Reference signal transmission method and device, network equipment and storage medium

Abstract

The invention discloses a reference signal transmission method and device, network equipment and a storage medium, and the method comprises the steps that first network equipment modulates an uplink reference signal sent by a terminal into a first signal, and sends the first signal to second network equipment; the first signal represents a space-time coding signal supported by the first network device.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a reference signal transmission method, apparatus, network device, and storage medium. Background Art

[0002] In related technologies, for coverage enhancement scenarios, it is necessary to generate a beam with a certain directivity to converge energy to the receiving end, so that a terminal in a non-connected state can access the base station from the reflected beam to supplement blind spots. After the terminal accesses, in order to provide dedicated pilot (UE-specific) services for the terminal in the connected state, beam training is traditionally used to find the optimal transmission direction. However, the traditional method of using beam training for angle estimation has a long training time. Summary of the Invention

[0003] To solve the related technical problems, embodiments of this application provide a reference signal transmission method, apparatus, network device, and storage medium.

[0004] The technical solution of the embodiments of this application is implemented as follows:

[0005] Embodiments of this application provide a reference signal transmission method, which is applied to a first network device, and the method includes:

[0006] Modulate the uplink reference signal sent by the terminal into a first signal, where the first signal represents the space-time coding signal supported by the first network device;

[0007] Send the first signal to a second network device.

[0008] In the above solution, the modulating the uplink reference signal sent by the terminal into a first signal includes:

[0009] Modulate the uplink reference signal sent by the terminal into the first signal according to a first parameter; where the first parameter represents the transmission parameter of the first network device in a first operating mode, and the first operating mode supports phase biasing and frequency biasing of the electromagnetic wave incident on a reconfigurable intelligent surface (RIS) of the first network device.

[0010] In the above solution, the method further includes:

[0011] Receive the first parameter sent by the second network device.

[0012] In the above solution, the method further includes:

[0013] Report the first information of the first network device to the second network device, where the first information includes at least one of the following:

[0014] The second working mode and the reflection coefficient codebook;

[0015] The first working mode and the second parameter; where,

[0016] The second working mode only supports phase biasing of the electromagnetic wave incident on the RIS of the first network device;

[0017] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0018] The length of the time coding sequence;

[0019] The time-varying period of the reflection coefficient;

[0020] The spatio-temporal coding matrix.

[0021] An embodiment of the present application further provides a reference signal transmission method, which is applied to a second network device. The method includes:

[0022] Receive a first signal sent by a first network device, where the first signal is obtained by modulating an uplink reference signal sent by a terminal by the first network device, and the first signal represents a spatio-temporal coding signal supported by the first network device.

[0023] In the above solution, the method further includes:

[0024] Determine the included angle between the second network device and the terminal according to the first signal.

[0025] In the above solution, the method further includes:

[0026] Send a first parameter to the first network device; where,

[0027] The first parameter represents the transmission parameter of the first network device in the first working mode, and is used to modulate the uplink reference signal sent by the terminal; the first working mode supports phase biasing and frequency biasing of the electromagnetic wave incident on the RIS of the first network device.

[0028] In the above solution, the method further includes:

[0029] Receive the first information reported by the first network device, where the first information includes at least one of the following:

[0030] The second working mode and the reflection coefficient codebook;

[0031] The first working mode and the second parameter; where,

[0032] The second operating mode only supports phase biasing of the electromagnetic wave incident on the RIS of the first network device;

[0033] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0034] Length of the time coding sequence;

[0035] Time-varying period of the reflection coefficient;

[0036] Space-time coding matrix.

[0037] In the above solution, the method further includes:

[0038] Sending second information to the terminal through the first network device; wherein, the second information includes at least one of the transmission frequency, symbol length, and transmission resource of the uplink reference signal.

[0039] In the above solution, the symbol length of the uplink reference signal is determined according to the length of the time coding sequence supported by the first network device and the time-varying period of the reflection coefficient.

[0040] In the above solution, before sending the second information to the terminal, the method further includes:

[0041] Receiving third information reported by the terminal through the first network device, where the third information includes the transmission frequency of the uplink reference signal supported by the terminal.

[0042] In the above solution, the transmission resource of the uplink reference signal has a spatial correlation relationship with the transmission resource of the first downlink reference signal; wherein,

[0043] The first downlink reference signal is reported by the terminal and represents the downlink reference signal with the strongest received signal strength among N downlink reference signals; the N downlink reference signals are sent by the second network device and are forwarded to the terminal by the first network device in the second operating mode using N beams.

[0044] An embodiment of the present application further provides a reference signal transmission device, including:

[0045] A modulation unit, configured to modulate the uplink reference signal sent by the terminal into a first signal, where the first signal represents the space-time coding signal supported by the first network device;

[0046] A first sending unit, configured to send the first signal to the second network device.

[0047] An embodiment of the present application further provides a reference signal transmission device, including:

[0048] A first receiving unit, configured to receive a first signal sent by a first network device, where the first signal is obtained by modulating an uplink reference signal sent by a terminal by the first network device, and the first signal represents a space-time coding signal supported by the first network device.

[0049] An embodiment of the present application further provides a first network device, including: a first processor and a first communication interface; where

[0050] The first processor is configured to modulate an uplink reference signal sent by a terminal into a first signal; the first signal represents a space-time coding signal supported by the first network device;

[0051] The first communication interface is configured to send the first signal to a second network device.

[0052] An embodiment of the present application further provides a second network device, including: a second processor and a second communication interface; where

[0053] The second communication interface is configured to receive a first signal sent by a first network device, where the first signal is obtained by modulating an uplink reference signal sent by a terminal by the first network device, and the first signal represents a space-time coding signal supported by the first network device.

[0054] An embodiment of the present application further provides a network device, including a processor and a memory for storing a computer program that can run on the processor,

[0055] where when the processor is configured to run the computer program, it executes the steps of any of the methods on the first network device side or the steps of any of the methods on the second network device side described above.

[0056] An embodiment of the present application further provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of any of the methods on the first network device side or implements the steps of any of the methods on the second network device side described above.

[0057] In the reference signal transmission method, apparatus, network device, and storage medium provided in the embodiments of the present application, a first network device modulates an uplink reference signal sent by a terminal into a first signal, where the first signal represents a space-time coding signal supported by the first network device; the first signal is sent to a second network device; the second network device receives the first signal sent by the first network device. In the above solution, the first network device sends the first signal to the second network device so that the second network device can estimate the angle between the second network device and the terminal according to the first signal; since the first signal represents a space-time coding signal supported by the first network device, and the space-time coding signal may include multiple coding signals with different frequencies and different phases, the second network device estimating the angle between the second network device and the terminal according to the first signal can reduce the time complexity and computational complexity of angle estimation and improve the angle estimation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 FIG. is an example diagram of direction finding and electromagnetic field manipulation based on asynchronous STCM applicable to the embodiments of the present application in the related art;

[0059] Figure 2 FIG. is a schematic flowchart of the implementation process of a reference signal transmission method according to an embodiment of the present application;

[0060] Figure 3 FIG. is a schematic flowchart of the implementation process of a reference signal transmission method according to an embodiment of the present application;

[0061] Figure 4 FIG. is a schematic interaction flowchart of a reference signal transmission method according to an embodiment of the present application;

[0062] Figure 5 FIG. is an example diagram of a RIS-assisted communication system when the second network device of the present application is located in the normal direction of the RIS;

[0063] Figure 6 FIG. is an example diagram of the change of the first network device modulating the uplink reference signal in the time domain and frequency domain;

[0064] Figure 7 FIG. is a schematic diagram of the maximum received signal strength and the corresponding phase of the first signal at each frequency;

[0065] Figure 8 FIG. is an example diagram of a RIS-assisted communication system when the second network device of the present application forms a certain angle with the normal direction of the RIS;

[0066] Figure 9 FIG. is a schematic structural diagram of a reference signal transmission apparatus according to an embodiment of the present application;

[0067] Figure 10 FIG. is a schematic structural diagram of a reference signal transmission apparatus according to an embodiment of the present application;

[0068] Figure 11 This is a schematic diagram of the structure of the first network device according to an embodiment of the present application;

[0069] Figure 12 This is a schematic diagram of the structure of the second network device according to an embodiment of the present application. Detailed implementation manners

[0070] To enhance coverage, the network adds RIS without a radio frequency source to forward the signals sent by the base station or the terminal. In this scenario, the link between the base station and the terminal is blocked by obstacles, and the signals transmitted by the base station or the terminal reach the destination through the reflection of the RIS. This scenario generally appears in high-frequency band communications where electromagnetic waves are not easily diffracted but are easily reflected.

[0071] The RIS is equipped with a controller for receiving and executing control instructions. Through the measurement and reporting process, the base station sends instructions such as phase adjustment to the controller of the RIS according to different network performance optimization goals to form a beam pattern that meets the communication performance requirements.

[0072] For the coverage enhancement scenario, it is necessary to generate a beam with a certain directivity to concentrate the energy on the receiving end, enabling the terminal in the non-connected state to access the base station through the reflected beam and supplement the blind area. After the terminal accesses, to provide UE-specific services to the terminal in the connected state, the traditional method is to use beam training to find the optimal transmission direction. Due to the passive reflection characteristic of the RIS, a large panel is usually used to achieve a better forwarding effect. As the number of integrated antenna elements increases, the beam generated by the antenna panel becomes narrower, and the traditional method of using beam training for angle estimation has a too long training time, which is not conducive to engineering applications.

[0073] Based on the above analysis, in the RIS-assisted communication system, the large aperture of the RIS can be used to effectively improve the accuracy of direction angle estimation, estimate the angle of arrival of the terminal to the RIS, and effectively solve the problem of determining the beam aligned with the terminal with a large training overhead in the coverage enhancement scenario.

[0074] Figure 1Shows an example diagram of direction finding and electromagnetic field manipulation based on asynchronous STCM, where STCM is the Space Time Coding Digital Metasurface. Asynchronous STCM has a direction finding function and can adaptively provide different electromagnetic field manipulation functions according to the incident angle of electromagnetic waves. Asynchronous STCM uses variable stimulation periods and coding sequences to achieve programmable frequency gradients. The frequency offset between the metasurface units in asynchronous STCM provides a time-varying dynamic phase gradient, enabling the beam to automatically scan at a certain speed, thus further increasing the manipulation dimension of the RIS. By applying different phase modulation waveforms to each metasurface unit respectively to generate multi-frequency single-tone signals, the reflected signals have natural orthogonality in the frequency domain. Thanks to this orthogonality, the incident direction angle information can be directly obtained without complex algorithms, and the incident direction angle can be accurately estimated with lower complexity. Compared with the existing RIS-based methods, the angle estimation scheme based on asynchronous STCM can successfully estimate the incident direction angle with lower complexity, simpler structure and higher efficiency.

[0075] Taking a single-frequency incident electromagnetic wave as an example, a simple introduction to this angle measurement algorithm is given.

[0076] Assume the incident direction angle is θ i , then the far-field scattering pattern in the time domain is:

[0077]

[0078] where E p (θ) is the far-field scattering pattern (also known as the far-field scattering mode) of the p-th column of metasurface units at the transmission frequency f c , λ c = c / f c is the wavelength of the incident wave, d is the spacing of the metasurface units, and Γ p (t) represents that the reflection coefficient of the p-th column of metasurface units is modulated on a periodic time coding sequence.

[0079]

[0080] where, is the I-th time coding sequence in the L-length sequence, T is the period, is the basic impulse function, defined as:

[0081]

[0082] Performing a Fourier series expansion on Γ p (t) and decomposing it into a series of harmonic components with a frequency interval of f0 = 1 / T,

[0083]

[0084] where k is the k-th harmonic component, f 0 << f c To ensure the correctness of (1), corresponding to the complex Fourier coefficients.

[0085]

[0086] where Sa(·) is the sampling function. An independent time coding sequence is applied to each column, so the entire metasurface can be characterized as a space-time coding (STC) matrix. Substituting (4) into (1) gives:

[0087]

[0088] (6) shows that each harmonic component has an independent scattering pattern controlled by the space-time coding matrix. Using this method, the magnetic field can be manipulated simultaneously in the spatial and frequency domains.

[0089] Select several harmonics k 1 ,..., k M Substitute them into (7) to obtain a series of equations:

[0090]

[0091] The matrix form of this equation is as follows:

[0092]

[0093] where, is the M received harmonic signals, is the complex harmonic spatial coefficient, is the profile of the phase. The common ratio of the geometric sequence is:

[0094]

[0095] Therefore, the incident direction angle is

[0096]

[0097] Theoretically, the N - 1 results should be the same, but considering the noise introduced by measurement, equipment, and environment, the final mean value is selected as the final estimated value:

[0098]

[0099] The above STCM-based angle estimation scheme will have a certain impact on the air interface protocol, including resource allocation, interaction between the terminal and the network side, etc., but there is no research on relevant refinement schemes.

[0100] Based on this, in order to be able to use the STCM-based angle estimation scheme in the RIS-assisted communication system, the present application provides a reference signal transmission scheme. In various embodiments of the present application, the first network device modulates the uplink reference signal sent by the terminal into a first signal, and the first signal represents the space-time coding signal supported by the first network device; sends the first signal to the second network device; the second network device receives the first signal sent by the first network device. In the above scheme, the first network device sends the first signal to the second network device so that the second network device can estimate the included angle between the second network device and the terminal according to the first signal; since the first signal represents the space-time coding signal supported by the first network device, and the space-time coding signal can include multiple coding signals with different frequencies and different phases, the second network device estimates the included angle between the second network device and the terminal according to the first signal, which can reduce the time complexity and computational complexity of angle estimation and improve the angle estimation efficiency.

[0101] The following further describes the present application in detail with reference to the drawings and embodiments.

[0102] The present application provides a reference signal transmission method, which is applied to a first network device. The first network device includes a RIS and a RIS controller. The RIS is used to assist the terminal to communicate with the second network device, and the RIS controller is used to control the RIS. The first network device is controlled by the second network device, and the second network device can be understood as a base station. As Figure 2 shown, the method includes:

[0103] Step 201: Modulate the uplink reference signal sent by the terminal into a first signal. Wherein,

[0104] The first signal represents the space-time coding signal supported by the first network device.

[0105] Here, the terminal sends an uplink reference signal; the first network device receives the uplink reference signal sent by the terminal and modulates the received uplink reference signal into a first signal. The uplink reference signal includes a sounding reference signal (SRS). The first signal can be an STCM signal, and the first signal is used for the second network device to estimate the included angle between the second network device and the terminal based on STCM.

[0106] In practical applications, the terminal may send an uplink reference signal when the terminal has completed initial access (the terminal has successfully accessed the second network device) through the beam under the coverage of the first network device. Specifically, the terminal may send an uplink reference signal according to the second information; the second information is configured and sent by the second network device and includes at least one of the transmission frequency, symbol length, and transmission resources of the uplink reference signal. The transmission frequency of the uplink reference signal is determined from the transmission frequencies of the uplink reference signals supported by the terminal.

[0107] To improve the accuracy or precision of the estimated angle based on the first signal, the transmission parameters of the first network device in the STCM mode may be used to modulate the uplink reference signal. Based on this, in one embodiment, modulating the uplink reference signal sent by the terminal into the first signal includes:

[0108] Modulating the uplink reference signal sent by the terminal into the first signal according to the first parameter; where

[0109] The first parameter characterizes the transmission parameters of the first network device in the first operating mode, and the first operating mode supports phase biasing and frequency biasing of the electromagnetic wave incident on the RIS of the first network device.

[0110] Here, the first network device obtains the first parameter and modulates the uplink reference signal sent by the terminal into the first signal according to the first parameter.

[0111] In practical applications, the first network device obtains the first parameter; when the first network device is in the first operating mode, the terminal sends an uplink reference signal, and the first network device receives the uplink reference signal sent by the terminal; in the first operating mode, the first network device modulates the uplink reference signal sent by the terminal into the first signal according to the first parameter. For example, in the first operating mode, the first network device performs phase biasing on the received uplink reference signal according to the first parameter. At the same time, the first network device controls the phase biasing of the received uplink reference signal by the antennas in different columns of the RIS in the first network device to change in different time periods to achieve frequency biasing on different columns of the RIS, thereby obtaining the first signal, and thus realizing modulating the uplink reference signal into the first signal. It should be noted that the first operating mode can be understood as the STCM mode. The information or signals sent by the terminal, such as the uplink reference signal, and the information or signals or parameters sent by the second network device are all carried on the electromagnetic wave.

[0112] The first parameter can be understood as an operating parameter or a transmission parameter; the first parameter may be sent by the second network device. For example, the second network device sends the first parameter according to the capability information of the first network device. The first parameter may also be pre-configured in the first network device.

[0113] The first parameter may include at least one of the following: the length of the time-coded sequence, the time-varying period of the reflection coefficient, and the spatio-temporal coding matrix. For example, in the first operating mode, the first network device may modulate the uplink reference signal sent by the terminal into a first signal according to the time-varying period of the reflection coefficient and the spatio-temporal coding matrix in the first parameter. Specifically, the first network device controls the antenna elements on the RIS in the first network device to perform a phase transformation on the uplink reference signal sent by the terminal according to the time-varying period of the reflection coefficient. The first network device biases the phase corresponding to each antenna element of the RIS based on the given time-varying period according to the spatio-temporal coding matrix, so as to perform a frequency bias on the signal obtained after the phase transformation, and obtain the first signal. Among them, the length of the time-coded sequence included in the first parameter can be determined from the lengths of the time-coded sequences supported by the first network device; the time-varying period of the reflection coefficient included in the first parameter can be determined from the time-varying periods of the reflection coefficients supported by the first network device, and the spatio-temporal coding matrix included in the first parameter can be determined from the spatio-temporal coding matrices supported by the first network device. The length of the time-coded sequence and the time-varying period of the reflection coefficient included in the first parameter can be used to determine the symbol length of the uplink reference signal that the terminal can send; the symbol length of the uplink reference signal should be greater than the time-varying period of the reflection coefficient, and the symbol length of the uplink reference signal should be within the range of the length of the time-coded sequence.

[0114] In one embodiment, the method further includes:

[0115] Receiving the first parameter sent by the second network device.

[0116] Here, the second network device may determine the first parameter according to the transmission parameters supported by the first network device in the first operating mode, and send the first parameter to the corresponding first network device. Thus, the first parameter can be adapted to the capabilities of the first network device.

[0117] In practical applications, the first network device may receive the first parameter sent by the second network device in the second operating mode; the first network device only supports phase biasing of the electromagnetic waves incident on the RIS in the first network device in the second operating mode. The second operating mode may be referred to as the directional beam forwarding mode, and the second operating mode may also be understood as a mode in which the electromagnetic waves incident on the RIS in the first network device are phase-biased element by element and then reflected.

[0118] It should be noted that the first parameters configured by the second network device for different first network devices may be the same or different. The first parameter may be carried in the downlink synchronization signal or the downlink reference signal, and the downlink reference signal may include a channel state information reference signal (CSI-RS, Channel State Information-Reference Signal).

[0119] The second network device can send down the first parameter according to the capabilities of the first network device to improve the accuracy of the first parameter and the adaptability of the first parameter to the capabilities of the first network device. Based on this, in one embodiment, the method further includes:

[0120] Reporting the first information of the first network device to the second network device, where the first information includes at least one of the following:

[0121] The second working mode and the reflection coefficient codebook;

[0122] The first working mode and the second parameter; where

[0123] The second working mode only supports phase biasing of the incident electromagnetic wave of the RIS;

[0124] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0125] The length of the time coding sequence;

[0126] The time-varying period of the reflection coefficient;

[0127] The spatio-temporal coding matrix.

[0128] Here, when a control link is successfully established between the first network device and the second network device, the first network device reports the first information of the first network device to the second network device. The first information can be understood as capability information, the capabilities of the first network device, or the capability information of the first network device, and the first information is used to indicate the working modes supported by the first network device and the corresponding parameters. The first network device supports at least the first working mode, or supports both the first working mode and the second working mode simultaneously.

[0129] When the first network device supports the first working mode, the first information may include the first working mode and the second parameter; the first parameter is determined from the second parameter. For example, the length of the time coding sequence included in the first parameter is determined from the length of the time coding sequence included in the second parameter; the time-varying period of the reflection coefficient included in the first parameter can be determined from the time-varying period of the reflection coefficient included in the second parameter, and the spatio-temporal coding matrix included in the first parameter can be determined from the spatio-temporal coding matrix included in the second parameter.

[0130] When the first network device supports both the first working mode and the second working mode, the first information may include the first working mode and the corresponding second parameter, and the second working mode and the corresponding reflection coefficient codebook. The reflection coefficient codebook includes at least one reflection coefficient.

[0131] That is to say, the first information includes at least a first operating mode and a second parameter, and may also include a second operating mode and a reflection coefficient codebook.

[0132] Step 202: Send the first signal to the second network device.

[0133] Here, the first network device may send the first signal to the second network device when a control link is successfully established between the first network device and the second network device. In practical applications, when a control link is successfully established between the first network device and the second network device and the first network device is in the first operating mode, the first signal is sent to the second network device.

[0134] Correspondingly, an embodiment of the present application further provides a reference signal transmission method, which is applied to the second network device. The second network device may be a base station, such as Figure 3 As shown, the method includes:

[0135] Step 301: Receive the first signal sent by the first network device.

[0136] Wherein, the first signal is obtained by modulating the uplink reference signal sent by the terminal by the first network device, and the first signal characterizes the space-time coding signal supported by the first network device.

[0137] Here, the second network device may instruct the first network device to start the first operating mode, or control the first network device to turn on the first operating mode, and the first network device starts the first operating mode; when the first network device is in the first operating mode, the terminal sends an uplink reference signal, the first network device receives the uplink reference signal sent by the terminal, the first network device modulates the received uplink reference signal into the first signal, and sends the first signal to the second network device; the second network device receives the first signal sent by the first network device.

[0138] Since the first network device can modulate the uplink reference signal into the first signal according to the first parameter, before the second network device receives the first signal, it is also necessary to send the first parameter to the first network device.

[0139] Based on this, in an embodiment, the method further includes:

[0140] Send the first parameter to the first network device; wherein,

[0141] The first parameter characterizes the transmission parameter of the first network device in the first operating mode and is used to modulate the uplink reference signal sent by the terminal; the first operating mode supports phase biasing and frequency biasing of the electromagnetic wave incident on the RIS.

[0142] Here, the second network device may send the first parameter to the first network device when the first network device is in the second working mode. The first parameter may include at least one of the following: the length of the time coding sequence, the time-varying period of the reflection coefficient, and the spatio-temporal coding matrix. The first parameter may include at least one length of the time coding sequence, and the first parameter may include at least one time-varying period of the reflection coefficient. The first parameter may be carried in the downlink synchronization signal or the downlink reference signal.

[0143] The second network device may send the first parameter according to the capabilities of the first network device to improve the accuracy of the first parameter and the compatibility between the first parameter and the capabilities of the first network device. Based on this, in one embodiment,

[0144] Receiving the first information reported by the first network device, the first information including at least one of the following:

[0145] The second working mode and the reflection coefficient codebook;

[0146] The first working mode and the second parameter; where

[0147] The second working mode only supports phase biasing of the electromagnetic wave incident on the RIS of the first network device;

[0148] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0149] The length of the time coding sequence;

[0150] The time-varying period of the reflection coefficient;

[0151] The spatio-temporal coding matrix.

[0152] Here, when a control link is successfully established between the first network device and the second network device, the first network device reports the first information of the first network device to the second network device, and the second network device receives the first information reported by the first network device.

[0153] When the second network device receives the first information reported by the first network device, it may instruct the first network device to start the second working mode, and the first network device starts the second working mode; when the first network device is in the second working mode and the first information includes the first working mode and the second parameter, the first parameter is determined from the second parameter and sent to the first network device.

[0154] The second network device may indicate information such as the transmission frequency, the coherence length, and the transmission resources of the uplink reference signal to the terminal, so that the terminal sends the uplink reference signal according to the information indicated by the second network device. Based on this, in one embodiment, the method further includes:

[0155] The first network device sends the second information to the terminal; wherein, the second information includes at least one of a transmission frequency, a symbol length, and a transmission resource of an uplink reference signal.

[0156] Here, the second network device may send the second information to the terminal through the RIS in the first network device, that is, the second information sent by the second network device is forwarded to the terminal by the RIS in the first network device. In practical applications, the second network device may send the second information to the terminal through the RIS in the first network device when the first network device is in the second working mode; that is, when the first network device is in the second working mode, the second network device sends the second information, the RIS in the first network device reflects the second information, and the terminal receives the second information reflected by the RIS in the first network device. The second information may be carried in a downlink synchronization signal or a downlink reference signal. The transmission frequency is also simply referred to as the frequency, and the transmission resource may be understood as the resource for transmitting the uplink reference signal.

[0157] The transmission frequency of the uplink reference signal may be at least one transmission frequency of the uplink reference signal supported by the terminal and may be determined from the transmission frequencies of the uplink reference signal supported by the terminal.

[0158] In order to enable the first network device to successfully receive the uplink reference signal, in one embodiment, the symbol length of the uplink reference signal is determined according to the length of the time coding sequence supported by the first network device and the time-varying period of the reflection coefficient.

[0159] Here, the symbol length of the uplink reference signal may be determined according to the length of the time coding sequence and the time-varying period of the reflection coefficient in the second parameter. Wherein, the symbol length of the uplink reference signal is greater than the time-varying period of the reflection coefficient, and the symbol length of the uplink reference signal is within the range of the length of the time coding sequence.

[0160] It should be noted that when the second information includes the symbol length of the uplink reference signal, the second information may be sent when the second network device receives the first information reported by the first network device. For example, when the second network device receives the first information reported by the first network device, it instructs the first network device to start the second working mode, and the first network device starts the second working mode; when the first network device is in the second working mode and the first information includes the first working mode and the second parameter, according to the length of the time coding sequence and the time-varying period of the reflection coefficient in the second parameter, the symbol length of the uplink reference signal is determined and the second information is sent to the terminal.

[0161] When the second information includes the transmission frequency of the uplink reference signal, before the second network device sends down the second information, it needs to first obtain the transmission frequency of the uplink reference signal supported by the terminal, so that the terminal can send the uplink reference signal at the transmission frequency specified by the second network device. Based on this, in one embodiment, before sending down the second information to the terminal, the method further includes:

[0162] Receiving third information reported by the terminal through the first network device, where the third information includes the transmission frequency of the uplink reference signal supported by the terminal.

[0163] Here, the terminal can send the third information to the second network device through the first network device, and the second network device receives the third information. For example, when a control link is successfully established between the first network device and the second network device, the terminal sends the third information, the RIS in the first network device reflects the third information, and the second network device receives the third information reflected by the RIS in the first network device.

[0164] The third information includes at least one transmission frequency of the uplink reference signal supported by the terminal. The transmission frequency of the uplink reference signal included in the second information is determined according to the third information.

[0165] In practical applications, when the second network device receives the first information reported by the first network device and the third information reported by the terminal, it can instruct the first network device to start the second working mode, and the first network device starts the second working mode; when the first network device is in the second working mode and the first information includes the first working mode and the second parameter, determine the symbol length of the uplink reference signal according to the second parameter, determine the transmission frequency of the uplink reference signal according to the third information, and send down the second information to the terminal.

[0166] In order to accurately determine the beam aligned with the terminal in the beam under the coverage of the RIS and the first network device, so as to improve the success rate of the first network device receiving the uplink reference signal sent by the terminal, in one embodiment, the transmission resource of the uplink reference signal has a spatial correlation relationship with the transmission resource of the first downlink reference signal; where

[0167] The first downlink reference signal is reported by the terminal and represents the downlink reference signal with the strongest received signal strength among N downlink reference signals; the N downlink reference signals are sent by the second network device and are forwarded to the terminal by the first network device using N beams in the second working mode.

[0168] Here, the second network device determines or configures the transmission resources of the uplink reference signal according to the transmission resources of the first downlink reference signal, and indicates to the terminal that the transmission resources of the uplink reference signal have a spatial association relationship with the transmission resources of the first downlink reference signal. In this way, the terminal can send the uplink reference signal according to the beam and reception direction of the received first downlink reference signal; for example, the terminal determines the beam and reception direction of the received first downlink reference signal, and sends the uplink reference signal in the reception direction of the beam.

[0169] Among them, in the second working mode, the first network device forwards N downlink reference signals sent by the second network device to the terminal by using N beams, and one beam corresponds to forwarding one downlink reference signal.

[0170] The implementation process for the second network device to determine or configure the transmission resources of the uplink reference signal is as follows:

[0171] The second network device sends the fourth information to the terminal through the RIS in the first network device, and sends the fourth information and the fifth information to the first network device; where the fourth information is used to indicate N downlink reference signals and the corresponding transmission resources; the transmission resources of the N downlink reference signals correspond to N wide beams under the coverage range of the first network device and in the terminal access direction, and N is less than the maximum number of beams Y supported by the first network device; the fifth information is used to indicate that the first network device starts the second working mode on the transmission resources of the N downlink reference signals, and uses N beams to forward the N downlink reference signals to the terminal.

[0172] The first network device receives the fourth information and the fifth information; according to the fifth information, starts the second working mode on the transmission resources of the N downlink reference signals; according to the reflection coefficient codebook of the second working mode, switches the reflection coefficient. The second network device sends N downlink reference signals according to the fourth information; the first network device, in the second working mode, in a polling manner, uses N beams to forward the N downlink reference signals sent by the second network device to the terminal, and one beam corresponds to forwarding one downlink reference signal; the terminal receives the N downlink reference signals and measures the received signal strength of each of the N downlink reference signals among the N downlink reference signals, and determines the first downlink reference signal among the N downlink reference signals according to the received signal strength of each downlink reference signal, and reports the sixth information to the second network device through the RIS in the first network device; the sixth information is used to indicate the first downlink reference signal. The sixth information includes at least the index of the first downlink reference signal, and may also include the received signal strength of the first downlink reference signal.

[0173] The second network device determines or configures the transmission resource of the uplink reference signal according to the transmission resource of the first downlink reference signal. Wherein, the second network device may determine the transmission resource of the first downlink reference signal as the transmission resource of the uplink reference signal, and indicate that the transmission resource of the uplink reference signal of the terminal has a spatial correlation relationship with the transmission resource of the first downlink reference signal.

[0174] To improve the accuracy of the angle between the second network device and the terminal and the angle estimation efficiency, in one embodiment, the method further includes:

[0175] Determine the angle between the second network device and the terminal according to the first signal.

[0176] Here, as described above, the first signal is obtained by modulating the received uplink reference signal after frequency offset and phase offset in the first operating mode of the first network device. The first signal represents the spatio-temporal coding signal supported by the first network device, and the spatio-temporal coding signal may include multiple coding signals with different frequencies and different phases. Therefore, in the process of receiving the first signal, the second network device can determine the frequency at which the first signal can be received, and determine the phase corresponding to the maximum received signal strength of the first signal at each frequency; determine the phase difference between adjacent frequencies according to the phase corresponding to the maximum received signal strength of the first signal at each frequency; determine the angle between the second network device and the terminal according to the speed of light and the phase difference between adjacent frequencies, and according to the transmission frequency of the uplink reference signal and the interval between the reflection units of the RIS in the first network device. The phase difference between adjacent frequencies may be an average value.

[0177] In practical applications, the formula can be used to determine the angle between the second network device and the terminal; where θ represents the angle between the second network device and the terminal; d represents the interval between the reflection units of the RIS in the first network device; f c represents the transmission frequency of the uplink reference signal; represents the phase difference between adjacent frequencies. d and f c are known to the second network device.

[0178] It should be noted that in the RIS-assisted communication system, the RIS in the first network device is deployed according to the networking mode and the network performance optimization goal. The position of the RIS is relatively fixed. And to ensure the reliability of the control of the RIS by the second network device and ensure that the link between the second network device and the RIS is a line-of-sight (LOS) path. Therefore, once the first network device completes the initial access, the channel state between the second network device and the first network device is known to the second network device, and the angle from the second network device to the RIS in the first network device is also known; the second network device can determine the angle between the second network device and the terminal according to the first information.

[0179] Next, the solution of the embodiment of the present application will be further described in conjunction with the interaction process schematic diagram.

[0180] Refer to Figure 4 , Figure 4 The shown reference signal transmission method includes:

[0181] Step 1: The first network device reports the first information of the first network device to the second network device.

[0182] Here, when a control link is successfully established between the first network device and the second network device, the first network device reports the first information of the first network device to the second network device, and the second network device receives the first information reported by the first network device.

[0183] Among them, the first information includes at least one of the following:

[0184] The second working mode and the reflection coefficient codebook;

[0185] The first working mode and the second parameter; among them,

[0186] The first working mode supports phase offset and frequency offset of the electromagnetic wave incident on the RIS;

[0187] The second working mode only supports phase offset of the electromagnetic wave incident on the RIS;

[0188] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0189] The time coding sequence length;

[0190] The reflection coefficient time-varying period;

[0191] The spatio-temporal coding matrix.

[0192] Step 2: The terminal reports the third information to the second network device through the first network device.

[0193] Here, when a control link is successfully established between the first network device and the second network device, the terminal sends third information, the RIS in the first network device reflects the third information, and the second network device receives the third information reflected by the RIS in the first network device. The third information includes the transmission frequency of the uplink reference signal supported by the terminal.

[0194] Step 3: The second network device sends the first parameter to the first network device according to the first information.

[0195] Among them, the first parameter characterizes the transmission parameter of the first network device in the first working mode and is used to modulate the uplink reference signal sent by the terminal.

[0196] Here, the second network device determines the first parameter according to the second parameter included in the first information; the second network device instructs the first network device to start the second working mode, and when the first network device is in the second working mode, sends the first parameter to the first network device. The first parameter may include at least one of the time coding sequence length, the reflection coefficient time-varying period, and the spatio-temporal coding matrix. The first parameter may be carried in the downlink synchronization signal or the downlink reference signal.

[0197] Step 4: The second network device sends the second information to the terminal through the first network device.

[0198] Here, when the first network device is in the second working mode, the second network device determines the second information and sends the second information; the RIS in the first network device reflects the second information, and the terminal receives the second information reflected by the RIS in the first network device. Among them, the second information includes at least one of the transmission frequency, symbol length, and transmission resource of the uplink reference signal. The second information may be carried in the downlink synchronization signal or the downlink reference signal.

[0199] The transmission frequency of the uplink reference signal included in the second information is determined from the transmission frequency of the uplink reference signal in the third information. The symbol length can be determined according to the time coding sequence length and the reflection coefficient time-varying period included in the first information. Among them, the symbol length of the uplink reference signal is greater than the reflection coefficient time-varying period, and the symbol length of the uplink reference signal is within the time coding sequence length range.

[0200] The transmission resource of the uplink reference signal is determined according to the transmission resource of the first downlink reference signal; the transmission resource of the uplink reference signal has a spatial correlation relationship with the transmission resource of the first downlink reference signal; among them,

[0201] The first downlink reference signal is reported by the terminal, representing the downlink reference signal with the strongest received signal strength among N downlink reference signals; the N downlink reference signals are sent by the second network device and are forwarded to the terminal by the first network device in the second operating mode using N beams.

[0202] Step 5: The terminal sends an uplink reference signal according to the second information.

[0203] Here, the second network device instructs the first network device to start the first operating mode. When the first network device is in the first operating mode, the terminal sends an uplink reference signal according to the second information.

[0204] Step 6: The first network device receives the uplink reference signal sent by the terminal and modulates the uplink reference signal into a first signal.

[0205] Here, the first network device, in the first operating mode, receives the uplink reference signal sent by the terminal and modulates the uplink reference signal into a first signal; the first signal represents the space-time coding signal supported by the first network device, and the first signal can be an STCM signal.

[0206] In practical applications, the first network device, in the first operating mode, can modulate the uplink reference signal into a first signal according to the first parameter. For example, the first network device, in the first operating mode, modulates the uplink reference signal sent by the terminal into a first signal according to the time-varying period of the reflection coefficient and the space-time coding matrix in the first parameter.

[0207] Step 7: The first network device sends the first signal to the second network device.

[0208] Here, the first network device, in the first operating mode, sends the first signal to the second network device.

[0209] Step 8: The second network device receives the first signal and determines the angle between the second network device and the terminal according to the first signal.

[0210] In practical applications, the second network device uses the formula to determine the angle between the second network device and the terminal.

[0211] Next, the solution of the embodiment of the present application will be further described in combination with application examples.

[0212] Application Example 1: In a coverage enhancement scenario, determine the beam aligned with the terminal with a relatively low training overhead

[0213] Step 1: When the initial access is completed through the beam under the coverage of the first network device at the terminal, the first network device establishes a control link with the second network device; when the control link is successfully established between the first network device and the second network device, the first network device reports the first information of the first network device to the second network device. The first information includes at least one of the following:

[0214] The second working mode and the reflection coefficient codebook;

[0215] The first working mode and the second parameter; where,

[0216] The first working mode supports phase offset and frequency offset for the incident electromagnetic wave of the RIS;

[0217] The second working mode only supports phase offset for the incident electromagnetic wave of the RIS;

[0218] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0219] The length of the time coding sequence;

[0220] The time-varying period of the reflection coefficient;

[0221] The spatio-temporal coding matrix.

[0222] Step 2: When the control link is successfully established between the first network device and the second network device, the terminal reports the third information to the second network device through the first network device.

[0223] Here, the terminal sends the third information, and the third information is reflected by the RIS in the first network device to the second network device.

[0224] Step 3: The second network device issues the first parameter to the first network device according to the first information.

[0225] Among them, Step 3 is the same as Step 3 in the corresponding embodiment, and for specific details, please refer to the relevant description above, which will not be elaborated here. Figure 4

[0226] Step 4: The second network device issues the second information to the terminal through the first network device.

[0227] Here, the second information sent by the second network device is transmitted to the terminal after being reflected by the RIS in the first network device. The second information includes the transmission frequency, symbol length, and transmission resources of the uplink reference signal. The transmission frequency of the uplink reference signal included in the second information is determined from the transmission frequency of the uplink reference signal in the third information. The symbol length is determined according to the length of the time coding sequence and the time-varying period of the reflection coefficient included in the first information.

[0228] When the second information includes the transmission resources of the uplink reference signal, the transmission resources of the uplink reference signal have a spatial correlation relationship with the transmission resources of the first downlink reference signal. The implementation process for the second network device to determine or configure the transmission resources of the uplink reference signal is as follows:

[0229] The second network device sends the fourth information to the terminal through the first network device, and sends the fourth information and the fifth information to the first network device; wherein, the fourth information is used to indicate N downlink reference signals and the corresponding transmission resources; the transmission resources of the N downlink reference signals correspond to N wide beams in the terminal access direction under the coverage range of the first network device, and N is less than the maximum number of beams Y supported by the first network device; the fifth information is used to indicate that the first network device starts the second working mode on the transmission resources of the N downlink reference signals and forwards the N downlink reference signals to the terminal using N beams.

[0230] The first network device receives the fourth information and the fifth information; according to the fifth information, starts the second working mode on the transmission resources of the N downlink reference signals; switches the reflection coefficient according to the reflection coefficient codebook of the second working mode. The second network device sends N downlink reference signals according to the fourth information; the first network device, in the second working mode, forwards the N downlink reference signals sent by the second network device to the terminal in a polling manner, with one beam corresponding to forwarding one downlink reference signal; the terminal receives the N downlink reference signals and measures the received signal strength of each of the N downlink reference signals among the N downlink reference signals, determines the first downlink reference signal among the N downlink reference signals according to the received signal strength of each downlink reference signal, and reports the sixth information to the second network device through the RIS in the first network device; the sixth information is used to indicate the first downlink reference signal. The sixth information includes at least the index of the first downlink reference signal, and may also include the received signal strength of the first downlink reference signal.

[0231] The second network device determines or configures the transmission resources of the uplink reference signal according to the transmission resources of the first downlink reference signal. Among them, the second network device may determine the transmission resources of the first downlink reference signal as the transmission resources of the uplink reference signal, and indicate that the transmission resources of the uplink reference signal have a spatial correlation relationship with the transmission resources of the first downlink reference signal.

[0232] Step 5: The terminal sends the uplink reference signal according to the second information.

[0233] Here, the second network device instructs the first network device to start the first working mode. In the first working mode, the first network device changes the reflection coefficient in the corresponding time and space according to the spatio-temporal coding matrix included in the first parameter; the terminal can send an uplink reference signal according to the second information based on the fact that the transmission resource of the uplink reference signal has a spatial correlation with the transmission resource of the first downlink reference signal. For example, on the transmission frequency of the uplink reference signal, the uplink reference signal is sent according to the symbol length of the uplink reference signal; the first network device receives the uplink reference signal on the transmission resource of the uplink reference signal.

[0234] Step 6: The first network device receives the uplink reference signal sent by the terminal and modulates the uplink reference signal into a first signal.

[0235] Here, the first network device can quantify the angle from the terminal to the RIS according to the reflection coefficient codebook of the second working mode.

[0236] Step 7: In the first working mode, the first network device sends the first signal to the second network device.

[0237] Step 8: The second network device receives the first signal and determines the included angle between the second network device and the terminal according to the first signal.

[0238] Application Example 2

[0239] Such as Figure 5 shown, in the scenario where the second network device is located in the normal direction of the RIS, the reference signal transmission method includes:

[0240] Step 1: The first network device reports the first information of the first network device to the second network device.

[0241] Among them, for the implementation process of Step 1, please refer to Figure 4 the relevant description of Step 1 therein, which will not be elaborated here.

[0242] Step 2: The terminal reports the third information to the second network device through the first network device.

[0243] Among them, for the implementation process of Step 2, please refer to Figure 4 the relevant description of Step 2 therein, which will not be elaborated here.

[0244] Step 3: The second network device sends the first parameter to the first network device according to the first information.

[0245] Here, the first parameter includes at least the reflection coefficient time-varying period and the spatio-temporal coding matrix, and may also include the time coding sequence length.

[0246] Step 4: The second network device sends the second information to the terminal via the first network device. The second information includes at least the transmission frequency of the uplink reference signal.

[0247] For the implementation process of step 4, please refer to Figure 4 the relevant description of step 4 in

[0248] Step 5: The terminal sends an uplink reference signal at the transmission frequency of the uplink reference signal included in the second information.

[0249] Here, the second network device controls the first network device to turn on the first working mode. In the first working mode, the first network device changes the reflection coefficient in the corresponding time and space according to the spatio-temporal coding matrix included in the first parameter. The terminal sends an uplink reference signal at the transmission frequency of the uplink reference signal included in the second information.

[0250] Step 6: The first network device receives the uplink reference signal sent by the terminal and modulates the uplink reference signal into a first signal.

[0251] Here, in the first working mode, the first network device modulates the uplink reference signal sent by the terminal into a first signal according to the reflection coefficient time-varying period and the spatio-temporal coding matrix included in the first parameter. The first signal can be an STCM signal. Specifically, the first network device controls the phase change of the uplink reference signal sent by the terminal by the antenna elements on the RIS in the first network device according to the reflection coefficient time-varying period, and the first network device biases the phase corresponding to each antenna element based on the given time-varying period according to the spatio-temporal coding matrix, so as to perform frequency offset on the signal obtained after phase change to obtain the first signal. Among them, the first signal received by the second network device can be expressed as:

[0252]

[0253] Among them, E(0°) is the far-field scattering pattern of the RIS antenna element in the normal direction, and the k-th column time-varying reflection coefficient Γ k (t) = exp(j2πkt / T), T is the reflection coefficient time-varying period, R k is the distance between the k-th column antenna element of the RIS and the second network device, and c is the speed of light. The changes of the first network device in modulating the uplink reference signal in the time domain and frequency domain are as Figure 6 shown.

[0254] Step 7: In the first working mode, the first network device sends the first signal to the second network device.

[0255] Step 8: The second network device receives the first signal and determines the angle between the second network device and the terminal according to the first signal.

[0256] Here, the second network device receives the first signal, determines the frequency at which the first signal is received, and the phase corresponding to the maximum received signal strength of the first signal at each frequency; wherein, the corresponding phase of the first signal at the maximum received signal strength at each frequency is as Figure 7 shown.

[0257] Express the phase difference between adjacent frequencies in Figure 7 as The second network device uses the formula to determine the angle between the second network device and the terminal.

[0258] Application Example 3

[0259] As Figure 8 shown, in the scenario where there is an angle α (α is known in the network deployment stage) between the normal direction of the second network device and the RIS, the difference between Application Example 3 and Application Example 2 is:

[0260] Step 6: The first network device receives the uplink reference signal sent by the terminal and modulates the uplink reference signal into the first signal.

[0261] Here, in the first operating mode, the first network device can modulate the uplink reference signal sent by the terminal into the first signal according to the time-varying period of the reflection coefficient and the spatio-temporal coding matrix in the first parameter, and the first signal can be an STCM signal. Among them, the first signal received by the second network device can be expressed as:

[0262]

[0263] where E(α) is the far-field scattering pattern of the RIS antenna element in the direction of the second network device at an angle α with the normal.

[0264] To implement the method on the first network device side in the embodiments of the present application, the embodiments of the present application further provide a reference signal transmission device, which is arranged on the first network device, as Figure 9 shown, and the device includes:

[0265] A modulation unit 901, configured to modulate the uplink reference signal sent by the terminal into the first signal, and the first signal represents a spatio-temporal coding signal supported by the first network device;

[0266] A first transmission unit 902, configured to send the first signal to the second network device.

[0267] In an embodiment, the modulation unit 901 is specifically configured to modulate the uplink reference signal sent by the terminal into the first signal according to the first parameter; wherein,

[0268] The first parameter characterizes the transmission parameter of the first network device in the first working mode, and the first working mode supports phase biasing and frequency biasing of the electromagnetic wave of the RIS incident on the first network device.

[0269] In one embodiment, the apparatus further comprises:

[0270] A second receiving unit, configured to receive the first parameter sent by the second network device.

[0271] In one embodiment, the apparatus further comprises:

[0272] A second sending unit, configured to report first information of the first network device to the second network device, where the first information includes at least one of the following:

[0273] The second working mode and the reflection coefficient codebook;

[0274] The first working mode and the second parameter; wherein,

[0275] The second working mode only supports phase biasing of the electromagnetic wave of the RIS incident on the first network device;

[0276] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0277] The length of the time coding sequence;

[0278] The time-varying period of the reflection coefficient;

[0279] The spatio-temporal coding matrix.

[0280] In practical applications, the modulation unit 901 may be implemented by a processor in the reference signal transmission device, and the first sending unit 902, the second receiving unit, and the second sending unit may be implemented by a processor in the reference signal transmission device in combination with a communication interface.

[0281] To implement the method on the second network device side in the embodiments of the present application, the embodiments of the present application further provide a reference signal transmission device, which is disposed on the second network device, as Figure 10 shown, the apparatus includes:

[0282] A first receiving unit 1001, configured to receive a first signal sent by a first network device, where the first signal is obtained by modulating an uplink reference signal sent by a terminal by the first network device, and the first signal characterizes the spatio-temporal coding signal supported by the first network device.

[0283] In one embodiment, the apparatus further comprises:

[0284] A determination unit, configured to determine an angle between the second network device and the terminal according to the first signal.

[0285] In one embodiment, the apparatus further includes:

[0286] A third sending unit, configured to send a first parameter to the first network device; wherein,

[0287] The first parameter characterizes transmission parameters of the first network device in a first working mode, and is used to modulate an uplink reference signal sent by the terminal; the first working mode supports phase biasing and frequency biasing of electromagnetic waves incident on the RIS of the first network device.

[0288] In one embodiment, the apparatus further includes:

[0289] A third receiving unit, configured to receive first information reported by the first network device, where the first information includes at least one of the following:

[0290] A second working mode and a reflection coefficient codebook;

[0291] The first working mode and a second parameter; wherein,

[0292] The second working mode only supports phase biasing of electromagnetic waves incident on the RIS of the first network device;

[0293] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0294] Length of a time coding sequence;

[0295] Time-varying period of a reflection coefficient;

[0296] Space-time coding matrix.

[0297] In one embodiment, the apparatus further includes:

[0298] A fourth sending unit, configured to send second information to the terminal through the first network device; wherein the second information includes at least one of a transmission frequency, a symbol length, and a transmission resource of the uplink reference signal.

[0299] In one embodiment, the symbol length of the uplink reference signal is determined according to the length of the time coding sequence supported by the first network device and the time-varying period of the reflection coefficient.

[0300] In one embodiment, the apparatus further includes:

[0301] A fourth receiving unit, configured to receive third information reported by the terminal through the first network device, where the third information includes a transmission frequency of the uplink reference signal supported by the terminal.

[0302] In one embodiment, the transmission resource of the uplink reference signal has a spatial association relationship with the transmission resource of the first downlink reference signal; wherein,

[0303] The first downlink reference signal is reported by the terminal and represents the downlink reference signal with the strongest received signal strength among N downlink reference signals; the N downlink reference signals are sent by the second network device and are forwarded to the terminal by the first network device using N beams in the second working mode.

[0304] In practical applications, the determining unit can be implemented by a processor in the reference signal transmission device, and the first receiving unit 1001, the third sending unit, the third receiving unit, the fourth sending unit, and the fourth receiving unit can be implemented by a processor in the reference signal transmission device in combination with a communication interface.

[0305] It should be noted that: when the above-mentioned embodiment provides a reference signal transmission device for reference signal transmission, only the above-mentioned division of each program module is used for illustration. In practical applications, the above-mentioned processing can be allocated to different program modules according to needs, that is, the internal structure of the device is divided into different program modules to complete all or part of the above-mentioned processing. In addition, the reference signal transmission device provided in the above-mentioned embodiment and the reference signal transmission method embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be elaborated here.

[0306] Based on the hardware implementation of the above program module, and in order to implement the method on the side of the first network device in the embodiment of the present application, the embodiment of the present application further provides a first network device, as Figure 11 shown, the first network device 1100 includes:

[0307] A first communication interface 1101 capable of information interaction with other network nodes;

[0308] A first processor 1102, connected to the first communication interface 1101 to realize information interaction with other network nodes, and used to execute the method provided by one or more technical solutions on the side of the first network device when running a computer program. And the computer program is stored on the first memory 1103.

[0309] Specifically, the first processor 1102 is used to modulate the uplink reference signal sent by the terminal into a first signal, and the first signal represents a space-time coding signal supported by the first network device;

[0310] The first communication interface 1101 is used to send the first signal to the second network device.

[0311] In one embodiment, the first processor 1102 is specifically configured to modulate the uplink reference signal sent by the terminal into the first signal according to a first parameter; wherein,

[0312] The first parameter characterizes the transmission parameter of the first network device in the first operating mode, and the

[0313] The first operating mode supports phase biasing and frequency biasing of the electromagnetic wave incident on the RIS of the first network device.

[0314] In one embodiment, the first communication interface 1101 is further configured to receive the first parameter sent by the second network device.

[0315] In one embodiment, the first communication interface 1101 is further configured to report the first information of the first network device to the second network device, and the first information includes at least one of the following:

[0316] The second operating mode and the reflection coefficient codebook;

[0317] The first operating mode and the second parameter; wherein,

[0318] The second operating mode only supports phase biasing of the electromagnetic wave incident on the RIS of the first network device;

[0319] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0320] The time coding sequence length;

[0321] The reflection coefficient time-varying period;

[0322] The spatio-temporal coding matrix.

[0323] It should be noted that: The specific processing procedures of the first processor 1102 and the first communication interface 1101 can be understood with reference to the above method.

[0324] Of course, in actual application, each component in the first network device 1100 is coupled together through the bus system 1104. It can be understood that the bus system 1104 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 1104 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clear illustration, in Figure 11 All kinds of buses are labeled as the bus system 1104.

[0325] The first memory 1103 in the embodiment of the present application is used to store various types of data to support the operation of the first network device 1100. Examples of these data include: any computer program for operating on the first network device 1100.

[0326] The method disclosed in the embodiment of the present application can be applied to or implemented by the first processor 1102. The first processor 1102 may be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the above method can be completed by the integrated logic circuit in hardware or instructions in software form in the first processor 1102. The above first processor 1102 may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The first processor 1102 can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiment of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. Combining the steps of the method disclosed in the embodiment of the present application, it can be directly embodied as being executed and completed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, and this storage medium is located in the first memory 1103. The first processor 1102 reads the information in the first memory 1103 and combines its hardware to complete the steps of the foregoing method.

[0327] In an exemplary embodiment, the first network device 1100 may be implemented by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontroller units (MCUs), microprocessors, or other electronic components for executing the foregoing method.

[0328] Based on the above hardware implementation of the program module and in order to implement the method on the second network device side in the embodiment of the present application, the embodiment of the present application further provides a second network device, as Figure 12 shown. The second network device 1200 includes:

[0329] A second communication interface 1201 capable of interacting with other network nodes;

[0330] A second processor 1202, connected to the second communication interface 1201 to enable information interaction with other network nodes, is configured to execute the method provided by one or more of the above-mentioned second network device side technical solutions when running a computer program. The computer program is stored on a second memory 1203.

[0331] Specifically, the second communication interface 1201 is configured to receive a first signal sent by a first network device, where the first signal is obtained by modulating an uplink reference signal sent by the terminal by the first network device, and the first signal represents a space-time coding signal supported by the first network device.

[0332] In one embodiment, the second processor 1202 is configured to determine an angle between the second network device and the terminal according to the first signal.

[0333] In one embodiment, the second communication interface 1201 is further configured to send a first parameter to the first network device; where the first parameter represents transmission parameters of the first network device in a first operating mode, and is used to modulate the uplink reference signal sent by the terminal; the first operating mode supports phase biasing and frequency biasing of electromagnetic waves incident on the RIS.

[0334] In one embodiment, the second communication interface 1201 is further configured to receive first information reported by the first network device, where the first information includes at least one of the following:

[0335] A second operating mode and a reflection coefficient codebook;

[0336] The first operating mode and a second parameter; where,

[0337] The second operating mode only supports phase biasing of electromagnetic waves incident on the RIS;

[0338] The first parameter is determined according to the second parameter, and the second parameter includes at least one of the following:

[0339] The length of the time coding sequence;

[0340] The time-varying period of the reflection coefficient;

[0341] The space-time coding matrix.

[0342] In one embodiment, the second communication interface 1201 is further configured to send second information to the terminal through the RIS controlled by the first network device; where the second information includes at least one of the transmission frequency, symbol length, and transmission resources of the uplink reference signal.

[0343] In one embodiment, the symbol length of the uplink reference signal is determined according to the length of the time coding sequence supported by the first network device and the time-varying period of the reflection coefficient.

[0344] In one embodiment, the second communication interface 1201 is further configured to receive third information reported by the terminal through the first network device, where the third information includes the transmission frequency of the uplink reference signal supported by the terminal.

[0345] In one embodiment, the transmission resource of the uplink reference signal has a spatial association relationship with the transmission resource of the first downlink reference signal; where

[0346] the first downlink reference signal is reported by the terminal, and represents the downlink reference signal with the strongest received signal strength among N downlink reference signals; the N downlink reference signals are sent by the second network device and are forwarded to the terminal by the first network device in the second operating mode using N beams.

[0347] It should be noted that: the specific processing procedures of the second processor 1202 and the second communication interface 1201 can be understood with reference to the above method.

[0348] Of course, in actual application, each component in the second network device 1200 is coupled together through the bus system 1204. It can be understood that the bus system 1204 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 1204 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clear illustration, in Figure 12 all kinds of buses are labeled as the bus system 1204.

[0349] The second memory 1203 in the embodiment of the present application is used to store various types of data to support the operation of the second network device 1200. Examples of these data include: any computer program for operating on the second network device 1200.

[0350] The method disclosed in the embodiments of the present application can be applied to or implemented by the second processor 1202. The second processor 1202 may be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the above method can be completed by the integrated logic circuit of the hardware in the second processor 1202 or instructions in software form. The above-mentioned second processor 1202 may be a general-purpose processor, DSP, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The second processor 1202 can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. Combining the steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed and completed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, and this storage medium is located in the second memory 1203. The second processor 1202 reads the information in the second memory 1203 and combines its hardware to complete the steps of the foregoing method.

[0351] In an exemplary embodiment, the second network device 1200 can be implemented by one or more ASICs, DSPs, PLDs, CPLDs, FPGAs, general-purpose processors, controllers, MCUs, Microprocessors, or other electronic components for executing the foregoing method.

[0352] It can be understood that the memories (the first memory 1103 and the second memory 1203) in the embodiments of the present application can be volatile memories or non-volatile memories, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM, Read Only Memory), a programmable read-only memory (PROM, Programmable Read-Only Memory), an erasable programmable read-only memory (EPROM, Erasable Programmable Read-Only Memory), an electrically erasable programmable read-only memory (EEPROM, Electrically Erasable Programmable Read-Only Memory), a ferromagnetic random access memory (FRAM, ferromagnetic random access memory), a flash memory (Flash Memory), a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM, Compact Disc Read-Only Memory); the magnetic surface memory can be a disk memory or a tape memory. The volatile memory can be a random access memory (RAM, Random Access Memory), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as a static random access memory (SRAM, Static Random Access Memory), a synchronous static random access memory (SSRAM, Synchronous Static Random Access Memory), a dynamic random access memory (DRAM, Dynamic Random Access Memory), a synchronous dynamic random access memory (SDRAM, Synchronous Dynamic Random Access Memory), a double data rate synchronous dynamic random access memory (DDR SDRAM, Double Data Rate Synchronous Dynamic Random Access Memory), an enhanced synchronous dynamic random access memory (ESDRAM, Enhanced Synchronous Dynamic Random Access Memory), a sync link dynamic random access memory (SLDRAM, SyncLink Dynamic Random Access Memory), and a direct rambus random access memory (DRRAM, Direct Rambus Random Access Memory).The memories described in the embodiments of this application are intended to include, but are not limited to, these and any other suitable types of memories.

[0353] In an exemplary embodiment, the embodiments of this application also provide a storage medium, specifically a computer storage medium, more specifically a computer-readable storage medium. For example, it includes a first memory 1103 that stores a computer program, and the above computer program can be executed by a first processor 1102 of a first network device 1100 to complete the steps described in the foregoing method on the first network device side. Another example is a second memory 1203 that stores a computer program, and the above computer program can be executed by a second processor 1202 of a second network device 1200 to complete the steps described in the foregoing method on the second network device side. The computer-readable storage medium can be a FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disc, or CD-ROM, etc.

[0354] It should be noted that: "first", "second", etc. are used to distinguish similar objects and do not necessarily describe a specific order or sequence.

[0355] In this document, the term "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" in this document represents any one of multiple or any combination of at least two of multiple. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set composed of A, B, and C.

[0356] In addition, the technical solutions described in the embodiments of this application can be arbitrarily combined without conflict.

[0357] The above is only a preferred embodiment of this application and is not used to limit the protection scope of this application.

Claims

1. A reference signal transmission method, characterized in that, applied to a first network device, the method includes: modulating an uplink reference signal sent by a terminal into a first signal, the first signal representing a space-time coding signal supported by the first network device; sending the first signal to a second network device.

2. The method according to claim 1, characterized in that, the modulating the uplink reference signal sent by the terminal into a first signal includes: modulating the uplink reference signal sent by the terminal into the first signal according to a first parameter; wherein, the first parameter represents a transmission parameter of the first network device in a first operating mode, and the first operating mode supports phase biasing and frequency biasing of electromagnetic waves incident on a reconfigurable intelligent surface (RIS) of the first network device.

3. The method according to claim 2, characterized in that, the method further includes: receiving the first parameter sent by the second network device.

4. The method according to claim 3, characterized in that, the method further includes: reporting first information of the first network device to the second network device, the first information including at least one of the following: a second operating mode and a reflection coefficient codebook; the first operating mode and a second parameter; wherein, the second operating mode only supports phase biasing of electromagnetic waves incident on the RIS of the first network device; the first parameter is determined according to the second parameter, and the second parameter includes at least one of the following: the length of a time coding sequence; the time-varying period of a reflection coefficient; a space-time coding matrix.

5. A reference signal transmission method, characterized in that, applied to a second network device, the method includes: receiving a first signal sent by a first network device, wherein the first signal is obtained by modulating an uplink reference signal sent by the terminal by the first network device, and the first signal represents a space-time coding signal supported by the first network device.

6. The method according to claim 5, characterized in that, the method further includes: determining an angle between the second network device and the terminal according to the first signal.

7. The method according to claim 5, characterized in that, the method further includes: sending a first parameter to the first network device; wherein, the first parameter represents a transmission parameter of the first network device in a first operating mode and is used to modulate the uplink reference signal sent by the terminal; the first operating mode supports phase biasing and frequency biasing of electromagnetic waves incident on the RIS of the first network device.

8. The method according to claim 7, characterized in that, the method further includes: receiving the first information reported by the first network device, the first information including at least one of the following: a second operating mode and a reflection coefficient codebook; the first operating mode and a second parameter; wherein, the second operating mode only supports phase biasing of electromagnetic waves incident on the RIS of the first network device; the first parameter is determined according to the second parameter, and the second parameter includes at least one of the following: the length of a time coding sequence; the time-varying period of a reflection coefficient; a space-time coding matrix.

9. The method according to any one of claims 5 to 8, characterized in that, the method further comprises: sending second information to the terminal through the first network device; wherein, the second information includes at least one of a transmission frequency, a symbol length, and a transmission resource of an uplink reference signal.

10. The method according to claim 9, characterized in that, the symbol length of the uplink reference signal is determined according to the length of a time coding sequence supported by the first network device and the time-varying period of a reflection coefficient.

11. The method according to claim 9, characterized in that, before sending the second information to the terminal, the method further comprises: receiving third information reported by the terminal through the first network device, where the third information includes a transmission frequency of an uplink reference signal supported by the terminal.

12. The method according to claim 9, characterized in that, the transmission resource of the uplink reference signal has a spatial correlation relationship with the transmission resource of a first downlink reference signal; wherein, the first downlink reference signal is reported by the terminal, and represents the downlink reference signal with the strongest received signal strength among N downlink reference signals; the N downlink reference signals are sent by the second network device and are forwarded to the terminal by the first network device in a second operating mode using N beams.

13. A reference signal transmission device, characterized in that, comprising: a modulation unit, configured to modulate an uplink reference signal sent by a terminal into a first signal, where the first signal represents a space-time coding signal supported by a first network device; a first sending unit, configured to send the first signal to a second network device.

14. A reference signal transmission device, characterized in that, comprising: a first receiving unit, configured to receive a first signal sent by a first network device, where the first signal is obtained by modulating an uplink reference signal sent by the terminal by the first network device, and the first signal represents a space-time coding signal supported by the first network device.

15. A first network device, characterized in that, comprising: a first processor and a first communication interface; wherein, the first processor is configured to modulate an uplink reference signal sent by a terminal into a first signal; the first signal represents a space-time coding signal supported by the first network device; the first communication interface is configured to send the first signal to a second network device.

16. A second network device, characterized in that, comprising: a second processor and a second communication interface; wherein, the second communication interface is configured to receive a first signal sent by a first network device, where the first signal is obtained by modulating an uplink reference signal sent by the terminal by the first network device, and the first signal represents a space-time coding signal supported by the first network device.

17. A network device, characterized in that, comprising a processor and a memory for storing a computer program capable of running on the processor, wherein, when the processor is configured to run the computer program, it executes the steps of the method according to any one of claims 1 to 4, or executes the steps of the method according to any one of claims 5 to 12.

18. A storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4, or implements the steps of the method according to any one of claims 5 to 12.

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