Communication method and communication apparatus

Abstract

The present application provides a communication method and a communication apparatus. The method comprises: on the basis of a first time domain resource, an RIS receives a first reference signal transmitted by a first communication apparatus; on the basis of a first phase, reflects the first reference signal to a second communication apparatus; on the basis of a second time domain resource, receives a second reference signal transmitted by the first communication apparatus, the first time domain resource and the second time domain resource having the same time domain length, and the first reference signal and the second reference signal being the same; and, on the basis of a second phase, reflects the second reference signal to the second communication apparatus, the second phase being opposite to the first phase. The first reference signal and the second reference signal may be used for the measurement of a direct channel (i.e., a channel between the first communication apparatus and the second communication apparatus) and / or a partially cascaded channel (i.e., a channel between the first communication apparatus and the RIS). By means of designing transmission rules of the reference signals and the phases of the reference signals reflected by the RIS, independent estimation of a direct channel or a partially cascaded channel can be achieved.

Description

Communication methods and communication devices

[0001] This application claims priority to Chinese Patent Application No. 202411579896.3, filed on November 6, 2024, entitled "Communication Method and Communication Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more specifically, to a communication method and a communication device. Background Technology

[0003] Multiple-input multiple-output (MIMO) systems can utilize spatial resources to achieve array gain, multiplexing and diversity gain, and interference cancellation gain in space without increasing system bandwidth, thus significantly improving the capacity and spectral efficiency of communication systems. However, with the ever-increasing demands for high-speed, high-reliability, and low-latency communication, modern communication systems will continue to face the challenges of greater capacity, wider coverage, and lower latency. To address these challenges, reconfigurable intelligent surfaces (RIS) have emerged as a promising technology and are being widely studied. Therefore, how to perform channel estimation in RIS-assisted MIMO systems is a question worth considering. Summary of the Invention

[0004] This application provides a communication method and a communication apparatus capable of channel estimation for RIS-assisted MIMO systems, such as channel estimation for the direct channel of a RIS-assisted MIMO system, and / or channel estimation for the cascaded channel of a RIS-assisted MIMO system.

[0005] Firstly, a communication method is provided, which can be executed by a communication device (such as a RIS device). This communication device can be a RIS device, or a component used in a RIS device (such as a chip or circuit, which can be a modem chip, also known as a baseband chip, or a system-on-chip (SoC) or system-in-package (SIP) chip containing a modem core, etc.), or a logic module or software capable of implementing some or all of the functions of the RIS device, etc., and this application does not limit this. The following description uses a RIS device as an example.

[0006] The method may include: receiving a first reference signal from a first communication device based on a first time-domain resource; reflecting the first reference signal to a second communication device based on a first phase; receiving a second reference signal from the first communication device based on a second time-domain resource, wherein the first time-domain resource and the second time-domain resource have the same time-domain length, and the first reference signal and the second reference signal are the same; reflecting the second reference signal to the second communication device based on a second phase, wherein the second phase is out of phase with the first phase; wherein the first reference signal and the second reference signal are used for measuring a first channel and / or a second channel, the first channel being a channel between the first communication device and the second communication device, and the second channel being a channel between the first communication device and the RIS device.

[0007] Based on the above technical solution, the RIS device can receive reference signals repeatedly transmitted by the first communication device on two time-domain resources of equal length, and when reflecting the reference signals to the second communication device, it reflects the reference signals on these two time-domain resources with out-of-phase reflection. Thus, by designing the transmission rules of the reference signals and the phase of the reference signals reflected by the RIS, channel estimation for direct channels or partially cascaded channels can be achieved. For example, the second communication device can process the reference signals on these two time-domain resources (such as adding them together). Since the phases of the reference signals reflected by the RIS on the two time-domain resources are out-of-phase, that is, the phases of the reference signals on the two time-domain resources in the cascaded channel are opposite, adding these out-of-phase reference signals can reduce the impact of the cascaded channel on the estimation of the direct channel, achieving independent estimation of the direct channel and the cascaded channel.

[0008] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: receiving a third reference signal from the first communication device based on F groups of time-domain resources, each group of time-domain resources in the F groups of time-domain resources including A time-domain units, the third reference signal on the A time-domain units in one group of time-domain resources is the same, the third reference signal on different groups of time-domain resources is different, A is an integer greater than 1, and F is an integer greater than 1; reflecting the third reference signal to the second communication device based on B phases, the B phases being used for each group of time-domain resources in the F groups of time-domain resources, and the correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources, the third reference signal, the first reference signal, and the second reference signal being used for the measurement of a third channel, the third channel being a channel between the second communication device and the RIS device, and B being an integer greater than or equal to 1 and less than or equal to A.

[0009] Based on the above technical solution, the RIS device can also receive F sets of reference signals on F sets of time-domain resources. The reference signals in each set of reference signals are the same, while the reference signals in different sets of reference signals are different. Furthermore, when the RIS reflects reference signals based on B phases, the order of the B phases is the same in different sets of reference signals, that is, the correspondence between the B phases and A time-domain units is the same in each set of time-domain resources. In this way, by designing the transmission rules of the reference signals and the phases of the RIS reflected reference signals, the estimation of the cascaded channel can be achieved.

[0010] Secondly, a communication method is provided, which can be executed by a communication device. This communication device can be a terminal device, or a component for a terminal device (such as a chip or circuit, which can be a modem chip, also known as a baseband chip, or a system-on-chip (SoC) or system-in-package (SIP) chip containing a modem core, etc.), or a logic module or software capable of implementing some or all of the functions of the terminal device, etc.; or it can be a network device, or a component for a network device (such as a chip, chip system, or circuit), or a logic module or software capable of implementing some or all of the functions of the network device, etc., and this application does not limit this.

[0011] The method may include: receiving a first reference signal from a first communication device and reflected by a configurable smart surface RIS device based on a first phase, based on a first time-domain resource; receiving a second reference signal from the first communication device and reflected by the RIS device based on a second phase, the second phase being out of phase with the first phase, the first time-domain resource and the second time-domain resource having the same time-domain length, and the first reference signal and the second reference signal being the same; obtaining channel information of a first channel and / or a second channel based on the first reference signal and the second reference signal, wherein the first channel is a channel between the first communication device and the second communication device, and the second channel is a channel between the first communication device and the RIS device.

[0012] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes: receiving a third reference signal from the first communication device and reflected by the RIS device based on B phases, based on F groups of time-domain resources, wherein the B phases are used for each group of time-domain resources in the F groups of time-domain resources, and the correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources, wherein each group of time-domain resources in the F groups of time-domain resources includes A time-domain units, the third reference signal on the A time-domain units in one group of time-domain resources is the same, the third reference signal on different groups of time-domain resources is different, A and F are integers greater than 1, and B is an integer greater than or equal to 1 and less than or equal to A; obtaining channel information of a third channel based on the third reference signal, the first reference signal, and the second reference signal, wherein the third channel is a channel between the second communication device and the RIS device.

[0013] In conjunction with the second aspect, in some implementations of the second aspect, obtaining the channel information of the third channel based on the third reference signal, the first reference signal, and the second reference signal includes: obtaining the channel information of the third channel based on the third reference signal, the first reference signal, the second reference signal, and reference channel information.

[0014] Based on the above technical solution, when estimating the channel between the second communication device and the RIS device, the second communication device can incorporate reference channel information, thus reducing the overhead of the reference signal. The method of obtaining the reference channel information is not limited. For example, the reference channel information can be measured by the second communication device, such as when a communication device sends a reference signal to the second communication device via the RIS, and the second communication device performs measurements based on this reference signal to obtain the reference channel information. Alternatively, the reference channel information can be estimated based on historical communication data.

[0015] Thirdly, a communication method is provided, which can be executed by a communication device. This communication device can be a terminal device, or a component for a terminal device (such as a chip or circuit, which can be a modem chip, also known as a baseband chip, or a system-on-chip (SoC) or system-in-package (SIP) chip containing a modem core, etc.), or a logic module or software capable of implementing some or all of the functions of the terminal device, etc.; or it can be a network device, or a component for a network device (such as a chip, chip system, or circuit), or a logic module or software capable of implementing some or all of the functions of the network device, etc., and this application does not limit this.

[0016] The method may include: transmitting a first reference signal to a second communication device via a configurable smart surface RIS device based on a first time-domain resource, the first reference signal corresponding to a first phase; transmitting a second reference signal to the second communication device via the RIS device based on a second time-domain resource, the second reference signal corresponding to a second phase, the second phase being out of phase with the first phase, the first time-domain resource and the second time-domain resource having the same time-domain length, and the first reference signal and the second reference signal being the same; wherein the first reference signal and the second reference signal are used for measuring a first channel and / or a second channel, the first channel being a channel between the first communication device and the second communication device, and the second channel being a channel between the first communication device and the RIS device.

[0017] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes: transmitting a third reference signal to the second communication device through the RIS device based on F groups of time-domain resources, wherein the third reference signal, together with the first reference signal and the second reference signal, is used for the measurement of a third channel, the third channel being a channel between the second communication device and the RIS device; wherein the third reference signal corresponds to B phases, the B phases are used for each group of time-domain resources in the F groups of time-domain resources, and the correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources; wherein each group of time-domain resources in the F groups of time-domain resources includes A time-domain units, the third reference signal on the A time-domain units in one group of time-domain resources is the same, the third reference signal on different groups of time-domain resources is different, A and F are integers greater than 1, and B is an integer greater than or equal to 1 and less than or equal to A.

[0018] In combination with any one of the first to third aspects, in some implementations, the value of F is greater than or equal to the number of paths corresponding to the second channel.

[0019] In combination with any one of the first to third aspects, in some implementations, the value of A is related to the number of elements in the RIS device.

[0020] In conjunction with any one of the first to third aspects, in some implementations, the value of A is greater than or equal to log(W), or the value of A is greater than or equal to log(W) / L; wherein L is the number of paths corresponding to the third channel, and W represents the number of elements of the RIS device.

[0021] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: receiving first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the F group of time-domain resources.

[0022] In conjunction with any one of the second to third aspects, in some implementations, the method further includes: sending or receiving first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the F group of time-domain resources.

[0023] In combination with any one of the first to third aspects, in some implementations, the first time-domain resource and the second time-domain resource are consecutive time-domain resources.

[0024] Based on the above technical solution, since the first reference signal and the second reference signal jointly estimate the first channel and / or the second channel, the time domain resources of the first reference signal and the time domain resources of the second reference signal can be designed to be continuous. This can reduce the channel changes caused by time variation and improve the accuracy of channel estimation.

[0025] In conjunction with any one of the first to third aspects, in some implementations, the time-domain lengths of the first time-domain resource and the second time-domain resource are associated with at least one of the following: the number of ports of the first communication device, the number of paths corresponding to the first channel, and the number of paths corresponding to the second channel. Wherein, the number of ports of the first communication device represents the number of ports used by the first communication device to transmit the first reference signal or the second reference signal, that is, the number of ports configured for the first reference signal or the second reference signal, and also the number of ports corresponding to the first reference signal or the second reference signal.

[0026] In conjunction with any one of the first to third aspects, in some implementations, the time-domain lengths of the first time-domain resource and the second time-domain resource satisfy: T≥max{I·log(Q), J·log(Q)}; where T represents the time-domain lengths of the first time-domain resource and the second time-domain resource, I represents the number of paths corresponding to the first channel, J represents the number of paths corresponding to the second channel, and Q represents the number of ports of the first communication device.

[0027] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: receiving second indication information, the second indication information indicating at least one of the following: the time domain length of the first time domain resource, the location of the first time domain resource, the time domain length of the second time domain resource, and the location of the second time domain resource.

[0028] In conjunction with any one of the second to third aspects, in some implementations, the method further includes: sending or receiving second indication information, the second indication information indicating at least one of the following: the time domain length of the first time domain resource, the location of the first time domain resource, the time domain length of the second time domain resource, and the location of the second time domain resource.

[0029] For the beneficial effects not described in detail in the second and third aspects, please refer to the relevant descriptions in the first aspect, which will not be repeated here.

[0030] Fourthly, a communication apparatus is provided for performing the method in any of the possible implementations of the first to third aspects described above. Specifically, the apparatus may include units and / or modules for performing the method in any of the possible implementations of the first to third aspects, such as processing units and / or communication units.

[0031] In one implementation, the device is a communication device (such as a terminal device, a network device, or a RIS device). When the device is a terminal device, the communication unit can be a transceiver or an input / output interface; the processing unit can be at least one processor. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0032] In another implementation, the device is a chip, chip system, or circuit for a communication device (such as a terminal device, a network device, or a RIS device). When the device is a chip, chip system, or circuit for a terminal device, the communication unit can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; the processing unit can be at least one processor, processing circuit, or logic circuit.

[0033] Fifthly, a communication apparatus is provided, comprising: at least one processor for executing a computer program or instructions stored in a memory to perform the method in any of the possible implementations of the first to third aspects described above. Optionally, the apparatus further comprises a memory for storing the computer program or instructions. Optionally, the apparatus further comprises a communication interface through which the processor reads the computer program or instructions from the memory.

[0034] In one implementation, the device is a communication device (such as a terminal device, a network device, or a RIS device).

[0035] In another implementation, the device is a chip, chip system, or circuit for a communication device (such as a terminal device, a network device, or a RIS device).

[0036] Sixthly, a processor is provided for executing the methods provided in the first to third aspects described above.

[0037] Unless otherwise specified, or if it does not contradict its actual function or internal logic in the relevant description, the transmission and acquisition / reception operations involved in the processor can be understood as processor output and reception, input and other operations, or as transmission and reception operations performed by radio frequency circuits and antennas. This application does not limit them in this regard.

[0038] Optionally, the device further includes: a memory for storing a program; correspondingly, at least one processor for executing the computer program or instructions in the memory.

[0039] Optionally, the device also includes a communication interface. The communication interface is coupled to the processor and can be used to input information to the processor or output information from the processor.

[0040] A seventh aspect provides a computer-readable storage medium storing program code for execution by a device, the program code including methods for performing any of the possible implementations of the first to third aspects described above.

[0041] Eighthly, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the method in any one of the possible implementations of the first to third aspects described above.

[0042] Ninth aspect, a chip is provided, the chip including a processor and a communication interface, the processor reading instructions from a memory through the communication interface and executing the method provided by any of the above-described implementations of any of the first to third aspects.

[0043] Optionally, as one implementation, the chip also includes a memory storing computer programs or instructions, and a processor for executing the computer programs or instructions in the memory. When the computer programs or instructions are executed, the processor is used to perform the method provided by any of the above implementations of any of the first to third aspects.

[0044] In a tenth aspect, a computer program product comprising instructions is provided, which, when run on a computer, causes the computer to perform the method provided by any of the above-described implementations of any of the first to third aspects.

[0045] Eleventhly, a communication system is provided, including one or more of the aforementioned RIS, first communication device, and second communication device. Attached Figure Description

[0046] Figure 1 is a schematic diagram of a wireless communication system applicable to an embodiment of this application.

[0047] Figure 2 is a schematic diagram of a communication method 200 provided in an embodiment of this application.

[0048] Figure 3 is a schematic diagram of a reference signal applicable to an embodiment of this application.

[0049] Figure 4 is a schematic flowchart of a communication method 400 applicable to an embodiment of this application.

[0050] Figures 5 and 6 are simulation diagrams.

[0051] Figure 7 is a schematic diagram of a communication device 700 provided in an embodiment of this application.

[0052] Figure 8 is a schematic diagram of another communication device 800 provided in an embodiment of this application.

[0053] Figure 9 is a schematic diagram of a chip system 900 provided in an embodiment of this application. Detailed Implementation

[0054] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0055] Before introducing the scheme of this application, the following points should be noted.

[0056] (1) In this application, "instruction" can include direct instruction, indirect instruction, explicit instruction, implicit instruction, etc. When describing a certain instruction information as being used to instruct A, it can be understood that the instruction information carries A, carries the identifier of A, carries B which is associated with A, carries the identifier of B which is associated with A, etc. In other words, if the receiving side of a certain instruction information can determine A based on the instruction information, it can be described as the instruction information being used to instruct A, and the specific method of determination is not limited. When it is understood that the instruction information carries A, "instruction" or "used to instruct" can be replaced with "includes". In this case, a statement similar to "sending / receiving instruction information, the instruction information being used to instruct A" can be replaced with "sending / receiving A".

[0057] In this application, the information indicated by the instruction information is called the information to be instructed. In specific implementations, there are many ways to indicate the information to be instructed, such as, but not limited to, directly indicating the information to be instructed, such as the information to be instructed itself or its index. It can also indirectly indicate the information to be instructed by indicating other information, where there is a relationship between the other information and the information to be instructed. It can also indicate only a part of the information to be instructed, while the other parts are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent. Furthermore, the information to be instructed can be sent as a whole or divided into multiple sub-information pieces, and the sending period and / or timing of these sub-information pieces can be the same or different.

[0058] (2) In this application, the expression " / " is used to indicate that the objects before and after are in an "or" relationship; for example, A / B can mean: A or B. The expression "and / or" is used to indicate that the objects before and after are in a relationship of either "and" or "or"; for example, A and / or B can mean the following: A exists alone, B exists alone, A and B exist simultaneously, where A and B can be single or multiple. "At least one of the following" or similar expressions are used to indicate any combination of the listed items; for example, at least one of A, B and / or C can mean the following: A exists alone, B exists alone, C exists alone, A and B exist simultaneously, B and C exist simultaneously, A and C exist simultaneously, A, B and C exist simultaneously, where A, B, and C can be single or multiple.

[0059] (3) In this application, "send" and "receive" indicate the direction of signal transmission. For example, "send information to XX" can be understood as the destination of the information being XX, which may include direct transmission via the air interface or indirect transmission by other units or modules via the air interface. "Receive information from YY" can be understood as the source of the information being YY, which may include direct reception from YY via the air interface or indirect reception from YY by other units or modules via the air interface. "Send" can also be understood as the "output" of the chip interface, and "receive" can also be understood as the "input" of the chip interface. In other words, sending and receiving can occur between devices, such as between network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via a bus, wiring, or interface.

[0060] (4) In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0061] (5) In this application, "first," "second," and "#1," "#2," and "#A" are merely for descriptive convenience and are used to distinguish objects, and are not intended to limit the scope of the embodiments of this application. They are not used to describe the order or sequence of features. It should be understood that such described objects can be interchanged where appropriate in order to describe solutions other than those in the embodiments of this application.

[0062] (6) In this application, "predefined" can mean a standard protocol predefined, or it can mean a pre-agreed or pre-negotiated agreement between devices. Here, "protocol" can refer to a standard protocol in the field of communications, for example, it may include fourth-generation (4G) protocols. th Generation 4G network, fifth generation (5G) network th This application does not limit the scope to network protocols such as 5G (generation, 5G), New Radio (NR), 5.5G, and related protocols applied in future communication networks.

[0063] (7) In this application, the words “exemplary,” “for example,” etc., are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as an “example” in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word “example” is intended to present the concept in a concrete manner. In the embodiments of this application, “of,” “corresponding, relevant,” and “corresponding” may sometimes be used interchangeably, and it should be noted that their intended meanings are consistent unless their distinction is emphasized.

[0064] (8) This application involves matrix transformations in several places. For ease of understanding, a unified explanation is provided here. The superscript T indicates transpose, such as A T This represents the transpose of matrix (or vector) A. The superscript * indicates conjugate, e.g., At * This represents the conjugate of matrix (or vector) A. The superscript H indicates the conjugate transpose, e.g., A H This represents the conjugate transpose of matrix (or vector) A. The superscript + indicates generalized conjugation, such as A... + This represents the generalized conjugate matrix of matrix (or vector) A. For the sake of brevity, explanations of identical or similar cases will be omitted in the following text.

[0065] (9) In this application, there are multiple instances of “receiving a first reference signal from… based on a first time domain resource”, “receiving a second reference signal from… based on a second time domain resource”, “sending a first reference signal through… based on a first time domain resource”, and “sending a second reference signal through… based on a second time domain resource”; among them, “receiving a first reference signal from… based on a first time domain resource” can be replaced by: “receiving a first reference signal from… on a first time domain resource”, “receiving a first reference signal from…, the first reference signal being carried / mapped on a first time domain resource”, “receiving a first reference signal from… that is carried / mapped on a first time domain resource” or “receiving a first reference signal from… carried by a first time domain resource”, of course, this application is not limited to this; similarly, “receiving a second reference signal from… based on a second time domain resource” and “receiving a third reference signal from… based on F group time domain resources” can be replaced by similar alternative expressions.

[0066] The phrase "transmitting a first reference signal based on a first time domain resource via..." can be replaced with "transmitting a first reference signal based on a first time domain resource via...", "transmitting a first reference signal via..., the first reference signal being carried / mapped on the first time domain resource", "transmitting a first reference signal carried / mapped on the first time domain resource via...", or "transmitting a first reference signal carried by the first time domain resource via...", and this application is not limited to these. Similarly, "transmitting a second reference signal based on a second time domain resource via..." and "transmitting a third reference signal based on F group time domain resources via..." can be replaced with similar expressions.

[0067] First, let me introduce the communication system to which this application applies.

[0068] The technical solutions provided in this application can be applied to various communication systems, such as 5th generation (5G) or new radio (NR) systems, frequency division duplex (FDD) systems, and time division duplex (TDD) systems. The technical solutions provided in this application can also be applied to future communication networks. Furthermore, the technical solutions provided in this application can be applied to device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), and Internet of Things (IoT) communication systems. The technical solutions provided in this application can also be applied to non-terrestrial network (NTN) systems such as inter-satellite communication and satellite communication.

[0069] As an example, a satellite communication system includes a satellite base station and terminal equipment. The satellite base station provides communication services to the terminal equipment. Satellite base stations can also communicate with each other. A satellite can act as a base station or as a terminal device. Here, "satellite" can refer to drones, hot air balloons, low-Earth orbit satellites, medium-Earth orbit satellites, high-Earth orbit satellites, etc. "Satellite" can also refer to non-terrestrial base stations or non-terrestrial equipment.

[0070] As an example, V2X communication can include: vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, and vehicle-to-network (V2N) communication.

[0071] In a communication system, a device can send signals to or receive signals from another device. These signals can include information, signaling, or data. The device can also be replaced by an entity, network entity, communication equipment, communication module, node, communication node, etc. This application uses a device as an example for description.

[0072] The terminal device in this application embodiment can be a device or module that accesses the aforementioned communication system and has corresponding communication functions. The terminal device can include various devices with wireless communication capabilities, which can be used to connect people, objects, machines, etc. The terminal device can be widely applied in various scenarios, such as: cellular communication, D2D, V2X, peer-to-peer, M2M, MTC, IoT, virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery, etc. The terminal device can be a terminal in any of the above scenarios, such as an MTC terminal, an IoT terminal, etc. Terminal equipment can be user equipment (UE), terminal, fixed equipment, mobile station equipment or mobile equipment, subscriber unit, handheld device, vehicle-mounted equipment, wearable device, cellular phone, smartphone, session initiation protocol (SIP) phone, wireless data card, personal digital assistant (PDA), computer, tablet computer, laptop computer, wireless modem, handset, laptop computer, computer with wireless transceiver capability, smart book, vehicle, satellite, global positioning system (GPS) device, target tracking device, aircraft (e.g., drone, helicopter, multiple helicopters, four helicopters, or airplanes), ship, remote control device, smart home device, industrial equipment, transportation vehicle with wireless communication capability, communication module, or roadside unit with terminal function, all conforming to the 3rd generation partnership project (3GPP) standard. The device may be a wireless communication unit (RSU), or a device built into the aforementioned device (e.g., a communication module, modem, or chip in the aforementioned device), or other processing devices connected to the wireless modem.

[0073] It should be understood that in certain scenarios, a UE can also be used as a base station. For example, a UE can act as a scheduling entity, providing sidelink signaling between UEs in scenarios such as V2X, D2D, or end-to-end.

[0074] In this embodiment, the device for implementing the functions of a terminal device, i.e., the terminal device, can be the terminal device itself, or it can be any device capable of supporting the terminal device in implementing the functions, such as a chip system, chip, circuit, or communication module (i.e., a communication module that performs communication functions). This device can be installed in the terminal device. In this embodiment, the chip system can be composed of chips, or it can include chips and other discrete devices. Furthermore, the device can also be configured with program instructions for performing corresponding communication functions.

[0075] The network device in this application embodiment can be a device or module with corresponding communication functions. The network device can be a device used to communicate with terminal devices; it can also be called an access network device or a wireless access network device, such as a base station. In this application embodiment, the network device can refer to a radio access network (RAN) node (or device) that connects the terminal device to the wireless network. A base station can broadly encompass, or be replaced by, various names including: NodeB, evolved NodeB (eNB), next-generation NodeB (gNB), relay station, access point, transmitting and receiving point (TRP), transmitter, master station, auxiliary station, multiple standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, micro base station, relay node, donor node, or similar, or a combination thereof. A base station can also refer to a communication module, modem, or chip installed within the aforementioned equipment or apparatus. A base station can also be a mobile switching center, a device that performs base station functions in D2D, V2X, and M2M communications, or a device that performs base station functions in future communication systems. A base station can support networks using the same or different access technologies. The embodiments of this application do not limit the specific technologies or device forms used in the network equipment.

[0076] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move depending on the location of the mobile base station. In other examples, a helicopter or drone can be configured as a device to communicate with another base station.

[0077] In some deployments, the network devices mentioned in the embodiments of this application may be devices including CU, or DU, or devices including CU and DU, or devices with control plane CU nodes (central unit-control plane (CU-CP)) and user plane CU nodes (central unit-user plane (CU-UP)) and DU nodes.

[0078] In some deployments, multiple RAN nodes collaborate to assist terminal devices in achieving wireless access, with different RAN nodes each implementing some of the base station's functions. For example, RAN nodes can be CUs, DUs, CU-CPs, CU-UPs, or radio units (RUs). CUs and DUs can be configured separately or included in the same network element, such as a BBU. RUs can be included in radio equipment or radio units, such as RRUs, AAUs, or RRHs.

[0079] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, a radio access network can also be an open radio access network (O-RAN or ORAN) architecture. In an O-RAN system, CU can also be called an open CU (openCU, O-CU), DU can also be called an open DU (open DU, O-DU), CU-CP can also be called an open CU-CP (O-CU-CP), CU-UP can also be called an open CU-UP (O-CU-UP), and RU can also be called an open RU (openRU, O-RU). Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

[0080] In this embodiment, the device for implementing the functions of a network device can be a network device itself, or a device capable of supporting the network device in implementing those functions, such as a chip system, chip, circuit, or communication module (i.e., a communication module that performs communication functions). This device can be installed within the network device. In this embodiment, the chip system can be composed of chips, or it can include chips and other discrete devices. Furthermore, the device can be configured with program instructions for performing corresponding communication functions. This embodiment only uses a network device as an example to illustrate the device for implementing the functions of a network device, and does not limit the solution of this embodiment.

[0081] Network devices and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and satellites. This application does not limit the scenario in which the network devices and terminal devices are located.

[0082] Referring to Figure 1, Figure 1 is a schematic diagram of a wireless communication system applicable to an embodiment of this application.

[0083] As shown in Figure 1, the wireless communication system includes at least one network device, such as network device 110 shown in Figure 1, and may also include at least one terminal device, such as terminal device 120 shown in Figure 1. Both the network device and the terminal device can be configured with multiple antennas, and the network device and the terminal device can communicate using multi-antenna technology.

[0084] As shown in Figure 1, the wireless communication system also includes a reconfigurable intelligent surface (RIS) 130. The RIS can be used to facilitate communication between devices, such as between network devices and terminal devices. For example, if the transmitting end (such as a network device or a terminal device) and the receiving end (such as a network device or a terminal device) cannot communicate directly, or if the signal is weak during direct communication, or if there are obstacles obstructing communication between the transmitting end and the receiving end, communication can be achieved through the RIS.

[0085] RIS, also known as an intelligent reflective surface (IRS) or large intelligent surface (LIS), will be used as the example below for simplicity. RIS is a subwavelength-scale artificial two-dimensional material, typically composed of metals, dielectrics, and tunable elements, and can be equivalently characterized as a radio link control (RLC) circuit. By adjusting the physical properties of the electromagnetic units, such as capacitive reactance, impedance, or inductive reactance, the radiation characteristics of the RIS can be altered, enabling unconventional physical phenomena such as irregular reflection, negative refraction, absorption, focusing, and polarization conversion, thereby dynamically controlling electromagnetic waves. RIS can generate the required electromagnetic behavior for each electromagnetic unit by controlling the bias voltage of varactor diodes, PIN switches, microelectromechanical systems (MEMS) switches, liquid crystals, graphene, etc.

[0086] The RIS can be considered as a reflective panel, which is a smart panel comprising multiple antenna elements 131 (referred to as elements). At least one element can act as a passive reflective device. By flexibly configuring the parameters of each element (such as amplitude and / or phase), the wireless channel fading can be controlled and the desired directional beam can be formed.

[0087] RIS can be installed in various environments, such as on large flat surfaces (e.g., indoor walls or ceilings, outdoor buildings or signs), to reflect radio frequency (RF) energy around obstacles and create a virtual line-of-sight (LoS) propagation path between the communication source and the target. For example, the advantages of RIS can include the following.

[0088] 1) Enhanced Spectrum Efficiency: Through intelligent control of pairs, RIS can further improve the communication quality of wireless links, enhance the useful signal strength at the receiver, reduce channel interference, and provide an entry point for the realization of future overall intelligent networks.

[0089] 2) Reduced energy consumption and equipment complexity: RIS can passively reflect the received signal. There is no need to configure transmit and receive units at the RIS end, and no need to encode and decode the data. Therefore, the actual hardware complexity of RIS can be greatly reduced compared with network equipment and terminal equipment, thereby achieving the goal of reducing the system energy consumption of wireless network.

[0090] 3) Easy to deploy: Due to the inclusion of passively reflecting and / or transmitting electromagnetic devices, RIS can be easily deployed on various building surfaces, interior walls, platforms, roadside billboards, highway signs, vehicle windows, and other equipment. Furthermore, RIS can be removed or redeployed at any time as needed by the network.

[0091] 4) Compatibility: RIS can be regarded as a supplementary device to existing networks, so it will not affect existing protocols and does not require changes to existing devices, thus having compatibility.

[0092] 5) Full-duplex: Compared to relay systems operating in half-duplex mode, RIS can perform only passive reflection, thus operating in full-duplex mode and improving spectral efficiency.

[0093] The above description of RIS is merely illustrative and is not intended to limit the scope of this application. Furthermore, while the following embodiments primarily use RIS as an example, any device or apparatus capable of implementing the functions of RIS is applicable to the embodiments of this application.

[0094] Furthermore, Figure 1 is only a schematic diagram. The wireless communication system may also include other devices, such as core network devices, wireless relay devices and / or wireless backhaul devices, as well as a greater number of network devices, terminal devices, etc., which are not shown in Figure 1.

[0095] To facilitate a better understanding of the technical solution of this application, some related technologies involved in the technical solution of this application are introduced.

[0096] 1. Multi-input multi-output (MIMO) technology: Utilizing spatial resources, signals can obtain array gain, multiplexing and diversity gain, and interference cancellation gain in space without increasing system bandwidth, thereby multiplying the capacity and spectral efficiency of the communication system.

[0097] 2. Reference signal (RS): Also known as pilot, reference sequence, reference signal, etc. For consistency, it will be described as reference signal below. A reference signal is a physical signal that transmits a sequence to achieve a specific function. Specifically, a reference signal is a physical signal generated by mapping a specific sequence onto corresponding resources according to a preset resource mapping method.

[0098] In a multiple-input multiple-output (MIMO) system, each port has an independent data channel. Based on a known reference signal, the receiver performs channel estimation for each port and reconstructs the transmitted data accordingly. Channel estimation refers to the process of reconstructing the received signal to compensate for channel fading and noise, using the known reference signals from both the transmitter and receiver to track the time and frequency domain variations of the channel.

[0099] In this application, the reference signal, as an example, can be any of the following: channel state information reference signal (CSI-RS), sounding reference signal (SRS), demodulation reference signal (DMRS), phase track reference signal (PT-RS), cell reference signal (CRS), etc. Among them, DMRS can be used for demodulation of the physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH). CSI-RS can be used for channel information measurement and to report channel state information (CSI), which includes at least one of the following: precoding matrix indicator (PMI), rank indicator (RI), and channel quality indicator (CQI).

[0100] It should be understood that the reference signals listed above are merely examples and should not be construed as limiting this application. This application does not preclude the possibility of defining other reference signals in future agreements to achieve the same or similar functions.

[0101] 3. Beam: A communication resource. Different beams can be considered different resources. The same information or different information can be transmitted through different beams.

[0102] In the NR protocol, beams can be represented as spatial domain filters, or spatial filters or spatial parameters. The beam used to transmit signals can be called the transmission beam (Tx beam), and the beam used to receive signals can be called the reception beam (Rx beam).

[0103] The transmit beam can refer to the distribution of signal strength in different directions in space after a signal is transmitted through an antenna, while the receive beam can refer to the distribution of signal strength in different directions in space of a wireless signal received from an antenna.

[0104] Furthermore, the beam can be a wide beam, a narrow beam, or other types of beam. The beamforming technology can be beamforming technology or other technologies. Specifically, beamforming technology can be digital beamforming technology, analog beamforming technology, or hybrid digital / analog beamforming technology, etc.

[0105] As an example, multiple beams with the same or similar communication characteristics can be considered as a single beam.

[0106] A beam can correspond to one or more antenna ports, used for transmitting data channels, control channels, and detection signals. The one or more antenna ports corresponding to a beam can also be regarded as a set of antenna ports.

[0107] 4. A time-domain unit, or time unit, represents the granularity of a resource in the time domain. A time-domain unit can be a symbol, an orthogonal frequency division multiplexing (OFDM) symbol, a mini-slot, a slot, a partial slot, a subframe, or a radio frame, etc. A slot can consist of 6, 7, 12, or 14 symbols; a mini-slot can include at least one symbol (e.g., 2, 7, or 14 symbols, or any number of symbols less than or equal to 14); the duration of a subframe in the time domain can be 1 millisecond (ms). It should be understood that the time-domain unit sizes listed above are merely for ease of understanding of the scheme in this application and do not constitute a limitation on the scope of protection of this application. It is understood that the above time-domain unit sizes can be other values, and this application does not limit them.

[0108] RIS is generally considered a passive reflector, and in MIMO systems, the number of RIS elements is usually large (e.g., possibly thousands). Directly estimating the RIS channel matrix itself requires a number of pilots on the order of the RIS elements, resulting in a bottleneck in overhead. Furthermore, since RIS lacks an RF chain for active transmission and reception, it cannot transmit, receive, or process signals, making it impossible to obtain channel state information using traditional channel estimation methods. Moreover, the dramatic increase in channel dimension with the increase in the number of reflector elements further complicates the acquisition of channel state information.

[0109] Without loss of generality, assuming the network device has N antennas, the RIS has M elements (or unit elements), and the terminal device has a single antenna, then the signal received by the network device (after removing the reference signal) includes the signal from the direct channel and the signal from the cascaded channel.

[0110] The direct channel, as shown by H0 in Figure 1, represents the channel between the network device and the terminal device (referred to as the BS-UE channel). If it is downlink transmission, that is, the network device sends a signal to the terminal device, the direct channel represents the downlink channel between the network device and the terminal device; if it is uplink transmission, that is, the terminal device sends a signal to the network device, the direct channel represents the uplink channel between the network device and the terminal device.

[0111] The cascaded channels, as shown in H1 and H2 in Figure 1, include the channel between the RIS and the terminal device (referred to as the RIS-UE channel) and the channel between the network device and the RIS (referred to as the BS-RIS channel). For downlink transmission, i.e., the network device sending signals to the terminal device, the cascaded channels include the channel between the network device and the RIS, and the channel between the RIS and the terminal device. For uplink transmission, i.e., the terminal device sending signals to the network device, the cascaded channels include the channel between the terminal device and the RIS, and the channel between the RIS and the network device. In the following embodiments, unless otherwise specified, "channel between RIS and terminal device," "channel between RIS and terminal device," "channel between terminal device and RIS," or "channel between terminal device and RIS" can refer to the channel from RIS to the terminal device (i.e., the downlink transmission scenario) or the channel from the terminal device to the RIS (i.e., the uplink transmission scenario). Similarly, "channel between RIS and network device", "channel between RIS and network device", "channel between network device and RIS" or "channel between network device and RIS" can refer to the channel from RIS to network device (i.e., the uplink transmission scenario) or the channel from network device to RIS (i.e., the downlink transmission scenario).

[0112] As can be seen from Equation 1, joint channel estimation for RIS-assisted MIMO systems faces at least the following challenges.

[0113] (1) Since the RIS does not have an RF chain for active transmission and reception, it cannot transmit, receive, or process signals. This makes it difficult for the RIS-assisted MIMO system to obtain channel state information using traditional channel estimation methods. Moreover, the rapid increase in channel dimension with the increase in the number of elements also increases the difficulty of obtaining channel state information.

[0114] (2) In actual communication, the direct channel (i.e., the BS-UE channel) and the cascaded channel (i.e., the BS-RIS-UE channel) may coexist, making it difficult to estimate the direct channel and the cascaded channel separately from the received signal.

[0115] For RIS-assisted MIMO systems, existing channel estimation schemes generally fall into two categories: one assumes the direct path is blocked and only considers the estimation of the cascaded path, which is not suitable for channel estimation when the direct path exists. The other category directly separates and estimates the direct path and cascaded path by switching the RIS, which suffers from power consumption and error propagation problems due to frequent RIS switching.

[0116] In view of this, for channel estimation in RIS-assisted MIMO systems when a direct channel exists, this application proposes to achieve independent estimation of the direct channel and the cascaded channel by jointly designing the transmission rules of the reference signal and the phase of the RIS.

[0117] The methods provided by the embodiments of this application will be described in detail below with reference to the accompanying drawings. The embodiments provided by this application can be applied to the scenarios shown in the above figures and are not limited thereto. Furthermore, the terms used below are explained in the preceding text and will not be repeated hereafter. For ease of description, terminal devices and network devices are used as examples in the following illustrative description. The terminal device can be replaced by a terminal device or a component of a terminal device (e.g., a chip, chip system, circuit, or communication module), and the network device can be replaced by a component of a network device (e.g., a chip, chip system, circuit, or communication module). Furthermore, the steps described below as being performed by a single execution entity can also be divided into steps performed by multiple execution entities, which can be logically and / or physically separated.

[0118] Referring to Figure 2, as an example, Figure 2 is a schematic diagram of a communication method 200 provided in an embodiment of this application. The method 200 shown in Figure 2 may include the following steps. In the following embodiments, RIS is mainly used as an example for description, but any device or apparatus capable of implementing the function of RIS is applicable to the embodiments of this application.

[0119] Method 200 includes steps S201, S202, S203, and S204, and there is no strict order among these steps. For example, steps S201 and S203 can be executed first, followed by steps S202 and S204; or steps S201 and S202 can be executed first, followed by steps S203 and S204; there is no restriction on this. These steps are described below.

[0120] S201, RIS receives a first reference signal from a first communication device based on a first time-domain resource.

[0121] Accordingly, the first communication device transmits a first reference signal based on a first time-domain resource. Specifically, the first communication device can transmit the first reference signal to the second communication device via a RIS.

[0122] S203, RIS receives a second reference signal from the first communication device based on the second time domain resources.

[0123] Accordingly, the first communication device transmits a second reference signal based on the second time-domain resources. Specifically, the first communication device can transmit the second reference signal to the second communication device via RIS.

[0124] In one possible scenario, the first communication device is a network device, and the second communication device is a terminal device. In this case, the first reference signal and the second reference signal are downlink reference signals, such as CSI-RS.

[0125] In another possible scenario, the first communication device is a terminal device, and the second communication device is a network device. In this case, the first reference signal and the second reference signal are uplink reference signals, such as SRS.

[0126] In another possible scenario, both the first and second communication devices are terminal devices. In this case, the first and second reference signals are sidelink (SL) reference signals, such as sidelink beam management reference signals.

[0127] The first reference signal and the second reference signal are the same, and the first time domain resource and the second time domain resource have the same length.

[0128] In this context, "identical reference signals" indicates identical sequences. Specifically, "identical first reference signal" and "identical second reference signal" mean that the sequences used to generate the first reference signal and the second reference signal are identical. In other words, the first communication device transmits the first reference signal based on first time-domain resources, and the first communication device repeatedly transmits the first reference signal based on second time-domain resources.

[0129] It can be understood that the first reference signal and the second reference signal represent the same type of reference signal. Specifically, the first reference signal is a reference signal on the first time-domain resource, which does not limit the number of reference signals on the first time-domain resource, nor does it limit the sequence of reference signals on the first time-domain resource to be the same; that is, the reference signals on each time-domain unit in the first time-domain resource may be different. The second reference signal is a reference signal on the second time-domain resource, which also does not limit the number of reference signals on the second time-domain resource, nor does it limit the sequence of reference signals on the second time-domain resource to be the same; that is, the reference signals on each time-domain unit in the second time-domain resource may be different.

[0130] The length of the time-domain resource, or the time-domain length of the time-domain resource, represents the number of time-domain units contained in the time-domain resource. Specifically, the first time-domain resource and the second time-domain resource have the same length, which means that the first time-domain resource contains the same number of time-domain units as the second time-domain resource.

[0131] The first reference signal and the second reference signal are the same, meaning the reference signal on the first time domain resource is the same as the reference signal on the second time domain resource. In other words, the reference signal on the first time domain resource is repeatedly transmitted based on the second time domain resource. For example, if multiple reference signals (i.e., the first reference signal) are transmitted sequentially on the first time domain resource, then these multiple reference signals (i.e., the second reference signal) are repeatedly transmitted sequentially based on the second time domain resource, and the order of the multiple reference signals on the second time domain resource is the same as the order of the multiple reference signals on the first time domain resource. For instance, the first communication device transmits a first reference signal based on the first time domain resource, and this first reference signal is represented as: S1, S2, S3, ..., S... T (These are all referred to as the first reference signal, but may be first reference signals with different sequences); the first communication device repeatedly transmits based on the second time-domain resources: S1, S2, S3, ..., S T (These are all referred to as the second reference signal, but may be second reference signals with different sequences). Where T represents the length of the first time-domain resource and the second time-domain resource; in other words, the first time-domain resource includes T time-domain units, and the second time-domain resource includes T time-domain units; S t This represents a reference signal, t = 1, 2, ..., T, meaning that a reference signal is transmitted in each time domain unit, and each reference signal may include G elements (in other words, the length of a reference signal is G; in other words, the sequence used to generate the reference signal contains G elements).

[0132] As mentioned earlier, the sequence of reference signals on the first time-domain resource may be the same or different. The reference signal on the second time-domain resource can be understood as a repeated transmission of the reference signal on the first time-domain resource; therefore, the sequence of reference signals on the second time-domain resource may be the same or different. In the example above, let T reference signals be S1, S2, S3, ..., S... T The examples provided are for illustration, but the embodiments of this application are not limited thereto. That is, the T reference signals can be completely different, or partially different, or completely the same, and there is no limitation thereto.

[0133] Optionally, the first time-domain resource and the second time-domain resource are continuous in the time domain. Let the first and second time-domain resources each include T time-domain units, and the first reference signal be represented as: S1, S2, S3, ..., S... T For example, the first time-domain resource and the second time-domain resource are continuous in the time domain, which can be understood as: the first communication device sequentially transmits S1, S2, S3, ..., S in 2·T consecutive time-domain units. T S1, S2, S3, ..., S T The above is an illustrative example, and the embodiments of this application are not limited thereto. For example, the first time-domain resource and the second time-domain resource may also be separated by one or more time-domain units in the time domain.

[0134] It is understood that the embodiments of this application mainly use the example of a first communication device transmitting a reference signal based on a first time domain resource and a second time domain resource for illustration. That is, the first communication device repeatedly transmits the first reference signal transmitted based on the first time domain resource based on a second time domain resource, which is not limited thereto. In other words, the first communication device can repeatedly transmit the first reference signal transmitted based on the first time domain resource based on multiple second time domain resources. As an example, the multiple second time domain resources can be multiple second time domain resources that are consecutive in the time domain.

[0135] Optionally, the length of the first time-domain resource (or the length of the first time-domain resource in the time domain) is related to at least one of the following: the number of ports of the first communication device, the number of paths corresponding to the first channel, and the number of paths corresponding to the second channel.

[0136] The first channel, also known as the direct channel, refers to the channel through which a signal (such as a reference signal) travels directly from the first communication device to the second communication device, that is, the channel between the first and second communication devices.

[0137] The second channel, also known as the channel on the first communication device side of the cascaded channel, represents the channel between the first communication device and the RIS. The cascaded channel refers to the channel that a signal (such as a reference signal) traverses when it is reflected from the first communication device through the RIS to the second communication device, that is, the channel between the first communication device, the RIS, and the second communication device, including: the channel between the first communication device and the RIS, and the channel between the RIS and the second communication device.

[0138] The number of ports of the first communication device refers to the number of ports corresponding to the first or second reference signal. In the embodiments of this application, the number of ports of the communication device (such as the first communication device) is mentioned multiple times. This number can be expressed as the number of ports configured for the reference signals. That is, if the communication device sends or receives reference signals through Q ports, then the number of ports of the communication device is Q, where Q is an integer greater than or equal to 1. For simplicity and ease of description, the following descriptions will use the number of ports of the communication device.

[0139] In the embodiments of this application, the number of paths is mentioned multiple times, such as the number of paths corresponding to the first channel, the number of paths corresponding to the second channel, and the number of paths corresponding to the third channel. This will be explained uniformly here. The number of paths, or the quantity of paths, can be any of the following: number of multiple paths, number of main paths, or number of sub-paths. The number of multiple paths can also be replaced by the number of path clusters (or simply the number of clusters). The meaning of each parameter will be explained uniformly here, and will not be repeated below.

[0140] Multipath: A signal travels from the transmitter to the receiver via multiple paths; these multiple paths are called multipath. Main Path: The primary path through which a signal travels from the transmitter to the receiver; the main path is usually the most direct and has the strongest signal. Sub-path: A secondary path through which a signal propagates from the transmitter to the receiver; these are usually paths formed by phenomena such as reflection, refraction, diffraction, and / or scattering. Path Cluster: In multipath propagation, a path cluster refers to a set of paths with similar propagation characteristics. A path cluster includes multiple sub-paths (or multiple paths) that typically have similar characteristics in time, frequency, or space, and therefore can be treated as a whole.

[0141] As an example, the length of the first time-domain resource is related to the number of ports of the first communication device, the number of paths corresponding to the first channel, and the number of paths corresponding to the second channel.

[0142] As an example, the length of the first time-domain resource satisfies Equation 2. T≥max{I·log(Q), J·log(Q)} Equation 2

[0143] Where T represents the length of the first time-domain resource; I represents the number of paths corresponding to the first channel; J represents the number of paths corresponding to the second channel; Q represents the number of ports of the first communication device, that is, the number of ports of the first communication device when transmitting the first reference signal or the second reference signal, that is, the number of ports configured for the first reference signal or the second reference signal, that is, the number of ports corresponding to the first reference signal or the second reference signal; max() represents the maximum value operation, and log() represents the logarithmic function.

[0144] Considering different first communication devices, the above formula 2 can also be transformed into: T k ≥max{I k ·log(Q k ), J k ·log(Q k )}. Here, the subscript k can represent the index (or identifier, or number, or sequence number) of the first communication device, which can be used to identify the first communication device. The value of k is different for different first communication devices.

[0145] The above is an illustrative example, and the embodiments of this application are not limited thereto. For example, the length of the first time-domain resource is related to one or both of the following: the number of ports of the first communication device, the number of paths corresponding to the first channel, and the number of paths corresponding to the second channel, such as T≥max{I·log(Q), ε}, where ε is a constant, such as a constant estimated based on historical communication data. As another example, the length of the first time-domain resource (i.e., T) can be a large value estimated based on historical communication data.

[0146] S202, RSI reflects the first reference signal based on the first phase. Correspondingly, the second communication device receives the first reference signal.

[0147] S204, RIS reflects the second reference signal based on the second phase. Accordingly, the second communication device receives the second reference signal.

[0148] The second phase is out of phase with the first phase. For example, the first communication device transmits a first reference signal based on a first time-domain resource, which can be represented as: {S1,S2,S3,……,S} T After receiving the first reference signal, RIS reflects the first reference signal based on the first phase (e.g., -e1), that is, the {S1, S2, S3, ..., S...} on the first time domain resource. T In the second time domain, the phase of each reference signal is (-e1); the first communication device transmits a second reference signal based on the second time domain resources, the second reference signal being: {S1,S2,S3,……,S} TAfter receiving the second reference signal, RIS reflects the second reference signal based on the second phase (e.g., denoted as e1), which is the {S1, S2, S3, ..., S} in the second time domain resource. T The phase of each reference signal in} is e1.

[0149] Referring to Figure 3, as an example, Figure 3 is a schematic diagram of reference signals applicable to embodiments of this application. As shown in Figure 3, the index of the first communication device is k, and the first communication device is based on the first time domain resource T (e.g., the T corresponding to the first communication device k is denoted as T). k A first reference signal is transmitted by 1 time-domain unit (e.g., time slot), which can be represented as: {S} k,1 ,S k,2 ,S k,3 ,……,S k,Tk After receiving the first reference signal, RIS reflects the first reference signal based on the first phase (-e1), that is, the {S} on the T time-domain units of the first time-domain resource. k,1 ,S k,2 ,S k,3 ,……,S k,Tk In the first time domain resource, the phase of each reference signal is (-e1); the first communication device transmits the second reference signal (i.e., repeatedly transmits the first reference signal) based on the T time domain units following the first time domain resource (i.e., the T time domain units of the second time domain resource); after receiving the second reference signal, the RIS reflects the second reference signal based on the second phase e1, that is, the {S} on the T time domain units of the second time domain resource. k,1 ,S k,2 ,S k,3 ,……,S k,Tk In this context, each reference signal has a phase of e1. As mentioned earlier, the sequences of reference signals on the first time-domain resource may be the same or different. In the example above, T... k The reference signals are S k,1 ,S k,2 ,S k,3 ,……,S k,Tk The example provided is for illustration only; however, the embodiments of this application are not limited to this, that is, T k The reference signals can be completely different, partially different, or completely identical; there is no limitation on this. Optionally, method 200 further includes: the second communication device performing channel estimation based on the first and second reference signals to determine channel information of the first channel and / or the second channel. The channel information can represent information reflecting channel characteristics and channel quality. The specific method for determining the channel information will be described in detail later.

[0150] Optionally, method 200 further includes: the RIS receiving a third reference signal from the first communication device based on F sets of time-domain resources; the RIS receiving the third reference signal based on B phase reflections. Accordingly, the first communication device transmits the third reference signal, and the second communication device receives the third reference signal.

[0151] Specifically, in this embodiment, the first communication device can be designed to transmit reference signals in two phases, referred to as phase 1 and phase 2. The reference signals in phase 1 can be used to estimate the first channel and / or part of the cascaded channel (i.e., the second channel), while the reference signals in phase 2 can be used to estimate the remaining cascaded channel (i.e., the third channel, which is the channel between the second communication device and the RIS). The first and second reference signals can be understood as reference signals in phase 1. The reference signals in phase 2, referred to as the third reference signal, are described below. It is understood that the third reference signal represents a class of reference signals, i.e., reference signals in phase 2, and does not limit the number of reference signals in phase 2, nor does it limit the sequence of reference signals in phase 2 to be identical.

[0152] In this context, each time-domain resource in group F comprises A time-domain units; in other words, each time-domain resource in group F has the same length. A is an integer greater than 1, F is an integer greater than 1, and B is an integer greater than or equal to 1 and less than or equal to A. As an example, group F consists of a continuous segment of time-domain resources.

[0153] The third reference signal is identical on A time-domain cells within a set of time-domain resources. Specifically, for any set of time-domain resources in set F, the third reference signal is identical on A time-domain cells within that set; in other words, for a given third reference signal, that third reference signal is repeatedly transmitted on A time-domain cells. For example, the third reference signal transmitted by the first communication device on a certain set of time-domain resources can be represented as: {S1,S1,S1,……,S1} A Alternatively, considering different first communication devices, on a certain set of time-domain resources, the reference signal transmitted by the first communication device can be expressed as: {S k,1 ,S k,1 ,S k,1 ,……,S k,1} A The subscript A indicates that there are A reference signals, meaning that reference signal S1 is repeatedly transmitted in A time domain units.

[0154] The third reference signal differs across different groups of time-domain resources. Specifically, for any two groups of time-domain resources within group F (e.g., referred to as the first group and the second group), the reference signals on the A time-domain cells of the first group are different from the reference signals on the A time-domain cells of the second group. For example, the third reference signal transmitted by the first communication device on group F of time-domain resources can be represented as: {S1,S1,S1,……,S1} A {S2,S2,S2,……,S2} A , ...{S F ,S F ,S F ,……,S F} A Alternatively, considering different first communication devices, the third reference signal transmitted by the first communication device based on the F group of time-domain resources can be expressed as: {S k,1 ,S k,1 ,S k,1 ,……,S k,1} A , {S k,2 ,S k,2 ,S k,2 ,……,S k,2} A , ...{S k,F ,S k,F ,S k,F ,……,S k,F} A Among them, {S k,j ,S k,j ,S k,j ,……,S k,j} A It can represent the reference signal sent on time-domain resource group #j, j = 1, 2, ..., F.

[0155] B phases are used for each time-domain resource in group F. That is, the phase of the third reference signal on each time-domain resource in group F is these B phases. The correspondence between the B phases and A time-domain units is the same in each time-domain resource group. The following explanation uses B equal to A as an example.

[0156] Specifically, for any set of time-domain resources, the A third reference signals (i.e., the third reference signals in the A time-domain units) of that set of time-domain resources correspond one-to-one with the A phases. The one-to-one correspondence between the third reference signals in the A time-domain units and the A phases can be understood as follows: the third reference signal in one time-domain unit uses one phase from the A phases, and different time-domain units use different phases from the A phases. For example, the third reference signals transmitted by the first communication device based on F sets of time-domain resources can be represented as: {S1,S1,S1,……,S1} A {S2,S2,S2,……,S2} A , ...{S F ,S F ,S F ,……,S F} A For any set of time-domain resources, such as the third reference signal {S} sent on time-domain resource group #j j ,S j ,S j ,……,S j} A When RIS reflects the third reference signal on the set of time-domain resources to the second communication device, the third reference signal S on the A time-domain units... j The phases are as follows: {e2, e3, ..., e A+1}. Where j = 1, 2, ..., F. Regarding whether the third reference signal and the first or second reference signal have the same phase, the embodiments of this application do not limit this. One possible scenario is that the third reference signal and the first or second reference signal have different phases, that is, e2, e3, ..., e A+1 Any value in the range is not equal to e1; another possible scenario is that the phases of the third reference signal and the first or second reference signal may have the same phase. For example, the phases of the third reference signal Sj in the A time-domain units can be: {e1, e2, ..., e...} A}

[0157] As can be understood, the above example of B equaling A was used for illustration. B can also be less than A. In this case, it can be understood that the phase of the third reference signal in at least two time-domain units of A time-domain units is the same.

[0158] Optionally, the value of A is related to the number of elements in the RIS. The number of elements in the RIS is not limited to the total number of elements on the RIS, but rather the number of elements on the RIS that reflect the signal. For example, if the total number of elements on the RIS is W', and after the RIS receives the third reference signal, if the RIS reflects the third reference signal through W elements out of W' elements, then the value of A is related to W, where W is an integer less than or equal to W'. For brevity, the following descriptions refer to the number of elements in the RIS.

[0159] As an example, the value of A satisfies Equation 3. A ≥ log(W) Equation 3

[0160] Where W represents the number of RIS elements. As an example, A is less than or equal to T.

[0161] Considering different first communication devices, the above formula 3 can also be transformed into: A k ≥log(W k The subscript k represents the index (or identifier, number, or sequence number) of the first communication device, which can be used to identify the first communication device. The value of k is different for different first communication devices.

[0162] Optionally, the value of F is related to the number of paths corresponding to the second channel. As an example, F satisfies Equation 4. F ≥ J Equation 4

[0163] Where J represents the number of paths corresponding to the second channel.

[0164] Considering different first communication devices, the above formula 4 can also be transformed into: F k ≥J k The subscript k represents the index (or identifier, number, or sequence number) of the first communication device, which can be used to identify the first communication device. The value of k is different for different first communication devices.

[0165] Furthermore, taking the first communication device as an example of a terminal device, a reference terminal device and a non-reference terminal device can be distinguished. A reference terminal device indicates that the network device can utilize the channel information corresponding to the reference terminal device to assist in estimating the channel information corresponding to the non-reference terminal device. In this case, as an example, the index k of the reference terminal device is 1. Taking Equation 3 as an example, A1 corresponding to the reference terminal device satisfies: A1≥log(W); A1 corresponding to the non-reference terminal device... k Satisfy: A k ≥log(W) / L, where L represents the number of paths corresponding to the third channel.

[0166] Optionally, method 200 further includes: the second communication device performing channel estimation based on the first reference signal, the second reference signal, and the third reference signal to determine the channel information of the third channel. The specific method for determining the channel information will be explained in detail later.

[0167] Optionally, method 200 further includes: sending or receiving first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the time-domain resources of group F. The following description combines two scenarios.

[0168] In a first possible scenario, the second communication device is a network device, and the first communication device is a terminal device. In this scenario, method 200 includes: the second communication device sending first instruction information to the first communication device, and correspondingly, the first communication device receiving the first instruction information.

[0169] In one example, the second communication device sends a first instruction message to the first communication device.

[0170] In another example, a first communication device sends a request message to a second communication device, the request message being for F groups of time-domain resources; the second communication device determines (e.g., initially determines, or updates) the F groups of time-domain resources and sends a first indication message to the first communication device. Based on this, the second communication device can send the first indication message to the first communication device after receiving the request from the first communication device. The triggering conditions for the first communication device to send the request message are not limited. For example, the first communication device can send the request message to the second communication device based on its mobility status, data transmission needs, environmental information, etc. The content of the request message is not limited; for example, the request message for requesting F groups of time-domain resources can also be replaced by: the request message for requesting resources for channel estimation. Any scheme in which the second communication device can send the first indication message based on the request message is applicable to the embodiments of this application.

[0171] In the second possible scenario, the second communication device is a terminal device, and the first communication device is a network device. In this scenario, method 200 includes: the first communication device sending first instruction information to the second communication device, and correspondingly, the second communication device receiving the first instruction information. This scenario can be referred to the first possible scenario, and will not be elaborated here.

[0172] As mentioned earlier, the first indication information indicates at least one of the following: the value of F, the value of A, and the location of the time-domain resources in group F. Several examples are provided below.

[0173] Example 1: The first indication information indicates the value of F.

[0174] Taking the first possible scenario as an example, the second communication device sends a first indication message to the first communication device, which indicates the value of F; based on the first indication message, the first communication device can determine the value of F. Further, as an example, the values ​​of A and F are related; based on the value of F indicated by the first indication message and this relationship, the first communication device can determine the value of A.

[0175] The location of the time-domain resources in group F can be predefined; or indicated by the second communication device to the first communication device; or determined based on the time-domain resources received from the first indication information. For example, if the interval between the starting position of the time-domain resources in group F and the position of the time-domain resources in the first indication information is h3 time-domain units, then the first communication device can determine the starting position of the time-domain resources in group F based on the time-domain resources in the first indication information. Further, the first communication device determines the location of the time-domain resources in group F based on the starting position of the time-domain resources in group F and the values ​​of F and A. Here, h3 is an integer greater than or equal to 0. As an example, h3 can be predefined or indicated, and is not limited.

[0176] Example 2: The first indication information indicates the value of A.

[0177] Taking the first possible scenario as an example, the second communication device sends a first indication message to the first communication device, which indicates the value of A; based on the first indication message, the first communication device can determine the value of A. Further, as an example, the values ​​of A and F are related; based on the value of A indicated by the first indication message and this relationship, the first communication device can determine the value of F.

[0178] The location of the time-domain resources in group F can be found in the description in Example 1, and will not be repeated here.

[0179] Example 3: The first indication information indicates the location of the time-domain resources in group F.

[0180] As an example, the location of the time-domain resources in group F includes at least one of the following: the starting position of the time-domain resources in group F, the ending position of the time-domain resources in group F, the length of the time-domain resources in group F, and the length of each group of time-domain resources in group F (i.e., the value of A).

[0181] Taking the first possible scenario as an example, the second communication device sends a first indication information to the first communication device, which indicates the location of the F group of time-domain resources. Based on the first indication information, the first communication device can determine the location of the F group of time-domain resources and then send a third reference signal at the corresponding location.

[0182] Example 4: The first indication information indicates the values ​​of F and A.

[0183] For details, please refer to the descriptions in Examples 1 and 2.

[0184] The above are descriptions of Examples 1-4, and the embodiments of this application are not limited thereto. For example, the first indication information indicates the location of a group of time-domain resources (such as the first group of time-domain resources) in the F group of time-domain resources, and then the first communication device can determine the location of the F group of time-domain resources based on the fact that each group of time-domain resources has the same length.

[0185] Optionally, method 200 further includes: sending or receiving second indication information, the second indication information indicating at least one of the following: the length of the first time-domain resource, the location of the first time-domain resource, the length of the second time-domain resource, and the location of the second time-domain resource. The second indication information and the first indication information may be carried in one signaling message or in different signaling messages, and there is no limitation thereto.

[0186] The following explanation will consider two scenarios.

[0187] In a first possible scenario, the second communication device is a network device, and the first communication device is a terminal device. In this case, method 200 includes: the second communication device sending second instruction information to the first communication device, and correspondingly, the first communication device receiving the second instruction information.

[0188] In one example, the second communication device sends a second instruction message to the first communication device.

[0189] In another example, a first communication device sends a request message to a second communication device, the request message being for a first time-domain resource; the second communication device determines (e.g., initially determines, or updates) the first time-domain resource and sends a second indication message to the first communication device. Based on this, the second communication device can send the second indication message to the first communication device after receiving the request message from the first communication device. The triggering conditions for the first communication device to send the request message are not limited. For example, the first communication device can send the request message to the second communication device based on its mobility status, data transmission needs, environmental information, etc. The content of the request message is not limited; for example, the request message for the first time-domain resource can also be replaced by: the request message for the channel estimation resource. Any scheme in which the second communication device can send the second indication message based on the request message is applicable to the embodiments of this application.

[0190] In the second possible scenario, the second communication device is a terminal device, and the first communication device is a network device. In this scenario, method 200 includes: the first communication device sending second instruction information to the second communication device, and correspondingly, the second communication device receiving the second instruction information. This scenario can be referred to in the first possible scenario, and will not be elaborated here.

[0191] As previously stated, the second indication information indicates at least one of the following: the length of the first time-domain resource, the location of the first time-domain resource, the length of the second time-domain resource, and the location of the second time-domain resource. Several examples are given below.

[0192] Example 1: The second indication information indicates the length of the first time domain resource.

[0193] Taking the first possible scenario as an example, the second communication device sends a second indication message to the first communication device, which indicates the length of the first time domain resource; based on the second indication message, the first communication device can determine the length of the first time domain resource and the length of the second time domain resource. Specifically, the length of the second time domain resource is the same as the length of the first time domain resource indicated by the second indication message.

[0194] Furthermore, the positions of the first and second time-domain resources can be predefined; or indicated by the second communication device to the first communication device; or determined based on the time-domain resources received from the second indication information. For example, if the interval between the position of the first time-domain resource and the position of the time-domain resource in the second indication information is h1 time-domain units, the first communication device can determine the position of the first time-domain resource based on the time-domain resources in the second indication information. Further, assuming the interval between the second and first time-domain resources is h2 time-domain units, the first communication device can determine the position of the second time-domain resource following the first time-domain resource based on the position of the first time-domain resource. Here, h1 and h2 are integers greater than or equal to 0. As an example, h1 and / or h2 are predefined or indicated, and are not limited.

[0195] Example 2: The second indication information indicates the location of the first time domain resource.

[0196] As an example, the location of the first time-domain resource includes at least one of the following: the start position of the first time-domain resource, the end position of the first time-domain resource, and the length of the first time-domain resource.

[0197] Taking the first possible scenario as an example, the second communication device sends a second indication message to the first communication device. This second indication message indicates the location of the first time-domain resource. After determining the location of the first time-domain resource, the first communication device can send a first reference signal at the corresponding location. Assuming the interval between the second and first time-domain resources is h² time-domain units, the first communication device can determine the location of the second time-domain resource based on the location of the first time-domain resource. After determining the location of the second time-domain resource, the first communication device can send a second reference signal at the corresponding location. Refer to Example 1 for the description of h².

[0198] Example 3: The second indication information indicates the length of the second time-domain resource.

[0199] Example 3 is similar to Example 1, and the details can be found in the description in Example 1, which will not be repeated here.

[0200] Example 4: The second indication information indicates the location of the second time-domain resource.

[0201] Example 4 is similar to Example 2, and the details can be found in the description in Example 2, which will not be repeated here.

[0202] The above is an illustrative example, and the embodiments of this application are not limited thereto. For example, the second indication information indicates multiple of the following: the length of the first time-domain resource, the position of the first time-domain resource, the length of the second time-domain resource, and the position of the second time-domain resource. As another example, the second indication information may also indicate that the first and second time-domain resources are continuous.

[0203] For ease of understanding, the following describes a specific process applicable to the embodiments of this application, using the first communication device as the terminal device and the second communication device as the network device. It is understood that the process described below is merely illustrative, and the embodiments of this application are not limited thereto. Content not described in detail below can be referred to the description in method 200, and will not be repeated hereafter.

[0204] Referring to Figure 4, as an example, Figure 4 is a schematic flowchart of a communication method 400 applicable to an embodiment of this application. The method 400 shown in Figure 4 may include the following steps.

[0205] S401, Network device obtains path count.

[0206] The path count includes the path count corresponding to the cascaded channel (i.e., an example of the second channel) on the terminal device side and the path count corresponding to the direct channel (i.e., an example of the first channel). The cascaded channel on the terminal device side refers to the channel between the terminal device and the RIS; the direct channel refers to the channel between the network device and the terminal device. As an example, the path count also includes the path count corresponding to the cascaded channel on the network device side, i.e., the path count corresponding to the channel between the RIS and the network device.

[0207] There is no limitation on how network devices obtain path counts. As an example, network devices may determine the path count through sensing or radio frequency mapping (RFmap).

[0208] S402, the network device determines T, A, and F.

[0209] Where T represents the length of the first and second time-domain resources. A represents the number of time-domain units contained in a time-domain resource group in phase 2; in other words, for a certain third reference signal, how many time-domain units the third reference signal is repeatedly transmitted on. F represents the number of time-domain resource groups, that is, how many different reference signals the terminal device needs to transmit in phase 2.

[0210] For example, network devices determine T based on the number of ports on the terminal devices, the number of paths corresponding to the direct channels, and the number of paths corresponding to the cascaded channels on the terminal device side. For example, T≥max{I·log(Q), J·log(Q)}.

[0211] For example, the network device determines A based on the number of RIS arrays, such as A ≥ log(W). Alternatively, the network device determines A based on the number of RIS arrays and the number of paths corresponding to the cascaded channels on the network device side, such as A... k ≥log(W) / L.

[0212] For example, network devices determine F based on the number of paths corresponding to the cascaded channels on the terminal device side, such as F≥J.

[0213] The meaning of each parameter can be found in the relevant description in Method 200 above, and will not be repeated here.

[0214] S403, the network device sends an indication message indicating T, A, and F. The terminal device receives the indication message accordingly.

[0215] Optionally, the RIS receives the indication information. For example, the network device sends the indication information to the terminal device via the RIS.

[0216] Among them, T, A, and F can be carried in one signaling (or one channel), or they can be carried in different signaling (such as different channels), without limitation.

[0217] In addition, when the indication information indicates T, A, and F, it can indicate T, A, and F; or it can indicate a partial parameter (one or two of T, A, and F), with the remaining parameters related to the partial parameter. In this way, the terminal device can determine T, A, and F based on the partial parameter.

[0218] Furthermore, the indication information indicating T can also be replaced with the indication information indicating the location of the first time-domain resource and / or the location of the second time-domain resource. Similarly, the indication information indicating A and F can also be replaced with the indication information indicating the location of the F group of time-domain resources.

[0219] For a description of the instruction information, please refer to the relevant descriptions of the first and second instruction information in method 200, which will not be repeated here.

[0220] Further optionally, prior to S403, method 400 further includes: the terminal device sending request information to the network device, the request information being used to trigger the network device to send indication information.

[0221] Optionally, method 400 further includes: the network device determining a reference terminal device. Specifically, the network device can interact with multiple terminal devices to determine the reference terminal device. As an example, the network device can determine the reference terminal device based on at least one of the following: terminal device service requirements, geographical location, channel quality, etc. For example, the network device can use a terminal device with high data transmission requirements as the reference terminal device; or, the network device can use a terminal device with good channel quality as the reference terminal device. The index k of the reference terminal device is 1. Taking Equation 3 as an example, A1 corresponding to the reference terminal device satisfies: A1≥log(W); A1 corresponding to non-reference terminal devices satisfies: A1≥log(W). k Satisfy: A k ≥log(W) / L, where L represents the number of paths corresponding to the cascaded channels on the network device side.

[0222] Subsequently, the network device and the terminal device transmit reference signals via RIS to measure channel information. In this embodiment, the terminal device transmits reference signals in two stages, referred to as Stage 1 and Stage 2. The reference signals in Stage 1 can be used to estimate the first channel (direct channel) and some cascaded channels (such as the channel between the terminal device and the RIS in a cascaded channel). The reference signals in Stage 2 can be used to estimate the remaining cascaded channels (such as the channel between the RIS and the network device in a cascaded channel). These two stages are described below.

[0223] Phase 1 includes S404-S406.

[0224] S404, the terminal device transmits the first reference signal and the second reference signal based on T.

[0225] Specifically, based on T indicated in step S403, the terminal device determines to transmit a first reference signal based on the first time domain resource (i.e., on T time domain units), which can be represented as: S k,1 ,S k,2 ,S k,3 ,……,S k,T The terminal device repeatedly transmits based on the second time domain resources (i.e., T time domain units) following the first time domain resource: S k,1 ,S k,2 ,S k,3 ,……,S k,T That is, in stage 1, the terminal device transmits a reference signal over 2·T consecutive time domain units, and the reference signal transmitted by the terminal device over 2·T consecutive time domain units is: S k,1 ,S k,2 ,S k,3 ,……,S k,T S k,1 ,S k,2,S k,3 ,……,S k,T As mentioned earlier, the sequences of reference signals on the first time-domain resource may be the same or different. The reference signals on the second time-domain resource can be understood as repeated transmissions of the reference signals on the first time-domain resource; therefore, the sequences of reference signals on the second time-domain resource may be the same or different. In the example above, let T reference signals be S... k,1 ,S k,2 ,S k,3 ,……,S k,T The examples provided are for illustration, but the embodiments of this application are not limited thereto. That is, the T reference signals can be completely different, or partially different, or completely the same, and there is no limitation thereto.

[0226] S405, RIS determines the first phase and the second phase.

[0227] The first phase and the second phase are out of phase.

[0228] One possible implementation is that RIS determines the first and second phases itself.

[0229] Another possible implementation is that the network device indicates the first phase and the second phase to the RIS. It is understood that step S405 may be performed before S404, simultaneously with S404, or after S404; this is not limited.

[0230] S406, RIS reflects the first reference signal based on the first phase, and RIS reflects the second reference signal based on the second phase.

[0231] Assume the first phase is -e1 and the second phase is e1, that is, the phase of the reference signal on the first time domain resource (i.e., the first reference signal) is -e1 and the phase of the reference signal on the second time domain resource (i.e., the second reference signal) is e1.

[0232] It is understood that steps S404-S406 are merely an example, and the order of sending the first reference signal, the second reference signal, determining the first phase, determining the second phase, reflecting the first reference signal, and reflecting the second reference signal is not limited.

[0233] Example 1: The terminal device can send a first reference signal and a second reference signal, and then the RIS reflects the first reference signal based on the first phase and reflects the second reference signal based on the second phase.

[0234] Example 2: The terminal device can send a first reference signal, and then the RIS reflects the first reference signal based on the first phase; then, the terminal device sends a second reference signal, and then the RIS reflects the second reference signal based on the second phase.

[0235] Example 3: The terminal device can send a second reference signal, and then the RIS reflects the second reference signal based on the second phase; then, the terminal device sends a first reference signal, and then the RIS reflects the first reference signal based on the first phase.

[0236] In Examples 1 to 3 above, the timing of the RIS determining the first phase and the second phase is not limited. For example, the RIS may determine the first phase and the second phase in advance, and after receiving the first reference signal and the second reference signal, reflect the first reference signal based on the predetermined first phase and reflect the second reference signal based on the second phase; or, the RIS may determine the first phase after receiving the first reference signal and determine the second phase after receiving the second reference signal; or, the RIS may determine the first phase and the second phase after receiving either the first reference signal or the second reference signal.

[0237] Phase 2 includes S407-S409.

[0238] S407, the terminal device sends a third reference signal based on A and F.

[0239] Specifically, based on A and F indicated in step S403, the terminal device determines that a third reference signal will be transmitted based on F groups of time-domain resources. Each group of time-domain resources in the F groups includes A time-domain units. The third reference signal on the A time-domain units in one group of time-domain resources is the same, while the third reference signal on different groups of time-domain resources is different. For example, in stage 2, the terminal device transmits a third reference signal based on consecutive F groups of time-domain resources, and the third reference signal transmitted by the terminal device based on consecutive F groups of time-domain resources is: {S k,1 ,S k,1 ,S k,1 ,……,S k,1} A , {S k,2 ,S k,2 ,S k,2 ,……,S k,2} A , ...{S k,F ,S k,F ,S k,F ,……,S k,F} A The subscript A indicates that there are A reference signals.

[0240] S408, RIS determines B phases.

[0241] As an example, it is not limited to whether all the phases of the B phases are different or whether at least two of the B phases are the same.

[0242] One possible implementation is that RIS determines B phases itself.

[0243] Another possible implementation is that the network device instructs B phases to the RIS.

[0244] It is understood that step S408 may be executed before S407, or simultaneously with S407, or after S407; there are no restrictions on this.

[0245] S409, RIS is based on B phase reflections of the third reference signal.

[0246] B phases are used for each group of time-domain resources in the F groups of time-domain resources. That is, the phase of the third reference signal on each group of time-domain resources in the F groups of time-domain resources is these B phases. The correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources. Taking the example in S407, assume that the third reference signal transmitted by the terminal device based on consecutive groups of F time-domain resources is: {S k,1 ,S k,1 ,S k,1 ,……,S k,1} A , {S k,2 ,S k,2 ,S k,2 ,……,S k,2} A , ...{S k,F ,S k,F ,S k,F ,……,S k,F} A B phases are {e2, e3, ..., e A+1}, then {S k,1 ,S k,1 ,S k,1 ,……,S k,1} A The phases are as follows: {e2, e3, ..., e A+1}, {S k,2 ,S k,2 ,S k,2 ,……,S k,2} A The phases are as follows: {e2, e3, ..., e A+1}, {S k,F ,S k,F ,S k,F ,……,S k,F} A The phases are as follows: {e2, e3, ..., e A+1}

[0247] S410, the network device determines the channel information for direct channels and cascaded channels.

[0248] Specifically, the network device determines the channel information of the direct channel and the cascaded channel on the terminal device side (i.e., the channel between the terminal device and the RIS) based on the reference signal of stage 1 (i.e., the first reference signal and the second reference signal); the network device determines the channel information of the cascaded channel on the network device side (i.e., the channel between the RIS and the network device) based on the reference signal of stage 2 (i.e., the third reference signal) and the reference signal of stage 1 (i.e., the first reference signal and the second reference signal).

[0249] S411, based on channel information, allows network devices and terminal devices to transmit data via RIS.

[0250] Specifically, based on the channel information estimated in S410, network devices and terminal devices transmit data via RIS.

[0251] In one possible scenario, the network device sends downlink data to the terminal device via RIS based on the channel information. Specifically, the network device can determine the downlink channel information based on the channel information determined in S410 (i.e., the uplink channel information) and the reciprocity of the uplink and downlink channels, and then send downlink data to the terminal device via RIS based on the downlink channel information.

[0252] Another possible scenario is that the network device receives uplink data from the terminal device via RIS based on this channel information.

[0253] Based on the above technical solutions, for RIS-assisted MIMO systems, independent estimation of direct and cascaded channels is achieved by jointly designing the phase of the reference signal and the RIS. Furthermore, compared to fine-tuned beam training and instantaneous channel estimation based on switched RIS, the above technical solutions can effectively reduce the complexity of channel estimation and the overhead of the reference signal, thereby significantly improving system transmission performance.

[0254] For ease of understanding, the first communication device is used as the terminal device and the second communication device is used as the network device to describe the method for determining channel information applicable to the embodiments of this application.

[0255] 1. Channel information of the direct channel (i.e., the first channel)

[0256] One possible implementation involves the second communication device adding the same signals on the first and second time-domain resources to obtain a measurement matrix; then, based on the measurement matrix, the channel information of the direct channel is obtained. Since the reference signals on the first and second time-domain resources are designed to be out of phase, adding the same reference signals can reduce the impact of cascaded channels on the estimation of the direct channel.

[0257] Figure 3 will be used as an example for illustration. Assume a time-domain unit is called a block, and the T of the first time-domain resource... k The time-domain units are respectively named block1-1, block1-2, ..., block1-T. k T of the second time domain resource k The time-domain units are respectively called block2-1, block2-2, ..., block2-T. k As shown in Figure 3, the reference signals for block1-t and block2-t are taken as a pair of signals, with a total duration of T. k For each pair of signals, the signals in the two time-domain units are added together to obtain a measurement matrix. Then, the channel information of the first channel (such as the channel matrix and / or angle information) is obtained based on the measurement matrix.

[0258] It is understood that the method for estimating channel information described above is merely an illustrative example, and the embodiments of this application are not limited thereto. In other words, any method that can obtain the channel information of the direct channel based on the measurement results of the first reference signal and the second reference signal is applicable to the embodiments of this application.

[0259] 2. Channel information of the channel between the first communication device and the RIS (i.e., the second channel).

[0260] One possible implementation involves the second communication device stacking the same signals on the first and second time-domain resources to obtain a measurement matrix; then, based on the measurement matrix, the channel information between the first communication device and the RIS is obtained. The stacking process can be interpreted as writing the signals on the two time-domain resources into a two-column matrix, meaning that the signal on each time-domain resource can be treated as a column vector.

[0261] Figure 3 is used as an example for illustration. Assume a time-domain unit is called a block, and the T of the first time-domain resource... k The time-domain units are respectively named block1-1, block1-2, ..., block1-T. k T of the second time domain resource k The time-domain units are respectively called block2-1, block2-2, ..., block2-T. k As shown in Figure 3, the reference signals for block1-t and block2-t are taken as a pair of signals, with a total duration of T. k For each pair of signals, stack the signals from the two time-domain units in each pair into a matrix with two columns, i.e., T k The signal is written as a two-column matrix, resulting in T. k 1 matrix, then T k Multiplying a matrix by a normalized vector v on the right, such as Get T k A measurement matrix is ​​used to obtain channel information (such as channel matrix and / or angle information) between the first communication device - RIS.

[0262] It is understood that the method for estimating channel information described above is merely an illustrative example, and the embodiments of this application are not limited thereto. In other words, any method that can obtain the channel information between the first communication device and the RIS based on the measurement results of the first reference signal and the second reference signal is applicable to the embodiments of this application.

[0263] 3. Channel information of the channel between the RIS and the second communication device (i.e., the third channel).

[0264] One possible implementation involves the second communication device stacking identical signals from the first time-domain resource, the second time-domain resource, and F groups of time-domain resources to obtain a measurement matrix; then, based on the measurement matrix, the channel information between RIS and the second communication device is obtained. The stacking process can be interpreted as writing the signals from the time-domain resources into a multi-column matrix, where each signal from a time-domain resource can be considered a column vector.

[0265] Figure 3 serves as an example for illustration. As shown in Figure 3, the calculation process is briefly explained.

[0266] 1) The first communication device k sequentially sends A k ·F k The third reference signals for each time-domain cell are: {S k,1 ,S k,1 ,……,S k,1 ,S k,2 ,S k,2 ,……,S k,2 ,S k,3 ,……,S k,Fk ,S k,Fk ,……,S k,Fk}, F k Less than or equal to T k Each reference signal S k,t Repeat A k Times, t = 1, 2, ..., F k The A k ·F k The third reference signal of each time-domain unit is divided into F k Groups, each containing A k The same reference signal, namely F k The reference signals for the group are: S k,1 ,S k,2 ,S k,3 ,……,S k,FkFor ease of description, let F be... k The groups are respectively called group 1, group 2, ... group F. k .

[0267] 2) The second communication device stacks the third reference signal transmitted by the first communication device k, along with the previously received first and second reference signals. As an example, the second communication device can combine the reference signals S separately. k,1 The signal and reference signal S of the time domain unit k,2 The signal in the time domain, ... the reference signal S k,Fk The signal of the time domain unit in which it is located. Referring to Figure 3, the combination process is briefly described: The second communication device can combine the S signals on the first time domain resource. k,1 S on the second time domain resources k,1 S in group 1 k,1 A set of signals is obtained; the second communication device can combine the S signals on the first time domain resources. k,2 S on the second time domain resources k,2 S on Group 2 k,2 A set of signals is obtained; ...; the second communication device can combine S on the first time domain resources. k,Fk S on the second time domain resources k,Fk S in group 2 k,Fk A set of signals is obtained, therefore, the second communication device can obtain F by stacking the third reference signal sent by the first communication device k and the previously received first and second reference signals. k Group of signals, each group of signals includes (A) k +2) identical reference signals.

[0268] 3) Perform similar processing on the reference signal of each first communication device to obtain a measurement matrix, and then obtain the channel information (such as channel matrix and / or angle information) between RIS and the second communication device based on the measurement matrix; or, obtain the channel information (such as channel matrix and / or angle information) between RIS and the second communication device based on the measurement matrix and the channel information between the first communication device and RIS.

[0269] It is understandable that Figure 3 is based on F k Less than or equal to T k And assume that the reference signals on the first and second time domain resources are: S k,1 ,S k,2 ,S k,3 ,……,S k,Fk ,……,S k,TkIn other words, the reference signal on the third time-domain resource can be understood as a repeated transmission of at least a portion of the reference signal on the first time-domain resource, that is, the following reference signals on the first time-domain resource are repeatedly transmitted on the third time-domain resource: S k,1 ,S k,2 ,S k,3 ,……,S k,Fk However, the embodiments of this application are not limited thereto.

[0270] In one example, some reference signals on a third time-domain resource are the same as reference signals on a first time-domain resource. In other words, the reference signals on the third time-domain resource can be understood as repeated transmissions of some or all of the reference signals on the first time-domain resource, and also include one or more reference signals that are different from the reference signals on the first time-domain resource. In this case, F k With T k The relationship is not limited, for example, F k It can be less than or equal to T k , or, F k It can be greater than T k In this scenario, as an example, the same reference signals on the first, second, and third time-domain resources can be processed (as in a similar stacking process to the previous one) to obtain a measurement matrix, and the channel information between the RIS and the second communication device can be determined based on the measurement matrix; alternatively, the channel information between the RIS and the second communication device can be determined based on the measurement matrix and the channel information between the first communication device and the RIS obtained from the channel estimation of the reference signals on the first and second time-domain resources. It can be understood that identical reference signals mean that the sequence of reference signals is the same; similarly, different reference signals mean that the sequence of reference signals is different.

[0271] In another example, the reference signal on the first time-domain resource is different from the reference signal on the third time-domain resource. In this case, F k With T k The relationship is not limited, for example, F k It can be less than or equal to T k , or, F k It can be greater than T kIn this scenario, as an example, the third reference signal can be processed (e.g., similar to the stacking process described earlier) to obtain a measurement matrix. Based on the measurement matrix and the channel information between the first communication device and the RIS estimated from the reference signals on the first and second time-domain resources, the channel information between the RIS and the second communication device can be determined. It is understood that different reference signals can be interpreted as different sequences of reference signals. It is also understood that the method for estimating channel information described above is merely an illustrative example, and the embodiments of this application are not limited thereto. In other words, any method that can combine the measurement results of the first, second, and third reference signals to obtain the channel information between the RIS and the second communication device is applicable to the embodiments of this application.

[0272] Referring to Figures 5 and 6, which are simulation diagrams as examples, the horizontal axis in Figure 5 represents the signal-to-noise ratio (SNR), and the vertical axis represents the minimum mean square error (MMSE). In Figure 6, the horizontal axis represents the path number I corresponding to the direct channel (i.e., the first channel), and the vertical axis represents the MMSE. Figures 5 and 6 compare the performance of three channel estimation methods, which can be referred to as Method 1, Method 2, and Method 3. Method 1 assumes that the network device knows all the angle information, meaning the network device only needs to estimate the gain; in other words, Method 1 is the ideal optimal solution. Method 2 estimates the direct channel and cascaded channel separately using the RIS switch. Method 3 is the method described in this embodiment, which estimates the direct channel and cascaded channel based on a two-stage reference signal. Figures 5 and 6 show the trend of MMSE variation when performing channel estimation using different methods (i.e., Method 1, Method 2, and Method 3).

[0273] As shown in Figure 5, when performing channel estimation based on the scheme of this application embodiment, the lower the MMSE as the SNR increases, that is, the better the channel estimation performance, and the channel estimation performance is close to that of method 1 and better than that of method 2.

[0274] As shown in Figure 6(a), line 1-1 represents the trend of MMSE with the path number I of the first channel when estimating the direct channel using method 1 within the first time range; line 2-1 represents the trend of MMSE with the path number I of the first channel when estimating the direct channel using method 2 within the first time range; and line 3-1 represents the trend of MMSE with the path number I of the first channel when estimating the direct channel using method 3 (i.e., the method provided in the embodiments of this application) within the first time range. Similarly, line 1-2 represents the trend of MMSE with the path number I of the first channel when estimating the direct channel using method 1 within the second time range; line 2-2 represents the trend of MMSE with the path number I of the first channel when estimating the direct channel using method 2 within the second time range; and line 3-2 represents the trend of MMSE with the path number I of the first channel when estimating the direct channel using method 3 (i.e., the method provided in the embodiments of this application) within the second time range. As can be seen from Figure 6(a), when estimating the direct channel based on the method provided in the embodiments of this application, the MMSE is relatively low, that is, the performance of the direct channel estimation is better, and the performance of the direct channel estimation is close to that of method 1 and better than that of method 2.

[0275] As shown in Figure 6(b), line 2-1 represents the trend of MMSE with the number of paths I of the first channel when estimating the concatenated channel using method 2 in the third time range, and line 3-1 represents the trend of MMSE with the number of paths I of the first channel when estimating the concatenated channel using method 3 (i.e., the method provided in the embodiments of this application) in the third time range. Similarly, line 2-2 represents the trend of MMSE with the number of paths I of the first channel when estimating the concatenated channel using method 2 in the fourth time range, and line 3-2 represents the trend of MMSE with the number of paths I of the first channel when estimating the concatenated channel using method 3 (i.e., the method provided in the embodiments of this application) in the fourth time range. Similarly, line 2-3 represents the trend of MMSE with the number of paths I of the first channel when estimating the concatenated channel using method 2 in the fifth time range, and line 3-3 represents the trend of MMSE with the number of paths I of the first channel when estimating the concatenated channel using method 3 (i.e., the method provided in the embodiments of this application) in the fifth time range. Line 1 can represent the trend of MMSE as a function of the number of paths I of the first channel when estimating the concatenated channel using method 1 within the fifth time range. As can be seen from Figure 6(b), when estimating the concatenated channel using the method provided in the embodiments of this application, the MMSE is relatively low, that is, the performance of the concatenated channel estimation is better, and the performance of the concatenated channel estimation is close to that of method 1 and better than that of method 2.

[0276] The first time range, second time range, third time range, fourth time range, and fifth time range mentioned above represent channel estimation within different time ranges, and the values ​​for each time range are not limited.

[0277] It is understood that Figures 5 and 6 are merely examples, and the embodiments of this application are not intended to limit the scope of the application.

[0278] It is understood that in the above method embodiments, the methods and operations implemented by the device can also be implemented by components of the device (such as chips or circuits), without limitation.

[0279] The methods provided by the embodiments of this application have been described in detail above with reference to Figures 2 to 6. The apparatus provided by the embodiments of this application will be described in detail below with reference to Figures 7 to 9. It should be understood that the descriptions of the apparatus embodiments correspond to the descriptions of the method embodiments; therefore, any content not described in detail can be referred to the method embodiments above, and for the sake of brevity, will not be repeated here.

[0280] Referring to Figure 7, which is a schematic diagram of a communication device 700 provided in an embodiment of this application, the communication device 700 includes a transceiver unit 710. The transceiver unit 710 can be used to implement corresponding communication functions. The transceiver unit 710 can also be referred to as a communication interface or a communication unit. Optionally, the device 700 further includes a processing unit 720. The processing unit 720 can be used to perform processing, such as measurement based on a reference signal.

[0281] Optionally, the device 700 further includes a storage unit, which can be used to store instructions and / or data, and the processing unit 720 can read the instructions and / or data in the storage unit to enable the device to implement the aforementioned method embodiments.

[0282] In a first possible design, the device 700 can be the RIS (as shown in Figure 2 or Figure 4) of the aforementioned embodiments. The device 700 can implement the steps or processes corresponding to those executed by the RIS in the above method embodiments. Specifically, the transceiver unit 710 can be used to perform transceiver-related operations of the RIS in the above method embodiments (such as sending and / or receiving data or messages); the processing unit 720 can be used to perform processing-related operations of the RIS in the above method embodiments, or operations other than transceiver (such as operations other than sending and / or receiving data or messages).

[0283] In one possible implementation, transceiver unit 710 is configured to receive a first reference signal from a first communication device based on a first time-domain resource; transceiver unit 710 is further configured to reflect the first reference signal to a second communication device based on a first phase; transceiver unit 710 is further configured to receive a second reference signal from the first communication device based on a second time-domain resource, wherein the first and second time-domain resources have the same time-domain length, and the first and second reference signals are identical; transceiver unit 710 is further configured to reflect the second reference signal to the second communication device based on a second phase, wherein the second phase is out of phase with the first phase; wherein the first and second reference signals are used for measuring a first channel and / or a second channel, the first channel being the channel between the first and second communication devices, and the second channel being the channel between the first communication device and the RIS device. Optionally, processing unit 720 is configured to determine the first phase and the second phase.

[0284] Optionally, the transceiver unit 710 is further configured to receive a third reference signal from the first communication device based on F groups of time-domain resources. Each group of time-domain resources in the F groups includes A time-domain units. The third reference signal on the A time-domain units in one group of time-domain resources is the same, and the third reference signal on different groups of time-domain resources is different. A is an integer greater than 1, and F is an integer greater than 1. The transceiver unit 710 is further configured to reflect the third reference signal to the second communication device based on B phases. The B phases are used for each group of time-domain resources in the F groups, and the correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources. The third reference signal, together with the first reference signal and the second reference signal, is used for the measurement of the third channel. The third channel is the channel between the second communication device and the RIS device. B is an integer greater than or equal to 1 and less than or equal to A.

[0285] Optionally, the transceiver unit 710 is further configured to receive first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the time domain resources of group F.

[0286] Optionally, the transceiver unit 710 is further configured to receive second indication information, the second indication information indicating at least one of the following: the length of the first time domain resource, the location of the first time domain resource, the length of the second time domain resource, and the location of the second time domain resource.

[0287] In a second possible design, the device 700 can be the second communication device in the aforementioned embodiments (the second communication device shown in FIG2, and the network device shown in FIG4). This device 700 can implement the steps or processes performed by the second communication device corresponding to those in the above method embodiments. Specifically, the transceiver unit 710 can be used to perform operations related to the transmission and reception of the second communication device in the above method embodiments (such as sending and / or receiving data or messages); the processing unit 720 can be used to perform processing-related operations of the second communication device in the above method embodiments, or operations other than transmission and reception (such as operations other than sending and / or receiving data or messages).

[0288] One possible implementation is that the transceiver unit 710 is configured to receive a first reference signal from the first communication device and reflected by the RIS device based on a first phase, based on a first time-domain resource; the transceiver unit 710 is further configured to receive a second reference signal from the first communication device and reflected by the RIS device based on a second phase, based on a second time-domain resource, wherein the second phase is out of phase with the first phase, the time-domain lengths of the first time-domain resource and the second time-domain resource are the same, and the first reference signal and the second reference signal are the same; and the processing unit 720 is configured to obtain channel information of a first channel and / or a second channel based on the first reference signal and the second reference signal, wherein the first channel is a channel between the first communication device and the second communication device, and the second channel is a channel between the first communication device and the RIS device.

[0289] Optionally, the transceiver unit 710 is further configured to receive a third reference signal from the first communication device and reflected by the RIS device based on B phases, based on F groups of time-domain resources. The B phases are used for each group of time-domain resources in the F groups of time-domain resources, and the correspondence between the B phases and A time-domain units is the same in each group of time-domain resources. Each group of time-domain resources in the F groups of time-domain resources includes A time-domain units. The third reference signal on the A time-domain units in one group of time-domain resources is the same, and the third reference signal on different groups of time-domain resources is different. A and F are integers greater than 1, and B is an integer greater than or equal to 1 and less than or equal to A. The processing unit 720 is further configured to obtain channel information of a third channel based on the third reference signal, the first reference signal, and the second reference signal. The third channel is the channel between the second communication device and the RIS device.

[0290] Optionally, the processing unit 720 is further configured to obtain channel information of the third channel based on the third reference signal, the first reference signal, and the second reference signal, including: the processing unit 720 is further configured to obtain channel information of the third channel based on the third reference signal, the first reference signal, the second reference signal, and the reference channel information.

[0291] Optionally, the transceiver unit 710 is also configured to send or receive first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the time domain resources of group F.

[0292] Optionally, the transceiver unit 710 is further configured to send or receive second indication information, the second indication information indicating at least one of the following: the length of the first time domain resource, the location of the first time domain resource, the length of the second time domain resource, and the location of the second time domain resource.

[0293] In a third possible design, the device 700 can be the first communication device in the aforementioned embodiments (the first communication device shown in FIG2, and the terminal device shown in FIG4). This device 700 can implement the steps or processes executed by the first communication device in the above method embodiments. Specifically, the transceiver unit 710 can be used to perform operations related to the transmission and reception of the first communication device in the above method embodiments (such as sending and / or receiving data or messages); the processing unit 720 can be used to perform processing-related operations of the first communication device in the above method embodiments, or operations other than transmission and reception (such as operations other than sending and / or receiving data or messages).

[0294] In one possible implementation, the transceiver unit 710 is configured to transmit a first reference signal to a second communication device via a RIS device based on a first time-domain resource, the first reference signal corresponding to a first phase; the transceiver unit 710 is further configured to transmit a second reference signal to the second communication device via a RIS device based on a second time-domain resource, the second reference signal corresponding to a second phase, the second phase being out of phase with the first phase, the time-domain lengths of the first time-domain resource and the second time-domain resource being the same, and the first reference signal and the second reference signal being identical; wherein, the first reference signal and the second reference signal are used for the measurement of a first channel and / or a second channel, the first channel being the channel between the first communication device and the second communication device, and the second channel being the channel between the first communication device and the RIS device.

[0295] Optionally, the transceiver unit 710 is further configured to transmit a third reference signal to the second communication device via the RIS device based on F groups of time-domain resources. The third reference signal, together with the first and second reference signals, is used for the measurement of a third channel, which is a channel between the second communication device and the RIS device. The third reference signal corresponds to B phases, which are used for each group of time-domain resources in the F groups. The correspondence between the B phases and A time-domain units is the same in each group of time-domain resources. Each group of time-domain resources in the F groups includes A time-domain units. The third reference signal on the A time-domain units in one group of time-domain resources is the same, while the third reference signal on different groups of time-domain resources is different. A and F are integers greater than 1, and B is an integer greater than or equal to 1 and less than or equal to A.

[0296] Optionally, the transceiver unit 710 is also configured to send or receive first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the time domain resources of group F.

[0297] Optionally, the transceiver unit 710 is further configured to send or receive second indication information, the second indication information indicating at least one of the following: the length of the first time domain resource, the location of the first time domain resource, the length of the second time domain resource, and the location of the second time domain resource.

[0298] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0299] It should also be understood that the device 700 here is embodied in the form of a functional unit. The term "unit" here can refer to an application-specific integrated circuit (ASIC), electronic circuitry, a processor (e.g., a shared processor, a proprietary processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, integrated logic circuitry, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that the device 700 can specifically be the communication device in the above embodiments, and can be used to execute the various processes and / or steps corresponding to the communication device in the above method embodiments; to avoid repetition, these will not be described again here.

[0300] The apparatus 700 of each of the above-described schemes has the function of implementing the corresponding steps performed by the communication device (such as RIS, the first communication device, or the second communication device) in the above-described methods. The function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions; for example, the transceiver unit can be replaced by a transceiver (e.g., the transmitting unit in the transceiver unit can be replaced by a transmitter, and the receiving unit in the transceiver unit can be replaced by a receiver), and other units, such as processing units, can be replaced by processors, respectively executing the transceiver operations and related processing operations in each method embodiment.

[0301] In addition, the transceiver unit 710 described above can also be a transceiver circuit (for example, it may include a receiving circuit and a transmitting circuit), and the processing unit can be a processing circuit.

[0302] It should be noted that the device in Figure 7 can be the communication device in the aforementioned embodiments (such as a RIS, the first communication device, or the second communication device), or it can be a chip or a chip system, such as a system on a chip (SoC). The transceiver unit can be an input / output circuit or a communication interface; the processing unit is a processor, microprocessor, or integrated circuit integrated on the chip. No limitations are imposed here.

[0303] Referring to Figure 8, as an example, Figure 8 is a schematic diagram of another communication device 800 provided in an embodiment of this application. The device 800 includes a processor 810, which is coupled to a memory 820. The memory 820 is used to store computer programs or instructions and / or data. The processor 810 is used to execute the computer programs or instructions stored in the memory 820, or to read the data stored in the memory 820, to perform the methods in the above method embodiments.

[0304] Optionally, there may be one or more processors 810.

[0305] Optionally, the memory 820 may be one or more.

[0306] Alternatively, the memory 820 can be integrated with the processor 810, or it can be set separately.

[0307] Optionally, as shown in FIG8, the device 800 further includes a transceiver 830 for receiving and / or transmitting signals. For example, the processor 810 is used to control the transceiver 830 to receive and / or transmit signals.

[0308] As an example, processor 810 may have the functions of processing unit 720 shown in FIG. 7, memory 820 may have the functions of storage unit, and transceiver 830 may have the functions of transceiver unit 710 shown in FIG. 7.

[0309] As one option, the device 800 is used to implement the operations performed by the communication device (such as RIS, or the first communication device, or the second communication device) in the various method embodiments described above.

[0310] For example, processor 810 is used to execute computer programs or instructions stored in memory 820 to implement the relevant operations of the communication device in the various method embodiments above.

[0311] It should be understood that the processor mentioned in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), ASICs, field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0312] It should also be understood that the memory mentioned in the embodiments of this application can be volatile memory and / or non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0313] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0314] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0315] Referring to Figure 9, as an example, Figure 9 is a schematic diagram of a chip system 900 provided in an embodiment of this application. The chip system 900 (or may also be referred to as a processing system) includes logic circuitry 910 and an input / output interface 920.

[0316] The logic circuit 910 can be a processing circuit in the chip system 900. The logic circuit 910 can be coupled to a memory unit, calling instructions from the memory unit, enabling the chip system 900 to implement the methods and functions of the embodiments of this application. The input / output interface 920 can be an input / output circuit in the chip system 900, outputting processed information from the chip system 900, or inputting data or signaling information to be processed into the chip system 900 for processing.

[0317] As one approach, the chip system 900 is used to implement the operations performed by the communication device (such as a RIS, a first communication device, or a second communication device) in the various method embodiments described above.

[0318] For example, logic circuit 910 is used to implement processing-related operations performed by a communication device (such as a RIS, a first communication device, or a second communication device) in the above method embodiments; input / output interface 920 is used to implement sending and / or receiving-related operations performed by a communication device (such as a RIS, a first communication device, or a second communication device) in the above method embodiments.

[0319] This application also provides a computer-readable storage medium storing a computer program or instructions for implementing the methods executed by a communication device (such as a RIS, a first communication device, or a second communication device) in the above-described method embodiments. For example, when the computer program or instructions are run on the communication device, the communication device (such as a RIS, a first communication device, or a second communication device) performs the above-described methods (such as method 200 or method 400).

[0320] This application also provides a computer program product comprising instructions that, when executed by a computer, implement the methods described above, which are performed by a communication device (such as a RIS, a first communication device, or a second communication device). For example, when the computer program or instructions are run on the communication device, the communication device (such as a RIS, a first communication device, or a second communication device) performs the methods described above (such as method 200 or method 400).

[0321] This application also provides a communication system, which includes one or more of the RIS, first communication device, and second communication device described in the above embodiments. For example, the system includes the RIS, first communication device, and second communication device shown in the embodiment of FIG2. As another example, the system includes the RIS, terminal device, and network device shown in the embodiment of FIG4.

[0322] The explanations and beneficial effects of the relevant contents in any of the devices provided above can be found in the corresponding method embodiments provided above, and will not be repeated here.

[0323] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of apparatus or units may be electrical, mechanical, or other forms.

[0324] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs). For example, the aforementioned available media include, but are not limited to, USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, and other media capable of storing program code.

[0325] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method applied to a configurable smart surface RIS device, characterized in that, The method includes: Receive a first reference signal from a first communication device based on the first time domain resources; The first reference signal is reflected to the second communication device based on the first phase; A second reference signal is received from the first communication device based on a second time-domain resource, wherein the first time-domain resource and the second time-domain resource have the same time-domain length, and the first reference signal and the second reference signal are the same; The second reference signal is reflected to the second communication device based on the second phase, wherein the second phase is out of phase with the first phase; Wherein, the first reference signal and the second reference signal are used for measuring the first channel and / or the second channel, the first channel being the channel between the first communication device and the second communication device, and the second channel being the channel between the first communication device and the RIS device.

2. The method according to claim 1, characterized in that, The method further includes: The third reference signal is received from the first communication device based on F groups of time-domain resources. Each group of time-domain resources in the F groups includes A time-domain units. The third reference signal on the A time-domain units in a group of time-domain resources is the same, and the third reference signal on different groups of time-domain resources is different. A is an integer greater than 1, and F is an integer greater than 1. The third reference signal is reflected to the second communication device based on B phases. The B phases are used for each group of time-domain resources in the F groups of time-domain resources, and the correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources. The third reference signal, together with the first reference signal and the second reference signal, is used for the measurement of the third channel, which is the channel between the second communication device and the RIS device. B is an integer greater than or equal to 1 and less than or equal to A.

3. The method according to claim 2, characterized in that, The value of F is greater than or equal to the number of paths corresponding to the second channel.

4. The method according to claim 2 or 3, characterized in that, The value of A is related to the number of elements in the RIS device.

5. The method according to any one of claims 2 to 4, characterized in that, The value of A is greater than or equal to log(W), or the value of A is greater than or equal to log(W) / L; Wherein, L is the number of paths corresponding to the third channel, and W represents the number of elements in the RIS device.

6. The method according to any one of claims 2 to 5, characterized in that, The method further includes: Receive first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the time domain resources of group F.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: Receive second indication information, the second indication information indicating at least one of the following: the length of the first time domain resource, the location of the first time domain resource, the length of the second time domain resource, and the location of the second time domain resource.

8. A communication method, characterized in that, Applied to a second communication device, the method includes: A first reference signal is received from a first communication device and reflected by a configurable smart surface RIS device based on a first phase, based on a first time domain resource. A second reference signal is received from the first communication device based on a second time-domain resource and reflected by the RIS device based on a second phase, wherein the second phase is out of phase with the first phase, the time-domain lengths of the first time-domain resource and the second time-domain resource are the same, and the first reference signal and the second reference signal are the same. Channel information of a first channel and / or a second channel is obtained based on the first reference signal and the second reference signal, wherein the first channel is the channel between the first communication device and the second communication device, and the second channel is the channel between the first communication device and the RIS device.

9. The method according to claim 8, characterized in that, The method further includes: The third reference signal is received from the first communication device based on F groups of time-domain resources and reflected by the RIS device based on B phases. The B phases are used for each group of time-domain resources in the F groups, and the correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources. Wherein, each group of time-domain resources in the F groups of time-domain resources includes A time-domain units. The third reference signal on the A time-domain units in a group of time-domain resources is the same, and the third reference signal on different groups of time-domain resources is different. A and F are integers greater than 1, and B is an integer greater than or equal to 1 and less than or equal to A. Based on the third reference signal, the first reference signal, and the second reference signal, channel information of the third channel is obtained, wherein the third channel is the channel between the second communication device and the RIS device.

10. The method according to claim 9, characterized in that, The step of obtaining channel information of the third channel based on the third reference signal, the first reference signal, and the second reference signal includes: The channel information of the third channel is obtained based on the third reference signal, the first reference signal, the second reference signal, and the reference channel information.

11. A communication method applied to a first communication device, characterized in that, include: Based on the first time-domain resources, a first reference signal is sent to the second communication device through a configurable smart surface RIS device, wherein the first reference signal corresponds to the first phase; Based on the second time-domain resource, the RIS device sends a second reference signal to the second communication device. The second reference signal corresponds to a second phase, which is out of phase with the first phase. The time-domain lengths of the first time-domain resource and the second time-domain resource are the same, and the first reference signal and the second reference signal are the same. Wherein, the first reference signal and the second reference signal are used for measuring the first channel and / or the second channel, the first channel being the channel between the first communication device and the second communication device, and the second channel being the channel between the first communication device and the RIS device.

12. The method according to claim 11, characterized in that, The method further includes: Based on the F-group time-domain resources, the RIS device sends a third reference signal to the second communication device. The third reference signal, together with the first reference signal and the second reference signal, is used for the measurement of a third channel, which is the channel between the second communication device and the RIS device. Wherein, the third reference signal corresponds to B phases, the B phases are used for each group of time-domain resources in the F groups of time-domain resources, and the correspondence between the B phases and the A time-domain units is the same in each group of time-domain resources; Wherein, each group of time-domain resources in the F groups includes A time-domain units. The third reference signal on the A time-domain units in a group of time-domain resources is the same, and the third reference signal on different groups of time-domain resources is different. A and F are integers greater than 1, and B is an integer greater than or equal to 1 and less than or equal to A.

13. The method according to any one of claims 9, 10, and 12, characterized in that, The value of F is greater than or equal to the number of paths corresponding to the second channel.

14. The method according to any one of claims 9, 10, 12, and 13, characterized in that, The value of A is related to the number of elements in the RIS device.

15. The method according to any one of claims 9, 10, 12, 13, and 14, characterized in that, The value of A is greater than or equal to log(W), or the value of A is greater than or equal to log(W) / L; Wherein, L is the number of paths corresponding to the third channel, and W represents the number of elements in the RIS device.

16. The method according to any one of claims 9, 10, 12, 13, 14, and 15, characterized in that, The method further includes: Send or receive first indication information, the first indication information indicating at least one of the following: the value of F, the value of A, and the location of the time-domain resources of group F.

17. The method according to any one of claims 8 to 16, characterized in that, The method further includes: Send or receive second indication information, the second indication information indicating at least one of the following: the length of the first time-domain resource, the location of the first time-domain resource, the length of the second time-domain resource, and the location of the second time-domain resource.

18. The method according to any one of claims 1 to 17, characterized in that, The first time-domain resource and the second time-domain resource are consecutive time-domain resources.

19. The method according to any one of claims 1 to 18, characterized in that, The time domain lengths of the first time domain resource and the second time domain resource are associated with at least one of the following: the number of ports of the first communication device, the number of paths corresponding to the first channel, and the number of paths corresponding to the second channel.

20. The method according to any one of claims 1 to 19, characterized in that, The time-domain lengths of the first time-domain resource and the second time-domain resource satisfy the following: T≥max{I·log(Q),J·log(Q)}; Where T represents the time domain length of the first time domain resource and the second time domain resource, I represents the number of paths corresponding to the first channel, J represents the number of paths corresponding to the second channel, and Q represents the number of ports of the first communication device.

21. A communication device, characterized in that, Includes modules or units for performing the method according to any one of claims 1 to 20.

22. A communication device, characterized in that, Includes a processor for executing a computer program or instructions in a memory to cause the apparatus to perform the method of any one of claims 1 to 20.

23. The apparatus according to claim 22, characterized in that, The device further includes the memory and / or a communication interface, the communication interface being coupled to the processor. The communication interface is used for inputting and / or outputting information.

24. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed on a communication device, cause the communication device to perform the method as described in any one of claims 1 to 20.

25. A computer program product, characterized in that, The computer program product includes a computer program or instructions for performing the method as described in any one of claims 1 to 20.

Images