WO2024060931A1

WO2024060931A1 - Method, device and system for communication

Info

Publication number: WO2024060931A1
Application number: PCT/CN2023/114971
Authority: WO
Inventors: 董妙妙; 达达里大卫; 陈翔; 韩伟; 白铂
Original assignee: 华为技术有限公司
Priority date: 2022-09-20
Filing date: 2023-08-25
Publication date: 2024-03-28
Also published as: CN117792442A

Abstract

The present application relates to a method, device and system for communication. According to the technical solution provided herein, a network device sends a reference signal to a terminal device, wherein the terminal device comprises an RIS, which serves as a transceiving unit; the terminal device generates, by means of the RIS, a reflection signal for the reference signal, wherein the reflection signal comprises data information associated with the terminal device; and the network device determines the data information from the reflection signal. Thus, the costs and power consumption of the terminal device can be reduced, and stable link transmission and improved communication efficiency can be realized.

Description

Methods, devices and systems for communications

Cross-references to related applications

This application claims priority to the Chinese invention patent application with application date of September 20, 2022, application number 202211146353.3, and titled “Methods, devices and systems for communication”.

Technical field

The present application relates to the field of communications, and in particular to methods, devices and systems for communications utilizing reconfigurable intelligent surfaces (RIS).

Background technique

RIS is a two-dimensional plane composed of a large number of low-cost passive reflective units. The size and internal structure of each passive reflective unit are uniquely designed. Different voltages are applied to the passive reflective unit through the controller, so that the surface of the unit presents different reflection coefficients. RIS has the characteristics of low production cost and low power consumption. RIS can be combined with existing communication systems to form a RIS-assisted communication system.

Contents of the invention

Embodiments of the present disclosure provide a communication solution using RIS, which can reduce the cost and power consumption of communication terminals and improve communication performance.

According to a first aspect of an embodiment of the present disclosure, a method for communication is provided. The method includes: a network device sending a reference signal to a terminal device, the terminal device including a reconfigurable smart surface as a transceiver unit; the network device receiving a reflected signal generated by the reconfigurable smart surface for the reference signal , the reflected signal includes data information associated with the terminal device; and the network device determines the data information from the reflected signal.

According to a second aspect of embodiments of the present disclosure, a method for communication is provided. The method includes: a terminal device receiving a reference signal from a network device, the terminal device including a reconfigurable smart surface as a transceiver unit; and the terminal device generating a reflected signal for the reference signal through the reconfigurable smart surface, The reflected signal includes data information associated with the terminal device.

According to a third aspect of an embodiment of the present disclosure, a network device is provided. The network device includes: a transceiver configured to send a reference signal to a terminal device and receive a reflected signal for the reference signal generated by the reconfigurable smart surface, the terminal device includes a reconfigurable smart surface as a transceiver unit, and the reflected signal includes data information associated with the terminal device; and a processor coupled to the transceiver and configured to determine the data information from the reflected signal.

According to a fourth aspect of embodiments of the present disclosure, a terminal device is provided. The terminal device includes: a reconfigurable smart surface configured to receive a reference signal from a network device, the reconfigurable smart surface serving as a transceiver unit of the terminal device; and a processor with the reconfigurable smart surface Coupled and configured to generate a reflected signal for the reference signal through the reconfigurable smart surface, the reflected signal including data information associated with the terminal device.

According to a fifth aspect of embodiments of the present disclosure, a communication system is provided. The system includes the devices in the aforementioned third and fourth aspects.

According to a sixth aspect of an embodiment of the present disclosure, a chip is provided, including a processor and a front-end circuit, the processor and the front-end circuit The circuits operate together for performing the method of the aforementioned first or second aspect.

According to a seventh aspect of embodiments of the present disclosure, a computer-readable storage medium is provided. The computer-readable storage medium includes machine-executable instructions that, when executed by a device, cause the device to perform the method according to the aforementioned first or second aspect.

According to an eighth aspect of embodiments of the present disclosure, a computer program product is provided. The computer program product includes computer program code which, when executed by a device, causes the device to perform a method according to the aforementioned first or second aspect.

It will be understood from the following description of example embodiments that according to the technical solution proposed herein, the hardware cost and power consumption of the communication device can be effectively reduced. In addition, the precoding design of the transceiver can be realized without the need for channel state information, and combined with the application of RIS, the signal-to-noise ratio of the link can be effectively improved.

It should be understood that the content described in this summary is not intended to define key or important features of the embodiments of the disclosure, nor to limit the scope of the disclosure. Other features of the present disclosure will become apparent from the description below.

Description of drawings

The above and other features, advantages, and aspects of various embodiments of the present disclosure will become more apparent with reference to the following detailed description taken in conjunction with the accompanying drawings. In the drawings, the same or similar reference numbers represent the same or similar elements, where:

FIG1 is a schematic diagram showing an example communication network in which embodiments of the present disclosure may be implemented;

Figure 2A shows a schematic diagram of a RIS in which embodiments of the present disclosure may be implemented;

2B shows a circuit schematic diagram of an RIS unit processing an incident signal in which embodiments of the present disclosure may be implemented;

Figure 3 shows a schematic diagram of an example communication process according to an embodiment of the present disclosure;

Figure 4 shows a simulation diagram of the signal-to-noise ratio (SNR) value of the RIS-based Internet of Things (IoT) communication system during the symbol iteration process according to an embodiment of the present disclosure;

Figure 5 shows a flow chart of a communication method implemented at a network device according to an embodiment of the present disclosure;

Figure 6 shows a flow chart of a communication method implemented at a terminal device according to an embodiment of the present disclosure;

Figure 7 shows a schematic block diagram of an example network device according to an embodiment of the present disclosure;

Figure 8 shows a schematic block diagram of an example terminal device according to an embodiment of the present disclosure; and

Figure 9 shows a simplified block diagram of an apparatus suitable for implementing embodiments of the present disclosure.

Detailed ways

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are illustrated in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather these embodiments are provided for A more thorough and complete understanding of this disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

As used herein, the term "include" and its variations are open-ended, that is, "including but not limited to." The term "based on" means "based at least in part on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one further embodiment". Relevant definitions of other terms will be given in the description below.

It will be understood that, although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the embodiments. As used herein, the term "and/or" includes any and all combinations of one or more of the listed terms.

As used herein, the term "circuit" means one or more of the following:

(a) Hardware circuitry only implementations (such as analog and/or digital circuitry only implementations); and

(b) A combination of hardware circuitry and software, such as, if applicable: (i) analog and/or digital hardware circuitry in combination with software/firmware, and (ii) any portion of a hardware processor with software, including those working together to digital signal processors, software and memory that enable the device to perform various functions); and

(c) Hardware circuitry and/or processors, such as a microprocessor or a portion of a microprocessor, which require software (eg, firmware) for operation, but may be without software when software is not required for operation.

The definition of circuit applies to all uses of this term in this application (including in any claims). As another example, the term "circuitry" as used herein also covers implementations of only a hardware circuit or processor (or processors), or a portion of a hardware circuit or processor, or accompanying software or firmware thereof. For example, if applicable to a particular claim element, the term "circuit" also covers a baseband integrated circuit or a processor integrated circuit or similar integrated circuits in other computing devices.

As used herein, the term "end device" refers to any device having wireless or wired communications capabilities. Examples of terminal devices include, but are limited to, customer premise equipment (CPE), user equipment (UE), personal computers, desktop computers, mobile phones, cellular phones, smart phones, personal digital assistants, PDAs), portable computers, tablets, wearable devices, IoT devices, machine type communication (MTC) devices, for vehicle to everything (V2X) (X refers to pedestrians, vehicles or infrastructure/networks ) communication vehicle-mounted devices, or image capture devices such as digital cameras, gaming devices, music storage and playback devices, or Internet devices capable of wireless or wired Internet access and browsing, etc.

In addition, the term "network equipment" refers to equipment that is capable of providing or hosting a cell or coverage area in which a terminal device can communicate. Examples of network equipment include, but are not limited to, Node B (NodeB or NB), evolved Node B (eNodeB or eNB), next generation Node B (gNB), transmission reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), low power nodes such as femto nodes, pico nodes, etc.

Example implementation of application environment

Figure 1 shows a schematic diagram of an example communications network 100 in which embodiments of the present disclosure may be implemented. As shown in FIG. 1 , the communication network 100 may include a network device 110 and a terminal device 120 . Network device 110 may provide a cell (not shown) and serve terminal devices within the cell. In this example, the terminal device 120 is located in a cell of the network device 110, and the network device 110 can serve the terminal device 120.

As shown in FIG. 1 , the terminal device 120 may include a RIS 121 as a transceiver unit. In some embodiments, the RIS 121 may replace the transceiver antenna and the radio frequency unit of the terminal device 120. In this case, the terminal device 120 can only reflect the signal through the RIS, but cannot actively transmit the signal. In some embodiments, the network device 110 may transmit a signal, which may be reflected by the RIS 121 and returned to the network device 110 along the original path. The network device 110 may operate in duplex mode to receive the reflected signal.

Network device 110 may communicate with terminal device 120 via a channel, such as a wireless communication channel. Communication in the communication network 100 may comply with any suitable standard, including but not limited to global system for mobile communication (GSM), long term evolution (LTE), LTE evolution, LTE-advanced ,LTE-A), wideband code division multiple access (WCDMA), code division multiple access (code division multiple access, CDMA), GSM EDGE radio access network (GERAN), MTC etc. Furthermore, communication can be performed according to any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), sixth generation (6G) communication protocols .

It should be understood that the number of devices in Figure 1 is given for illustrative purposes and does not imply any limitation on the present disclosure. Communications network 100 may include any suitable number of network devices and/or terminal devices suitable for implementing the present disclosure. In addition, the communication network 100 may include more additional components not shown or may omit certain components shown, and the embodiments of the present disclosure are not limited thereto. The implementation of the communication network 100 is also not limited to the specific examples described above, but may be implemented in any suitable manner.

In some embodiments, communication network 100 may be an IoT communication network. The network device 110 may be an IoT network device, and the terminal device 120 may be an IoT terminal device. It should be understood that any other suitable communication network is also feasible, and the embodiments of the present disclosure are not limited thereto.

FIG. 2A shows a schematic diagram 200A of a RIS in which an embodiment of the present disclosure can be implemented. As shown in FIG. 200A , different voltages can be applied to each passive reflection unit (also referred to herein as a RIS unit) of the RIS by a controller, so that the surface of the RIS unit presents different reflection coefficients. These reflection coefficients can be encoded. For example, if a RIS unit has two different reflection coefficients g1 and g2, digital bit 1 can correspond to reflection coefficient g1, and digital bit 0 can correspond to reflection coefficient g2. If a unit has four different reflection coefficients g1, g2, g3, and g4, digital bit 10 can correspond to reflection coefficient g1, digital bit 01 can correspond to reflection coefficient g2, digital bit 11 can correspond to reflection coefficient g3, and digital bit 00 can correspond to reflection coefficient g4. According to specific digital bit information, a specific reflection coefficient can be configured to reflect a signal. It should be understood that this is only an example, and any other suitable mapping method of digital bits and reflection coefficients is also feasible.

In some embodiments, the reflection coefficient of the RIS unit may be expressed as a complex number ge ^jφ , where g represents the magnitude of the reflection coefficient and e ^jφ represents the phase of the reflection coefficient. Generally, the reflection coefficient amplitude g of the RIS unit does not change with its applied voltage, but only the phase φ changes with the voltage. If the voltage is V1, then φ=0; if the voltage is V2, then φ=π. It should be understood that this is only an example and the reflection coefficient may also be expressed in any other suitable way.

In addition to configuring the reflection coefficient to reflect signals, RIS can also implement simple signal processing through the circuit design inside each RIS unit. 2B illustrates a circuit schematic 200B of a RIS unit processing an incident signal in which embodiments of the present disclosure may be implemented. According to the circuit shown in Figure 2B, each RIS unit can implement conjugation processing of the incident signal. For example, if the signal with incident carrier frequency f ₀ is a complex number x(t)=a+jb, then the conjugated signal is x*(t)=a-jb. It should be understood that the circuit design of FIG. 2B is only an example, and any other suitable circuit design is also feasible.

In a known RIS-assisted communication system, the RIS can be used as a large-size antenna deployed at the base station to replace the traditional antenna array. In this scenario, the RIS is part of the base station. In another known RIS-assisted communication system, the RIS can be placed between the base station and the user, ie, the base station and the user can communicate by means of the RIS. In this scenario, RIS is independent of both base stations and users. In these communication systems, communication system performance can be improved by configuring the reflection coefficient of RIS.

However, the terminal equipment still needs to have a radio frequency unit to send and receive signals and perform signal processing, resulting in high power consumption and hardware costs. In addition, when configuring the reflection coefficient of the RIS, it is necessary to obtain the channel state information of the link, and the time complexity of obtaining the channel state information is high. Especially for IoT communication systems, the primary problem to be solved is how to achieve stable link transmission and low-power, low-cost IoT terminal equipment.

In view of this, embodiments of the present disclosure propose a RIS-assisted communication system to overcome the above and other potential problems. According to an aspect of the communication system of the embodiment of the present disclosure, the RIS may be deployed on the terminal device side to serve as a transceiver unit of the terminal device. The network device may send the reference signal to the terminal device, and the terminal device may generate a reflected signal for the reference signal through the RIS, such that the reflected signal includes data information associated with the terminal device. Accordingly, the network The device can receive the reflected signal and determine the data information from the reflected signal. In this way, the transceiver unit of the terminal device can be replaced by the RIS, thereby reducing the cost and power consumption of the terminal device. In other words, a low-cost and low-power consumption communication system based on RIS can be realized.

According to another aspect of the communication system of the embodiment of the present disclosure, the network device may update the precoding vector based on the reflected signal, and use the updated precoding vector for the transmission of subsequent reference signals. Through this iterative update method, precoding design can be implemented without the need for channel state information, thereby achieving stable link transmission and improving communication efficiency.

For ease of understanding, a more detailed description will be given below in conjunction with Figures 3 and 4.

Example implementation of communication process

Figure 3 shows a schematic diagram of an example communication process 300 in accordance with an embodiment of the present disclosure. For convenience, FIG. 3 will be described here in conjunction with the example of FIG. 1 . The process 300 may involve network device 110 and end device 120. It should be understood that the process of Figure 3 may include other additional steps not shown, or some of the steps shown may be omitted. The scope of the present disclosure is not limited in this regard. In this example, the terminal device 120 includes a RIS 121 as a transceiver unit.

As shown in Figure 3, the network device 110 sends 310 a reference signal to the terminal device 120. In some embodiments, the reference signal may include a pilot signal. In some embodiments, the reference signal may include at least one of the following: channel state information-reference signal (CSI-RS), sounding reference signal (Sounding reference signal, SRS), phase tracking reference signal (phase-tracking reference signal, PTRS), positioning reference signal (positioning reference signal, PRS) or demodulation reference signal (demodulation reference signal, DMRS). It should be understood that any other known or future-developed reference signals are feasible, and the embodiments of the present disclosure are not limited thereto.

In some embodiments, network device 110 may utilize precoding vectors to transmit reference signals. For example, the network device 110 may map the reference signal s to the antenna through the precoding vector x for transmission. Assuming s=1, the transmitted symbol is sx=x. In some embodiments, randomly generated precoding vectors may be used in the initial symbol period. Iteratively updated precoding vectors may be used in subsequent symbol periods. Of course, in some alternative embodiments, network device 110 may use predefined precoding vectors. It should be understood that the precoding vector in the initial symbol period can be determined in any suitable manner and is not limited to these examples. Furthermore, it should be understood that the reference signal may be sent in any suitable manner and is not limited to the above example.

As shown in FIG3 , after receiving the reference signal, the terminal device 120 generates 320 a reflection signal for the reference signal through the RIS 121, so that the reflection signal includes data information associated with the terminal device 120. In some embodiments, the terminal device 120 may map the data information to the reflection coefficient of the RIS 121. In other words, the data information (e.g., bit 0 or 1) to be sent by the terminal device 120 may be mapped to the reflection coefficient of the RIS. Assume that there are two optional phases of the reflection coefficient of each RIS unit, g1 and g2. For example, when transmitting bit 0, all RIS units of the RIS 121 may adopt the reflection coefficient g1, and when transmitting bit 1, all RIS units of the RIS 121 may adopt the reflection coefficient g2. It should be understood that this is only an example and is not intended to limit the embodiments of the present disclosure to this, but any other suitable mapping method is feasible.

After receiving the incident reference signal, the RIS 121 can perform conjugation processing on the reference signal. For example, the reference signal sent by the network device 110 in the k-1th symbol period reaches the RIS 121 of the terminal device 120 along the wireless channel H. The arrival signal can be expressed as equation (1):

where z[k-1] represents the arrival signal in the k-1th symbol period, P _T represents the transmit power of the reference signal, x[k-1] represents the precoding vector in the k-1th symbol period, H represents the downlink channel matrix, eta[k-1] represents the k-1th symbol period downlink noise.

The signal after conjugation processing can be expressed as equation (2):

where z ^* [k-1] represents the conjugate signal of the arriving signal in the k-1th symbol period, P _T represents the transmit power of the reference signal, x ^* [k-1] represents the conjugate signal in the k-1th symbol period The conjugate signal of the precoding vector, H ^* represents the conjugate matrix of the channel matrix H, and eta ^* [k-1] represents the conjugate signal of the downlink noise in the k-1th symbol period.

Then, the RIS 121 may generate a reflection signal based on the reflection coefficient and the conjugated reference signal. For example, the reflected signal can be expressed as equation (3):

where r[k-1] represents the reflected signal in the k-1th symbol period, ge ^jφ[k-1] represents the reflection coefficient, z ^* [k-1] represents the arrival signal in the k-1th symbol period conjugate signal. It should be understood that the above formulas (1) to (3) are only exemplary and not restrictive. In addition, it should be understood that the above-mentioned method of generating a reflected signal is only an example, and the data information to be transmitted by the terminal device can also be added to the reflected signal through any other suitable method.

The reflected signal r[k-1] is received 330 by the network device 110 along the uplink channel ^HT , and can be expressed as equation (4):

Among them, y[k-1] represents the reflected signal of the k-1th symbol received, w[k-1] represents the uplink noise, A represents the matrix completely determined by the uplink and downlink channel matrix H, and n[k-1] represents Noise in uplink and downlink, * indicates conjugate processing.

Continuing to refer to FIG. 3 , after receiving the reflected signal, the network device 110 may update 340 the precoding vector in the current symbol period based on the reflected signal for sending the reference signal in the next symbol period. In some embodiments, the network device 110 may update the precoding vector in the k-th symbol period based on the following equation (5):

Where (a) is obtained by substituting the formula of x[k-1], x[k-2], …, x[0] (in the form of equation (4)) into equation (5), and x[k] represents the precoding vector in the kth symbol period after the update. Note that the numerator of equation (5) can be written as

where v _j is the j-th eigenvector of matrix A, λ _j is the eigenvalue corresponding to the j-th eigenvector, j=1,2,…,N, x _j [0] is the j-th eigenvector of vector x[0] elements. Because λ _j decreases as j increases, less than 1. Put this equation (6) into (5) to get the following equation (7):

Where x[k] represents the updated precoding vector in the k-th symbol period, and v ₁ represents the first eigenvector of matrix A.

It should be understood that the above formulas (5) to (7) are only exemplary and not restrictive. The precoding vector may also be updated in any other suitable manner.

Continuing to refer to FIG. 3 , after the network device 110 receives the reflected signal generated by the RIS 121 , the data information associated with the terminal device 120 can be determined 350 from the reflected signal. In some embodiments, the network device 110 may determine the reflection coefficient used by the RIS 121 based on the precoding vector associated with the transmission of the reference signal, and extract or demodulate data information from the reflected signal based on the determined reflection coefficient. In some embodiments, the network device 110 may obtain an estimate of the reflection coefficient of the RIS 121 in the current symbol period by calculating the inner product of the precoding vector in the previous symbol period and the current symbol period, for example, an estimate of the reflection coefficient The value can be expressed as equation (8):

where u[k-1] represents the estimated value of the reflection coefficient in the k-1th symbol period, x[k-1] represents the precoding vector in the k-1th symbol period, and x[k] represents the k-th The precoding vector in symbol period, v ₁ represents the first eigenvector of the channel matrix A in formula (4), is the conjugate transpose operator.

By judging the phase of u[k-1], the reflection coefficient of RIS in the k-1th symbol period can be extracted, for example, as shown in equation (9):

where φ[k-1] is the estimated reflection coefficient in the k-1th symbol period, and arg{x} represents the phase of the extracted complex number x. Through the mapping relationship between data signal bits 0 and 1 and the reflection coefficient, the data bit information corresponding to the reflection coefficient φ[k-1] can be determined. It should be understood that the above formulas (8) to (9) are only exemplary and not restrictive. The reflection coefficient can also be estimated and the data bit information determined from the reflection coefficient in any other suitable manner.

Based on the updated precoding vector, the operations described in conjunction with 310 to 350 in Figure 3 may be repeated. As a result, precoding design on the network device side can be implemented through an iterative strategy without the need for channel state information. In this way, the performance of the communication system can be effectively improved. An example is explained below with reference to Figure 4.

FIG. 4 shows a simulation diagram 400 of the SNR value of the RIS-based IoT communication system during the symbol iteration process according to an embodiment of the present disclosure. Reference numeral 410 in Figure 4 represents the simulation results of the present invention under the condition of P _T =30dBm, where it is assumed that the distance between the network equipment and the terminal equipment in the free space channel environment is 10 meters, and the network equipment side is 20*20 square meters. Two-dimensional planar antenna, the RIS of the terminal equipment is a 10*10 two-dimensional plane, and the carrier frequency is 28GHz. Reference numeral 420 in Figure 4 represents the simulation results for the case where the terminal device has only one antenna when P _T =30dBm.

It can be seen from the curve shown as number 410 that the SNR under the 240KHz bandwidth reaches a maximum value of 38dB after 5 iterations. This shows that the iterative strategy proposed by the present invention can complete the optimal precoding design in a short period of time (about 5 times), and the precoding can effectively improve the performance of the communication system. It can be seen from the curve shown by reference numeral 420 that the result does not change as the symbol period increases. That is, when the terminal device has only one antenna and no channel state information, the precoding vector cannot be designed. When the terminal device has only one antenna, there is no more antenna gain, and the SNR is -56dB. Therefore, compared with the traditional IoT device using a single transceiver antenna solution, the solution of the present invention can effectively improve the SNR of the link through precoding on the network device side and multiple RIS units on the IoT device side.

So far, the communication process according to the embodiment of the present disclosure has been described. It should be understood that the general process described above in conjunction with Figures 3 and 4 The order of steps in the letter process is for illustrative purposes only and is not intended to be limiting. Furthermore, these communication processes may include more steps not shown or some steps shown may be omitted, without being limited to the above description.

According to the solutions of the embodiments of the present disclosure, there is no need to process radio frequency signals in the terminal equipment, which effectively reduces the hardware cost and power consumption of the terminal equipment. In addition, the precoding on the network device side can also be designed without channel state information, effectively saving the time complexity of channel estimation and occupied time-frequency resources.

Example implementation of communication methods

Corresponding to the above communication process, embodiments of the present disclosure provide a communication method implemented at a network device and a communication method implemented at a terminal device. Figure 5 shows a flowchart of a communication method 500 implemented at a network device according to an embodiment of the present disclosure. The method 500 may be implemented at the network device 110 of FIG. 1 . For convenience, the following is explained with reference to the example in Figure 1. It should be understood that the method of Figure 5 may include other additional steps not shown, or some steps shown may be omitted. The scope of the present disclosure is not limited in this regard.

As shown in Figure 5, at block 510, the network device 110 sends a reference signal to the terminal device 120, and the terminal device 120 includes the RIS 121 as a transceiver unit.

In some embodiments, network device 110 may transmit the reference signal using the precoding vector in the current symbol period. As a result, precoding design can be performed without channel state information, thereby improving link quality.

At block 520, network device 110 receives the reflected signal generated by RIS 121 for the reference signal. The reflected signal includes data information associated with the terminal device 120 . By embedding the data information to be transmitted by the terminal device in the reflected signal of the RIS, there is no need for radio frequency signal processing, which can reduce the cost and power consumption of the terminal device.

At block 530, network device 110 determines data information from the reflected signal.

In some embodiments, the network device 110 may determine the reflection coefficient used by the RIS based on the precoding vector, and demodulate the data information from the reflected signal based on the reflection coefficient. By demodulating data information through the reflection coefficient of RIS, the terminal device can transmit and demodulate information bits without a radio frequency link.

In some embodiments, the network device 110 may update the precoding vector based on the reflected signal for transmitting the reference signal in the next symbol period. Thus, the precoding design at the network device end may be implemented through an iterative strategy, effectively saving the time complexity of channel estimation and the occupied time-frequency resources.

In some embodiments, the network device 110 and the terminal device 120 may be IoT devices. As a result, the hardware cost and power consumption of IoT devices can be effectively reduced, and the performance of the IoT communication system can be effectively improved.

According to the method in Figure 5, data information from the terminal device can be obtained by receiving the signal reflected by the RIS of the terminal device, without the need for processing of radio frequency signals on the terminal device side.

FIG. 6 shows a flowchart of a communication method 600 implemented at a terminal device according to an embodiment of the present disclosure. The method 600 may be implemented at the terminal device 120 of FIG. 1 . For convenience, the description will be given here in conjunction with the example in Figure 1. It should be understood that the method of Figure 6 may include other additional steps not shown, or some steps shown may be omitted. The scope of the present disclosure is not limited in this regard.

As shown in Figure 6, at block 610, the terminal device 120 receives the reference signal from the network device 110, and the terminal device 120 includes the RIS 121 as a transceiver unit.

At block 620, the terminal device 120 generates a reflected signal for the reference signal via the RIS 121, the reflected signal including data information associated with the terminal device 120.

In some embodiments, the terminal device 120 can perform conjugation processing on the reference signal through the RIS 121, map the data information into the reflection coefficient of the RIS 121, and use the RIS 121 to perform conjugation processing on the reference signal based on the reflection coefficient and the conjugation process. Generate a reflected signal. Therefore, the data information to be transmitted by the terminal device can be embedded in the reflection coefficient of the RIS without the need for RF signal processing, thereby reducing the cost and power consumption of terminal equipment.

According to the method in Figure 6, by embedding data information in the reflected signal of the RIS, there is no need for radio frequency signal processing on the terminal device side, so the cost and power consumption of the terminal device can be reduced.

Exemplary implementation of communication device

Corresponding to the above methods, embodiments of the present disclosure also provide network devices and terminal devices that can implement these methods. This is described below in conjunction with Figures 7 and 8.

Figure 7 shows a block diagram of an example network device 700 in accordance with an embodiment of the present disclosure. It should be understood that the block diagram of FIG. 7 is for illustrative purposes only and is not intended to be limiting. The device of Figure 7 may include more or fewer components.

As shown in Figure 7, network device 700 may include a transceiver 710 and a processor 720. The transceiver 710 is configured to transmit a reference signal to a terminal device and receive a reflected signal for the reference signal generated by the RIS, the terminal device including the RIS as a transceiver unit. The reflected signal includes data information associated with the terminal device. Processor 720 is coupled to transceiver 710 and configured to determine data information from the reflected signals.

In some embodiments, transmitting the reference signal includes transmitting, by the transceiver 710, the reference signal using the precoding vector in the current symbol period. As a result, precoding design can be performed without channel state information, thereby improving link quality.

In some embodiments, the processor 720 is further configured to update the precoding vector based on the reflected signal for transmission of the reference signal in the next symbol period. As a result, the precoding design on the network device side can be implemented through an iterative strategy, effectively saving the time complexity of channel estimation and occupied time-frequency resources.

In some embodiments, determining the data information includes: determining, by the processor 720, a reflection coefficient used by the RIS based on the precoding vector; and demodulating the data information from the reflected signal based on the reflection coefficient by the processor 720. By demodulating data information through the reflection coefficient of RIS, the terminal device can transmit and demodulate information bits without a radio frequency link.

In some embodiments, the terminal device and the network device are IoT devices. Of course, this is only an example, and the embodiments of the present disclosure are also applicable to terminal devices and network devices in other communication systems.

Figure 8 shows a block diagram of an example terminal device 800 according to an embodiment of the present disclosure. It should be understood that the block diagram of FIG. 8 is for illustrative purposes only and is not intended to be limiting. The device of Figure 8 may include more or fewer components.

As shown in Figure 8, the terminal device 800 may include a RIS 810 and a processor 820. The RIS 810 is configured to receive a reference signal from a network device, and the RIS 810 serves as a transceiver unit of the terminal device 800. The processor 820 is coupled to the RIS 810 and is configured to generate, via the RIS 810, a reflected signal for the reference signal, the reflected signal including data information associated with the terminal device 800.

In some embodiments, processor 820 may also be configured to map the data information into reflection coefficients of RIS 810. The RIS 810 can also be configured to conjugate the reference signal and generate a reflection signal based on the reflection coefficient and the conjugated reference signal.

FIG9 is a simplified block diagram of a device 900 suitable for implementing an embodiment of the present disclosure. The device 900 may be provided to implement a network device or a terminal device, such as any of the network device 110 and the terminal device 120 shown in FIG1 . As shown in the figure, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processor 910, and one or more communication modules 940 coupled to the processor 910.

In network device embodiments, communication module 940 is used for duplex communications. The communication module 940 has a communication interface to facilitate communication. A communication interface may represent any interface necessary to communicate with other network elements.

In the embodiment of the terminal device, the communication module 940 includes a RIS, which is only used to reflect signals and does not actively transmit signals.

Processor 910 may be of any type suitable for the local technology network, and may include, by way of limiting example, one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors, and multi-core processor-based architectures. processor. Device 900 may have multiple processors, such as application specific integrated circuit chips, that are time-slave to a clock that is synchronized with the main processor.

Memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, read-only memory (ROM) 924, electrically programmable read-only memory (EPROM), flash memory, hard drives, compact disks (CD), digital video disks (DVD), and other magnetic storage and/or or optical storage device. Examples of volatile memory include, but are not limited to, random access memory (RAM) 922 and other volatile memory that does not persist for the duration of a power outage.

Computer program 930 includes computer-executable instructions executed by associated processor 910 . Program 930 may be stored in ROM 920. Processor 910 may perform any suitable actions and processing by loading program 930 into RAM 920.

Embodiments of the present disclosure may be implemented with the aid of program 930 such that device 900 performs the processes of the present disclosure as discussed with reference to FIGS. 1-6. The device 900 may correspond to the above-mentioned network device 110 or the terminal device 120, and the functional modules in the network device 110 or the terminal device 120 may be implemented using the software of the device 900. In other words, the functional modules included in the network device 110 or the terminal device 120 are generated by the processor 910 of the device 900 after reading the program code stored in the memory 920 . Embodiments of the present disclosure may also be implemented in hardware or in a combination of software and hardware.

In some embodiments, program 930 may be tangibly embodied in a computer-readable medium, which may be included in device 900 (such as in memory 920 ) or other storage device accessible by device 900 . Program 930 can be loaded from computer-readable media into RAM 922 for execution. Computer-readable media may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard drive, CD, DVD, etc.

Generally speaking, the various example embodiments of the present disclosure may be implemented in hardware or special purpose circuitry, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While aspects of embodiments of the present disclosure are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, devices, systems, techniques, or methods described herein may be used as non-limiting Examples are implemented in hardware, software, firmware, special purpose circuitry or logic, general purpose hardware or controllers, or other computing devices, or some combination thereof. Examples of hardware devices that can be used to implement embodiments of the present disclosure include, but are not limited to: Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standard Products (ASSPs), Systems on Chips (SOCs), Complex Programmable Logic devices (CPLD), etc.

By way of example, embodiments of the present disclosure may be described in the context of machine-executable instructions, such as included in a program module executing in a device on a target's real or virtual processor. Generally speaking, program modules include routines, programs, libraries, objects, classes, components, data structures, etc., which perform specific tasks or implement specific abstract data structures. In various embodiments, the functionality of program modules may be combined or split between the described program modules. Machine-executable instructions for program modules can execute locally or on a distributed device. In a distributed device, program modules can be located in both local and remote storage media.

Computer program code for implementing the methods of the present disclosure may be written in one or more programming languages. These computer program codes may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that The program code, when executed by a computer or other programmable data processing apparatus, causes the functions/operations specified in the flowcharts and/or block diagrams to be performed. The program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server.

In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, and the like.

Examples of signals may include electrical, optical, radio, acoustic, or other forms of propagated signals, such as carrier waves, infrared signals, and the like.

A machine-readable medium may be any tangible medium that contains or stores a program for or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media may include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or devices, or any suitable combination thereof. More detailed examples of machine-readable storage media include an electrical connection with one or more wires, laptop computer disk, hard drive, random memory accessor (RAM), read-only memory (ROM), erasable programmable read-only memory Memory (EPROM or flash memory), optical storage device, magnetic storage device, or any suitable combination thereof.

Additionally, although operations are depicted in a specific order, this should not be understood as requiring that such operations be completed in the specific order shown or in sequential order, or that all illustrated operations be performed to obtain desired results. In some cases, multitasking or parallel processing can be beneficial. Likewise, while the foregoing discussion contains certain specific implementation details, this should not be construed as limiting the scope of any invention or claims, but rather as a description of specific embodiments that may be directed to a particular invention. Certain features that are described in this specification in the context of separate embodiments can also be implemented collectively in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A method for communicating that includes:

The network device sends the reference signal to the terminal device, where the terminal device includes a reconfigurable smart surface as a transceiver unit;

The network device receives a reflected signal generated by the reconfigurable smart surface for the reference signal, the reflected signal including data information associated with the terminal device; and

The network device determines the data information from the reflected signal.
The method of claim 1, wherein sending the reference signal includes:

The network device uses a precoding vector to send the reference signal in the current symbol period.
The method of claim 2, further comprising:

The network device updates the precoding vector based on the reflected signal for use in sending a reference signal in a next symbol period.
The method of claim 2, wherein determining the data information includes:

the network device determines a reflection coefficient used by the reconfigurable smart surface based on the precoding vector; and

The network device demodulates the data information from the reflected signal based on the reflection coefficient.
The method according to claim 1, wherein the terminal device and the network device are Internet of Things devices.
A method for communicating that includes:

A terminal device receives a reference signal from a network device, the terminal device including a reconfigurable smart surface as a transceiver unit; and

The terminal device generates a reflected signal for the reference signal through the reconfigurable smart surface, and the reflected signal includes data information associated with the terminal device.
The method of claim 6, wherein generating the reflected signal includes:

The terminal device performs conjugate processing on the reference signal through the reconfigurable smart surface;

The terminal device maps the data information into a reflection coefficient of the reconfigurable smart surface; and

The terminal device generates the reflection signal through the reconfigurable smart surface based on the reflection coefficient and the conjugated reference signal.
The method according to claim 6, wherein the terminal device and the network device are Internet of Things devices.
A network device that includes:

a transceiver configured to transmit a reference signal to a terminal device and receive a reflected signal generated by the reconfigurable smart surface for the reference signal, the terminal device including the reconfigurable smart surface as a transceiver unit, the The reflected signal includes data information associated with the terminal device; and

A processor coupled to the transceiver and configured to determine the data information from the reflected signal.
The network device of claim 9, wherein sending the reference signal includes:

The reference signal is transmitted by the transceiver using a precoding vector in the current symbol period.
The network device of claim 10, wherein the processor is further configured to:

The precoding vector is updated based on the reflected signal for sending a reference signal in a next symbol period.
The network device of claim 10, wherein determining the data information includes:

determining, by the processor, a reflection coefficient used by the reconfigurable smart surface based on the precoding vector; and

The data information is demodulated by the processor from the reflected signal based on the reflection coefficient.
The network device according to claim 9, wherein the terminal device and the network device are Internet of Things devices.
A terminal device including:

A reconfigurable smart surface configured to receive a reference signal from a network device, the reconfigurable smart surface serving as a transceiver unit of the terminal device; and

a processor coupled to the reconfigurable smart surface and configured to generate a reflected signal for the reference signal via the reconfigurable smart surface, the reflected signal including data associated with the end device information.
The terminal device of claim 14, wherein the processor is further configured to map the data information into a reflection coefficient of the reconfigurable smart surface, and

The reconfigurable smart surface is further configured to perform conjugate processing on the reference signal, and generate the reflection signal based on the reflection coefficient and the conjugated reference signal.
The terminal device according to claim 14, wherein the terminal device and the network device are Internet of Things devices.
A system for communications consisting of:

A network device according to any one of claims 9 to 13; and

A terminal device according to any one of claims 14 to 16.
A computer-readable storage medium comprising machine-executable instructions that, when executed by a device, cause the device to perform a method according to any one of claims 1-5 or any one of claims 6-8 the method described.