CN114600384B

CN114600384B - Channel measurement method and communication device

Info

Publication number: CN114600384B
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: 2023-09-12
Anticipated expiration: 2039-10-30
Also published as: CN114600384A; WO2021081847A1

Abstract

The application provides a channel measurement method and a communication device. The method comprises the following steps: the method comprises the steps that a terminal device generates and sends first indication information, the first indication information is used for indicating P groups of weighting coefficients corresponding to P emission ports, a reference signal of each emission port in the P emission ports is obtained by precoding the reference signal based on a time delay vector and/or an angle vector, and the weighting coefficient corresponding to each emission port in the P emission ports and the time delay vector and/or the angle vector corresponding to each emission port are used for constructing a precoding matrix; the P-th group weighting coefficient corresponding to the P-th transmitting port in the P transmitting ports is obtained by performing time domain transformation on channel information between the P-th transmitting port and R receiving ports of the terminal equipment. The CSI of the downlink channel is obtained by exploiting the partial reciprocity between the uplink and downlink channels. 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 may reduce interference between multiple users and interference between multiple signal streams of the same user through precoding, which is beneficial to improving signal quality, implementing space division multiplexing, and improving spectrum utilization.

The terminal device may determine the precoding matrix based on, for example, downlink channel measurements and may wish to cause the network device to obtain, via feedback, the same or a similar precoding matrix as 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 introduces a large feedback overhead.

In some communication technologies, such as time division duplex (time division duplexing, TDD) technology, where there is reciprocity between the uplink and downlink channels, the network device may estimate the uplink channel based on measurements of the uplink channel. However, in other communication technologies, such as frequency division duplex (frequency division duplexing, FDD) technologies, the uplink and downlink channels are not completely reciprocal. Therefore, how to obtain accurate channel states of the downlink channels by the network device by utilizing partial reciprocity between the uplink and downlink channels is a technical problem to be solved.

Disclosure of Invention

The application provides a channel measurement method and a communication device, which are used for obtaining channel state information (channel state information, CSI) of a downlink channel by utilizing partial reciprocity between an uplink channel and a downlink channel and providing transmission performance of a system.

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-on-chip, etc.) disposed 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, a reference signal of each transmitting port in the P transmitting ports is obtained by precoding the reference signal 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 weighting coefficient corresponding to the P-th transmitting port in the P transmitting ports is obtained by performing time domain transformation on channel information between the P-th transmitting port and R receiving ports of terminal equipment, wherein the P-th transmitting port is any transmitting port in 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. The application is not limited in this regard. The terminal device may perform channel measurement based on the received reference signal to feed back the weighting coefficients corresponding to the respective transmit ports. It is understood that the weighting coefficients corresponding to the respective transmit ports may also refer to weighting coefficients corresponding to the angle vector and the delay vector.

Based on the above technical solution, the network device may, for example, precode 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 performs precoding on the reference signal based on the reciprocal angle and/or time delay of the uplink and downlink channels, the terminal device can not need to feed back the space domain and/or frequency domain vectors (such as the angle vectors and/or time delay vectors), thereby greatly reducing the feedback overhead of the terminal device.

In addition, when the terminal equipment performs channel measurement based on the received pre-coding reference signal, the measured channel of the frequency domain is converted into the time domain, and the value obtained by the time domain transformation is fed back as a weighting coefficient of the angle delay pair. Therefore, the problem of inaccurate channel recovery caused by the weighting coefficient obtained by accumulating and summing a plurality of discontinuous equivalent channels can be avoided, and higher feedback precision can be obtained, so that the network equipment can determine the precoding matrix matched with the downlink channel based on feedback, and the transmission performance of the system can be improved.

With reference to the first aspect, in some possible implementation manners of the first aspect, each set of weighting coefficients in the P sets of weighting coefficients includes R' weighting coefficients, where 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 in the R receiving ports; r is more than or equal to R 'is 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 weighting on channel information between one transmitting port and a plurality of receiving ports. The application is not limited in this regard.

Further, each set of weighting coefficients in the P sets of weighting coefficients includes R weighting coefficients corresponding to the R receiving ports, and an R weighting coefficient in 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 receiving port in the R receiving ports.

That is, each weighting coefficient in each set of weighting coefficients may be obtained by performing a time domain transform on channel information between a transmit port and a receive port.

With reference to the first aspect, in certain possible implementation manners 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 set of weighting coefficients is the n-th weighting coefficient in the vector obtained by the time domain transformation _p，r A value; wherein the vector determined by the channel information between the p-th transmitting port and the r-th receiving port comprises N values, the N values comprise the channel information respectively corresponding to N frequency domain units for bearing the reference signal of the p-th transmitting port, and N is more than or equal to 0 _p，r ≤N-1，N≥1，n _p，r And N are integers.

Optionally, the time domain transformation comprises: inverse fast fourier transform (inverse fast Fourier transform, IFFT) or inverse discrete fourier transform (inverse discrete Fourier Transform, IDFT).

The above provides a way to obtain the weighting coefficients by a time domain transform. It should be understood that the above list is merely exemplary and should not be construed as limiting the application in any way. The application is not limited to a specific implementation of the time domain transformation.

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

Since the first time domain transform value (i.e., the direct current component) of the N time domain transform values obtained after IFFT transformation is exactly equal to the sum of the N channel estimate values, the N channel estimate values are estimated based on the reference signal of the same transmit port received on the N frequency domain units. Thus, n can be _p，r Defined as 0.

It should be understood that the IFFT is used herein as an example to describe n in detail for ease of understanding only _p，r The reason defined as 0. But this should not be construed as limiting the application in any way. Since the manner of time domain transformation is not limited to that listed above, in different implementations, for n _p，r The definition of (c) may also be different. The application is not limited in this regard.

Optionally, 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，r Is a value of (2).

That is, the terminal device can decide by itself which of the N time domain transformed values to determine as the weighting factor, i.e. the terminal device can determine by itself N _p，r And reporting the value of the network device.

With reference to the first aspect, in certain possible implementation manners of the first aspect, the method further includes: filtering the transformed vector based on a predetermined filter coefficient to obtain an r-th weighting coefficient in a 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 Nth of the elements _p，r The elements.

As previously described, the terminal device may select a value from the vector obtained by the time domain transformation as a weighting coefficient. The specific process that the terminal device takes one value of the N time domain transformation values as a weighting coefficient can be realized through filtering. The above provides a filtering method, which performs filtering processing on a vector obtained by the time domain transformation through a predetermined filtering coefficient, so that a terminal device can conveniently obtain a value which can be used as a weighting coefficient from the vector.

Illustratively, based on n listed above _p，r =0, the filter coefficient can be expressed as [1 0 … 0, for example] _1×N 。

It should be understood that the above listed methods and filter coefficients are examples only and should not be construed as limiting the application in any way. The present application is not limited to a specific manner of filtering and a specific form of filter coefficient.

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-on-chip, etc.) disposed 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 emission ports, the reference signal of each emission port in the P emission ports is obtained by precoding the reference signal at least based on a time delay vector, and the weighting coefficient corresponding to each emission port in the P emission ports and the time delay vector corresponding to each emission port are used for constructing a precoding matrix; the P-th group weighting coefficient corresponding to the P-th transmitting port in the P transmitting ports is the sum of a plurality of values obtained by respectively filtering channel information of one or more frequency domain unit groups, each frequency domain unit group in the one or more frequency domain unit groups comprises a plurality of frequency domain units, the total number of the frequency domain units included in the one or more frequency domain unit groups is the number of the frequency domain units used for bearing reference signals of the P-th transmitting port, the P-th transmitting port is any transmitting port in 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, and P is an integer; and transmitting the second indication information.

It should be understood that the reference signal corresponding to each transmitting port may be obtained based on time delay vector precoding, or may be obtained by precoding based on an angle vector and a time delay vector. The application is not limited in this regard. The terminal device may perform channel measurement based on the received reference signal to feed back the weighting coefficients corresponding to the respective transmit ports. It is understood that the weighting coefficients corresponding to the respective transmit ports may also refer to weighting coefficients corresponding to the angle vector and the delay vector.

Based on the above technical solution, the network device may, for example, precode 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 performs precoding on the reference signal based on reciprocal time delay of the uplink and downlink channels, the terminal device can not need to feed back related information of the frequency domain (such as the time delay vector), and the feedback overhead of the terminal device is greatly reduced.

In addition, by performing filtering processing on the channel information estimated and obtained 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 matched with the downlink channel based on feedback, and the transmission performance of the system can be improved.

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

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

With reference to the second aspect, in certain possible implementations of the second aspect, the method further includes: based on the time delay tau corresponding to the p-th transmitting port _p Or time delay tau _p The filter coefficients are determined, wherein each delay corresponds to a delay vector.

It can be seen that the filter coefficients are related to the delay corresponding to the transmit port. That is, the filtering 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 , wherein ,/>A correlation matrix, which represents the correlation between each frequency domain unit in a frequency domain unit group for carrying the reference signal of the p-th transmitting port; />For correction values for->Make corrections (I)>For the delay tau corresponding to the p-th transmitting port _p Or and delay tau _p N represents the number of frequency domain units used to carry the reference signal of the p-th transmit port, N > 1 and is an integer; />For->Performing correction to obtain a correlation matrix; SNR is the signal-to-noise ratio; i represents a unit array.

An example of wiener filter coefficients is given above. In the embodiment of the application, the correction value related to 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 original discontinuous equivalent channel can be subjected to joint filtering to a greater extent. Therefore, the problem of inaccurate channel estimation caused by the fact that frequency domain resources cannot be bound in the prior art can be solved.

It should be understood that the wiener filter coefficients listed above are merely examples and should not be construed as limiting the 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 certain possible implementations of the second aspect, the method further includes: and receiving third indication information, wherein the third indication information is used for indicating delay or related parameters of delay corresponding to each of the P transmitting ports, and each delay corresponds to one delay vector.

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

Optionally, the third indication information indicates a delay corresponding to each of the P transmit ports as a delay corresponding to each transmit port.

Optionally, the third indication information indicates, for each of the P transmit ports, a related parameter of a delay corresponding to the transmit port as follows: the P portsTime delay tau corresponding to the first transmitting port in the network ₀ And the delay corresponding to the rest of the P emission ports except the first emission port is different from the delay corresponding to the first emission port by delta tau.

The above provides two possible implementations for indicating the time delay. It is to be understood that the above list is merely exemplary and should not be construed as limiting the application in any way. The application is not limited to a specific implementation of indicating the delay corresponding to the transmit port.

In a third aspect, there is provided a communication device comprising individual modules or units for performing the method in any one of the possible implementations of the first aspect.

In a fourth aspect, a communication device is provided that includes a processor. The processor is coupled to the memory and 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, and the processor is 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 device. When the communication means is a chip arranged in the 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, there is provided a communication device comprising individual modules or units for performing the method in any one of the possible implementations of the second aspect.

In a sixth aspect, a communication device is provided that includes a processor. The processor is coupled to the memory and operable to execute instructions in the memory to implement the method of any one of the possible implementations of the second aspect described above. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, and the processor is coupled to the communication interface.

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

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

In a seventh aspect, there is provided a processor comprising: input circuit, output circuit and processing circuit. The processing circuit is configured to receive signals via the input circuit and to transmit signals via the output circuit, such that the processor performs the method of 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 trigger, 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 output signal may be output by, for example and without limitation, a transmitter and transmitted by a transmitter, and the input circuit and the output circuit may be the same circuit, which functions as the input circuit and the output circuit, respectively, at different times. The embodiment of the application does not limit the specific implementation modes of the processor and various circuits.

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

Optionally, the processor is one or more, and the memory is one or more.

Alternatively, the memory may be integrated with the processor or the memory may be separate from the processor.

In a specific implementation process, the memory may be a non-transient (non-transitory) memory, for example, 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 should be appreciated that the related data interaction process, for example, transmitting the indication information, may be a process of outputting the indication information from the processor, and the receiving the capability information may be a process of receiving the input capability information by the processor. Specifically, the data output by the processing may be output to the transmitter, and the input data received by the processor may be from the receiver. Wherein the transmitter and receiver may be collectively referred to as a transceiver.

The apparatus in the 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 in the processor, or may reside outside the processor, and exist separately.

In a ninth aspect, there is provided a 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) which, when run on a computer, causes the computer to perform the method of any one of the possible implementations of the first and second aspects.

An eleventh aspect provides a communication system comprising the aforementioned terminal device and network device.

Drawings

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

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

fig. 5 is a schematic flow chart of a channel measurement method according to still 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 according to 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 scheme of the 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, such as: long term evolution (Long Term Evolution, LTE) system, LTE frequency division duplex (frequencv division duplex, FDD) system, LTE time division duplex (time division duplex, TDD), universal mobile telecommunications system (universal mobile telecommunication system, UMTS), worldwide interoperability for microwave access (worldwide interoperabilitv for microwave access, wiMAX) telecommunications system, future fifth generation (5th Generation,5G) mobile telecommunications system, or new radio access technology (new radio Access Technology, NR). The 5G mobile communication system may include a non-independent Networking (NSA) and/or an independent networking (SA), among others.

The technical scheme provided by the application can be also applied to machine type communication (machine type communication, MTC), inter-machine communication long term evolution (Long Term Evolution-machine, LTE-M), device-to-device (D2D) network, machine-to-machine (machine to machine, M2M) network, internet of things (internet ofthings, ioT) network or other networks. The IoT network may include, for example, an internet of vehicles. The communication modes in the internet of vehicles system are generally called as vehicle to other devices (V2X, X may represent anything), for example, the V2X may include: vehicle-to-vehicle (vehicle to vehicle, V2V) communication, vehicle-to-infrastructure (vehicle to infrastructure, V2I) communication, vehicle-to-pedestrian communication (vehicle to pedestrian, V2P) or vehicle-to-network (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. The application is not limited in this regard.

In the embodiment of the application, the network device can be any device with a wireless receiving and transmitting function. The apparatus includes, but is not limited to: an evolved Node B (eNB), a radio network controller (radio network controller, RNC), a Node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (home evolved NodeB, or a home Node B, HNB, for example), a Base Band Unit (BBU), an Access Point (AP) in a wireless fidelity (wireless fidelity, wiFi) system, a wireless relay Node, a wireless backhaul Node, a transmission point (transmission point, TP), or a transmission reception point (transmission and reception point, TRP), etc., may also be 5G, e.g., NR, a gNB in a system, or a transmission point (TRP or TP), one or a group of base stations (including multiple antenna panels) in a 5G system, or may also be a network Node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a Distributed Unit (DU), etc.

In some deployments, the gNB may include a Centralized Unit (CU) and DUs. The gNB may also include an active antenna unit (active antenna unit, AAU). The CU implements part of the functionality of the gNB and the DU implements part of the functionality of the gNB, e.g. the CU is responsible for handling non-real time protocols and services, implementing radio resource control (radio resource control, RRC), packet data convergence layer protocol (packet data convergence protocol, PDCP) layer functions. The DUs are responsible for handling physical layer protocols and real-time services, implementing the functions of the radio link control (radio link control, RLC), medium access control (medium access control, MAC) and Physical (PHY) layers. The AAU realizes part of physical layer processing function, radio frequency processing and related functions of the active antenna. Since the information of the RRC layer may eventually become information of the PHY layer or be converted from the information of the PHY layer, under this architecture, higher layer signaling, such as RRC layer signaling, may also be considered to be transmitted by the DU or by the du+aau. It is 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 (radio access network, RAN), or may be divided into network devices in a Core Network (CN), which the present application is not limited to.

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

In the embodiment of the present application, the 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 with wireless connectivity, an in-vehicle device, etc. Currently, some examples of terminals may be: a mobile phone (mobile phone), a tablet (pad), a computer with wireless transceiver function (e.g., a notebook, a palm, etc.), a mobile internet device (mobile internet device, MID), a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in an industrial control (industrial control), a wireless terminal in an unmanned (self-drive), a wireless terminal in a telemedicine (remote medical), a wireless terminal in a smart grid (smart grid), a wireless terminal in a transportation security (transportation safety), a wireless terminal in a smart city (smart city), a wireless terminal in a smart home (smart home), a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a wireless local loop (wireless local loop, WLL) station, a personal digital assistant (personal digital assistant, PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a wireless terminal in a wearable device, a land-based device, a future-mobile terminal in a smart city (smart city), a public network (35G) or a future mobile communication device, etc.

The wearable device can also be called as a wearable intelligent device, and is a generic name for intelligently designing daily wearing and developing wearable devices by applying a wearable technology, such as glasses, gloves, watches, clothes, shoes and the like. The 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 can realize a powerful function through software support, data interaction and cloud interaction. The generalized wearable intelligent device includes full functionality, large size, and may not rely on the smart phone to implement complete or partial functionality, such as: smart watches or smart glasses, etc., and focus on only certain types of application functions, and need to be used in combination with other devices, such as smart phones, for example, various smart bracelets, smart jewelry, etc. for physical sign monitoring.

Furthermore, the terminal device may also be a terminal device in an internet of things (internet of things, ioT) system. IoT is an important component of future information technology development, and its main technical feature is to connect an item with a network through a communication technology, so as to implement man-machine interconnection and an intelligent network for object interconnection. IoT technology can enable massive connectivity, deep coverage, and terminal power saving through, for example, narrowband NB technology.

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

To facilitate understanding of the embodiments of the present application, a communication system suitable for the method provided in the embodiment of the present application will be described in detail with reference to fig. 1. Fig. 1 shows a schematic diagram of a communication system 100 suitable for use in the method provided by an embodiment of the application. As shown, the communication system 100 may include at least one network device, such as network device 101 in the 5G system shown in fig. 1; the communication system 100 may also comprise at least one terminal device, such as the terminal devices 102 to 107 shown in fig. 1. Wherein the terminal devices 102 to 107 may be mobile or stationary. One or more of network device 101 and 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 the 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; as another example, the network device may send downstream 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 the terminal devices may be achieved, for example, using D2D technology or the like. As shown in the figure, communication may be directly performed between the terminal devices 105 and 106 and between the terminal devices 105 and 107 using D2D technology. Terminal device 106 and terminal device 107 may communicate with terminal device 105 separately or simultaneously.

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

It should be appreciated that fig. 1 illustrates schematically one network device and a plurality of terminal devices, as well as communication links between the communication devices. Alternatively, the communication system 100 may include a plurality of network devices, and the coverage area of each network device may include other numbers of terminal devices, such as more or fewer terminal devices. The application is not limited in this regard.

Each of the above-described communication apparatuses, such as the network apparatus 101 and the terminal apparatuses 102 to 107 in fig. 1, may be configured with a plurality of antennas. The plurality of antennas may include at least one transmitting antenna for transmitting signals and at least one receiving antenna for receiving signals. In addition, each communication device may additionally include a transmitter chain and a receiver chain, each of which may include a plurality of components (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.) associated with the transmission and reception of signals, as will be appreciated by one skilled in the art. Thus, communication between the network device and the terminal device may be via multiple antenna technology.

Optionally, the wireless communication system 100 may further include a network controller, a mobility management entity, and other network entities, which are not limited thereto according to the embodiments of the present application.

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

The network device may process code words in the physical channel. Wherein the codeword may be encoded bits that are encoded (e.g., including channel coding). The codeword is scrambled (scrambling) to generate scrambled bits. The scrambled bits are subjected to modulation mapping (modulation mapping) to obtain modulation symbols. The modulation symbols are mapped to a plurality of layers (layers), or transport layers, through layer mapping (layer mapping). The modulation symbols after layer mapping are subjected to precoding (precoding) to obtain a precoded signal. The precoded signal is mapped to a plurality of Resource Elements (REs) after being mapped. These REs are then orthogonally multiplexed (orthogonal frequency division multiplexing, OFDM) modulated and transmitted through an antenna port (antenna port).

It should be understood that the above described processing of the downstream signal is only an exemplary description and should not be construed as limiting the application in any way. The processing procedure of the downlink signal may refer to the prior art, and a detailed description of the specific procedure is omitted herein for brevity.

In order to facilitate understanding of the embodiments of the present application, the following terms used in connection with the embodiments of the present application are briefly described.

1. Precoding technology: the network device can process the signal to be transmitted by means of the precoding matrix matched with the channel state under the condition that the channel state is known, so that the precoded signal to be transmitted is matched with the channel, and the complexity of eliminating the influence among the channels of the receiving device is reduced. Thus, by precoding the signal to be transmitted, the received signal quality (e.g., signal-to-interference plus noise ratio (signal to interference plus noise ratio, SINR), etc.) is improved. Therefore, by adopting the precoding technology, the transmission of the sending device and the multiple receiving devices on the same time-frequency resource can be realized, that is, multi-user multiple input multiple output (multiple user multiple input multiple output, MU-MIMO) is realized. It should be understood that the description herein of the precoding technology is merely exemplary for easy understanding, and is 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 channel information (such as, but not limited to, a channel matrix) cannot be known, precoding is performed using a pre-set precoding matrix or a weighting method. For brevity, the details thereof are not described in detail herein.

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 the same within 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 the reciprocity of the uplink and downlink channels, the network device may measure the uplink channel from an uplink reference signal, such as a sounding reference signal (sounding reference signal, SRS). And the downlink channel can be estimated from 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 may not have complete reciprocity because the band spacing of the uplink and downlink channels is much greater than the coherence bandwidth, and the use of the uplink channel to determine the precoding matrix for downlink transmission may not be able to adapt to the downlink channel. However, the uplink and downlink channels in FDD mode still have partial reciprocity, e.g., angle reciprocity and delay reciprocity. Thus, the angle and the time delay may also be referred to as reciprocity parameters.

Signals may travel multiple paths from a transmitting antenna to a receiving antenna as they travel through a wireless channel. Multipath delays cause frequency selective fading, i.e., variations in the frequency domain channel. The time delay is the transmission time of the wireless signal on different transmission paths, and is determined by the distance and the speed, and has no relation with the frequency domain of the wireless 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 profile of the uplink and downlink channels is the same over the delay. Thus, the uplink and downlink channels with delay in FDD mode may be considered the same, or reciprocal.

The angle may be an angle of arrival (AOA) at which a signal arrives at a receiving antenna via a wireless channel, or an angle of departure (angle of departure, AOD) at which a signal is transmitted via a transmitting antenna. In the embodiment of the application, the angle may refer to an arrival angle of an uplink signal reaching the network device, or may refer to an departure angle of the network device transmitting a downlink signal. The angle of arrival of the uplink reference signal and the angle of departure of the downlink reference signal may be considered reciprocal due to the reciprocity of the transmission paths of the uplink and downlink channels on different frequencies.

In an embodiment of the present application, each angle may be characterized by an angle vector. Each delay may be characterized by a delay vector. Thus, in embodiments of the present application, an angle vector may represent an angle and a delay vector may represent a delay.

3. Reference Signal (RS) and pre-coded reference signal: the reference signal may also be referred to as 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 (channel state information reference signal, CSI-RS) for downlink channel measurement or an SRS for uplink channel measurement. It should be understood that the above listed reference signals are merely examples and should not be construed as limiting the application in any way. The application does not exclude the possibility of defining other reference signals in future protocols to achieve the same or similar functionality.

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. The beamforming may be implemented, for example, by precoding the downlink reference signal based on one or more angle vectors, and the phase rotation may be implemented, for example, 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 precoded reference signal; the reference signal that is not precoded is simply referred to as a reference signal.

In the embodiment of the application, the downlink reference signal is precoded based on one or more angle vectors, which may also be referred to as loading the one or more angle vectors onto the downlink reference signal, so as to achieve beamforming. Precoding the downlink reference signal based on the one or more delay vectors may also be referred to as loading the one or more delay vectors onto the downlink reference signal to achieve phase rotation.

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

Wherein a transmit port may be understood as a virtual antenna identified 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 independent transmit unit (TxRU).

Alternatively, the port may also refer to a port after beamforming. 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. It is understood that if the reference signal is beamformed, 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 less than the number of transmit antenna ports.

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

Alternatively, the port may also refer to a port after 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. The port may also be referred to as a port of the precoded reference signal.

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

In the embodiments shown below, when reference is made 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 ports are referred to, in different embodiments, it may refer to the transmit antenna ports as well as to the ports where reference signals are precoded. The particular meaning expressed by a port may be determined according to particular embodiments. Hereinafter, for convenience of distinction, the port of the precoded reference signal will be referred to as a reference signal port.

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

5. Angle vector: it can be understood as a precoding vector used for beamforming the reference signal. The reference signal transmitted by the transmitting device can have a certain space directivity through wave beam forming. Thus, the process of precoding the reference signal based on the angle vector may also be regarded as a process of spatial domain (or simply, spatial domain) precoding. The angle vector may also be referred to as a spatial vector, a beam (beam) vector, or the like.

The number of ports of the pre-coded reference signal obtained by pre-coding 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 smaller 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 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 vector of length T.

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

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

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

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

Such as

wherein ,I₁ For the number of antenna ports of the same polarization direction contained in each column (or row) in the antenna array, I ₂ The number of antenna ports for each row (or column) in the antenna array that contain the same polarization direction. In the present embodiment, t=i ₁ ×I ₂ 。O ₁ and O₂ Is an oversampling factor. i.e ₁ and i₂ Satisfying 0.ltoreq.i ₁ ≤(O ₁ ×I ₁ -1)，0≤i ₂ ≤(O ₂ ×I ₂ -1)。

Optionally, the angle vector is a steering vector of a uniform linear array (uniform linear array, ULA). As an example of the presence of a metal such as, wherein ,θ_k For angle, k=1, 2. K represents the number of angle vectors; lambda is the wavelength and d is the antenna spacing.

The steering vector may represent a phase difference that exists between the arrival angle of one path and the response of different antennas. Guide vector a (θ) _k ) Vector in DFT matrixThe method meets the following conditions: />

Optionally, the angle vector is a steering vector for a uniform area array (uniform plane array, UPA). The steering vector may be, for example, a steering vector containing horizontal and pitch angle information. As an example of the presence of a metal such as, wherein ,θ_k Is horizontal angle +.>Is a pitch angle; ρ _t For three-dimensional coordinates of the T-th transmit antenna port, t=1, 2,..; u (u) _k The unit sphere base vector corresponding to the kth angle: />/>

Hereinafter, for convenience of explanation, the angle vector will be denoted as a (θ _k )。

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

Assuming that the transmitting device is configured with a single polarized antenna, the number of ports of the transmitting antenna is T; the frequency domain unit number 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 nxt for one receiving port of the receiving device. If the reference signal is spatially precoded based on one angle vector, the angle vectors may be loaded onto the reference signal, 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 on each receiving port, each frequency domain unit, the dimension of the channel estimated by the terminal device based on the received precoded reference signal may be 1 x 1.

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

6. Time delay vector: may also be referred to as a frequency domain vector. The delay vector may be used as a vector representing the law of variation of the channel in the frequency domain. As previously described, multipath delays result in frequency selective fading. The time delay of the signal in the time domain can be equivalent to the phase gradation in the frequency domain as known from fourier transform.

For example, for signal g (t), the signal may be transformed into the frequency domain by a fourier transform:for signal g (t-t ₀ ) The signal may be transformed into the frequency domain by fourier transformation:wherein ω is a frequency variable, and the phase rotations corresponding to different frequencies are different; t and t-t ₀ Representing the time delay.

The two delayed signals may be expressed as x (t) =g (t) +g (t-t) ₀ ) From this, a function of the frequency variation can be obtainedLet g (ω) ≡1, we can get +.>Thus, 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 the time delay vector. In other words, the delay vector may be used to represent the delay characteristics of the channel.

The reference signal is precoded based on the delay vector, which may essentially mean that each frequency domain unit in the frequency domain is phase rotated based on elements in the delay vector to pre-compensate for the frequency-selective characteristics caused by multipath delay by precoding the reference signal. Thus, 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 phase rotating each frequency domain unit of the channel based on different delay vectors. Moreover, the phase rotation angle may also be different for different resources (e.g., resource Element (RE)) in the same frequency domain unit due to different loaded delay vectors. To distinguish between different delays, the network device may separately precode the reference signal based on each of the L delay vectors.

Optionally, the length of the delay vector is N, where N may refer to the number of frequency domain units used to carry the reference signal (e.g., the reference signal that is not precoded or the reference signal that is precoded), N is greater than or equal to 1, and N is an integer.

Alternatively, the first of the L delay vectors may be denoted as b (τ _l )，Wherein, l=1, 2,. -%; l may represent the number of delay vectors; f (f) ₀ ，f ₁ ，......，f _N-1 The carrier frequencies of the 1 st, 2 nd to nth frequency domain units are represented, respectively.

Alternatively, the delay vector is taken from the DFT matrix. Such asEach vector in the DFT matrix may be referred to as a DFT vector.

wherein ,O_f For oversampling factor, O _f 1 or more; k is the index of DFT vector and satisfies 0.ltoreq.k.ltoreq.O _f XN-1 or 1-O _f ×N≤k≤0。

For example, when k < 0, b (τ _l ) Vector u in DFT matrix _k Can satisfy the following conditions:

b(τ _l )＝u _k β _l and is also provided with wherein />Δf＝f _n -f _n+1 ，1≤n≤N-1。

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

In the embodiment of the present application, for ease of understanding, a specific process of performing frequency domain precoding on a reference signal is described using a Resource Block (RB) as an example of a frequency domain unit. When an RB is taken as an example of the frequency domain unit, each frequency domain unit may be considered to include only one RB for carrying the 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 a 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 may be transmitted to the terminal device through the downlink channel, the channel measured by the terminal device according to the received precoded reference signal is equivalent to the channel loaded with the delay vector. If the reference signal is frequency domain precoded based on a delay vector of length N, then N elements in the delay vector may be loaded onto the reference signals carried on N RBs, respectively. Channel V loading the nth element of the delay vector onto the nth RB ⁽ⁿ⁾ Can be expressed, for example, as

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

For ease of understanding, the following is a detailed description of the method based on the delay vector b (τ _l ) A process of precoding the reference signal.

Fig. 2 shows a time delay vector b (τ) ₁ ) An example of frequency domain precoding is performed on reference signals carried on N RBs. The N RBs may include RB#0, RB#1 to 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 in each RB, the RE on the first subcarrier. As indicated by the shaded squares in the figure. In this case, a time domain vector b (τ) can be loaded on REs on the first subcarrier, the first time domain symbol 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.

Assuming a delay vectorIf the delay vector b (tau ₁ ) Loaded on the N frequency domain units, the N frequency domain units can be subjected to phase rotation. The N elements in the delay vector may be in one-to-one correspondence with the N frequency domain units. For example, the frequency domain vector b (τ ₁ ) Element 0->Can be loaded on rb#0, the frequency domain vector b (τ ₁ ) Element 1->Can be loaded on rb#1, delay vector b (τ ₁ ) N-1 elements of->May be loaded on rb#n-1. Similarly, the delay vector b (τ ₁ ) N element->Can be used forLoaded on rb#n. For brevity, this is not a list.

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

It should also be appreciated that the delay vector is one form proposed by the present application for representing the delay. The delay vector is named for ease of distinction from angle only and should not be construed as limiting the application in any way. The application does not exclude the possibility of defining other names in future protocols to represent the same or similar meanings.

In addition, if the network device is configured with a monopole antenna, the number of transmit antenna ports is T, and the number of frequency domain units is N. The channel estimated based on the received reference signal may be represented as a matrix of dimension nxt for one receiving port of the terminal device. If the reference signal is frequency domain precoded based on L delay vectors, then for one receiving port of the terminal device, the channel estimated based on the received precoded reference signal may be represented as a matrix with dimension nxl. And on each receiving port, each frequency domain unit, the dimension of the channel estimated by the terminal device based on the received precoded reference signal may be 1×l.

7. Frequency domain unit: the units of frequency domain resources may represent different granularity of frequency domain resources. The frequency domain units may include, for example, but are not limited to, subbands (subbands), resource Blocks (RBs), resource block groups (resource block group, RBGs), precoding resource block groups (precoding resource block group, PRGs), and so on.

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

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

In the embodiment of the application, the method is based on an angle vector a (theta _k ) And a delay vector b (tau _l ) When the reference signal is precoded, the precoding matrix used for precoding the reference signal may be expressed as a product of an angle vector and a conjugate transpose of a delay vector, and may be expressed as a (θ _k )×b(τ _l ) ^H The dimension may be t×n. Alternatively, the precoding matrix used for precoding the reference signal may be expressed as a Kronecker product (Kronecker) of an angle vector and a delay vector, for example, asIts dimension may be t×n.

It should be understood that the various mathematical expressions listed above are examples only and should not be construed as limiting the application in any way. For example, the precoding matrix used to precode the reference signal may also be expressed as a product of a delay vector and a conjugate transpose of an angle vector, or a kronecker product of a delay vector and an angle vector, whose dimension may be n×t. Alternatively, the precoding matrix used to precode the reference signal may also be represented as a mathematical transformation of the various expressions described above. For brevity, this is not a list.

In embodiments of the present application, a weighted sum of one or more angular delay pairs may be used to determine a space-frequency matrix. The matrix of dimensions txn determined based on an angular delay pair may be referred to as a component of the space-frequency matrix, simply a space-frequency component matrix. In the following embodiments, for convenience of explanation, it is assumed that a matrix of dimensions t×n determined by one angle delay pair is defined by a (θ _k )×b(τ _l ) ^H Obtained.

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

In the embodiment of the application, the space-frequency matrix can be determined based on the receiving port or the transmission layer. As previously described, the space-frequency matrix may be determined by a weighted sum of one or more angular delay pairs, so the dimension of the space-frequency matrix may also be nxt.

If the space-frequency matrix is determined based on the receiving ports, the space-frequency matrix may be referred to as a space-frequency matrix corresponding to the receiving ports. The space-frequency matrix corresponding to the receiving port can be used to construct a downlink channel matrix of each frequency domain unit, so as to determine a precoding matrix corresponding to each frequency domain unit. 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 a space-frequency matrix corresponding to each receiving port. If the n-th column vector in the space-frequency matrix corresponding to each receiving port is extracted, a matrix with dimension of T multiplied by R can be obtained by arranging the n-th column vectors from left to right according to the sequence of the receiving ports, R represents the number of the receiving ports, and R is more than or equal to 1 and is an integer. The matrix is subjected to conjugate transposition to obtain a channel matrix V of an nth frequency domain unit ⁽ⁿ⁾ . The relationship between the channel matrix and the space-frequency matrix will be described in detail hereinafter, and a detailed description of the relationship will be omitted here.

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 unit. The precoding matrix corresponding to a certain frequency domain unit may be configured by, for example, column vectors corresponding to the same frequency domain unit in the space-frequency matrix corresponding to each transmission layer. If the n-th column vector in the space-frequency matrix corresponding to each transmission layer is extracted, a matrix with dimension of T multiplied by Z can be obtained by arranging the n-th column vectors from left to right according to the sequence of the transmission layers, Z represents the number of transmission layers, and Z is more than or equal to 1 and is an integer. The matrix can be used as a precoding matrix W of an nth frequency domain unit ⁽ⁿ⁾ 。

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

The relation between the space frequency matrix and the downlink channel matrix and the pre-coding matrix is simply described.

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

In FDD mode, due to the reciprocity of the uplink and downlink channels of time delay and angle, the space-frequency matrix H is obtained by measuring the uplink channel _UL Can be expressed as H _UL ＝SC _UL F ^H Space-frequency matrix H obtained by downlink channel measurement _DL Can be expressed as H _DL ＝SC _DL F ^H . Therefore, in the embodiment of the present application, the coefficient matrix C corresponding to the feedback downlink channel is determined by downlink channel measurement _DL A precoding matrix may be determined that is compatible with the downlink channel.

As described previously, the space-frequency component matrix is defined as a (θ _k )×b(τ _l ) ^H Determining, thereby determining the space-frequency matrix H _DL The dimensions of (2) are: the number of transmit antenna ports x the number of frequency domain units. For example, the space-frequency matrix corresponding to the downlink channel has dimensions t×n. In the following embodiments, unless otherwise specified, the space-frequency matrices refer to the above-described moment of dimension T NArray H _DL 。

However, this is not necessarily a space-frequency matrix determined by the actual channel. In the usual case, the dimensions of the channel matrix are defined as: the number of receiving ports×the number of transmitting ports, for example, the dimension of the downlink channel is r×t. The space-frequency matrix determined by the channel matrix has dimension N x T and is equal to the space-frequency matrix H _DL Is the exact opposite of dimension T x N. Therefore, in the embodiment of the present application, the real channel may be formed by the above space-frequency matrix H _DL And (3) conjugate transposition of the determined channel matrix. In other words, by space-frequency matrix H _DL The determined downlink channel matrix may be a conjugate transpose of the real channel.

Further, by space-frequency matrix H _DL A precoding matrix may be determined. The precoding matrix of the nth frequency domain unit may be an nth column vector construction in a space-frequency matrix corresponding to each transmission layer.

Taking singular value decomposition (singular value decomposition, SVD) of the channel matrix as an example, the conjugate transpose of the precoding matrix can be obtained by performing SVD on the channel matrix V. If the channel matrix is subjected to conjugate transposition and then SVD, namely, V ^H And (3) performing SVD, and exactly obtaining the precoding matrix. Therefore, in the embodiment of the application, the space-frequency matrix H is determined by the conjugate transpose of the real channel _DL The precoding matrix corresponding to each frequency domain unit may be directly determined.

And then combine with the above formula H _UL ＝SC _UL F ^H To understand the relationship of the space-frequency matrix and the downlink channel matrix.

For H _DL ＝SC _DL F ^H The deformation can obtain S ^H H _DL ＝C _DL F ^H Further deformation can give (H) _DL ^H S) ^H ＝C _DL F ^H Thereby, coefficient matrix C can be obtained _DL ＝(H _DL ^H S) ^HF. wherein ,H_DL ^H Is a space-frequency matrix determined by the real channel; h _DL ^H S is the real channel after space domain pre-coding. C in the coefficient matrix _DL Can be respectively formed by (H) _DL ^H S) ^H Is multiplied by one of the columns in F. In other words, matrix coefficient C _DL The elements in (a) can be represented by a real channel H _DL ^H Conjugate transpose of S (H _DL ^H S) ^H Is multiplied by a column of F, or by the real channel H _DL ^H The conjugate transpose of one column of S is multiplied by one column of F.

Therefore, in the embodiment of the application, the space-frequency matrix H is determined based on the weighting coefficient of each angle delay pair fed back by the terminal equipment _DL May 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 real channel V (i.e., V ^H ) Obtained.

It should be appreciated that the real channel and space frequency matrix H _DL The relationship of (2) is not fixed. Different definitions of the space frequency matrix and the space frequency component matrix may cause the real channel to be identical to the space frequency matrix H _DL The relationship between them changes. For example, a space-frequency matrix H _DL May be obtained from the conjugate transpose of the real channel or from the transpose of the real channel.

When the definition of the space frequency matrix and the space frequency component matrix is different, the operation executed by the network device is also different when the time delay and the angle are loaded, and the operation executed by the terminal device when the channel measurement and the feedback are carried out correspondingly changes. But this is merely an implementation behavior of the terminal device and the network device and should not constitute any limitation of the application. The embodiment of the application only shows the case that the space-frequency matrix is obtained by conjugate transpose of the real channel for easy understanding. The application is not limited to definition of channel matrix, dimension of space frequency matrix, definition thereof and conversion relation between the two. Similarly, the application is not limited to the conversion relation between the space-frequency matrix and the precoding matrix.

10. Antenna delay pairs: may be a combination of a transmit antenna port and a delay vector. Each antenna delay pair may include a transmit antenna port and a 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 is not limited to 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 easy understanding, the following will briefly describe the main parameters involved in the present application:

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

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

r: the number of receiving ports, R is a positive integer;

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

n: the frequency domain unit number is used for bearing a reference signal, and N is a positive integer;

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

l: the time delay vector number, L is a positive integer;

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

second, in the embodiment of the present application, for convenience of description, when numbering is referred to, numbering may be continuously performed from 0. For example, the K angle vectors may include 0 th to K-1 th angle vectors, the L delay vectors may include 0 th to L-1 th delay vectors, etc., which are not listed here for brevity. Of course, the specific implementation is not limited thereto. For example, the serial numbers may be numbered from 1. For example, the K angle vectors may include 1 st to K th angle vectors, the L delay vectors may include 1 st to L th delay vectors, and the like.

It should be understood that the foregoing is provided for the purpose of illustrating the technical solutions provided by the embodiments of the present application, and is not intended to limit the scope of the present application.

Third, in the present application, multiple points are involved in the transformation of matrices and vectors. The same description is made here for ease of understanding. The superscript T denotes the transpose, e.g. A ^T Representing a transpose of matrix (or vector) a; superscript x denotes conjugate, e.g. A ^* Representing the conjugate of matrix (or vector) a; the upper corner mark H indicates the conjugate transpose, e.g. A ^H Representing the conjugate transpose of matrix (or vector) a. Hereinafter, for the sake of brevity, description of the same or similar cases will be omitted.

Fourth, in the embodiments shown below, the embodiments provided by the present application are described by taking the angle vector and the delay vector as column vectors as examples, but this should not be construed as limiting the present application in any way. Other and further possible manifestations will occur to those skilled in the art based on the same concepts.

Fifth, in the present application, "for indicating" may include both for direct indication and for indirect indication. When describing that certain indication information is used for indicating A, the indication information may be included to directly indicate A or indirectly indicate A, and does not represent that the indication information is necessarily carried with A.

The information indicated by the indication information is referred to as information to be indicated, and in a specific implementation process, there are various ways of indicating the information to be indicated, for example, but not limited to, the information to be indicated may be directly 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 indicated indirectly by indicating other information, wherein the other information and the information to be indicated have an association relation. It is also possible to indicate only a part of the information to be indicated, while other parts of the information to be indicated are known or agreed in advance. For example, the indication of the specific information may also be achieved by means of a pre-agreed (e.g., protocol-specified) arrangement sequence of the respective information, thereby reducing the indication overhead to some extent. And meanwhile, the universal part of each information can be identified and indicated uniformly, so that the indication cost caused by independently indicating the same information is reduced. For example, it will be appreciated 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 portion in terms of composition or other properties.

The specific indication means may be any of various existing indication means, such as, but not limited to, the above indication means, various combinations thereof, and the like. Specific details of various indications may be referred to the prior art and are not described herein. As can be seen from the above, for example, when multiple pieces of information of the same type need to be indicated, different manners of indication of different pieces of information may occur. In a specific implementation process, a required indication mode can be selected according to specific needs, and the selected indication mode is not limited in the embodiment of the present application, so that the indication mode according to the embodiment of the present application is understood to cover various methods that can enable a party to be indicated to learn information to be indicated.

In addition, there may be other equivalent forms of information to be indicated, for example, a row vector may be represented as a column vector, a matrix may be represented by a transposed matrix of the matrix, a matrix may also be represented as a vector or an array, the vector or array may be formed by interconnecting respective row vectors or column vectors of the matrix, and so on. The technical solutions provided by the embodiments of the present application should be understood to cover various forms. For example, some or all of the features described in the embodiments of the present application are to be understood to encompass various manifestations of such features.

The information to be indicated can be sent together as a whole or can be divided into a plurality of pieces of sub-information to be sent separately, and the sending periods and/or sending occasions of the sub-information can be the same or different. Specific transmission method the present application is not limited. The transmission period and/or the transmission 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 transmitting configuration information to the receiving end device. The configuration information may include, for example, but not limited to, one or a combination of at least two of radio resource control signaling, medium access control (media access control, MAC) layer signaling, and physical layer signaling. Wherein radio resource control signaling such as packet radio resource control (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 (downlink control information, DCI).

Sixth, the definitions of the present application listed for many characteristics (e.g., kronecker product, channel state information (channel state information, CSI), RBs, angles, and delays, etc.) are merely used to explain the function of the characteristics by way of example, and reference is made to the prior art for details.

Seventh, the first, second and various numerical numbers in the embodiments shown below are merely for convenience of description and are not intended to limit the scope of the embodiments of the present application. For example, different indication information is distinguished, etc.

Eighth, "predefined" or "preconfiguration" may be implemented by pre-storing corresponding codes, tables, or other manners in which related information may be indicated in devices (e.g., including terminal devices and network devices), and the present application is not limited to a specific implementation thereof. Where "save" may refer to saving in one or more memories. The one or more memories may be provided separately or may be integrated in an encoder or decoder, processor, or communication device. The one or more memories may also be provided separately as part of a decoder, processor, or communication device. The type of memory may be any form of storage medium, and the application is not limited in this regard.

Ninth, the "protocol" referred to in the embodiments of the present application may refer to a standard protocol in the field of communications, and may include, for example, an LTE protocol, an NR protocol, and related protocols applied in a future communication system, which is not limited in the present application.

Tenth, "at least one" means one or more, and "plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a alone, a and B together, and B alone, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). 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 can be single or multiple respectively.

Eleventh, in the embodiment of the present application, descriptions such as "when..times", "in the case of..times", "if" and "if" each refer to that a device (e.g., a terminal device or a network device) will make a corresponding process under some objective condition, are not limited in time, nor do the devices (e.g., terminal devices or network devices) require an action of determining when implemented, nor are other limitations meant to exist.

Twelfth, in the embodiment of the present application, a transmitting port and a receiving port are mentioned at plural points. To avoid ambiguity, the following is made: the transmit port may refer to a port that transmits a reference signal (e.g., a precoded reference signal, etc.). The receiving port may refer to a port that receives a reference signal (e.g., a precoded reference signal, etc.). In the embodiment of the application, the transmitting port may be a port of the network device end, and the receiving port may be a port of the terminal device end.

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

It should be understood that the following details of the method provided by the embodiment of the present application are given only for easy understanding and explanation, taking the interaction between the terminal device and the network device as an example. This should not be construed as limiting the subject matter of the implementation of the method provided by the present application. 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 with components (such as chips or chip systems) or the like configured in the network devices.

The embodiments shown below are not particularly limited to the specific structure of the execution body of the method provided by the embodiment of the present application, as long as communication can be performed in the method provided according to the embodiment of the present application by running a program recorded with the code of the method provided by the embodiment of the present application, and for example, the execution body of the method provided by the embodiment of the present application may be a terminal device or a network device, or a functional module in the terminal device or the network device that can call a program and execute the program.

For ease of understanding, a brief description of several embodiments is presented 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 on a plurality of frequency-domain units corresponding to the same transmit port. I.e. the channel change in the frequency domain is converted to the time domain to obtain a strongest value. And the terminal equipment feeds back the strongest obtained by the time domain transformation to the network equipment. The value fed back by the terminal device to the network device is the weighting coefficient corresponding to the same transmitting port. The above-described channel measurement method based on the time domain transform is described in detail below in connection with the embodiments described in fig. 3 and 4.

The application further 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 pre-encoded reference signal of each transmitting port, and perform frequency domain filtering on the channel information obtained by the estimation. The terminal device may filter channel information on frequency domain units in the same frequency domain unit group in units of the frequency domain unit group. When the precoding reference signal of the same transmitting port is carried by the frequency domain units in the multiple frequency domain unit groups, the terminal device may accumulate the results of the channel information on the frequency domain units in the multiple frequency domain unit groups after filtering. The terminal device may feed back the accumulated result to the network device. The value fed back by the terminal device to the network device is the weighting coefficient corresponding to the same transmitting port. The above-described channel measurement method based on the frequency domain filtering is described in detail below in connection with the embodiments described in fig. 5 and 6.

In the following embodiments, the network device may precode the reference signal based on the delay vector and the angle vector, or may precode the reference signal based on the delay vector or the angle vector, which is not limited by the present application.

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

For easy understanding, the process of channel measurement and feedback by the terminal device will be described in detail below by taking a precoding reference signal transmitted by a transmitting antenna with one polarization direction as an example. The transmitting antenna with one polarization direction may be any one of the J transmitting antennas with polarization directions configured by the network device. The application is not limited to the number J of polarization directions of the transmitting antennas configured by the network device.

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

In this embodiment, the network device may precode the reference signal based on K angle vectors and L delay vectors. The combination of various angle vectors and delay vectors can be obtained from the K angle vectors and the L delay vectors. 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 a reference signal to obtain a precoded reference signal corresponding to one port. Thus, the precoded reference signal obtained by the network device based on the K angle 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 angle vectors and one of the L delay vectors. Alternatively, the pre-encoded reference signal for each port may be obtained by pre-encoding the reference signal based on a combination of an angle vector and a delay vector.

In one possible implementation, the network device may combine each of the K angle vectors and each of the L delay vectors two by two to obtain k×l combinations of the angle vectors and the delay vectors, or k×l angle delay pairs. 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 performs precoding on the reference signal based on the kth (K is more than or equal to 1 and less than or equal to K, K is an integer) angle vector in the K angle vectors, each delay vector in the L delay vectors can be traversed to perform precoding on the reference signal; or, when the network device performs precoding on the reference signal based on the first (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, each angle vector in the K angle vectors can be traversed to perform precoding on the reference signal. In other words, the K angle vectors may be considered common to each of the delay vectors, and the L delay vectors may also be considered common to each of the angle vectors. Alternatively, the K angle vectors and the L delay vectors are common to each other.

In another possible implementation, 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 _k Integer) each of the delay vectors precodes the reference signal. L in the L delay vectors can satisfy:in such an implementation, the delay vectors corresponding to the at least two angle vectors are different.

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

The time delay vectors corresponding to the two angle vectors are different, which may mean that the time delay vectors corresponding to the two angle vectors are completely different, that is, the time delay vectors corresponding to the two angle vectors are not repeated, or in other words, there is no intersection. 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(τ₃ ). The time delay vectors corresponding to the two angle vectors are different, which may also mean that the time delay vectors corresponding to the two angle vectors are partially different, that is, the time delay vectors corresponding to the two angle vectors are partially repeated but not completely identical, or that the time delay vectors corresponding to the two angle vectors are intersected but not completely identical. For example, a (θ ₁ ) The corresponding delay vector includes b (τ ₂) and b(τ₃ ) Angle vector a (θ ₂ ) The corresponding delay vector includes b (τ ₁) and b(τ₃ )。

When the delay vectors corresponding to any two angle vectors in the K angle vectors are not repeated,when there are partial repetitions in the delay vectors corresponding to two or more of the K angle vectors, the +_h is given to>Thus, the network device can obtain +.>A combination of an angle vector and a delay vector.

In yet another possible implementation, the network device is based on the first delay in the L delay vectorsWhen the vector pre-codes the reference signal, K corresponding to the first time delay vector can be traversed _l (1≤K _l ≤K，K _l Integer) precodes the reference signal for each of the plurality of angle vectors. K of the K angle vectors mentioned above may satisfy: In such an implementation, the angle vectors corresponding to the at least two delay vectors are different.

Here, the angle vectors corresponding to at least two delay vectors are different, which may mean that at least two delay vectors among the L delay vectors are different, 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 respective delay vectors are partially or completely different.

The angle vectors corresponding to the two delay vectors are different, which may mean that the angle vectors corresponding to the two delay vectors are completely different, that is, the angle vectors corresponding to the two delay vectors are not repeated, or, in other words, there is no intersection. For example, the delay vector b (τ ₁ ) The corresponding angle vector includes a (θ ₂ ) Time delay vector b (τ ₂ ) The corresponding angle vector includes a (θ 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 identical, or that the angle vectors corresponding to the two delay vectors are intersected but not identical. For example, the delay vector b (τ ₁ ) The corresponding angle vector includes a (θ ₂ ) Time delay vector b (τ ₂ ) The corresponding angle vector includes a (θ ₁) and a(θ₂ ). When the angle vectors corresponding to any two of the L delay vectors are not repeated with each other,when the angle vectors corresponding to two or more than two delay vectors in the L delay vectors are partially repeated, the L delay vectors are ++>Thus, the network device can obtain +.>A combination of an angle vector and a delay vector.

It should be understood that the foregoing is merely for convenience of understanding, and the correspondence between the angle vectors and the delay vectors is enumerated, but should not be construed to limit the present application in any way. The application does not limit the corresponding relation between the angle vector and the time delay vector.

It will be appreciated that if the network device precodes the reference signal based on K angle vectors and L delay vectors, the number of ports of the precoded reference signal transmitted may be the number of combinations determined by the K angle vectors and the L delay vectors. That is, the number P of transmit ports may be determined by the number of combinations determined by K angle vectors and L delay vectors. In several different implementations described above, the value of P is different, e.g., p=k×l, or, or ,/>

Since the angle and delay have uplink and downlink channel reciprocity, the K angle vectors and the L delay vectors may be determined based on uplink channel measurements.

Specifically, the network device may determine K angles and L delays according to the 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 a number of 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 together for the L delay vectors, or may be determined separately for each of the L delay vectors. The application is not limited in this regard. Optionally, each angle vector in the set of angle vectors is taken from the DFT matrix. The K angle vectors may be determined, for example, by DFT of the uplink channel matrix. Optionally, each angle vector in the set of angle 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 K angle vectors together or may be determined for each of the K angle vectors separately. The application is not limited in this regard. 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 of 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 using, for example, a joint angle and delay estimation (joint angle and delay estimation, jace) algorithm in the prior art. Specifically, the estimation algorithm may be, for example, a multiple signal classification algorithm (multiple signal classification algorithm, MUSIC), a Bartlett algorithm, or a rotation invariant subspace algorithm (estimation of signal parameters via rotation invariant technique algorithm, ESPRIT), or the like. The network device may also determine K angle vectors and L delay vectors by performing a DFT on a space-frequency matrix determined based on uplink channel measurements. The specific method for determining the K angle vectors and the L delay vectors by the network equipment is not limited.

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

The network device can determine the uplink channel through channel estimation, and then determine the space-frequency matrix H of the uplink channel _UL . The network device can estimate the uplink channel to obtain the space-frequency matrix H _UL Performing DFT conversion of space domain and frequency domain to obtain coefficient matrix C _UL The following are provided: c (C) _UL ＝U _s ^H H _UL U _f . For ease of understanding, the space-frequency matrix H of the uplink channel will be described herein _UL Dimension H of the space-frequency matrix of the downlink channel and the dimension of (i) the space-frequency matrix of the downlink channel _DL And keep the same. The dimensions of the space-frequency matrix of the downlink channel and the relation to the downlink channel, the space-frequency matrix H determined by the uplink channel, have been described above _UL The dimension of (c) may be nxt.

It should be appreciated that the space-frequency matrix H of the uplink channel shown here _UL Is used for determining the coefficient matrix C _UL The calculation formula of (c) is merely an example, and should not be construed as limiting the present application in any way. For space-frequency matrix H _UL Defining different dimensions for determining the coefficient matrix C _UL The calculation formula of (2) is also different.

From which the network device can derive the coefficient matrix C _UL The stronger K rows are determined. The stronger K rows may be used to determine K angle vectors. For example, if p=k×l, the network device may be based on the coefficient matrix C _UL The size of the sum of squares of the modes of the elements of each row determines K rows with larger sum of squares of the modes. The K rows with the larger sum of squares of the modulus can be used to determine K angle vectors. The K line-in-line coefficient matrixes C _UL Can be used to determine the positions of the K angle vectors in the set of angle vectors described above. For example, the K rows are in coefficient matrix C _UL The row number in (c) may be the column number of K angle vectors in the set of angle vectors. From this, K angle vectors can be determined. The K angular vectors, i.e., the angular directions selected for precoding the downlink reference signal in the set of angular vectorsAmount of the components.

From which the network device can derive the coefficient matrix C _UL The stronger L columns are determined. Each of the stronger L columns may be used to determine L delay vectors. For example, the network device may be based on coefficient matrix C _UL The size of the sum of squares of the modes of the elements of each column determines the L columns for which the sum of squares of the modes is larger. The larger sum of squares of the modulus can be used to determine the L delay vectors. The L are listed in coefficient matrix C _UL The positions of the L delay vectors in the set of delay vectors can be used. For example, the L columns are arranged in coefficient matrix C _UL The column numbers in (a) may be the column numbers of the L delay vectors in the set of delay vectors. From this, L delay vectors can be determined. The L delay vectors are delay vectors selected from the set of delay vectors to be used for precoding the downlink reference signal.

The network device can also be based on coefficient matrix C _UL Each of the K stronger rows determines one or more stronger delay vectors. For example, ifFor the kth row of the K rows, the network device may determine one or more elements of the pattern having a square greater than a preset value, e.g., L, from the square of the pattern of elements _k And each. The preset value may be, for example, a predefined value. For example, it may be 80% of the sum of squares of the modes of the column of elements. L of the modulus squared being greater than a preset value _k The individual elements may be used to determine L _k And a delay vector. For example, the square of the modulus is greater than L of a preset value _k The individual elements are in coefficient matrix C _UL The column in which (a) is located can be used to determine L _k The positions of the delay vectors in the predefined set of delay vectors. For example, the L _k The individual elements are in coefficient matrix C _UL The column number in (b) may be L _k Column numbers of individual delay vectors in the set of delay vectors. For K angle vectors, the total number of delay vectors may be L. The L delay vectors are selected from the set of delay vectors.

The network device can also be based on coefficient matrix C _UL Middle strongerEach of the L columns of (a) determines one or more angle vectors that are stronger. For example, if For the first of the L rows, the network device may determine one or more elements of the pattern having a square greater than a preset value, e.g., K, from the square of the pattern of the elements _l And each. 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 repeated herein for brevity.

It should be appreciated that the foregoing is merely for ease of understanding, and that several possible methods for the network device to determine K angle vectors and L delay vectors are listed. But this should not be construed as limiting the application in any way. The application is not limited to the specific implementation manner of determining the K angle vectors and the L delay vectors by the network device.

In addition, the uplink channel matrix may be estimated by the network device according to a pre-received uplink reference signal, such as SRS, or may be obtained according to a data signal after being correctly decoded, which is not limited in the present 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 for brevity, a detailed description of the specific method is omitted here. Under the FDD mode, the angles and the time delays of the uplink and downlink channels can be reciprocal, so that K angle vectors and L time delay vectors obtained by uplink channel measurement can be loaded to the downlink reference signals, and the terminal equipment can conveniently measure the downlink channels based on the received precoding reference signals. Of course, K angle vectors obtained by uplink channel measurement may be loaded to the downlink reference signal, or L delay vectors obtained by uplink channel measurement may be loaded to the downlink reference signal. The present embodiment mainly describes in detail the case of loading K angle vectors and L delay vectors into the downlink reference signal.

It should be appreciated 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 predefined, for example, as defined by a protocol; alternatively, it may be determined by the network device based on one or more previous downlink channel measurement statistics. The application is not limited in the way of obtaining K angle vectors and L delay vectors.

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

The precoding reference signal obtained by the network device precoding the downlink reference signal based on the K angle vectors and the L delay vectors can be transmitted through a preconfigured reference signal resource. 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 units. When the N frequency domain units are used for carrying the precoding reference signals of the P transmission ports, different transmission ports can be distinguished by, for example, frequency division multiplexing (frequency division duplexing, FDD), time division multiplexing (time division duplexing, TDD), code division multiplexing (code division duplexing, CDD), and the like. The application is not limited in this regard.

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

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

In the embodiment of the present application, the terminal device may feed back P sets of weighting coefficients corresponding to P transmit ports based on the receive ports. Each set of weighting coefficients corresponding to the P transmit ports indicated by the first indication information 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.

Alternatively, R' =1. That is, each set of weighting coefficients includes one weighting coefficient. The weighting coefficient may be obtained by weighting channel information obtained by performing channel estimation based on precoding reference signals received on the R receiving ports after time domain transformation, or obtained by performing time domain transformation after weighting; or channel information obtained by performing channel estimation based on a pre-coding reference signal received on one of the R receiving ports is obtained after time domain transformation; channel information obtained by channel estimation based on a precoded reference signal received on one of the receiving ports (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 based on a pre-encoded reference signal received on one receiving port.

Alternatively, R' < R. That is, each set of weighting coefficients includes fewer than R weighting coefficients. For example, the number of receiving ports is plural (i.e., R > 1), and one or more of the R' weighting coefficients may be obtained by time-domain transforming and weighting channel information obtained by channel estimation based on the pre-encoded reference signal received on a part of the receiving ports, or by time-domain transforming after weighting.

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. The weighting coefficients corresponding to the Z transmission layers may be determined based on the result obtained by performing time domain transformation on channel information obtained by performing channel estimation based on the precoding reference signal received by each receiving port. The specific procedure of how to determine the P-group weighting coefficients based on the transport layer will be described in detail later, and will be omitted here for brevity.

For any one of the P transmitting ports, such as 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 executing the following procedure.

The following steps i and ii are repeatedly performed to determine the weighting coefficients corresponding to the p-th transmitting port and the R-th receiving port, by taking the R traversal value in the range of 0 to R-1:

step 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;

ii, performing time domain transformation on the channel information respectively corresponding to the N frequency domain units determined in the step i, and obtaining the nth value in the N values through the time domain transformation _p，r The value is determined as a weighting coefficient corresponding to the p-th transmit port and the r-th receive port.

And (3) taking the value of P traversal in the range of 0 to P-1, and repeatedly executing the above flow to obtain P groups of weighting coefficients corresponding to the P transmitting ports.

The process of determining the P sets of weighting coefficients corresponding to the P transmit ports when the terminal device feeds back the weighting coefficients based on the receive ports will be described in detail.

For ease of understanding, it is first assumed that r=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., one 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 ports that the terminal device can recognize are ports corresponding to the precoded reference signals, the terminal device can perform channel estimation based on the received precoded reference signals for each transmission port.

If precoding of the reference signal is not considered, the dimension of the downlink channel estimated by the terminal device based on the received precoded reference signal may be nxt for each receiving port. The dimension of the downlink channel received on each RB may be 1×t. Since the network device performs precoding on the reference signal based on the angle vector and the delay vector, the dimension of each angle vector may be tx 1, and after the angle vector and the delay vector perform precoding on the reference signal, the dimension of the downlink channel received by the terminal device on each receiving port and each RB may be tx 1. The downlink channel with dimension of 1×1 is channel information obtained by performing channel estimation on one RB based on the precoded reference signal. Alternatively, the channel information may specifically be a channel estimation value obtained by performing channel estimation based on the received pre-encoded reference signal. It will be appreciated that the channel estimate may in particular be equivalent channel information, i.e. channel information loaded with precoding.

Since the network device precodes the reference signals based on K angle vectors and L delay vectors, the precoded reference signals carried by each RB may correspond to one or more transmit ports, e.g., P transmit ports as described above. The P transmit ports may have a one-to-one correspondence with P angular delay pairs. The precoding reference signal corresponding to the P-th transmitting port in the P transmitting ports may be obtained by precoding the reference signal based on the K-th angle vector in the K angle vectors and the L-th delay vector in the L delay vectors, for example. That is, the p-th transmit port corresponds to the kth angle vector and the l-th delay vector. In other words, the pre-encoded reference signal corresponding to the p-th transmit 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, the weighting coefficient of the p-th angle delay pair. Thus, the weighting coefficients described above for the p-th transmit port are those of the p-th angular delay pair.

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

For the precoding reference signal of the p-th transmitting port, the terminal device may determine a weighting coefficient of the p-th angle delay pair based on a channel estimation value obtained by performing channel estimation on the precoding reference signal received on N RBs at one receiving port. The weighting coefficients for the p-th angular delay pair may be determined by the N channel estimates over the N RBs.

Assume that a channel estimation value obtained by the terminal device performing channel estimation based on a precoding reference signal of a p-th transmitting port received on an n-th RB is recorded asThe channel estimation value obtained by the terminal device performing channel estimation based on the pre-encoded reference signal of the p-th transmitting port can be recorded as: />There are N total channel estimates. It can be seen that the N channel estimates correspond to N RBs, i.e., 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 performing channel estimation based on the precoding reference signal of the p-th transmitting port, the N channel estimation values are channel estimation values corresponding to the p-th angle delay pair.

As previously described, the space-frequency matrix H _DL Satisfy H _DL ＝SC _DL F ^H . In the embodiment of the application, H _DL The dimension of (2) may be t×n; the number of the angle vectors can be K, the length of each angle vector can be T, and the dimension of S can be T multiplied by K; each delay vector may be L, and the length of each delay vector may be N, and the dimension of F may be nxl. The above variants can be obtained: s is S ^H H _DL ＝C _DL F ^H Further, it is possible to obtain (H _DL ^H S) ^H ＝C _DL F ^H . Couple (H) _DL ^H S) ^H ＝C _DL F ^H Further deformation can obtain coefficient matrix C _DL ＝(H _DL ^H S) ^H F。

When the network device performs spatial pre-coding on the reference signal based on K angle vectors, namely, multiplying the real channel by S to obtain H _DL ^H S。H _DL ^H S is the real channel after space domain pre-coding. In the embodiment of the present application, the dimension may be nxk. When the network device performs frequency domain precoding on the reference signal after space domain precoding based on the L delay vectors, the reference signal can be coded by (H _DL ^H S) ^H F. In the embodiment of the present application, the dimension may be kxl.

C in the coefficient matrix _DL Can be respectively formed by (H) _DL ^H S) ^H Is multiplied by one of the columns in F. In other words, matrix coefficient C _DL The elements in (a) can be represented by a real channel H _DL ^H The conjugate transposed of S is multiplied by one column of F.

E.g. coefficient matrix C _DL The element of the first row and the kth column in (b) is (H) _DL ^H S) ^H The first row of (c) and the kth column of F). Coefficient matrix C _DL The element of the kth column of the first row is the weighting factor corresponding to the kth angle vector and the kth delay vector.

As can be seen from the matrix multiplication operation, (H) _DL ^H S) ^H The number of elements included in each row vector is the same as the number of elements included in each column vector in F. In the present embodiment, (H) _DL ^H S) ^H The number of elements included in each row vector and the number of elements included in each column vector in F may be N. When the row vector is multiplied by the column vector, the elements in the row vector (such as the nth element, N being traversed to take values from 1 to N) are multiplied by the corresponding elements in the column vector (such as the nth element, N being traversed to take values from 1 to N) respectively and then summed to obtain (H) _DL ^H S) ^H The N elements in each row of the array correspond to N frequency domain units (e.g., RBs, subbands, etc.). However, the network device cannot know the correlation of the downlink channel between the frequency domain units (e.g., RBs) in advance, and thus cannot complete (H _DL ^H S) ^H F (F)The operation is performed by loading only the elements in each delay vector onto each RB of the downlink channel.

For ease of understanding, it is assumed here that K angle vectors and L delay vectors are loaded on each of N RBs. Will be described above as C _DL ＝(H _DL ^H S) ^H Further deformation of F can result in: c (C) _DL ＝(F ^H H _DL ^H S) ^H ＝(F ^H H _DL ′S) ^H. wherein ,H_DL ' represents a space-frequency matrix determined by a real downlink channel, H due to the real channel dimension of RxT _DL The dimension of' is NxT. The H is _DL ' may include N row vectors of dimension 1×T, e.g., including h ₀ ，h ₁ To h _N-1 Corresponding to the 0 th to N-1 th RBs among the N RBs, respectively.

It can be understood that the space-frequency matrix H defined in the embodiment of the present application _DL And the space-frequency matrix H determined by the real channel above _DL ' satisfy H between _DL ′＝H _DL ^H . This is due to the space-frequency matrix H defined in the present application _DL Is determined by the conjugate transpose of the real channel.

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

wherein ,b(τ₀ ) To b (tau) _L-1 ) Can represent L delay vectors in F; b (τ) ₀ ) _n Can be represented as b (τ) ₀ ) The nth element, b (τ _L-1 ) _n Can be represented as b (τ) _L-1 ) N-th element of the N elements of (a) n=0, 1,..the term "N-1; s may represent a matrix of dimension T x K constructed from K angle vectors. Thus, b (τ) _l ) _n ^H h _n S (n=0, 1,) N-1;l =0, 1,) can be vitaminA row vector with a degree of 1 xk.

That is, a matrixThe n-th row of (a) may represent a channel estimation value obtained by performing channel estimation based on the precoding reference signals of the plurality of ports received on the n-th RB. Matrix arrayMay include k×l elements, which may correspond to k×l ports, or k×l angular delay pairs, respectively.

Since the precoding reference signal received by the terminal equipment experiences the downlink channel, the correlation of the downlink channel among the RBs can be known, and the summation operation can be completed. I.e. matrixThe elements of each column of the array are summed separately. That is, will->The sum of elements corresponding to the same time delay vector and the same angle vector can be obtained: (b (τ) ₀ ) ^H H _DL ′S…b(τ _L-1 ) ^H H _DL ′S) ^H . For each delay vector and each angle vector, or for each transmit port, the above operation can be understood as summing the channel estimates over N RBs.

wherein ,b(τ_l ) ^H H _DL ' S (l=1, 2.,. The term "L") may be a row vector having a dimension of 1×k, corresponding to the first 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 ) ^H H _DL The kth element in' S may correspond to the estimated value of the downlink channel obtained by channel estimation based on the p-th port pre-encoded reference signal as described above

Will (b (τ) ₁ ) ^H H _DL ′S…b(τ _L ) ^H H _DL ′S) ^H After rearrangement, coefficient matrix C with dimension of KxL can be obtained _DL ，The coefficient matrix C _DL The element of the kth row and the kth column corresponds to the kth angle vector and the kth delay vector, i.e., corresponds to the weighting coefficient of the angle delay pair consisting of the kth angle vector and the kth delay vector.

Therefore, the terminal device may determine the weighting coefficient corresponding to each angle delay pair obtained by combining each angle vector and delay vector by summing the channel estimation values of the 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 p-th angle delay pair may be obtained by cumulatively summing N channel estimation values corresponding to the p-th angle delay pair. However, when the network device performs precoding on the reference signal based on the delay vector, N different elements in the delay vector are respectively loaded on N RBs corresponding to the same transmitting port. The channel estimate estimated by the terminal device on each RB may be discontinuous. If the N channel estimation values are directly accumulated and summed to be used as the weight coefficient feedback of the p-th angle delay pair, the recovered downlink channel may also have a larger difference from the real channel, so that the determined precoding matrix for downlink transmission cannot be well matched with the real channel, and thus the transmission performance of the system is affected.

In the embodiment of the application, the terminal equipment can convert the frequency domain channel into the time domain by performing time domain transformation on the N channel estimation values, and the weighting coefficient of the p-th angle delay pair is represented by the value obtained by the time domain transformation.

In one implementation, the terminal device may time-domain transform the vector constructed of the N channel estimates. N values (hereinafter referred to as time domain transformed values for convenience of description) can be obtained by time domain transformation. The terminal device may convert one of the N time domain transformed values (e.g. the nth _p A value) is fed back as a weighting coefficient corresponding to the p-th angular delay pair.

One of the N time domain transformed values may be fed back as a weighting coefficient corresponding to the angular delay pair because if the N channel estimated values are time domain transformed, if IFFT is performed, the direct current component of the N time domain transformed values (i.e., the 0 th value of the N time domain transformed values) is exactly equal to the sum of the N channel estimated values accumulated based on the precoding reference signal estimation received on the N frequency domain units, if there is no delay deviation in the uplink and downlink. 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 accumulated may be understood as the sum of the frequency domain accumulated for the N frequency domain units.

For example, if based on the delay vector b (τ ₁) and b(τ₂ ) The reference signal is precoded and the terminal device performs a precoding operation on the reference signal for one of the ports (e.g., with b (τ) ₁ ) Corresponding port) may be expressed as: wherein h_n The channel estimation value of the nth frequency domain unit is represented, and the value of l is 1 and 2.

Wherein each superposition term is respectively as follows: substitution into the above formula can result in: />

Since the bases are orthogonal, the multiplied is 0. Thus, in the above formula c=nα ₁ 。

From the above deductions, it can be seen that the 0 th value (i.e., direct current component) nα of the N time domain transformed values obtained by IFFT ₁ Exactly equal to the sum of the accumulated N channel estimates.

The specific procedure of the terminal device for determining the weighting coefficient of the p-th angle delay pair by performing time domain transformation on the N channel estimation values will be described in detail.

If the N channel estimation values are recorded as a vector, the vector may represent a channel vector estimated by the precoding reference signal of the p-th transmit port. The vector may be expressed, for example, as:or alternatively, the first and second heat exchangers may be,in this embodiment, for convenience of explanation, the channel vector formed by the N channel estimation values is denoted as +.>

Alternatively, the time domain transform comprises an IFFT or an IDFT. Taking IFFT as an example, the above and channel vectors The IFFT is performed to obtain N time domain transformed values. The terminal device may determine a value of the N time domain transformed values as a weighting coefficient corresponding to the p-th angle delay pair.

Assuming that the terminal device can convert the nth of the N delay conversion values _p The value is determined as a weighting coefficient corresponding to the p-th angular delay pair. E.g. obtained from IFFT andthe weight coefficient c corresponding to the p-th angle delay pair _p Can be expressed as:namely, the weighting coefficient c corresponding to the kth angle vector and the ith delay vector _k，l Can be expressed as:

above n _p The value of (c) may be predefined, such as predefined by a protocol, may be determined by the terminal device itself, or may be indicated by the network device, as the application is not limited in this respect. It will be appreciated that 0.ltoreq.n _p N-1 is less than or equal to N _p Is an integer.

Alternatively, n _p Is a predefined value. Illustratively n _p Is 0. In other words, the terminal device may use the 0 th value of the N time domain transformed values as the weighting coefficient corresponding to the p-th angle delay pair.

It should be understood that n _p A value of 0 is only one possible implementation and should not be taken as limiting the application in any way. For example, in the case where there is a deviation in the uplink and downlink timings, n _p Other values are possible, for example, they may be determined in advance from empirical values, or predefined protocols, etc. The application is not limited in this regard.

Alternatively, n _p Is determined by the terminal device. Optionally, the first indication information indicates n _p Is a value of (2).

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

Alternatively, n _p Determined for the network device. Optionally, before step 320, the method further includes: the terminal equipment receives fourth indication information, wherein the fourth indication information is used for indicating n _p Is a value of (2). Correspondingly, the network device transmits the fourth indication information.

It should be understood that the pairs n listed above _p Values of (2)Is merely exemplary and should not be construed as limiting the application in any way.

The specific process of the terminal device taking one value of the N time domain transformation values as the weighting coefficient of the p-th angle delay pair can be realized by filtering, for example. For example, the vector of the N time domain transform values is multiplied by a filter coefficient to obtain a weighting coefficient of the p-th angle delay pair. The filter coefficients may comprise N elements, which may be noted as vectors of dimension 1 x N, or vectors of dimension N x 1, for example. For convenience of distinction, a vector composed of N elements in the filter coefficient is referred to as a filter coefficient vector. The N elements included in the filter coefficients may include N-1 zero elements and 1 non-zero element, which may be the nth element of the N elements (or, alternatively, a filter coefficient vector of dimension 1×N or a filter coefficient vector of dimension N×1) _p The elements.

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, for example, it is referred to as a time domain transform vector.

The terminal device may multiply the time domain transform vector with dimension n×1 by a filter coefficient vector with dimension 1×n, or may multiply the time domain transform vector with dimension 1×n by a filter coefficient vector with dimension n×1 to the right, thereby obtaining a weighting coefficient corresponding to the p-th angle delay pair.

For example, the N time domain transform values may form a time domain transform vector having a dimension of nx1. Let n be the above _p The filter coefficient vector formed by the filter coefficients can be expressed as [1 0 … 0] _1×N . The N time domain transforms to filtering can be performed by multiplying the above-mentioned dimension nx1 time domain transform vector by a filter coefficient vector 1 0 … 0] _1×N To realize the method. Thus, the 0 th value of the N time domain transformed values can be obtained.

It should be understood that the filter coefficients listed herein are only one possible form and should not be construed as limiting the application in any way. Since specific processes of filtering can refer to the prior art, they are not illustrated here for brevity. It should also be understood that filtering is only one possible implementation and should not be construed as limiting the application in any way. The application is not limited to a specific implementation manner in which the terminal device selects a certain value from the N time domain transformed values.

It should also be understood that the above naming of the vectors is for ease of distinction and illustration only and should not be construed as limiting the application in any way.

The specific process of determining the weighting coefficient corresponding to the p-th transmitting port by the terminal device is described in detail above by taking r=1 as an example for easy understanding only. But this should not be construed as limiting the application in any way. The number of receiving ports R 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 received on each receive port, the p-th transmit port on each RB.

Assuming that the set of weighting coefficients corresponding to the p-th 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 r-th receiving port, the p-th transmitting port's precoding reference signal received on 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. So that R weighting coefficients corresponding to the p-th transmitting port and the R receiving ports can be obtained.

Illustratively, for the r-th receive port, the p-th transmit port, the terminal device may convert the nth of the N time domain transformed values to _p，r The value is determined as the r coefficient of the weighting coefficients corresponding to the r receiving port and the p transmitting port, namely the p angle delay pair.

Optionally, the method further comprises: performing time domain transformation on a vector determined by channel information between a p-th transmitting port and an r-th receiving port to obtain a transformed vector, wherein the n-th vector is a vector of the p-th transmitting port and the r-th receiving port _p，r The value is the r-th weighting coefficient from the p-th set of weighting coefficients.

As described above, the specific implementation of the terminal device using one of the N time domain transformed values as the weighting coefficient of the p-th angle 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 the R-th receiving port and the p-th transmitting port by a filter coefficient to obtain a weighting coefficient of the p-th angle delay pair, where the weighting coefficient may correspond to the R-th receiving port.

The filter coefficients may include N elements, and may be described as a vector having a dimension of 1×n, or a vector having a dimension of n×1, for example. Corresponding to the above, this vector may be 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 of 1×N or the filter coefficient vector with dimension of n×1) _p，r The elements.

After determining the filter coefficient vector, the terminal device may determine the weighting coefficients corresponding to the r-th receive port, p-th transmit port based on the same manner as described above. Taking the value of R through the range of 0 to R-1, the R weighting coefficients corresponding to the R receiving ports and the p transmitting port, i.e., the set of weighting coefficients corresponding to the p transmitting port, can be obtained.

It should be understood that filtering is only one possible implementation and should not be construed as limiting the application in any way. The application is not limited to a specific implementation manner in which the terminal device selects a certain value from the N time domain transformed values.

It will also be appreciated that for different values of r, n _p，r The values of (2) may be the same or different. The application is not limited in this regard. For example, in one implementation, for any value of r, n _p，r All 0. That is, the 0 th value of the N time domain transform values corresponding to the r-th receiving port and the p-th transmitting port is taken as the weighting coefficient corresponding to the r-th receiving port and the p-th transmitting port.

Regarding n _p，r Can be referred to above for n _p For the sake of brevity,and will not be repeated here.

In fact, the number of weighting coefficients corresponding to each transmit port is not necessarily the same as the number of receive ports. As previously described, R.gtoreq.1, the weighting coefficient corresponding to each transmit port may be R's, 1.ltoreq.R'.ltoreq.R. That is, when R > 1, the weighting coefficients corresponding to each transmit port may be R or less.

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 device performs channel estimation on the precoded reference signal received on only one of the receiving ports. The terminal device may estimate N channel estimation values based on the pre-encoded reference signal of each (e.g. the p-th) transmitting port received at the receiving port, where the N channel estimation values may be subjected to time domain transformation to obtain a weighting coefficient corresponding to the p-th transmitting port.

The protocol may predefine rules to facilitate the terminal device's decision to determine the reported weighting coefficients based on the pre-coded reference signals received on which receiving port. Alternatively, the protocol may define the terminal device in advance or the network device may signal in advance to the terminal device to determine the weighting coefficients based on the precoding reference signal received on which receiving port. Alternatively still, the terminal device may decide itself to determine the weighting coefficients based on which of the received pre-coded signals on the receiving ports. The application is not limited in this regard.

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

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

It should be understood that the foregoing is merely illustrative of the correspondence between some receiving ports and weighting coefficients, but these examples are merely illustrative of the application and should not be construed as limiting the application in any way. The application does not limit the corresponding relation between the receiving port and the weighting coefficient.

It should also be understood that the manner in which the receiving ports are weighted as described above is merely an example, and the present application is not limited to the weight 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 coefficients corresponding to each transmission port.

The first indication information may be used to indicate P sets of weighting coefficients corresponding to the P transmit ports, for example, to construct a matrix having a dimension of p×r'. For ease of distinction and explanation, the matrix constructed from the P sets of weighting coefficients is referred to as the coefficient matrix. Each row in the coefficient matrix may correspond to one transmit port. The number of weighting coefficients included in each row is the number of weighting coefficients corresponding to one transmit port. It can be understood that when R' =r, the weighting coefficient corresponding to each transmit port corresponds 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，r The weighting coefficients corresponding to the p-th transmit port (or p-th angular delay pair, corresponding to the kth angular vector and the ith delay vector), and the r-th receive port may be represented.

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

The terminal device may, for example, determine the weighting coefficient with the greatest magnitude from the P sets of weighting coefficients (for ease of distinction and explanation, for example, note the magnitude of the weighting coefficient as the greatest magnitude). The terminal device may divide the magnitudes of the rest of the weighting coefficients except the weighting coefficient by the maximum magnitude, respectively, to obtain ratios corresponding to the weighting coefficients. After normalizing the P groups of weighting coefficients, the terminal equipment normalizes the maximum amplitude to 1, and the rest weighting coefficients are respectively corresponding ratios. After normalization, the terminal device may generate the first indication information based on a quantized value or a non-quantized value of a result after each normalization.

It should be appreciated that the normalization process described above is processed over a range of P transmit ports, i.e., the normalization unit is P transmit ports. But this is only illustrated for ease of understanding. The normalization unit may be a transmitting port, that is, normalization is performed on each row in the coefficient matrix. The present application is not limited to the normalization unit.

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

As previously described, a network device may be configured with J polarization directions, J.gtoreq.1. The terminal device may perform channel estimation according to the method described above based on the pre-encoded reference signal of the transmitting port in each polarization direction, to obtain a 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 for the P transmit ports for each of the 2 polarization directions. A coefficient matrix having a dimension of 2p×r (assuming R' =r) can be constructed from weighting coefficients corresponding to 2P transmission 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 P transmit ports in the first polarization direction. The back P rows in the coefficient matrix correspond to P transmit ports in the second polarization direction. The weighting coefficients in the latter P rows are P sets of weighting coefficients corresponding to P transmit ports in the second polarization direction.

It should be understood that the foregoing is only for ease of understanding, and the weighting coefficients corresponding to the P transmit ports determined by the terminal device are shown in the form of a matrix. But this should not be construed as limiting the application in any way. The terminal device may not necessarily generate the coefficient matrix during 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 the multiple polarization directions, the terminal device may, for example, sequentially indicate in a predetermined order.

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

For another example, the terminal device may normalize the weighting coefficients corresponding to the transmitting ports in the two polarization directions, and generate the first indication information based on the normalization result. In this case, the normalization unit may be 2P transmit 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 weighting coefficients corresponding to the transmission ports in the respective polarization directions are indicated by the first indication information, the terminal device does not necessarily indicate that the first indication information includes an indication of all the weighting coefficients. The first indication information may be considered to indicate all weighting coefficients as long as the network device can determine all weighting coefficients from the first indication information.

For example, when the weighting coefficients corresponding to P transmission ports in one polarization direction are indicated by the first indication information, such as the p×r 'weighting coefficients described above, the terminal device 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 a position corresponding to the maximum amplitude (such as a corresponding transmitting port and receiving port or a row and column in a coefficient matrix) and a ratio of the amplitude of other weighting coefficients to the maximum amplitude. That is, as long as the network device can restore the p×r 'weighting coefficients based on the first instruction information, the first instruction information can be regarded as being for instructing the p×r' weighting coefficients.

In addition, since each transmitting port corresponds to an angle vector and a delay vector, or an angle delay pair, each weighting coefficient is a weighting coefficient corresponding to an angle delay pair. The network device may determine the angle delay pair corresponding to each weighting coefficient according to the corresponding relationship between each transmitting port and the angle vector and 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 CSI, or may be a part of cells in CSI, or may be other information. Illustratively, the first indication information is a precoding matrix indication (precoding matrix indicator, PMI). The application is not limited in this regard. The first indication information may be carried in one or more messages in the prior art and sent to the network device by the terminal device, or may be carried in one or more messages in the new design and sent to the network device by the terminal device. The terminal device may send the first indication information to the network device, for example, through a physical uplink resource, such as a physical uplink shared channel (physical uplink share channel, PUSCH) or a physical uplink control channel (physical uplink control channel, PUCCH), 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 for brevity, detailed description of the specific process is omitted here.

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

Optionally, the method further comprises: the terminal device transmits fifth instruction information for indicating the number of receiving ports R. Accordingly, the network device receives the fifth indication information.

The number of the weighting coefficients indicated by the first indication information is determined by indicating the number of the receiving ports to the network device so that the network device can determine the number of the weighting coefficients indicated by the first indication information according to the number of the receiving ports.

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 the present application.

It should be understood that the feedback of the P sets of weighting coefficients corresponding to the P transmit ports by the terminal device based on the receive ports is only one possible implementation. The application should not be construed as being limited in any way.

In another implementation, the terminal device may also feedback P sets of weighting coefficients corresponding to the P transmit ports based on the transport layer. In this implementation, among the P sets of weighting coefficients corresponding to the P transmission ports indicated by the first indication information, each set of weighting coefficients may include Z weighting coefficients corresponding to the Z transmission layers.

For ease of understanding, the process by which the terminal device determines the weighting coefficients based on the feedback of the transmission layer will be described herein by taking the weighting coefficients corresponding to the respective transmission ports in the two polarization directions as an example.

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

each weighting coefficient in the coefficient matrix is denoted by d to distinguish 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 second P rows may correspond to a second polarization direction. The Z columns correspond to the 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 transport layers. Wherein the weighting coefficients of the P-th row and the z-th column in the P-th row represent the weighting coefficients of the P-th transmitting port and the z-th transmission layer corresponding to the first polarization direction; the weighting coefficients of the P-th row and the z-th column in the P-th row represent weighting coefficients corresponding to the P-th transmission port and the z-th transmission layer in the second polarization direction.

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

The terminal device may generate the first indication information based on the P-group weighting coefficients corresponding to the P transmission ports in each polarization direction, so as to indicate the P-group weighting coefficients corresponding to the P transmission ports in each polarization direction by the first indication information. The specific method of the terminal device indicating the weighting coefficient based on the feedback of the transmission layer through the first indication information is similar to the specific method of indicating the P groups of weighting coefficients corresponding to the P transmitting ports based on the feedback of the receiving ports through the first indication information, for example, the weighting coefficients may be normalized. Since the specific process that the terminal device indicates the weighting coefficient based on the feedback of the receiving port through the first indication information has been described in detail above, the detailed description is omitted herein for brevity.

It should be understood that the above exemplary process of determining the weighting coefficients based on the feedback of the transmission layer by the terminal device is only an example and should not constitute any limitation to the present application. The specific method for determining the weighting coefficient based on the feedback of the transmission layer by the terminal equipment is not limited.

Optionally, the method further comprises: the terminal device sends sixth indication information, where the sixth indication information is used to indicate the transmission layer number Z. Correspondingly, the network device receives the sixth indication information.

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

In step 340, the network device determines a precoding matrix based on the first indication information.

As described above, the terminal device may feed back the P sets of weighting coefficients corresponding to the P transmit ports based on the receive ports, or may feed back the P sets of weighting coefficients corresponding to the P transmit ports based on the transport layer. The network device may determine the precoding matrix from the first indication information based on different feedback granularities.

The specific process of determining the precoding matrix by the network equipment according to the first indication information in the two cases is described in detail below.

If the terminal device feeds back the P groups of weighting coefficients corresponding to the 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 pairs 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 deviceThe weighting coefficients include R weighting coefficients corresponding to R receiving ports. Then, the P weighting coefficients corresponding to each receiving port may respectively correspond to the P angle delay pairs one to one. The network device may construct a space-frequency matrix corresponding to each receiving port based on the P weighting coefficients corresponding to each receiving port of the terminal device, and the angle vector and the delay vector included in each of the P angle delay pairs. For convenience of distinction and explanation, in the embodiment of the present application, the space-frequency matrix corresponding to the receiving port is denoted as H _DL，R 。Representing a space-frequency matrix corresponding to the R-th receive port, R may 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 angle 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 described above, the K-th angle vector a (θ _k ) And the first delay vector b (τ _l ) A space-frequency component matrix a (θ) can be constructed _k )×b(τ _l ) ^H . Space-frequency matrix corresponding to the r-th receiving portMay be a weighted sum of P space-frequency component matrices. I.e.)> And represents the weighting coefficient corresponding to the kth angle vector and the ith delay vector based on the feedback of the nth receiving port. The dimension of the space-frequency matrix may be t×n.

The space-frequency matrix shown aboveThe calculation formula of (1) assumes that K angle vectors and L delay vectors are mutually shared. When the delay vectors corresponding to the at least two angle vectors are different, the above equation may be modified as: />Alternatively, when the angle vectors corresponding to at least two delay vectors are different, the above formula may be modified to +.>

Hereinafter, for convenience of explanation, all of them will be described in detail For illustration. It can be understood that no matter 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, the method for determining the precoding matrix is not affected.

It should be noted that, for convenience of understanding, a 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. But 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 ,representing a weighting coefficient corresponding to the kth angle vector and the ith delay vector in the first polarization direction based on feedback of the (r) th receiving port; />And represents the weighting coefficients corresponding to the kth angle vector and the ith delay vector in the second polarization direction based on the feedback of the kth receiving port.

It will be appreciated that the space-frequency matrix defined above for 2 polarization directionsThe calculation formula of (c) 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 can determine the space-frequency matrix based on the P weighting coefficients corresponding to each receiving portTo->Thus, the network device can determine the downlink channel matrix corresponding to each frequency domain element.

RB is an example of the frequency domain unit. For an nth RB of the N RBs, the network device may determine a conjugate transpose (V ⁽ⁿ⁾ ) ^H . Wherein the matrix (V ⁽ⁿ⁾ ) ^H Can be R space-frequency matrixes respectively determined by the R receiving portsTo->An nth column vector in each of the space-frequency matrices. For example, will->Is used as a matrix (V ⁽ⁿ⁾ ) ^H Column 0 of (2), will->Is used as a matrix (V ⁽ⁿ⁾ ) ^H Column 1 of (2); similarly, +.>Is used as a matrix (V ⁽ⁿ⁾ ) ^H R-1 column of (C). Thus, a matrix (V) ⁽ⁿ⁾ ) ^H Further, a downlink channel matrix V corresponding to the nth RB can be determined ⁽ⁿ⁾ 。

The downlink channel matrix corresponding to each RB can be determined based on the above method.

The network device may further determine a precoding matrix for each RB based on the downlink channel matrix for 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 determine the precoding matrix by performing eigenvalue decomposition (eigenvalue decomposition, EVD) on the covariance matrix of the downlink channel matrix.

It should be understood that, for a specific manner of determining the precoding matrix by the network device according to the channel matrix, reference may be made to the prior art, and the determining manner of the precoding matrix is not limited in the present application.

It should also be understood that the foregoing description illustrates a specific process in which the network device determines the downlink channel matrix, and thus the precoding matrix, based on the space-frequency matrix, for ease of understanding only. But this should not be construed as limiting the application in any way. The network device may also directly determine the precoding matrix from the space-frequency matrix.

It should be noted that the foregoing only shows the case where the terminal device corresponds to one receiving port based on each weighting coefficient in the P sets of weighting coefficients for the sake of understanding. As described above, when the terminal device feeds back the weighting coefficients based on the receiving ports, the number of weighting coefficients in each group is not necessarily equal to the number of receiving ports. For example, the number of receiving ports is greater than 1, but the terminal device performs channel estimation and feedback based on only the precoding reference signal received on one of the receiving ports. Each set of weighting coefficients may include 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, the number of the receiving ports is greater than 1, and the terminal device performs time domain transformation and feedback after weighting the channel estimation values of the plurality of receiving ports. Each set of weighting coefficients includes a number of weighting coefficients less than the number of receiving ports. In this case, the network device may determine the precoding matrix according to the method described above by using the weighting coefficients fed back by the plurality of receiving ports as the weighting coefficients of the plurality of receiving ports. The specific mode of the network equipment for determining the precoding matrix based on the received weighting coefficients is not limited.

If the terminal device feeds back P sets of weighting coefficients corresponding to the P transmitting 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 a space-frequency matrix corresponding to the transmission layer based on the weighting coefficient corresponding to each transmission layer and the angle delay pair corresponding to each weighting coefficient, thereby determining a precoding matrix of each frequency domain unit.

Specifically, since the P weighting coefficients corresponding to each transport layer may correspond to the P angle delay pairs one to one, respectively. The network device may construct a space-frequency matrix corresponding to each transport layer based on the P weighting coefficients corresponding to each transport layer, and the angle vector and the delay vector included in each of the P angle delay pairs. For convenience of distinction and explanation, in the embodiment of the present application, the space-frequency matrix corresponding to the receiving port is denoted as H _DL，Z 。Representing a space-frequency matrix corresponding to the Z-th transport layer, Z may take any integer value from 0 to Z-1.

In this embodiment, the space-frequency matrix corresponding to the z-th transmission layerCan be determined by P angular delay pairs and P weighting coefficients corresponding to the z-th transport 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 P space-frequency component matrices. I.e.) > And represents the weighting coefficient corresponding to the kth angle vector and the ith delay vector based on the feedback of the nth receiving port. The dimension of the space-frequency matrix may be t×n.

Hereinafter, for convenience of explanation, all of them will be described in detailFor illustration. 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 angle vectors are the same or not, has no influence on the determination of the precoding matrix.

wherein ,representing a weighting coefficient corresponding to the kth angle vector and the ith delay vector in the first polarization direction based on the feedback of the z-th transmission layer; />And represents the weighting coefficients corresponding to the kth angle vector and the ith delay vector in the second polarization direction based on the z-th transport layer feedback.

For Z transport layers, the network device may determine the space-frequency matrix corresponding to each transport layer based on the P weighting coefficients corresponding to each transport layerTo->Thus, the network device can determine and associate with eachPrecoding matrix W corresponding to RB ⁽ⁿ⁾ 。

RB is an example of the frequency domain unit. For an nth RB of the N RBs, the network device may determine a conjugate transpose (V ⁽ⁿ⁾ ) ^H . Wherein the matrix (V ⁽ⁿ⁾ ) ^H Can be R space-frequency matrixes respectively determined by the R receiving ports To->An nth column vector in each of the space-frequency matrices.

Precoding matrix W corresponding to nth RB ⁽ⁿ⁾ May be Z space-frequency matrices respectively determined by the above-mentioned Z transmission layersTo->An nth column vector in each of the space-frequency matrices. For example, will->The nth column of (a) is used as a downlink channel matrix W ⁽ⁿ⁾ Column 0 of (2), will->The nth column of (a) is used as a downlink channel matrix W ⁽ⁿ⁾ Column 1 of (2); similarly, +.>The nth column of (a) is used as a downlink channel matrix W ⁽ⁿ⁾ Z-1 column (B). The precoding matrix corresponding to each RB can be determined based on the above method.

It should be appreciated that the foregoing is merely for ease of understanding and that the specific process by which the network device determines the precoding matrix is described in detail by taking the space-frequency component matrix as an example. But 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. One skilled in the art may construct P space-frequency basic units in different forms based on the P angle delay pairs, thereby determining the precoding matrix. The manner of determining the precoding matrix based on the weighted sum of the P space-frequency basic units is within the protection scope of the present application.

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

It should also be understood that the above-described determination process of the precoding matrix corresponding to each frequency domain unit is described with RB as an example of the frequency domain unit. The determined downlink channel is a downlink channel corresponding to the RB, and the determined precoding matrix is a precoding matrix corresponding to the RB. The precoding matrix corresponding to an RB may be a precoding matrix determined based on a channel matrix corresponding to the RB with an RB as granularity, or, alternatively, a precoding matrix determined based on a precoding reference signal received on the RB may be used to precode data transmitted through the RB. The downlink channel corresponding to an 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 a precoding matrix corresponding to the RB as a precoding matrix corresponding to the frequency domain unit to which the RB 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 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, in turn, take, for example, an average of precoding matrices corresponding to the plurality of RBs in the same frequency domain unit as the precoding matrix corresponding to the frequency domain unit, and so on.

It should be appreciated that the specific method for the network device to determine the precoding matrix of the frequency domain unit according to the precoding matrices corresponding to the 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 matrix corresponding to the plurality of RBs in the frequency domain unit of the network equipment is not limited.

It should also be understood that the weighting coefficients mentioned above in the description correspond to a certain angle vector and a certain delay vector, i.e. the weighting coefficients correspond to an angular delay pair consisting of a certain angle vector and a certain delay vector. For example, the weighting coefficients corresponding to the kth angle vector and the ith delay vector, that is, the weighting coefficients corresponding to the angle delay pair constituted by the kth angle vector and the ith delay vector. For brevity, no further illustration is provided here.

In the embodiment of the application, the network device can pre-encode 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 the downlink channel measurement according to the pre-encoded reference signal. Because the network device performs precoding on the reference signal based on the reciprocal angle and time delay of the uplink and downlink channels, the information of the downlink channels detected by the terminal device is information without reciprocity. Therefore, the terminal equipment does not need to feed back the vectors (such as the angle vector and the time delay vector) of the space domain and the frequency domain, and the feedback overhead of the terminal equipment is greatly reduced. In addition, by converting the channel of the frequency domain into the time domain, the value obtained by the time domain transformation is fed back as the weighting coefficient, and the problem of inaccurate channel recovery based on the weighting coefficient obtained by frequency domain accumulation 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 high feedback precision can be ensured. Furthermore, by performing spatial precoding on the downlink reference signal, the number of ports of the reference signal can be reduced, and thus pilot overhead can be reduced.

It should be understood that, in the embodiment of the present application, only for convenience of understanding, a specific process of measuring and determining a precoding matrix by a downlink channel is shown in the case that a space-frequency matrix is obtained by conjugate transpose of a real channel. But this should not be construed as limiting the application in any way. Real channel and space frequency matrix H _DL The relationship of (2) is not fixed. Different definitions of the space frequency matrix and the space frequency component matrix may cause the real channel to be identical to the space frequency matrix H _DL The relationship between them changes. For example, a space-frequency matrix H _DL May be obtained from the conjugate transpose of the real channel or from the transpose of the real channel.

When the definition of the relation between the space frequency matrix and the channel matrix is different, the operation executed by the network device is also different when the time delay and the angle are loaded, and the operation executed by the terminal device when the channel measurement and the feedback are executed correspondingly changes. But this is merely an implementation behavior of the terminal device and the network device and should not constitute any limitation of the application. The application is not limited to definition of channel matrix, dimension of space frequency matrix, definition thereof and conversion relation between the two. Similarly, the application is not limited to the conversion relation between the space-frequency matrix and the precoding matrix.

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

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

For ease of understanding, the process of channel measurement and feedback by the terminal device will be described in detail below with reference to precoding signals transmitted by the transmitting antennas in one polarization direction. The transmitting antenna with one polarization direction may be any one of the J transmitting antennas with polarization directions configured by the network device. The application is not limited to the number J of polarization directions of the transmitting antennas configured by the network device.

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

The reference signal is precoded based on L delay vectors, and the obtained precoded reference signal may correspond to L groups of ports. Each set of ports may correspond to a precoded reference signal obtained by precoding reference signals for T transmit antenna ports based on the same delay vector. Each set of ports may include a maximum of 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 a delay vector and a transmit antenna port.

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

In another possible implementation, the network device may traverse L delay vectors, precode reference signals carried on a portion of the N frequency domain units based on one or more of the L delay vectors, and transmit the precoded reference signals through T transmit antenna ports. The precoded reference signals obtained based on different delay vector precoding may be mapped onto different frequency domain units. The precoded reference signal carried on each frequency domain unit may be derived based on partial delay vector precoding among the L delay vectors. In the plurality of RBs, the 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 the L delay vectors through T transmitting antenna ports, different combinations of the delay vectors and the transmitting antenna ports can be obtained to be T multiplied by L ', wherein L ' is less than or equal to 1 and less than L, and L ' is an integer.

It should be understood that the foregoing is merely for ease of understanding, and the correspondence between the transmit antenna ports and the delay vectors is enumerated, but should not be construed to limit the present application in any way. The application does not limit the corresponding relation between the transmitting antenna port and the delay vector.

It may be appreciated that if the network device precodes the reference signal based on L delay vectors, the number of ports of the precoded reference signal transmitted 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 transmit ports is denoted as L groups, and each group of transmit ports may include a delay vector and one or more transmit antenna ports corresponding to the delay vector. In the following, for ease of understanding and explanation, 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 delay has reciprocity of uplink and downlink channels, all the L 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 uplink channel measurements has been described in detail in the above method 300, for brevity, a detailed description is omitted here.

It should be appreciated that determining L delay vectors based on uplink channel measurements is not the only implementation, and the L delay vectors may be predefined, such as a protocol definition, for example; alternatively, the feedback may be statistically determined based on the results of one or more previous downlink channel measurements. The application is not limited in this regard.

In the FDD mode, the time delay of the uplink and downlink channels can be reciprocal, so that L time delay vectors obtained by uplink channel measurement 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 over a pre-configured reference signal resource. Since the process of precoding the reference signal based on the delay vector has been described in detail above in connection with fig. 2, and the manner in which the network device is configured to distinguish between different transmitting ports when transmitting the precoded reference signal through the reference signal resource is described in detail in the method 300, for brevity, the description is omitted here.

In step 420, the terminal device generates seventh indication information for indicating P sets 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 sets of weighting coefficients corresponding to P angular delay pairs. Wherein each set of weighting coefficients may include 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 weights of the P angle delay pairs may be used to construct the 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 angle-related information to the terminal device in advance by signaling. There are many possible ways in which the indication of the angle-related information by the network device may be. 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 a measurement result of the uplink channel; for another example, the network device may indicate, through signaling, an angle corresponding to each of the L delay vectors, so that the terminal device determines 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 ease of distinction and explanation) corresponding to each of the L delay vectors, a difference or ratio of the other angles to the reference angle, and so on. For brevity, no one-to-one illustration is provided herein.

If the angle vector corresponding to any two of the L delay vectors is the same, the L delay vectors may be considered to correspond to the same K angle vectors, or the K angle vectors may be considered to be common to each delay vector.

In another implementation, the terminal device may perform channel measurement based on other received downlink reference signals (such as demodulation reference signals (demodulation reference signal, DMRS) and the like) to obtain K angle vectors with stronger downlink channels.

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

It should be understood that the specific ways in which the terminal device acquires K angle vectors listed above are just a few possible implementations, and should not be construed as limiting the application in any way. The application is not limited to a specific way for the terminal device to acquire K angle vectors.

In the embodiment of the application, the terminal equipment can feed back the P groups of weighting coefficients corresponding to the P angle delay pairs based on the receiving port. The seventh indication information indicates P sets of weighting coefficients corresponding to the P angular delay pairs, and 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. The relationship between each of the P sets of weighting coefficients and the R receiving ports under different values of R' has been described in detail in the above method 300, and will not be described herein for brevity.

The procedure of determining the P sets of weighting coefficients corresponding to the P angle delay pairs when the terminal device determines the weighting coefficients based on the receiving ports will be described first.

For ease of understanding, it is first assumed that r=1, i.e., each set of weighting coefficients may include one weighting coefficient. The precoded reference signals for each set of transmit ports may be carried over N RBs (i.e., one instance of a frequency domain unit). 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 the L groups of transmit ports.

Since the transmission ports that the terminal device can recognize 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 where the number of reception 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 transmission port can be obtained by cumulatively summing 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 may process the estimated channel information according to predetermined angle vectors corresponding to the respective delay vectors to determine a set of weighting coefficients corresponding to each of the angular delay pairs.

As described above, if the network device precodes the reference signal based on the L delay vectors, the real channel received by the terminal device may be represented as F ^H H _DL ^H The dimension may be lxt. Coefficient matrix C _DL By calculation C _DL ＝S ^H (F ^H H _DL ^H ) ^H And (5) determining. The coefficient matrix C _DL The elements in (a) can be respectively formed by real channels F after frequency domain precoding ^H H _DL ^H Conjugate transpose (F) ^H H _DL ^H ) ^H Left-hand S ^H Obtained.

As can be seen from the matrix multiplication, the matrix multiplication will (F ^H H _DL ^H ) ^H Left-hand S ^H When (F) ^H H _DL ^H ) ^H Each column vector in (a) includes a number of elements and S ^H Each row vector of (c) includes the same number of elements. In the present embodiment, (F) ^H H _DL ^H ) ^H Each column vector in (a) includes a number of elements and S ^H The number of elements included in each row vector may be T. When the row vector is multiplied by the column vector, each element in the row vector (such as the T-th element, where T is traversed from 1 to T) is multiplied by the corresponding element in the column vector (such as the T-th element, where T is traversed from 1 to T) and then summed. Therefore, after the angle vector is loaded to the channel estimation values on each RB, the terminal device sums up the channel estimation values on 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 appreciated that the space-frequency matrix H shown herein _DL The relationship to the channel matrix is merely an example. Different definitions may cause a change in the relationship between the two. But in any case defined, only the internal implementation of the network device and the terminal device is affected, and therefore no limitation should be put on the present application. The application is not limited to the internal implementation behavior of the network device and the terminal device.

In this embodiment, if the network device precodes a reference signal carried on the same RB based on each 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 coefficients corresponding to each angular delay pair based on channel information estimated from the precoded reference signals received on one receive port for each set of transmit ports.

The terminal device may determine channel information corresponding to each group of transmission ports on the nth RB according to the precoding reference signal corresponding to the same group of transmission ports received on the nth RB of the N RBs. For example, based on the precoded reference signals of the first group of transmit ports, the estimated channel information may be a vector of dimension 1×t, e.g., denoted as

Assuming that K angle vectors are angle vectors common to the L delay vectors, for the kth angle vector a (θ _k ) The channel information of the angle delay pair formed by the kth angle vector and the ith delay vector on the nth RB can be expressed as

Assuming that one or more of the K angle vectors corresponds to one of the L delay vectors, e.g., the first delay vector of the L delay vectors corresponds to K of the K angle vectors _l K of K angle vectors corresponding to the first time delay vector _l And an angle vector. Then, on the nth RB, and the first delay vector and K _l Kth in the respective angle vector _l The channel information of the angle delay pairs formed by the angle vectors can be expressed as, for example

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

It should be understood that the above listed methods and formulas for determining the weighting coefficients of each angular delay pair are merely examples and should not be construed as limiting the application in any way. The application is not limited to a specific method for determining the weighting coefficients of each angle delay pair. Furthermore, the calculation formula may also vary due to the different definition of the angle vector. The present application is not limited to the specific form of each vector, and thus is not limited to the operation mode between vectors.

As described above, since the precoded reference signal received by the terminal device is a reference signal precoded based on a time-domain vector, the equivalent channel received by the terminal device is discontinuous in the frequency domain. Therefore, the channel information corresponding to the same angle delay pair on each RB determined based on the 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 mode may still be used to obtain a more accurate weighting coefficient.

The terminal device may perform time domain transformation on channel information on N RBs corresponding to the same angle delay pair to obtain transformed N values. The nth of the N values _p The value may be used as a weighting factor corresponding to the p-th 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 time domain filtering in step 320 of method 300 has been described in detail above, and is not described here again for brevity.

Based on the method described above, the terminal device may determine P sets of weighting coefficients corresponding to P pairs of angle delays combined with L delay vectors and K angle vectors. Each set of weighting coefficients may include R ' weighting coefficients, 1.ltoreq.R '. Ltoreq.R, R ' being an integer. The weighting coefficients within each group may correspond to one or more of the R receive ports. It should be understood that the determination process of the terminal device for each of the R' weighting coefficients may refer to the method described above, and will not be repeated herein for brevity.

In another implementation, the terminal device may further use P sets of weighting coefficients corresponding to the P angular delay pairs based on the transport layer feedback. The specific implementation process of the terminal device in determining the P sets of weighting coefficients corresponding to the P transmitting ports based on the feedback of the transmission layer according to the P sets of weighting coefficients corresponding to the P transmitting ports determined based on the receiving antenna may refer to the description related to step 320 of the method 300. Since the specific process is described in detail in step 320 of method 300 above, it is not repeated here for brevity.

It should be understood that the above is only for easy understanding, and shows a process of channel measurement and feedback based on the precoding reference signals transmitted by the P transmission ports of one polarization direction. But this should not be construed as limiting the application in any way. For a plurality of 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 appreciated that the specific process of the terminal device generating the seventh 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 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 based on the seventh indication information.

It should be appreciated that the specific process of steps 430 through 440 may be the same as the specific process of steps 330 through 340 in method 300 above. The descriptions of steps 430 through 440 may be referred to above for steps 330 through 340 of method 300 and are not repeated here for brevity.

In the embodiment of the application, the network equipment 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 equipment performs downlink channel measurement according to the precoded reference signal. Because the network device performs precoding on the reference signal based on the reciprocal time delay 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 the vectors (such as the angle vector and the time delay vector) of the space domain and the frequency domain, and the feedback overhead of the terminal equipment is greatly reduced. In addition, by converting the channel of the frequency domain to the time domain, feeding back the value obtained by the time domain conversion as a weighting coefficient, the problem of inaccuracy of the channel recovered based on the weighting coefficient obtained by cumulatively summing a plurality of discrete equivalent channels can be avoided, which is advantageous in improving the transmission performance. Therefore, the feedback overhead is reduced, and high feedback precision can be ensured.

It should be understood that the foregoing is merely for ease of understanding, and shows an example in which the network device performs precoding on the reference signal based on the delay vector only, and the terminal device performs channel measurement and feedback based on the precoded reference signal. But 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 the channel information estimated based on the precoded reference signal based on a similar method as described above, to obtain P sets of weighting coefficients corresponding to P angle delay pairs. Since the specific processes are similar to those described above, detailed description will not be given here for brevity.

Fig. 5 is a schematic flow chart of a channel measurement method 500 provided by an embodiment of the present application from the perspective of device interaction. The method 500 illustrated 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 a 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 description of step 510 may be referred to above in connection with step 310 of method 300 and will not be repeated here for brevity.

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

In the embodiment of the present application, the terminal device may feed back P sets of weighting coefficients corresponding to P transmit ports based on the receive ports. Each set of weighting coefficients corresponding to the P transmit ports indicated by the first indication information 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. The relationship between each of the P sets of weighting coefficients and the R receiving ports under different values of R' has been described in detail in the above method 300, and will not be described herein for brevity.

As described above, 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. The specific procedure of how to determine the P-group weighting coefficients based on the transport layer will be described in detail later, and will be omitted here for brevity.

and i, performing channel estimation based on the precoding reference signal of the p-th transmitting port received on the r-th 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 frequency domain units of the N frequency domain units;

step ii, respectively carrying out 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 so as to obtain N filtered values;

and 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 ports that the terminal device can identify are ports corresponding to the precoded reference signals, the terminal device can perform channel estimation based on the received precoded reference signals 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 pre-encoded reference signal. It will be appreciated that the channel estimate may in particular be an equivalent channel, i.e. a channel loaded with precoding.

As previously described, P transmit ports may have a one-to-one correspondence with P angular delay pairs. The precoding reference signal corresponding to the P-th transmitting port in the P transmitting ports may be obtained by precoding the reference signal based on the K-th angle vector in the K angle vectors and the L-th delay vector in the L delay vectors, for example. Thus, the weighting coefficients described above for the p-th transmit port are those of the p-th angular delay pair.

For the precoding reference signal of the p-th transmitting port, the terminal device may determine a weighting coefficient of the p-th angle delay pair based on a channel estimation value obtained by channel estimation of the precoding reference signal received on the N RBs of one receiving port. The weighting coefficients for the p-th angular delay pair may be determined by the N channel estimates over the N RBs. Assume that a channel estimation value obtained by the terminal device performing channel estimation based on a precoding reference signal of a p-th transmitting port received on an n-th RB is recorded asThe channel estimation value obtained by the terminal device performing channel estimation based on the pre-encoded reference signal of the p-th transmitting port can be recorded as: />There are N total channel estimates. It can be seen that the N channel estimates correspond to N RBs, i.e., N frequency domain units.

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

As previously described, the weighting coefficient corresponding to the p-th transmit port may be the accumulated sum of channel estimates over N RBs. However, when the network device performs precoding on the reference signal based on the delay vector, N elements in the delay vector are respectively loaded on N RBs corresponding to the same transmitting port. The channel estimation value estimated by the terminal device on each RB is discontinuous. If the N channel estimation values are directly accumulated and summed to be used as the weight coefficient feedback of the p-th angle delay pair, the recovered downlink channel may also have a larger difference from the real channel, so that the determined precoding matrix for downlink transmission cannot be well matched with the real channel, and thus the transmission performance of the system is affected.

In the embodiment of the present application, the terminal device may perform filtering processing on the N channel estimation values before performing accumulated summation on the N channel estimation values. For example, the terminal device may divide the N RBs into one or more RB groups, each of which may include a plurality of RBs, and the RBs in the respective RB groups are not repeated with 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 will be appreciated that the filtered values are still N) are summed together to obtain a weighting factor corresponding to the p-th transmit port.

For example, assuming n=20, every 4 RBs are divided into one RB group. For example, rb#0 to rb#3 are taken as one RB group, rb#4 to rb#7 are taken as one RB group, rb#8 to rb#11 are taken as one RB group, rb#12 to rb#15 are taken as one RB group, and rb#16 to rb#19 are taken as one RB group. The terminal device may filter the 5 RB groups, respectively, to obtain a filtered value. 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.

Wherein, one or more RBs divided for filtering in one RB group may be referred to as bundled RBs (or RB Bundle).

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

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

Because 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 _p Can be expressed as:

wherein ,W_p Representing the filter coefficients corresponding to the p-th transmit port.Representing the modified correlation matrix +.>For example, the correction can be obtained by:

wherein ,as the correlation matrix, the correlation between RBs in one RB group for carrying the reference signal of the p-th transmission port (it can be understood that the reference signal is a precoded reference signal) is represented, or in case that the pilot density is greater than 1, the correlation between REs of reference signals in one RB group for carrying the reference signal of the p-th transmission port may be represented. About the correlation matrix->Reference is made to the prior art for wiener filtering, which is not described in detail here for the sake of brevity.

Is the correction value. In the embodiment of the application, the correction value can be used for +.>And (5) performing correction. In the embodiment of the present application, the correction value may be an m×m dimensional matrix, where M represents the number of RBs included in each RB group. Hereinafter, for convenience of explanation, < +.>SNR is the signal-to-noise ratio, abbreviated as signal-to-noise ratio. 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 units are divided into t frequency domain unit groups, each including M frequency domain units. N=t×m.

As can be seen, for a correlation matrixCorrection value beta for correction _p Is associated with a time delay. Wherein->The first delay tau corresponding to the p-th transmit port _l And (5) correlation. For example, it may be a time delay τ _p May also be a time delay tau _p Is a mathematical transformation of (a). The application is not limited in this regard. For example, a->Or (I)>Etc. For brevity, no one-to-one illustration is provided herein. Here, will be defined by a time delay τ _p Is a sum of the mathematical transformations of (a) and the time delay tau _p The relevant parameter is Shi Yan _p Is a parameter related to (a) is provided. It should be understood that the application is not limited to the particular manner of transforming the data.

Since the correction value is related to the delay, the terminal device needs to acquire in advance when determining the weighting coefficient corresponding to the p-th transmitting portOr, the time delay τ _l Or time delay tau _l Is a parameter related to (a) is provided.

In one possible implementation, the network device may indicate to the terminal device in advance by signaling the delay or a parameter related to the delay corresponding to each transmit port.

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

Wherein each delay may correspond to a delay vector used by the network device when precoding the reference signal.

Optionally, the indication of the delay by the network device may be, for example, the delay, or an index of the corresponding delay vector. For example, the network device pair delay τ _l The indication of (c) may be, for example, τ _l τ may also be _l Corresponding delay vector b (τ _l ) Is a reference to (a).

Optionally, the indication of the relevant parameter of the delay by the network device may be: the delay tau corresponding to the first transmitting port in the P ports ₀ And a difference delta tau between the delays corresponding to the rest of the P transmitting ports except the first transmitting port and the delay corresponding to the first transmitting port.

Wherein the first transmit port may be, for example, a certain transmit port predefined by the protocol. For example, the first transmitting port may be the 0 th transmitting port of the P transmitting ports, or the P-1 th transmitting port of the P transmitting ports, or the arbitrarily designated transmitting port τ ₀ . Taking the first transmitting port as the 0 th transmitting port in the P transmitting ports as an example, the corresponding time delay is recorded as, for example. Terminal (A)The indication of the related parameter of the delay by the end device may be, for example, the delay τ corresponding to the 0 th transmitting port corresponding to the delay of each of the 1 st transmitting port to the P-1 st transmitting port ₀ Is a difference in (c).

Of course, the indication of the delay corresponding to each transmitting port by indicating the difference is only one possible implementation, for example, the delay τ corresponding to the first transmitting port may also be indicated ₀ And the time delay corresponding to the rest of the P emission ports except the first emission port is equal to the time delay tau corresponding to the first emission port ₀ Indicating the corresponding delay of each transmitting port by means of the ratio of (a) to (b). The application is not limited to the specific manner of indicating the relevant parameters of the time delay.

The above description is for convenience of understanding only, and each frequency domain cell group includes a relevant number of frequency domain cells. 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 units included in each frequency domain unit group may be the same or different. When the number of frequency domain units included in each frequency domain unit group is different, the correction value β is set to be the same as the correction value β _p May be of dimension M _max ×M _max Is a matrix of (a) in the matrix. Wherein M is _max The maximum number of frequency domain units included in each frequency domain unit group is indicated. That is, the number of frequency domain units contained in each frequency domain unit group is less than or equal to M _max . That is, the correction value β _p The dimension of (a) may be the maximum value M of the number of frequency domain units contained in each frequency domain unit group _max . It will be appreciated that if the above N frequency domain units are taken as a frequency domain unit group, M _max ＝N。

It should be understood that the filtering of the channel estimation values in each frequency domain unit by wiener filtering is only one possible implementation, and should not be construed as limiting the 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 constructed based on other criteria (such as non-MMSE), first-order or higher-order interpolation, kalman filtering, and the like. For brevity, this is not a list.

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

It should be understood that, for ease of understanding only, the terminal device has been described in detail with r=1 as an example, and the weighting coefficient corresponding to each transmitting port is obtained by the frequency domain filtering process. But this should not be construed as limiting the application in any way. As previously described, in embodiments of the present application, R.gtoreq.1, the weighting coefficients corresponding to each transmit port may include R 'weighting coefficients, where R.gtoreq.R'. Gtoreq.1.

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

In addition, as described above, the terminal device may also feed back P sets of weighting coefficients corresponding to the P transmit ports based on the transport layer. The terminal device may determine P sets of weighting coefficients corresponding to P transmit ports based on the feedback of the transport layer according to the P sets of weighting coefficients corresponding to P transmit ports determined based on the receive antennas. For a specific implementation, reference may be made to the description of the method 300 above in step 320. Since the specific process is described in detail in step 320 of method 300 above, it is not repeated here for brevity.

It should also be appreciated 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 method 300 above. 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 based on the second indication information.

It should be appreciated that the specific process of steps 540 through 550 may be the same as the specific process of steps 330 through 340 in method 300 above. The descriptions of steps 540 through 550 may be referred to above in the method 300 for steps 330 through 340 and are not repeated here for brevity.

In the embodiment of the application, the network equipment performs precoding on the downlink reference signal based on the angle and the time delay determined by uplink channel measurement, for example, so that the terminal equipment performs downlink channel measurement according to the precoded reference signal. Because the network device performs precoding on the reference signal based on the reciprocal angle and time delay of the uplink and downlink channels, the information of the downlink channels detected by the terminal device is information without reciprocity. Therefore, the terminal equipment does not need to feed back the related information (such as the angle vector and the time delay vector) of the space domain and the frequency domain, and the feedback overhead of the terminal equipment is greatly reduced. In addition, by performing filtering processing on the channel information obtained by estimation on the plurality of frequency domain units based on the filter coefficient determined by the time delay corresponding to each transmitting port, noise can be reduced, and correlation among pilots on the plurality of frequency domain units is fully utilized, so that the channel information obtained by filtering and corresponding to each frequency domain unit is more accurate. In addition, by compensating the filter coefficient, the original discontinuous equivalent channel can perform the joint filtering to a greater extent, so that the problem of inaccurate channel estimation caused by the fact that the frequency domain cannot be bound in the prior art is solved, and the transmission performance is further improved. Therefore, the feedback overhead is reduced, and meanwhile, higher feedback precision can be ensured, so that the transmission performance of the system is improved. Furthermore, by performing spatial precoding on the downlink reference signal, the number of ports of the reference signal can be reduced, and thus pilot overhead can be reduced.

The above embodiments take precoding of the reference signal based on the angle vector and the delay vector as an example, and describe the channel measurement method provided by the present application in detail. But this should not be construed as limiting the application in any way. The network device may also precode the reference signal based only on the delay vector or the angle vector, so that the terminal device performs downlink channel measurement based on the precoded reference signal. The following embodiments take precoding of reference signals based on delay vectors only 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 a further embodiment of the present application from the perspective of device interaction. The method 600 illustrated in fig. 6 may include steps 610 through 650. The steps in method 600 are described in detail below.

In step 610, the terminal device receives a precoded reference signal. Correspondingly, the network device transmits a 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 refer to frequency domain precoding. The specific process by which the network device precodes the reference signal based on L delay vectors and the transmit port number versus L are described in detail above in step 410 of method 400. The specific process of step 610 in this embodiment may refer to the description related to step 410 in method 400 above, and will not be repeated here for brevity.

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

First, the terminal device may perform channel estimation based on the precoding reference signal of each transmission port received on each RB to obtain channel information corresponding to each transmission port on N RBs. The terminal equipment processes each channel estimation value based on the angle vector corresponding to each time delay vector obtained in advance so as to obtain channel information corresponding to each angle time delay pair on 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 frequency domain filtering method described above. For example, the N RBs are divided into one or more RB groups, each of which 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 for performing the frequency domain filtering may refer to the description related to step 520 in the method 500 above. For brevity, no further description is provided herein.

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

Optionally, the method 600 further includes: in step 630, the network device sends ninth indication information, where the ninth indication information is used to indicate L delays or related parameters of the delays. 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 by signaling has been described in detail in step 530 of method 500 above, and is not repeated here for brevity.

It should also be appreciated 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 based on the eighth indication information.

It should be appreciated that the specific process of steps 640 through 650 may be the same as the specific process of steps 330 through 340 in method 300 above. The descriptions relating to steps 640 through 650 may be referred to the descriptions relating to steps 330 through 340 in method 300 above and are not repeated here for brevity.

In the embodiment of the application, the network equipment performs precoding on the downlink reference signal based on the time delay determined by the uplink channel measurement, so that the terminal equipment performs downlink channel measurement according to the precoded reference signal. Because the network device performs precoding on the reference signal based on reciprocal time delay of the uplink and downlink channels, the terminal device can not need to feed back related information of the frequency domain (such as the time delay vector), and the feedback overhead of the terminal device is greatly reduced. In addition, by performing filtering processing on the channel information obtained by estimation on the plurality of frequency domain units based on the filter coefficient determined by the time delay corresponding to each transmitting port, noise can be reduced, and correlation among pilots on the plurality of frequency domain units is fully utilized, so that the channel information obtained by filtering and corresponding to each frequency domain unit is more accurate. In addition, by compensating the filter coefficient, the original discontinuous equivalent channel can perform the joint filtering to a greater extent, so that the problem of inaccurate channel estimation caused by the fact that the frequency domain cannot be bound in the prior art is solved, and the transmission performance is further improved. Therefore, the feedback overhead is reduced, and meanwhile, higher feedback precision can be ensured, so that the transmission performance of the system is improved.

It should be understood that the foregoing is merely for ease of understanding, and shows an example in which the network device performs precoding on the reference signal based on the delay vector only, and the terminal device performs channel measurement and feedback based on the precoded reference signal. But 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 frequency-domain filter the channel information estimated based on the precoded reference signal based on a similar method as described above, to obtain P sets of weighting coefficients corresponding to P angle delay pairs. Since the specific processes are similar to those described above, detailed description will not be given here for brevity.

It should also 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 embodiments of the present application may perform other operations or variations of the various operations. Furthermore, the various steps may be performed in a different order than presented in the various embodiments, and it is possible that not all of the operations in the embodiments of the application may be performed. The sequence number of each step does not mean the sequence of execution sequence, and the execution sequence of each process should be determined by its function and internal logic, 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 by an embodiment of the present application. As shown in fig. 7, the communication apparatus 1000 may include a processing unit 1100 and a transceiving unit 1200.

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

It is to be understood that the communication apparatus 1000 may correspond to the terminal 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 terminal device in the methods 300 to 600 in fig. 3 to 6. And, each unit in the communication device 1000 and the other operations and/or functions described above are respectively for implementing the respective flows of any one of the methods 300 in fig. 3 to 600 in fig. 6.

Wherein, when the communication device 1000 is used to perform the method 300 in fig. 3, the processing unit 1100 may be used to perform the step 320 in the method 300, and the transceiver unit 1200 may be used to perform the steps 310 and 330 in the method 300. It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

When the communication device 1000 is used to perform the method 400 in fig. 4, the processing unit 1100 may be used to perform the step 420 in the method 400, and the transceiver unit 1200 may be used to perform the steps 410 and 430 in the method 400. It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

When the communication device 1000 is used to perform the method 500 of fig. 5, the processing unit 1100 may be used to perform the step 520 of the method 500, and the transceiver unit 1200 may be used to perform the steps 510, 530 and 540 of the method 500. It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

When the communication device 1000 is used to perform the method 600 in fig. 6, the processing unit 1100 may be used to perform the step 620 in the method 600, and the transceiver unit 1200 may be used to perform the steps 610, 630 and 640 in the method 600. It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

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 through an input/output interface, and the processing unit 1100 in the communication device 1000 may be implemented through a processor, a microprocessor, an integrated circuit, or the like integrated on the chip or the chip system.

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

It is to be understood that the communication apparatus 1000 may correspond to the network device of 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 of the methods 300 to 600 of fig. 3 to 6. And, each unit in the communication device 1000 and the other operations and/or functions described above are respectively for implementing the respective flows of any one of the methods 300 in fig. 3 to 600 in fig. 6.

Wherein, when the communication device 1000 is used to perform the method 300 in fig. 3, the processing unit 1100 may be used to perform the step 340 in the method 300, and the transceiver unit 1200 may be used to perform the steps 310 and 330 in the method 300. It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

When the communication device 1000 is used to perform the method 400 in fig. 4, the processing unit 1100 may be used to perform the step 440 in the method 400, and the transceiver unit 1200 may be used to perform the steps 410 and 430 in the method 400. It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

When the communication device 1000 is used to perform the method 500 of fig. 5, the processing unit 1100 may be used to perform the step 550 of the method 500, and the transceiver unit 1200 may be used to perform the steps 510, 530 and 540 of the method 500. It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

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

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

Fig. 8 is a schematic structural diagram of a terminal device 2000 according to an embodiment of the present application. The terminal device 2000 may be applied to a system as shown in fig. 1, and perform the functions of the terminal device in the above-described method embodiment. As shown, the terminal device 2000 includes a processor 2010 and a transceiver 2020. Optionally, the terminal device 2000 further comprises a memory 2030. Wherein the processor 2010, the transceiver 2002 and the memory 2030 may communicate with each other through an internal connection path, and transfer control and/or data signals, the memory 2030 is used for storing a computer program, and the processor 2010 is used for calling and running 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 for transmitting uplink data and uplink control signaling output by the transceiver 2020 through a wireless signal.

The processor 2010 and the memory 2030 may be combined into a single processing device, and the processor 2010 is configured to execute program codes stored in the memory 2030 to implement the functions described above. In particular implementations, the memory 2030 may also be integrated within the processor 2010 or separate from the processor 2010. The processor 2010 may correspond to the processing unit of 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 circuitry) and a transmitter (or transmitter, transmitting circuitry). Wherein the receiver is for receiving signals and the transmitter is for transmitting signals.

It should be understood that the terminal device 2000 shown in fig. 8 is capable of implementing the respective processes involving the terminal device in the method embodiments shown in fig. 3 to 6. The operations and/or functions of the respective modules in the terminal device 2000 are respectively for implementing the corresponding flows in the above-described method embodiment. Reference is specifically made to the description in the above method embodiments, and detailed descriptions are omitted here as appropriate to avoid repetition.

The above-described processor 2010 may be used to perform the actions described in the previous method embodiments as being performed internally by the terminal device, while the transceiver 2020 may be used to perform the actions described in the previous method embodiments as being transmitted to or received from the network device by the terminal device. Please refer to the description of the foregoing method embodiments, and details are not repeated herein.

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

In addition, in order to make the functions of the terminal device more complete, 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, which may be, for example, a base station, according to an embodiment of the present application. The base station 3000 may be applied to the system shown in fig. 1, and perform the functions of the network device in the above method embodiment. As shown, the base station 3000 may include one or more radio frequency units, such as a remote radio frequency unit (remote radio unit, RRU) 3100 and one or more baseband units (BBUs) (also 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 transceiver unit 3100 may also be referred to as a transceiver, a transceiver circuit, or a 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, which may correspond to a receiver (or receiver, receiving circuit), and a transmitting unit, which may correspond to a transmitter (or transmitter, transmitting circuit). The RRU 3100 is mainly configured to receive and transmit a radio frequency signal and convert the radio frequency signal to a baseband signal, for example, to send indication information to a terminal device. The BBU 3200 portion is mainly used for performing baseband processing, controlling a base station, and the like. The RRU 3100 and BBU 3200 may be physically disposed together, or may be physically disposed separately, i.e. a distributed base station.

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 performing baseband processing functions, such as channel coding, multiplexing, modulation, spreading, and so on. For example, the BBU (processing unit) may be configured to control the base station to perform the operation procedure with respect to the network device in the above-described method embodiment, for example, generate the above-described indication information, etc.

In one example, the BBU 3200 may be configured by one or more single boards, where the multiple single boards may support a single access radio access network (such as an LTE network) together, or may support radio access networks of different access systems (such as an LTE network, a 5G network, or other networks) respectively. 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 configured to control the base station to perform necessary actions, for example, to control the base station to perform the operation procedure 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 the processor may be separately provided on each board. It is also possible that multiple boards 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 is capable of implementing various processes involving network devices 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 is specifically made to the description in the above method embodiments, and detailed descriptions are omitted here as appropriate to avoid repetition.

The BBU 3200 described above may be used to perform actions described in the foregoing method embodiments as being implemented internally by a network device, while the RRU 3100 may be used to perform actions described in the foregoing method embodiments as being transmitted to or received from a terminal device by the network device. Please refer to the description of the foregoing method embodiments, and details are not repeated herein.

It should be understood that the base station 3000 shown in fig. 9 is only one possible configuration of a network device, and should not be construed as limiting 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, but also CUs and/or DUs, or BBUs and adaptive radio units (adaptive radio unit, ARUs), or BBUs; the present application is not limited to the specific form of the network device, and the customer premise equipment (customer premises equipment, CPE) may be used.

Wherein a CU and/or DU may be used to perform actions described in the previous method embodiments as being implemented internally by a network device, and an AAU may be used to perform actions described in the previous method embodiments as being transmitted to or received from a terminal device by the network device. Please refer to the description of the foregoing method embodiments, and details are 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 method embodiments described above.

It should 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 (field programmable gate array, FPGA), an application specific integrated chip (application specific integrated circuit, ASIC), a system on chip (SoC), a central processing unit (central processor unit, CPU), a network processor (network processor, NP), a digital signal processing circuit (digital signal processor, DSP), a microcontroller (micro controller unit, MCU), a programmable controller (programmable logic device, PLD) or other integrated chip.

In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in a hardware processor for execution, or in a combination of hardware and software modules in the processor for execution. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method. To avoid repetition, a detailed description is not provided herein.

It should be noted that the processor in the embodiments of the present application may be an integrated circuit chip with signal processing capability. In implementation, the steps of the above method embodiments may be implemented by integrated logic circuits of hardware in a processor or instructions in software form. The processor 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, or discrete hardware components. The disclosed methods, steps, and logic blocks 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 embodied directly in the execution of a hardware decoding processor, or in the execution of a combination of hardware and software modules in a decoding processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.

It will be appreciated that the memory in embodiments of the application may be volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile 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. The volatile memory may be random access memory (random access memory, RAM) which acts as an external cache. By way of example, and not limitation, many forms of RAM are available, such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous DRAM (SLDRAM), and direct memory bus 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 a method provided by an embodiment of the present application, the present application also provides a computer program product, including: 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, where a program code is stored, which when executed on a computer, causes the computer to perform the method performed by the terminal device and the network device in the embodiments shown in fig. 3 to 6, respectively.

According to the method provided by the embodiment of the application, the application also provides a system which comprises the one or more terminal devices and one or more network devices.

The network device in the above-mentioned respective apparatus embodiments corresponds entirely to the network device or the terminal device in the terminal device and method embodiments, the respective steps are performed by respective modules or units, for example, the steps of receiving or transmitting in the method embodiments are performed by the communication unit (transceiver), and other steps than transmitting and receiving may be performed by the processing unit (processor). Reference may be made to corresponding method embodiments for the function of a specific unit. Wherein the processor 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 may reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between 2 or more computers. Furthermore, 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 one another 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 (illustrative logical block) and steps (steps) described in connection with the embodiments disclosed herein can 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 solution. 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 will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown 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 may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

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

In the above-described embodiments, the functions of the respective functional units may be implemented in whole or in part 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). When the computer program instructions (program) are loaded and executed on a computer, the processes or functions according to the embodiments of the present application are fully or partially produced. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of 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 high-density digital video disc (digital video disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

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 this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of channel measurement, comprising:

generating first indication information, wherein the first indication information is used for indicating P groups of weighting coefficients corresponding to P emission ports, the reference signal of each emission port in the P emission ports is obtained by precoding the reference signal based on a time delay vector and/or an angle vector, and the weighting coefficient corresponding to each emission port in the P emission ports and the time delay vector and/or the angle vector corresponding to each emission port are used for constructing a precoding matrix; the P-th group weighting coefficient corresponding to the P-th transmitting port in the P transmitting ports is obtained by performing time domain transformation on channel information between the P-th transmitting port and R receiving ports of terminal equipment, wherein the P-th transmitting port is any transmitting port in 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.

2. 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 'is more than or equal to 1, and R' is an integer.

3. The method of claim 2, wherein each set of weighting coefficients in the P sets of weighting coefficients includes R weighting coefficients corresponding to the R receiving ports, and wherein an R weighting coefficient in the P-th set of weighting coefficients is obtained by time-domain transforming channel information between the P-th transmitting port and an R receiving port in the R receiving ports.

4. A method as claimed in 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 set of weighting coefficients is the n-th weighting coefficient in the vector obtained by the time domain transformation _p,r A value; wherein the vector determined by the channel information between the p-th transmitting port and the r-th receiving port comprises N values, the N values comprise the channel information respectively corresponding to N frequency domain units for bearing the reference signal of the p-th transmitting port, and N is more than or equal to 0 _p,r ≤N-1，N≥1，n _p,r And N are integers.

5. The method of claim 4, whereinThe n is _p,r Is a predefined value.

6. The method of claim 5, wherein n _p,r ＝0。

7. The method of claim 4, 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,r Is a value of (2).

8. The method of any one of claims 4 to 7, wherein the method further comprises:

filtering 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 nth element of the N elements _p,r The elements.

9. The method of any of claims 1 to 7, wherein the time domain transformation comprises: an inverse fast fourier transform IFFT or an inverse discrete fourier transform IDFT.

10. A method of channel measurement, comprising:

generating second indication information, wherein the second indication information is used for indicating P groups of weighting coefficients corresponding to P emission ports, the reference signal of each emission port in the P emission ports is obtained by precoding the reference signal at least based on a delay vector, and the weighting coefficient corresponding to each emission port in the P emission ports and the delay vector corresponding to each emission port are used for constructing a precoding matrix; the P-th set of weighting coefficients corresponding to the P-th transmitting ports are the sum of a plurality of values obtained by filtering channel information of one or more frequency domain unit sets respectively, each frequency domain unit set in the one or more frequency domain unit sets comprises a plurality of frequency domain units, the total number of the frequency domain units included in the one or more frequency domain unit sets is the number of the frequency domain units used for bearing reference signals of the P-th transmitting ports, the P-th transmitting port is any transmitting port in the P-th 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, and P is an integer;

And sending the second indication information.

11. The method of claim 10, wherein the method further comprises:

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

and summing the filtered values of the one or more frequency domain unit groups to obtain a weighting coefficient corresponding to the p-th transmitting port.

12. The method of claim 11, wherein the method further comprises:

based on the time delay tau corresponding to the p-th transmitting port _p Or time delay tau _p The filter coefficients are determined, wherein each delay corresponds to a delay vector.

13. The method of claim 12, wherein the filter coefficients are:

wherein , wherein ,/>Is a correlation matrix, representingCorrelation between frequency domain units in a frequency domain unit group for carrying a reference signal of the p-th transmit port; />For correction values for->Make corrections (I)>For the time delay tau corresponding to the p-th transmitting port _p Or time delay tau _p N represents the number of frequency domain units used to carry the reference signal of the p-th transmit port, N > 1 and is an integer; / >For->Performing correction to obtain a correlation matrix; SNR is the signal-to-noise ratio; i represents a unit array.

14. The method of any one of claims 10 to 13, wherein the method further comprises:

and receiving third indication information, wherein the third indication information is used for indicating time delay or related parameters of the time delay corresponding to each of the P transmitting ports, and each time delay corresponds to one time delay vector.

15. The method of claim 14, wherein the third indication information indicates a delay corresponding to each of the P transmit ports as a delay corresponding to each transmit port.

16. The method of claim 14, wherein the third indication information pairThe indication of the relevant parameters of the delay corresponding to each of the P transmitting ports is: the delay tau corresponding to the first transmitting port in the P ports ₀ And a difference delta tau between the delays corresponding to the rest of the P transmitting ports except the first transmitting port and the delay corresponding to the first transmitting port.

17. A communication device, comprising:

the processing unit is used for generating first indication information, the first indication information is used for indicating P groups of weighting coefficients corresponding to P emission ports, the reference signal of each emission port in the P emission ports is obtained by precoding the reference signal based on a time delay vector and/or an angle vector, and the weighting coefficient corresponding to each emission port in the P emission ports and the time delay vector and/or the angle vector corresponding to each emission port are used for constructing a precoding matrix; the P-th group weighting coefficient corresponding to the P-th transmitting port in the P transmitting ports is obtained by performing time domain transformation on channel information between the P-th transmitting port and R receiving ports of terminal equipment, wherein the P-th transmitting port is any transmitting port in 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 receiving and transmitting unit is used for transmitting the first indication information.

18. The apparatus of claim 17, 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 'is more than or equal to 1, and R' is an integer.

19. The apparatus of claim 18, wherein each of the P sets of weighting coefficients comprises R weighting coefficients corresponding to the R receive ports, and wherein an R 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.

20. The apparatus of claim 19, wherein the processing unit is further configured to time-domain transform the vector determined by the channel information between the p-th transmit port and the r-th receive port to obtain a transformed vector, the r-th weighting coefficient in the p-th set of weighting coefficients being an nth one of the vectors obtained by the time-domain transform _p,r A value; wherein the vector determined by the channel information between the p-th transmitting port and the r-th receiving port comprises N values, the N values comprise the channel information respectively corresponding to N frequency domain units for bearing the reference signal of the p-th transmitting port, and N is more than or equal to 0 _p,r ≤N-1，N≥1，n _p,r And N are integers.

21. The apparatus of claim 20, wherein n _p,r Is a predefined value.

22. The apparatus of claim 21, wherein n _p,r ＝0。

23. 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,r Is a value of (2).

24. 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 set 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 nth element of the N elements _p,r The elements.

25. The apparatus of any of claims 17 to 23, wherein the time domain transform comprises: an inverse fast fourier transform IFFT or an inverse discrete fourier transform IDFT.

26. A communication device, comprising:

the processing unit is used for generating second indication information, the second indication information is used for indicating P groups of weighting coefficients corresponding to P emission ports, the reference signal of each emission port in the P emission ports is obtained by precoding the reference signal at least based on a time delay vector, and the weighting coefficient corresponding to each emission port in the P emission ports and the time delay vector corresponding to each emission port are used for constructing a precoding matrix; the P-th set of weighting coefficients corresponding to the P-th transmitting ports are the sum of a plurality of values obtained by filtering channel information of one or more frequency domain unit sets respectively, each frequency domain unit set in the one or more frequency domain unit sets comprises a plurality of frequency domain units, the total number of the frequency domain units included in the one or more frequency domain unit sets is the number of the frequency domain units used for bearing reference signals of the P-th transmitting ports, the P-th transmitting port is any transmitting port in the P-th 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, and P is an integer;

and the receiving and transmitting unit is used for generating the second indication information.

27. The apparatus of claim 26, wherein the processing unit is further configured to filter the channel information for the one or more sets 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 sets of frequency domain units to obtain a weighting factor corresponding to the p-th transmit port.

28. The apparatus of claim 27, wherein the processing unit is further forBased on the time delay tau corresponding to the p-th transmitting port _p Or time delay tau _p The filter coefficients are determined, wherein each delay corresponds to a delay vector.

29. The apparatus of claim 28, wherein the filter coefficients are:

wherein , wherein ,/>A correlation matrix, which represents the correlation between each frequency domain unit in a frequency domain unit group used for bearing the reference signal of the p-th transmitting port; />For correction values for->Make corrections (I)>For the time delay tau corresponding to the p-th transmitting port _p Or time delay tau _p N represents the number of frequency domain units used to carry the reference signal of the p-th transmit port, N > 1 and is an integer; / >For->Proceeding withCorrecting the obtained correlation matrix; SNR is the signal-to-noise ratio; i represents a unit array.

30. The apparatus of any one of claims 26 to 29, wherein the transceiver unit is further configured to receive third indication information, the third indication information being configured to indicate a delay or a parameter related to a delay corresponding to each of the P transmit ports, each delay corresponding to a delay vector.

31. The apparatus of claim 30, wherein the third indication information indicates a delay for each of the P transmit ports as a delay for each transmit port.

32. The apparatus of claim 30, wherein the third indication information indicates, for each of the P transmit ports, a related parameter of a corresponding delay: the delay tau corresponding to the first transmitting port in the P ports ₀ And a difference delta tau between the delays corresponding to the rest of the P transmitting ports except the first transmitting port and the delay corresponding to the first transmitting port.

33. A communication device comprising at least one processor for executing a computer program stored in a memory to cause the communication device to implement the method of any one of claims 1 to 16.

34. 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.