:

based on a predetermined filter coefficient, carrying out filter processing on the transformed vector to obtain an r-th weighting coefficient in the p-th group of weighting coefficients; wherein the filter coefficient comprises N elements, the N elements comprise a non-zero element and N-1 zero elements, and the non-zero element is the N-th element of the N elements_p,rAnd (4) each element.
The method of any one of claims 1 to 8, wherein the time-domain transformation comprises: an inverse fast fourier transform IFFT or an inverse discrete fourier transform IDFT.
A method of channel measurement, comprising:

generating second indication information, where the second indication information is used to indicate P groups of weighting coefficients corresponding to P transmission ports, a reference signal of each of the P transmission ports is obtained by precoding the reference signal based on at least one delay vector, and the weighting coefficient corresponding to each of the P transmission ports and the delay vector corresponding to each transmission port are used to construct a precoding matrix; wherein, a P-th group weighting coefficient corresponding to a P-th transmitting port of the P transmitting ports is a sum of a plurality of values obtained by filtering channel information of one or more frequency domain unit groups respectively, each of the one or more frequency domain unit groups includes a plurality of frequency domain units, a total number of the frequency domain units included in the one or more frequency domain unit groups is a number of frequency domain units used for carrying reference signals of the P-th transmitting port, the P-th transmitting port is any one of the P transmitting ports, P is greater than or equal to 0 and less than or equal to P-1, P is greater than or equal to 1, and P are integers;

And sending the second indication information.
The method of claim 10, wherein the method further comprises:

respectively filtering the channel information of the one or more frequency domain unit groups based on a predetermined filtering coefficient corresponding to the p-th transmitting port to obtain a filtered value;

summing the filtered values of the one or more groups of frequency domain units to obtain a weighting coefficient corresponding to the pth transmit port.
The method of claim 11, wherein the method further comprises:

based on a time delay tau corresponding to the p-th transmitting port_pOr time delay τ_pOf determining saidFilter coefficients, where each delay corresponds to a delay vector.
The method of claim 12, wherein the filter coefficients are:

wherein the content of the first and second substances,
wherein, the first and the second end of the pipe are connected with each other,
a correlation matrix representing correlation between frequency domain units in a frequency domain unit group for carrying reference signals of the p-th transmitting port;
as a correction value for
The correction is carried out so that the correction is carried out,
for a time delay tau corresponding to the p-th transmitting port_pOr time delay τ_pN represents the number of frequency domain units for carrying reference signals of the p-th transmission port, N > 1 and is an integer;
Is a pair of
Correcting to obtain a correlation matrix; SNR is signal to noise ratio; i represents a unit matrix.
The method of any of claims 10 to 13, further comprising:

and receiving third indication information, where the third indication information is used to indicate a time delay corresponding to each of the P transmit ports or a relevant parameter of the time delay, and each time delay corresponds to a time delay vector.
The method of claim 14, wherein the third indication information indicates a latency for each of the P transmit ports as a latency corresponding to each transmit port.
The method of claim 14, wherein the indication of the third indication information for the parameter related to the time delay corresponding to each of the P transmit ports is: a time delay tau corresponding to a first transmitting port of the P ports₀And the time delay corresponding to the rest of the P transmitting ports except the first transmitting port is different from the time delay corresponding to the first transmitting port by the difference delta tau.
A communications apparatus, comprising:

a processing unit, configured to generate first indication information, where the first indication information is used to indicate P groups of weighting coefficients corresponding to P transmit ports, a reference signal of each of the P transmit ports is obtained by precoding the reference signal based on a delay vector and/or an angle vector, and the weighting coefficient corresponding to each of the P transmit ports and the delay vector and/or the angle vector corresponding to each transmit port are used to construct a precoding matrix; the P-th group of weighting coefficients corresponding to the P-th transmitting port of the P transmitting ports are obtained by carrying out time domain transformation on channel information between the P-th transmitting port and R receiving ports of the terminal equipment, wherein the P-th transmitting port is any one of the P transmitting ports, P is more than or equal to 0 and less than or equal to P-1, P is more than or equal to 1, R is more than or equal to 1, and P, P and R are integers;

And the transceiving unit is used for sending the first indication information.
The apparatus as recited in claim 17 wherein each of said P sets of weighting coefficients comprises R' weighting coefficients, said P-th set of weighting coefficients being obtained by time-domain transforming channel information between said P-th transmit port and one or more of said R receive ports; r is more than or equal to R 'and more than or equal to 1, and R' is an integer.
The apparatus as recited in claim 18 wherein each of said P sets of weighting coefficients comprises R weighting coefficients corresponding to said R receive ports, wherein an R-th weighting coefficient of said P-th set of weighting coefficients is obtained by time-domain transforming channel information between said P-th transmit port and an R-th receive port of said R receive ports.
The apparatus as claimed in claim 19, wherein said processing unit is further configured to perform time-domain transformation on a vector determined by channel information between the p-th transmitting port and the r-th receiving port to obtain a transformed vector, wherein an r-th weighting coefficient in the p-th group of weighting coefficients is an n-th weighting coefficient in the time-domain transformed vector _p,rA value; wherein the vector determined by the channel information between the p-th transmitting port and the r-th receiving port includes N values, the N values include channel information corresponding to N frequency domain units for carrying reference signals of the p-th transmitting port, and N is greater than or equal to 0 and greater than or equal to N_p,r≤N-1，N≥1，n _p,rAnd N are integers.
The apparatus of claim 20, wherein n is n_p,rIs a predefined value.
The apparatus of claim 21, wherein n is_p,r＝0。
The apparatus of claim 20, wherein the first indication information is further for indicating n corresponding to a channel between the p-th transmit port and the r-th receive port_p,rThe value of (c).
The apparatus according to any one of claims 20 to 23, wherein the processing unit is further configured to perform a filtering process on the transformed vector based on a predetermined filter coefficient, to obtain an r-th weighting coefficient in the p-th group of weighting coefficients; wherein the filter coefficient comprises N elements, the N elements comprise a non-zero element and N-1 zero elements, and the non-zero element is the N-th element in the N elements_p,rAnd (4) each element.
The apparatus of any one of claims 17 to 24, wherein the time-domain transform comprises: an inverse fast fourier transform IFFT or an inverse discrete fourier transform IDFT.
A communications apparatus, comprising:

a processing unit, configured to generate second indication information, where the second indication information is used to indicate P groups of weighting coefficients corresponding to P transmission ports, a reference signal of each of the P transmission ports is obtained by precoding the reference signal based on at least one delay vector, and the weighting coefficient corresponding to each of the P transmission ports and the delay vector corresponding to each transmission port are used to construct a precoding matrix; wherein, a P-th group weighting coefficient corresponding to a P-th transmitting port of the P transmitting ports is a sum of a plurality of values obtained by filtering channel information of one or more frequency domain unit groups respectively, each of the one or more frequency domain unit groups includes a plurality of frequency domain units, a total number of the frequency domain units included in the one or more frequency domain unit groups is a number of frequency domain units used for carrying a reference signal of the P-th transmitting port, the P-th transmitting port is any one of the P transmitting ports, P is greater than or equal to 0 and less than or equal to P-1, P is greater than or equal to 1, and P are integers;

and the transceiving unit is used for generating the second indication information.
The apparatus of claim 26, wherein the processing unit is further configured to filter the channel information of the one or more groups of frequency-domain units respectively based on predetermined filter coefficients corresponding to the p-th transmit port to obtain filtered values; and for summing the filtered values of the one or more groups of frequency domain units to obtain a weighting coefficient corresponding to the p-th transmit port.
The apparatus of claim 27, wherein the processing unit is further for basing the time delay τ corresponding to the pth transmit port_pOr time delay τ_pDetermines the filter coefficients, wherein each delay corresponds to a delay vector.
The apparatus of claim 28, wherein the filter coefficients are:

wherein the content of the first and second substances,
wherein the content of the first and second substances,
a correlation matrix representing correlation between frequency domain units in a frequency domain unit group for carrying reference signals of the p-th transmitting port;
as a correction value for
The correction is carried out so that the correction is carried out,
for a time delay tau corresponding to the p-th transmitting port_pOr time delay τ_pN represents the number of frequency domain units for carrying reference signals of the p-th transmission port, N > 1 and is an integer;
Is a pair of
Correcting to obtain a correlation matrix; SNR is signal to noise ratio; i denotes a unit matrix.
The apparatus according to any one of claims 26 to 29, wherein the transceiver unit is further configured to receive third indication information, where the third indication information is used to indicate a delay or a parameter related to a delay corresponding to each of the P transmit ports, and each delay corresponds to a delay vector.
The apparatus of claim 30, wherein the third indication information indicates a latency for each of the P transmit ports as a latency corresponding to each transmit port.
The apparatus as claimed in claim 30, wherein the indication of the third indication information for the parameter related to the delay corresponding to each of the P transmit ports is: a time delay tau corresponding to a first transmitting port of the P ports₀And the time delay corresponding to the rest of the P transmitting ports except the first transmitting port is different from the time delay corresponding to the first transmitting port by the difference delta tau.
A communications apparatus, comprising at least one processor configured to execute a computer program stored in memory to cause the communications apparatus to implement the method of any of claims 1 to 16.
A computer-readable medium, comprising a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 16.