Doppler frequency shift compensation method and device, equipment and storage medium

Abstract

The invention relates to the field of wireless communication, and provides a Doppler frequency shift compensation method and device, equipment and a storage medium. The method comprises the following steps: acquiring ephemeris information of a satellite, a first frequency shift value estimated based on the ephemeris information and a beam position center, and a synchronization signal block SSB in a compensation beam position, sending a pre-compensation SSB to a terminal, and then based on a second frequency shift value after interpolation update, compensating an uplink signal and a downlink signal in the beam position, and sending a pre-compensation downlink signal to the terminal. The terminal performs Doppler frequency offset compensation under the condition of not depending on GNSS position information, terminal cost and use power consumption are reduced, frequency sweeping times of the terminal in an initial access stage are reduced, and delay of accessing a cell by the terminal is shortened.

Description

Technical Field

[0001] This application relates to the field of wireless communication and provides a Doppler frequency shift compensation method, apparatus, device, and storage medium. Background Technology

[0002] In satellite communication systems of non-terrestrial networks (NTNs), the high-speed movement of satellites relative to the ground causes changes in the frequency of signals received by ground stations; this phenomenon is called Doppler shift.

[0003] To mitigate the negative impact of Doppler shift, the terminal performs coarse Doppler shift compensation through a series of operations, including synchronous grid scanning, primary synchronization signal (PSS) / secondary synchronization signal (SSS) detection, and physical broadcast channel (PBCH) decoding. This is combined with Doppler shift compensation based on satellite broadcast ephemeris information and locally acquired Global Navigation Satellite System (GNSS) position information, as well as Doppler shift compensation based on demodulation reference signal (DMRS) or other reference signals, to achieve more accurate Doppler shift compensation for downlink signals.

[0004] Non-terrestrial network protocol standards stipulate that a terminal must simultaneously acquire valid GNSS location information and satellite ephemeris information to perform Doppler shift compensation; otherwise, the terminal cannot establish network communication with the cell. When the global navigation satellite signal is good, the GNSS module can achieve centimeter-level positioning of the terminal. However, in scenarios such as when global navigation satellites are in medium or high orbits, in cloudy or rainy weather, or in dense forests, the positioning accuracy and signal strength of the GNSS module will decrease significantly. The terminal cannot acquire its own GNSS location information in these application scenarios, resulting in the inability to complete Doppler shift compensation and affecting network communication with the cell. Moreover, for low-cost IoT terminals and slow-moving or stationary broadband terminals, using a GNSS module will increase terminal cost and power consumption.

[0005] During the initial cell search, the terminal initiates a frequency scan, scanning various frequency points across all supported frequency bands to search for accessible cells. Due to Doppler shift in the downlink signal from the satellite base station, the downlink signal frequencies within the band are far from the preset frequencies, resulting in a very large range of Global Synchronization Channel Numbers (GSCNs) that the terminal needs to scan, and a large number of frequency points to scan. The terminal first attempts to scan the frequency band with a larger frequency offset step size, then attempts with a smaller step size, selecting the cell with the best signal quality by evaluating the received PSS / SSS signal quality during frequency scanning. Frequent frequency scans increase the terminal's latency during cell search, thus increasing the latency of cell access and impacting network communication. Summary of the Invention

[0006] This application provides a Doppler frequency shift compensation method, apparatus, device, and storage medium to solve the problem of compensating for the Doppler frequency shift of downlink signals when a terminal does not have a GNSS module installed or cannot obtain GNSS location information.

[0007] In a first aspect, embodiments of this application provide a Doppler frequency shift compensation method, which is applied to a spaceborne base station and includes:

[0008] Obtain satellite ephemeris information;

[0009] Based on the ephemeris information and the first frequency shift value estimated by the wave position center, the synchronization signal block SSB in the wave position is compensated, and the pre-compensated SSB is sent to the terminal.

[0010] Based on the interpolated updated second frequency shift value, the uplink and downlink signals within the compensated frequency band are compensated, and the pre-compensated downlink signal is sent to the terminal.

[0011] Optionally, the first frequency shift value of the wave position center can be estimated using the following method:

[0012] Based on the ephemeris information, the ground projection point of the satellite, the direction of satellite motion, and the satellite orbital altitude are obtained;

[0013] Based on the distance between the wave position center and the ground projection point and the direction of satellite motion, the first angle between the ground projection point and the direction of satellite motion, and between the ground projection point and the wave position center are obtained; and based on the distance between the wave position center and the ground projection point, the current position of the Earth's center and the satellite, and the second angle between the Earth's center and the wave position center are obtained.

[0014] Based on the ephemeris information, the first included angle, and the second included angle, a Doppler frequency shift estimation is performed on the wave position center to obtain the first frequency shift value of the wave position center.

[0015] Optionally, the interpolated updated second frequency shift value can be obtained using the following method:

[0016] Based on the Doppler frequency shift deviation rate and the time interval of the SSB period, the first frequency shift value of the wave position center is interpolated and updated to obtain the second frequency shift value generated by the wave position center in the time interval.

[0017] Secondly, embodiments of this application also provide a Doppler frequency shift compensation method, which is applied to a terminal and includes:

[0018] Receive the pre-compensated synchronization signal block (SSB) sent by the first cell, where the signal quality of the first cell meets the evaluation criteria.

[0019] Based on the pre-compensated SSB, the fundamental frequency shift value of the terminal relative to the wave position center is estimated, and the fundamental frequency shift value is used to compensate for the Doppler frequency shift of the first downlink signal;

[0020] The system uses a first downlink signal with basic frequency shift compensation to compensate for the Doppler frequency shift of the second downlink signal, and estimates the dynamic frequency shift value generated by the terminal within the SSB period time interval based on the pre-compensated downlink signal transmitted by the first cell. The dynamic frequency shift value is used to compensate for the Doppler frequency shift of the second downlink signal.

[0021] Optionally, estimating the fundamental frequency shift of the terminal relative to the wave position center based on the pre-compensated SSB includes:

[0022] Detect the primary synchronization signal PSS and the secondary synchronization signal SSS in the pre-compensated SSB;

[0023] A first reference signal is received in the Physical Broadcast Channel (PBCH), the channel position of which is determined based on the time domain position of the PSS and the frequency domain position of the SSS.

[0024] Based on the phase difference between the received first reference signal and the local first reference signal, the fundamental frequency shift value of the terminal relative to the wave position center is estimated.

[0025] Optionally, estimating the dynamic frequency shift value generated by the terminal within the SSB period time interval based on the pre-compensated downlink signal transmitted by the first cell includes:

[0026] The downlink signal is based on the pre-compensated downlink signal transmitted by the first cell to obtain a second reference signal; based on the phase difference between the received second reference signal and the local second reference signal, the dynamic frequency shift value of the terminal relative to the wave position center is estimated.

[0027] Thirdly, embodiments of this application also provide a Doppler frequency shift compensation device, which is applied to a spaceborne base station and includes:

[0028] The first frequency shift compensation unit is used to acquire the satellite's ephemeris information;

[0029] Based on the ephemeris information and the first frequency shift value estimated by the wave position center, the synchronization signal block SSB in the wave position is compensated, and the pre-compensated SSB is sent to the terminal.

[0030] The second frequency shift compensation unit is used to compensate the uplink and downlink signals within the waveform based on the interpolated updated second frequency shift value, and to send the pre-compensated downlink signal to the terminal.

[0031] Optionally, the first frequency shift compensation unit estimates the first frequency shift value of the wave position center in the following manner:

[0032] Based on the ephemeris information, the ground projection point of the satellite, the direction of satellite motion, and the satellite orbital altitude are obtained;

[0033] Based on the distance between the wave position center and the ground projection point and the direction of satellite motion, the first angle between the ground projection point and the direction of satellite motion, and between the ground projection point and the wave position center are obtained; and based on the distance between the wave position center and the ground projection point, the current position of the Earth's center and the satellite, and the second angle between the Earth's center and the wave position center are obtained.

[0034] Based on the ephemeris information, the first included angle, and the second included angle, a Doppler frequency shift estimation is performed on the wave position center to obtain the first frequency shift value of the wave position center.

[0035] Optionally, the second frequency shift compensation unit obtains the interpolated and updated second frequency shift value in the following manner:

[0036] Based on the Doppler frequency shift deviation rate and the time interval of the SSB period, the first frequency shift value of the wave position center is interpolated and updated to obtain the second frequency shift value generated by the wave position center in the time interval.

[0037] Fourthly, embodiments of this application also provide a Doppler frequency shift compensation device, which is applied to a terminal and includes:

[0038] The basic frequency shift compensation unit is used to receive the pre-compensated synchronization signal block (SSB) sent by the first cell, which is a cell whose signal quality meets the evaluation criteria.

[0039] Based on the pre-compensated SSB, the fundamental frequency shift value of the terminal relative to the wave position center is estimated, and the fundamental frequency shift value is used to compensate for the Doppler frequency shift of the first downlink signal;

[0040] The dynamic frequency shift compensation unit is used to compensate for the Doppler frequency shift of the second downlink signal based on the first downlink signal with basic frequency shift compensation, and to estimate the dynamic frequency shift value generated by the terminal within the time interval of the SSB period based on the pre-compensated downlink signal transmitted by the first cell, wherein the dynamic frequency shift value is used to compensate for the Doppler frequency shift of the second downlink signal.

[0041] Optionally, the basic frequency shift compensation unit is used for:

[0042] Detect the primary synchronization signal PSS and the secondary synchronization signal SSS in the pre-compensated SSB;

[0043] A first reference signal is received in the Physical Broadcast Channel (PBCH), the channel position of which is determined based on the time domain position of the PSS and the frequency domain position of the SSS.

[0044] Based on the phase difference between the received first reference signal and the local first reference signal, the fundamental frequency shift value of the terminal relative to the wave position center is estimated.

[0045] Optionally, the dynamic frequency shift compensation unit is used for:

[0046] The downlink signal is based on the pre-compensated downlink signal transmitted by the first cell to obtain a second reference signal; based on the phase difference between the received second reference signal and the local second reference signal, the dynamic frequency shift value of the terminal relative to the wave position center is estimated.

[0047] Fifthly, embodiments of this application also provide a computer device, including a processor and a memory, wherein the memory stores program code, and when the program code is executed by the processor, the processor performs the steps of any of the above-described Doppler frequency shift compensation methods.

[0048] Sixthly, embodiments of this application also provide a computer-readable storage medium including program code, which, when the program product is run on a computer device, is used to cause the computer device to perform the steps of any of the above-described Doppler frequency shift compensation methods.

[0049] The beneficial effects of this application are as follows:

[0050] This application provides a Doppler frequency shift compensation method, apparatus, device, and storage medium. The method is applied to a satellite base station and includes: acquiring satellite ephemeris information; compensating for the synchronization signal block (SSB) within the bandgap based on the ephemeris information and a first frequency shift value estimated by the bandgap center; sending the pre-compensated SSB to the terminal; and then compensating for the uplink and downlink signals within the bandgap based on the interpolated and updated second frequency shift value, and sending the pre-compensated downlink signal to the terminal.

[0051] This application proposes a Doppler frequency shift compensation method for satellite-borne base stations. Since the satellite-borne base station pre-compensates for the Doppler frequency shift of the SSB based on ephemeris information and the wavefront center, and the terminal-estimated base frequency shift value changes slowly in the radial direction with satellite motion, the terminal can still perform Doppler frequency shift compensation for downlink signals based on the pre-compensated SSB-estimated base frequency shift value of the terminal relative to the wavefront center even without installing a GNSS module or being unable to obtain GNSS location information. This reduces the terminal's dependence on GNSS in non-terrestrial network communication, reduces terminal cost and power consumption, reduces the number of frequency sweeps during the initial cell search process, and reduces the delay of the terminal accessing the cell.

[0052] The satellite base station compensates for the uplink and downlink signals within the waveband based on the interpolated updated second frequency shift value, and sends a pre-compensated downlink signal to the terminal. This allows the terminal to combine the base frequency shift value estimated by the first downlink signal based on the base frequency shift compensation with the dynamic frequency shift value estimated based on the pre-compensated downlink signal to compensate for the Doppler frequency shift of the downlink signal, thereby canceling the Doppler frequency shift caused by satellite motion and ensuring that the frequency tracking accuracy of the terminal meets the requirements.

[0053] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0054] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0055] Figure 1A This is a schematic diagram illustrating the logic of Doppler frequency shift compensation for downlink signals by the terminal under related technologies.

[0056] Figure 1B This is a reference schematic diagram for estimating Doppler frequency shift at the terminal using related technologies;

[0057] Figure 2AThis is a schematic diagram illustrating the process of Doppler frequency shift compensation for uplink and downlink signals by a spaceborne base station provided in an embodiment of this application.

[0058] Figure 2B This is a schematic diagram illustrating the logic of a spaceborne base station performing Doppler frequency shift compensation on uplink and downlink signals, as provided in an embodiment of this application.

[0059] Figure 2C A reference schematic diagram illustrating the continuous deployment of multiple spectral positions within a satellite-covered cell, as provided in an embodiment of this application;

[0060] Figure 2D This is a reference schematic diagram showing the Doppler frequency shift values ​​of each wave position center in the radial direction of satellite motion, provided in an embodiment of this application.

[0061] Figure 2E A reference schematic diagram for estimating the Doppler frequency shift value of the wave position center provided in the embodiments of this application;

[0062] Figure 2F This is a schematic diagram illustrating the logic for Doppler frequency shift compensation of a radio frequency transceiver signal, provided in an embodiment of this application.

[0063] Figure 3A This is a schematic diagram illustrating the process of a terminal performing Doppler frequency shift compensation on a downlink signal, as provided in an embodiment of this application.

[0064] Figure 3B A schematic diagram illustrating the logic of Doppler frequency shift compensation for downlink signals provided in the embodiments of this application;

[0065] Figure 3C A reference schematic diagram showing the position with the largest Doppler frequency shift value deviation from the wave position center, provided in an embodiment of this application;

[0066] Figure 3D This is a schematic diagram of the Doppler frequency shift deviation between the wavefront center and the wavefront edge provided in an embodiment of this application;

[0067] Figure 3E This is a schematic diagram illustrating the variation of the Doppler frequency shift deviation value at the wavefront edge under different wavefront widths, provided in an embodiment of this application.

[0068] Figure 4 This application provides a schematic diagram of the structure of a Doppler frequency shift compensation device applied to a spaceborne base station.

[0069] Figure 5 A schematic diagram of a Doppler frequency shift compensation device applied to a terminal, provided in an embodiment of this application;

[0070] Figure 6 This is a schematic diagram of the composition structure of a computer device provided in the embodiments of this application;

[0071] Figure 7 This is a schematic diagram of the structure of a computing device in an embodiment of this application. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this application. Obviously, the described embodiments are only some embodiments of the technical solutions of this application, and not all embodiments. Based on the embodiments recorded in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the technical solutions of this application.

[0073] The following explanations of some terms used in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0074] 1. Non-terrestrial networks: These are communication networks that do not rely on ground infrastructure. Instead, they provide communication services through aerial or space platforms such as satellites and high-altitude platforms (e.g., stratospheric balloons and drones). They can extend the coverage of traditional terrestrial cellular networks and are particularly suitable for remote areas, oceans, mountains, and other places where it is difficult to lay ground base stations.

[0075] 2. Doppler shift: This refers to the change in wave frequency caused by the relative motion between the wave source and the observer. This phenomenon exists in sound waves, light waves, and electromagnetic waves, but it is particularly important in wireless communication because it affects the quality of signal reception.

[0076] 3. Satellite: A satellite is a device located in Earth's orbit used to provide communication services. Based on their orbital altitude, satellites can be classified as Low Earth Orbit (LEO), Medium Earth Orbit (MEO), and High Earth Orbit (GEO).

[0077] 4. Satellite-borne base station: This refers to communication equipment installed on a satellite. It is similar to a base station (BS) in a terrestrial cellular network and is responsible for demodulating, encoding, decoding and other processing of signals from ground terminals and transmitting wireless signals.

[0078] 5. Cell: A cell is a geographical area covered by a single base station (whether terrestrial or satellite-based). Each cell has a unique identifier (such as Physical Cell ID, PCI). The base station transmits signals to terminals within the cell via antennas, including the Synchronization Signal Block (SSB), PBCH, and reference signals.

[0079] 6. Frequency band: This refers to the range of frequencies used for signal transmission in a wireless communication system. Different communication standards and technologies use different frequency bands to avoid mutual interference.

[0080] 7. Frequency point: refers to a specific center frequency within a particular frequency band. Each frequency point represents a carrier wave used for data transmission. The selection of the frequency point determines the communication frequency between the terminal and the base station. In a multi-carrier system, multiple frequency points can be used simultaneously to increase the overall system capacity.

[0081] 8. Ground gateway station: also known as a ground station or ground gateway station, is a fixed facility located on the Earth's surface. It is a key component of the satellite communication system and is used to communicate with the satellite and transmit data received by the satellite to the ground network, or to send data from the ground network to the satellite.

[0082] Ground gateway stations play a crucial role in satellite communication systems. They are responsible not only for signal relay and processing but also for providing the interface with terrestrial networks, ensuring the efficient operation of the satellite communication system. Through ground gateway stations, satellite communication can be extended globally, providing a variety of communication services.

[0083] The design concept of the embodiments of this application is briefly introduced below:

[0084] In satellite communication systems on non-terrestrial networks, the high-speed movement of satellites relative to the ground causes changes in the frequency of signals received by ground stations; this phenomenon is called Doppler shift.

[0085] To mitigate the negative effects of Doppler frequency shift, such as Figure 1A As shown, the terminal performs coarse Doppler shift compensation through a series of operations such as synchronous grid scanning, PSS / SSS detection, and PBCH decoding. Then, it combines Doppler shift compensation based on satellite broadcast ephemeris information and locally acquired GNSS position information, as well as Doppler shift compensation based on DMRS or other reference signals, to achieve more accurate Doppler shift compensation for downlink signals.

[0086] Currently, the formula for calculating the maximum Doppler frequency shift at terminals of non-terrestrial networks is: In the formula, c represents the speed of light, and F... c The vector represents the transmission frequency of the satellite-borne base station, V represents the satellite's orbital velocity vector, R represents the Earth's radius, h represents the satellite's orbital altitude, γ represents the satellite's relative altitude to the Earth's surface, and F... d This represents the Doppler frequency shift value of the terminal. Figure 1B In the reference diagram shown, S represents a satellite moving in a circular orbit, M represents the terminal, O is the center of the Earth, and θ represents the direction of the satellite's motion. The included angle between them, μ represents and The angle between them.

[0087] Non-terrestrial network protocol standards stipulate that a terminal must simultaneously acquire valid GNSS location information and satellite ephemeris information to perform Doppler shift compensation; otherwise, the terminal cannot establish network communication with the satellite. When the signal from global navigation satellites is good, the GNSS module can provide centimeter-level positioning for the terminal. However, in scenarios such as when global navigation satellites are in medium or high orbits, during cloudy or rainy weather, or in dense forests, the positioning accuracy and signal strength of the GNSS module will significantly decrease. The terminal cannot acquire its own GNSS location information in these application scenarios, resulting in the inability to complete Doppler shift compensation and affecting network communication with the cell. Moreover, for low-cost IoT terminals and slow-moving or stationary broadband terminals, using a GNSS module will increase terminal cost and power consumption.

[0088] During the initial cell search, the terminal initiates a frequency scan, scanning various frequency points across all supported frequency bands to search for accessible cells. Due to Doppler frequency shift in the downlink signal from the satellite base station, the downlink signal's frequency points within the frequency band are far from the preset frequency points, resulting in a very large GSCN range and numerous frequency points that the terminal needs to scan. The terminal first attempts to scan the frequency band with a large frequency offset step size, then attempts with a smaller frequency offset step size, evaluating the signal quality of the received PSS / SSS during frequency scanning to select the cell with the best signal quality. Frequent frequency scans increase the terminal's latency during cell search, consequently increasing the latency of cell access and impacting network communication.

[0089] In view of this, this application proposes a Doppler frequency shift compensation method for satellite-based base stations. The method specifically includes: acquiring satellite ephemeris information; compensating for the synchronization signal block (SSB) within the bandgap based on the ephemeris information and a first frequency shift value estimated by the bandgap center; sending the pre-compensated SSB to the terminal; and then compensating for the uplink and downlink signals within the bandgap based on the interpolated updated second frequency shift value; and sending the pre-compensated downlink signal to the terminal.

[0090] Because the satellite base station pre-compensates for the Doppler frequency shift of the SSB, the frequency point of the pre-compensated SSB in the frequency band is closer to the preset frequency point of the signal. The terminal can receive the pre-compensated SSB by scanning around the preset frequency point with a smaller frequency offset step size, which reduces the number of frequency scans the terminal needs to perform during the initial cell search process and reduces the delay of the terminal accessing the cell.

[0091] The satellite-borne base station pre-compensates for the Doppler frequency shift of the SSB based on ephemeris information and the position center. Furthermore, the terminal's estimated base frequency shift changes slowly in the radial direction with satellite motion. This allows the terminal to compensate for the Doppler frequency shift of the downlink signal based on the pre-compensated SSB-estimated base frequency shift relative to the position center, even without a GNSS module or GNSS location information. This reduces the terminal's dependence on GNSS in non-terrestrial network communications, thereby lowering terminal costs and power consumption.

[0092] The satellite-based base station compensates for the uplink and downlink signals within the waveform based on the interpolated updated second frequency shift value, and sends a pre-compensated downlink signal to the terminal. This enables the terminal to compensate for the Doppler frequency shift of the downlink signal based on the dynamic frequency shift value estimated by the pre-compensated downlink signal, thereby canceling the Doppler frequency shift caused by satellite motion and ensuring that the frequency tracking accuracy of the terminal meets the requirements.

[0093] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0094] Satellite communication systems consist of satellites and terminals. To reduce the negative impact of Doppler shift, a reliable two-way communication connection is established between the satellite and the terminal. The terminal and the satellite respectively perform Doppler shift compensation on the uplink and downlink signals to ensure that the satellite can correctly receive the signals sent by the terminal, and the terminal can correctly receive the signals sent by the satellite, thus ensuring the stability and reliability of the entire satellite communication system.

[0095] like Figure 2A-2B As shown, this application describes how a satellite-borne base station uses the method provided in this application to perform Doppler frequency shift compensation on uplink and downlink signals.

[0096] S201: Obtain satellite ephemeris information.

[0097] During its movement, the satellite can obtain ephemeris information and position center from ground gateway stations in advance.

[0098] Ephemeris information describes the orbital position and motion of a satellite, and is crucial for satellite communication systems, GNSS, and other satellite-dependent applications. Ephemeris information includes orbital parameters, time parameters, and other relevant information, enabling receivers to accurately calculate the satellite's position, thus achieving high-precision positioning and time synchronization.

[0099] In satellite communication systems, to improve system capacity, coverage, and signal quality, satellites may need to deploy multiple spectral positions consecutively within their coverage cell, each with the same spectral width. When calculating the spectral center position of each spectral position, ground gateways need to comprehensively consider factors such as spectral width, satellite orbital velocity vector, and cell diameter.

[0100] like Figure 2C As shown, the satellite orbital altitude is 600 km, the satellite orbital velocity vector is 7.56 km / s, and the cell diameter along the radial direction of satellite motion is 1000 km. Multiple prepositions are continuously deployed along the radial direction of satellite motion, with each preposition having a preposition width of 25 km. The ground gateway station determines the preposition coverage diameter by using the preposition width and the satellite orbital altitude. Based on the cell diameter and the preposition coverage diameter, it determines the required number of prepositions. The center position of each preposition is calculated using geometric methods, thus obtaining the center positions of multiple prepositions within the cell.

[0101] However, considering that the position of the wavefront center will change as the satellite moves, the position of the wavefront center is recalculated based on the satellite's orbital velocity vector and orbital parameters after each time step, and the position of the wavefront center is updated in real time.

[0102] S202: Based on the ephemeris information and the first frequency shift value estimated by the wave position center, compensate for the synchronization signal block SSB within the wave position and send the pre-compensated SSB to the terminal.

[0103] The radial direction refers to the straight-line distance between the satellite and the ground terminal, such as... Figure 2C As shown, multiple wave positions are continuously deployed in the radial direction of satellite motion. The radial direction of satellite motion and the direction of satellite motion are in the same plane. The Doppler frequency shift value at the center of the wave position in the radial direction is the largest compared with the Doppler frequency shift value in other directions. Therefore, the satellite base station of this application completes Doppler frequency shift compensation by estimating the Doppler frequency shift at the center of the wave position. Figure 2D The image shows the Doppler frequency shift values ​​of each wave position center in the radial direction of satellite motion. The horizontal axis represents the wave position center, and the vertical axis represents the Doppler frequency shift value. It can be clearly seen that the maximum Doppler frequency shift value of the wave position at the edge of the cell is 31.6KHz.

[0104] This application combines ephemeris information and wave position center to derive a formula for calculating the Doppler frequency shift of the wave position center: In the formula, c represents the speed of light, and F...c The vector represents the transmission frequency of the satellite-borne base station, V represents the satellite's orbital velocity vector, R represents the Earth's radius, h represents the satellite's orbital altitude, γ represents the satellite's relative altitude to the Earth's surface, and F... d 'Represents the Doppler frequency shift value of the wave position center L'. Figure 2E In the reference diagram shown, S represents a satellite moving in a circular orbit, L' represents the wavefront center, O is the Earth's center, α represents the first angle between the ground projection point and the satellite's direction of motion, and between the ground projection point and the wavefront center, μ represents the second angle between the Earth's center and the satellite's current position, and between the Earth's center and the wavefront center, L represents the intersection of the plane containing the satellite's direction of motion and the ground plane, and θ represents the angle between the orbital velocity components v' and v”.

[0105] The process of using the above formula to estimate Doppler frequency shift by a spaceborne base station is as follows:

[0106] First, based on ephemeris information, the satellite's ground projection point and satellite motion direction are obtained.

[0107] Secondly, based on the distance between the wave position center and the ground projection point and the direction of satellite motion, the direction of satellite motion and the first angle between the ground projection point and the wave position center are obtained. Also, based on the distance between the wave position center and the ground projection point, the current position of the Earth's center and the satellite and the second angle between the Earth's center and the wave position center are obtained.

[0108] Finally, substitute the ephemeris information, the first included angle, and the second included angle into the formula. In the process, Doppler frequency shift estimation is performed on the wave position center to obtain the first frequency shift value of the wave position center.

[0109] Based on the first frequency shift value, the synchronization signal block (SSB) within the compensation wavelet is calculated. The SSB is crucial for satellite communication systems. The SSB comprises the PSS, SSS, and PBCH, and is used to achieve frequency synchronization, time synchronization, cell identification, and broadcasting of system information.

[0110] S203: Based on the second frequency shift value updated by interpolation, compensate the uplink and downlink signals within the waveform and send the pre-compensated downlink signal to the terminal.

[0111] The frequency tracking accuracy of the terminal is controlled within 0.1 ppm, meaning that when the satellite carrier frequency band is S-band (2 GHz), the Doppler frequency shift value needs to be controlled within 200 Hz. Therefore, the satellite-borne base station of this application compensates for the Doppler frequency shift of the wavelet center according to the SSB period to ensure the accuracy of the terminal's frequency shift estimation based on the pre-compensated SSB.

[0112] Furthermore, the SSB period is divided into multiple time intervals. Based on the Doppler frequency shift deviation rate and the time interval of the SSB period, the first frequency shift value of the wave position center is interpolated and updated to obtain the second frequency shift value generated by the wave position center in the time interval. The second frequency shift value will also be reflected in the dynamic frequency shift estimation of the terminal, satisfying the Doppler frequency shift tracking accuracy of terminals inside the wave position and reducing the design complexity of the terminal channel estimation algorithm.

[0113] For example, if the Doppler frequency shift deviation rate is 2.7%, the time interval is 100ms, and the first frequency shift value of the wave position center is 1000Hz, then the second frequency shift value generated by the wave position center within 100ms is (100×2.7%)+1000=1002.7, and the second frequency shift value generated by the wave position center within 200ms is (200×2.7%)+1000=1005.4.

[0114] Figure 2F This paper demonstrates a typical signal processing flow for an RF transceiver, including signal reception, processing, and transmission. The entire flow is divided into two parts: the receive path (RX) and the transmit path (TX). In the receive path, the signal undergoes amplification, down-conversion, digitization, Doppler shift compensation, and automatic gain control. In the transmit path, power amplification, up-conversion, Doppler shift compensation, filtering, and inverse fast Fourier transform are performed. The satellite-borne base station in this application combines ephemeris information and the position of the ground wavefront center to estimate the Doppler shift value of the ground wavefront center in advance, and pre-compensates the Doppler shift value in the uplink and downlink digital signal processing.

[0115] However, in 5G New Radio (5GNR) non-terrestrial networks, the uplink and downlink carrier frequencies are different in Frequency Division Duplex (FDD) mode. Therefore, when calculating the Doppler shift value, Doppler shift estimation must be performed separately for the uplink and downlink carrier frequencies, resulting in different Doppler shift values. In 5GNR non-terrestrial networks, the uplink and downlink carrier frequencies are the same in Time Division Duplex (TDD) mode, and the estimated Doppler shift value can be simultaneously compensated for by the uplink and downlink processing links.

[0116] like Figures 3A-3B As shown, the terminal uses the method provided in this application to perform Doppler frequency shift compensation on the downlink signal.

[0117] S301: Receive the pre-compensated synchronization signal block SSB sent by the first cell, where the signal quality meets the evaluation criteria.

[0118] The terminal uses a synchronous grid scanning method to perform an initial cell search, and selects the cell with the best signal quality as the first cell.

[0119] In the initial cell search process using related technologies, the terminal initiates a frequency scan, scanning various frequency points across all supported frequency bands to search for accessible cells. Due to Doppler frequency shift in the downlink signal of the satellite base station, the frequency points of the downlink signal within the frequency band are far from the preset frequency points, resulting in a very large GSCN range and numerous frequency points that the terminal needs to scan. The terminal first attempts to scan the frequency band with a large frequency offset step size, then attempts to scan with a smaller frequency offset step size, selecting the cell with the best signal quality by evaluating the signal quality of the received PSS / SSS during frequency scanning. Frequent frequency scans increase the terminal's latency during cell search, thereby increasing the latency of cell access and affecting the terminal's network communication.

[0120] Because the satellite-borne base station of this application pre-compensates for the Doppler frequency shift of the SSB, the frequency point of the pre-compensated SSB in the frequency band is closer to the preset frequency point of the signal. The terminal does not need to use a large frequency offset step size to scan the frequency, but can use a smaller frequency offset step size to scan around the preset frequency point to receive the pre-compensated SSB. This reduces the number of frequency scans the terminal needs to perform during the initial cell search process, reduces the signal processing load when evaluating the cell, reduces the latency of the terminal accessing the cell, and improves the user experience.

[0121] S302: Based on the pre-compensated SSB, estimate the fundamental frequency shift value of the terminal relative to the wave position center. The fundamental frequency shift value is used to compensate for the Doppler frequency shift of the first downlink signal.

[0122] In a wave position, the Doppler frequency shift value is the largest at the center of the wave position. Although the satellite base station compensates for the Doppler frequency shift of the SSB based on the first frequency shift value at the center of the wave position, a certain amount of Doppler frequency shift deviation will still occur when the terminal is not at the center of the wave position.

[0123] According to the Doppler frequency shift calculation formula, in a continuous distribution of wave positions along the radial direction of satellite motion, the maximum Doppler frequency shift deviation from the center of the wave position will occur at the edge of the wave position along the radial direction of satellite motion, i.e. Figure 3C The gray dots inside. Figure 3D This demonstrates the residual Doppler frequency shift between the wavefront center and edge in scenarios with wavefront widths of 25 km and 50 km. Specifically, at a wavefront width of 25 km, the maximum Doppler frequency shift is 1050 Hz, occurring at the nadir position (i.e.,...). Figure 2F (At the gray dot in the image); when the wavelength is 50 km, the maximum Doppler frequency shift deviation is 2098 Hz, which occurs at the nadir position.

[0124] Depend on Figure 3DIt can be seen that the maximum residual Doppler frequency shift deviation under different waveband widths is 1kHz or 2kHz. Figure 3E It is known that the Doppler frequency shift value at the edge of the waveband changes slowly in the radial direction under different waveband widths, with the maximum rate of change occurring near the nadir position. Therefore, the base frequency shift value estimated by the terminal based on the pre-compensated SSB will be less than 1 kHz or 2 kHz. This base frequency shift value is continuously compensated into subsequent uplink and downlink signals to offset the Doppler frequency shift caused by satellite motion, reducing the terminal's dependence on GNSS in non-terrestrial network communications and compressing terminal costs and power consumption.

[0125] The terminal performs the following operation to estimate the fundamental frequency shift of the terminal relative to the wave position center:

[0126] First, the primary synchronization signal PSS and the secondary synchronization signal SSS in the pre-compensation SSB are detected. PSS is used for time synchronization with the first cell, and SSS is used for frequency synchronization with the first cell.

[0127] Secondly, the first reference signal is received in the physical broadcast channel PBCH, and the channel position of PBCH is determined based on the time domain position of PSS and the frequency domain position of SSS.

[0128] The first reference signal can be DMRS, Tracking Reference Signal (TRS), or other reference signals. DMRS is used for channel estimation during data demodulation, while TRS is used for channel estimation and time / frequency synchronization in the connected state, especially in high-speed mobile scenarios.

[0129] Finally, based on the phase difference between the received first reference signal and the local first reference signal, the fundamental frequency shift value of the terminal relative to the wave position center is estimated.

[0130] The terminal compensates for the Doppler frequency shift of the first downlink signal based on the fundamental frequency shift value. After completing the fundamental frequency shift estimation, the terminal accesses the first cell and formally establishes a connection with the first cell.

[0131] S303: A first downlink signal based on basic frequency shift compensation, compensating for the Doppler frequency shift of the second downlink signal, and estimating the dynamic frequency shift value generated by the terminal within the time interval of the SSB period based on the pre-compensated downlink signal transmitted by the first cell, the dynamic frequency shift value being used to compensate for the Doppler frequency shift of the second downlink signal.

[0132] The terminal performs the following operation to estimate the dynamic frequency shift value generated by the terminal within the time interval of the SSB cycle:

[0133] Based on the pre-compensated downlink signal transmitted from the first cell, a second reference signal is obtained. Then, based on the phase difference between the second received reference signal and the local second reference signal, the dynamic frequency shift value of the terminal relative to the beam center is estimated. The pre-compensated downlink signal is either a Physical Downlink Control Channel (PDCCH) or a Physical Downlink Shared Channel (PDSCH), and the second reference signal can be a DMRS, TRS, or other reference signal.

[0134] As in formula F d (Terminal) = F d (Basic) + F d As shown in the (dynamic) diagram, the terminal obtains the basic frequency shift value by processing the first downlink signal with basic frequency shift compensation, then compensates for the Doppler frequency shift of the second downlink signal based on the basic frequency shift value, and compensates for the Doppler frequency shift of the second downlink signal based on the dynamic frequency shift value estimated by the pre-compensated downlink signal, thereby offsetting the Doppler frequency shift caused by satellite motion. Even without adding a GNSS module or being unable to obtain GNSS position information, the downlink signal can still be compensated for Doppler frequency shift to meet frequency tracking accuracy.

[0135] Therefore, idle terminals in non-terrestrial networks do not need to wait to acquire ephemeris and GNSS position information, eliminating the pre-wake-up time and reducing terminal power consumption. They also eliminate the step of re-estimating Doppler shift during pre-synchronization after waking up idle terminals, further reducing system power consumption. Connected terminals in non-terrestrial networks reduce periodic ephemeris calculations and GNSS position update operations, lowering terminal power consumption. For terminals initiating reselection and handover in non-terrestrial networks, acquiring ephemeris information from neighboring cells is unnecessary, shortening latency during reselection and handover, reducing system overhead, and effectively improving user experience.

[0136] When using the method proposed in this application to perform Doppler shift compensation on low-speed or stationary broadband terminals and low-cost IoT terminals in non-terrestrial networks, there is no need to acquire GNSS location information, reducing the terminal's dependence on external GNSS devices and lowering terminal costs. However, for high-speed mobile terminals, this application also uses GNSS location information to acquire the terminal's moving speed, thereby compensating for the Doppler shift caused by the terminal's own movement.

[0137] Based on the same inventive concept as the above-described method embodiments, this application also provides a Doppler frequency shift compensation device applied to a spaceborne base station. For example... Figure 4 As shown, the Doppler frequency shift compensation device 400 may include:

[0138] The first frequency shift compensation unit 401 is used to acquire the satellite's ephemeris information;

[0139] Based on the ephemeris information and the first frequency shift value estimated by the wave position center, the synchronization signal block SSB in the wave position is compensated, and the pre-compensated SSB is sent to the terminal.

[0140] The second frequency shift compensation unit 402 is used to compensate the uplink and downlink signals within the waveform based on the interpolated updated second frequency shift value, and send the pre-compensated downlink signal to the terminal.

[0141] Optionally, the first frequency shift compensation unit 401 estimates the first frequency shift value of the wave position center in the following manner:

[0142] Based on the ephemeris information, the ground projection point of the satellite, the direction of satellite motion, and the satellite orbital altitude are obtained;

[0143] Based on the distance between the wave position center and the ground projection point and the direction of satellite motion, the first angle between the ground projection point and the direction of satellite motion, and between the ground projection point and the wave position center are obtained; and based on the distance between the wave position center and the ground projection point, the current position of the Earth's center and the satellite, and the second angle between the Earth's center and the wave position center are obtained.

[0144] Based on the ephemeris information, the first included angle, and the second included angle, a Doppler frequency shift estimation is performed on the wave position center to obtain the first frequency shift value of the wave position center.

[0145] Optionally, the second frequency shift compensation unit 402 obtains the interpolated updated second frequency shift value in the following manner:

[0146] Based on the Doppler frequency shift deviation rate and the time interval of the SSB period, the first frequency shift value of the wave position center is interpolated and updated to obtain the second frequency shift value generated by the wave position center in the time interval.

[0147] Based on the same inventive concept as the above-described method embodiments, this application also provides a Doppler frequency shift compensation device applied to a terminal. For example... Figure 5 As shown, the Doppler frequency shift compensation device 500 may include:

[0148] The basic frequency shift compensation unit 501 is used to receive the pre-compensated synchronization signal block SSB sent by the first cell, where the first cell is a cell whose signal quality meets the evaluation criteria.

[0149] Based on the pre-compensated SSB, the fundamental frequency shift value of the terminal relative to the wave position center is estimated, and the fundamental frequency shift value is used to compensate for the Doppler frequency shift of the first downlink signal;

[0150] The dynamic frequency shift compensation unit 502 is used to compensate for the Doppler frequency shift of the second downlink signal based on the first downlink signal with basic frequency shift compensation, and to estimate the dynamic frequency shift value generated by the terminal within the time interval of the SSB period based on the pre-compensated downlink signal transmitted by the first cell, wherein the dynamic frequency shift value is used to compensate for the Doppler frequency shift of the second downlink signal.

[0151] Optionally, the basic frequency shift compensation unit 501 is used for:

[0152] Detect the primary synchronization signal PSS and the secondary synchronization signal SSS in the pre-compensated SSB;

[0153] A first reference signal is received in the Physical Broadcast Channel (PBCH), the channel position of which is determined based on the time domain position of the PSS and the frequency domain position of the SSS.

[0154] Based on the phase difference between the received first reference signal and the local first reference signal, the fundamental frequency shift value of the terminal relative to the wave position center is estimated.

[0155] Optionally, the dynamic frequency shift compensation unit 502 is used for:

[0156] The downlink signal is based on the pre-compensated downlink signal transmitted by the first cell to obtain the second reference signal; based on the phase difference between the second received reference signal and the local second reference signal, the dynamic frequency shift value of the terminal relative to the wave position center is estimated.

[0157] For ease of description, the above sections are divided into modules (or units) according to their functions and described separately. Of course, in implementing this application, the functions of each module (or unit) can be implemented in one or more software or hardware components.

[0158] Having introduced the Doppler frequency shift compensation method and apparatus according to exemplary embodiments of this application, we will now introduce a computer device according to another exemplary embodiment of this application.

[0159] Those skilled in the art will understand that various aspects of this application can be implemented as a system, method, or program product. Therefore, various aspects of this application can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, collectively referred to herein as a "circuit," "module," or "system."

[0160] Based on the same inventive concept as the above-described method embodiments, this application also provides a computer device, see below. Figure 6As shown, the computer device 600 may include at least a processor 601 and a memory 602. The memory 602 stores program code, which, when executed by the processor 601, causes the processor 601 to perform the steps of any of the aforementioned Doppler frequency shift compensation methods.

[0161] In some possible implementations, the computing device according to this application may include at least one processor and at least one memory. The memory stores program code that, when executed by the processor, causes the processor to perform the steps in the Doppler frequency shift compensation method according to the various exemplary embodiments of this application described above. For example, the processor may perform actions such as... Figure 2A Or the steps shown in 3A.

[0162] The following reference Figure 5 To describe a computing device 700 according to this embodiment of the present application. Figure 7 The computing device 700 is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0163] like Figure 7 As shown, the computing device 700 is presented in the form of a general-purpose computing device. The components of the computing device 700 may include, but are not limited to: at least one processing unit 701, at least one storage unit 702, and a bus 703 connecting different system components (including storage unit 702 and processing unit 701).

[0164] Bus 703 represents one or more of several bus architectures, including a memory bus or memory controller, peripheral bus, processor, or a local bus using any of the various bus architectures.

[0165] Storage unit 702 may include a readable medium in the form of volatile memory, such as random access memory (RAM) 7021 and / or cache memory 7022, and may further include read-only memory (ROM) 7023.

[0166] Storage unit 702 may also include a program / utility 7025 having a set (at least one) program module 7024, such program module 7024 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0167] The computing device 700 can also communicate with one or more external devices 704 (e.g., keyboard, pointing device, etc.), one or more devices that enable a user to interact with the computing device 700, and / or any device that enables the computing device 700 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 705. Furthermore, the computing device 700 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 706. As shown, network adapter 706 communicates with other modules used in the computing device 700 via bus 703. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the computing device 700, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0168] Based on the same inventive concept as the above-described method embodiments, various aspects of the Doppler frequency shift compensation method provided in this application can also be implemented as a program product, which includes program code. When the program product is run on a computer device, the program code is used to cause the computer device to perform the steps in the Doppler frequency shift compensation method according to the various exemplary embodiments of this application described above. For example, the computer device can perform actions such as... Figure 2A Or the steps shown in 3A.

[0169] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0170] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0171] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method of Doppler shift compensation, characterized by, The method is applied to a satellite-based base station, and comprises: obtaining ephemeris information of a satellite; compensating for a synchronization signal block (SSB) in a wave position based on a first frequency shift value estimated for a wave position center and the ephemeris information, and sending a pre-compensated SSB to a terminal; compensating for uplink and downlink signals in the wave position based on a second frequency shift value updated by interpolation, and sending a pre-compensated downlink signal to the terminal.

2. The method of claim 1, wherein, The first frequency shift value of the wave position center is estimated in the following manner: based on the ephemeris information, obtaining a ground projection point of the satellite, a satellite movement direction and a satellite orbit height; based on a distance between the wave position center and the ground projection point and the satellite movement direction, obtaining a first included angle between the ground projection point and the satellite movement direction and between the ground projection point and the wave position center, and based on the distance between the wave position center and the ground projection point, obtaining a second included angle between a geocenter and a current position of the satellite and between the geocenter and the wave position center; based on the ephemeris information, the first included angle and the second included angle, performing Doppler frequency shift estimation on the wave position center to obtain the first frequency shift value of the wave position center.

3. The method of claim 1, wherein, The second frequency shift value updated by interpolation is obtained in the following manner: based on a Doppler frequency shift deviation change rate and a time interval of an SSB period, performing interpolation update on the first frequency shift value of the wave position center to obtain a second frequency shift value of the wave position center generated in the time interval.

4. A method of Doppler shift compensation, characterized by, The method is applied to a terminal, and comprises: receiving a pre-compensated synchronization signal block (SSB) sent by a first cell, the first cell being a cell whose signal quality meets an evaluation criterion; based on the pre-compensated SSB, estimating a basic frequency shift value of the terminal relative to a wave position center, the basic frequency shift value being used to compensate for a Doppler frequency shift of a first downlink signal; based on the first downlink signal compensated by the basic frequency shift, compensating for a Doppler frequency shift of a second downlink signal, and based on a pre-compensated downlink signal sent by the first cell, estimating a dynamic frequency shift value of the terminal generated in a time interval of an SSB period, the dynamic frequency shift value being used to compensate for the Doppler frequency shift of the second downlink signal.

5. The method of claim 4, wherein, The estimation of the basic frequency shift value of the terminal relative to the wave position center based on the pre-compensated SSB comprises: detecting a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in the pre-compensated SSB; receiving a first reference signal in a physical broadcast channel (PBCH), a channel position of the PBCH being determined based on a time domain position of the PSS and a frequency domain position of the SSS; based on a phase difference between the received first reference signal and a local first reference signal, estimating the basic frequency shift value of the terminal relative to the wave position center.

6. The method of claim 4, wherein, The estimation of the dynamic frequency shift value of the terminal generated in the time interval of the SSB period based on the pre-compensated downlink signal sent by the first cell comprises: the downlink signal acquires a second reference signal based on the pre-compensated downlink signal sent by the first cell, and estimates the dynamic frequency shift value of the terminal relative to the wave position center based on a phase difference between the received second reference signal and a local second reference signal.

7. A Doppler shift compensation device, characterized by The device is applied to a satellite-based base station, and comprises: A first frequency shift compensation unit is configured to obtain ephemeris information of a satellite; Based on the ephemeris information and a first frequency shift value estimated by a wave position center, a pre-compensated SSB is obtained, and the pre-compensated SSB is sent to a terminal; A second frequency shift compensation unit is configured to compensate uplink and downlink signals in a wave position based on a second frequency shift value updated by interpolation, and send a pre-compensated downlink signal to the terminal.

8. The apparatus of claim 7, wherein, The first frequency shift compensation unit estimates the first frequency shift value of the wave position center in the following manner: Based on the ephemeris information, a ground projection point of the satellite, a satellite movement direction and an orbital height of the satellite are obtained; Based on the distance between the wave position center and the ground projection point and the satellite movement direction, a first included angle between the ground projection point and the satellite movement direction and between the ground projection point and the wave position center is obtained, and based on the distance between the wave position center and the ground projection point, a second included angle between the earth center and the current position of the satellite and between the earth center and the wave position center is obtained; Based on the ephemeris information, the first included angle and the second included angle, Doppler shift estimation is performed on the wave position center to obtain the first frequency shift value of the wave position center.

9. The apparatus of claim 7, wherein, The second frequency shift compensation unit obtains the second frequency shift value updated by interpolation in the following manner: Based on the Doppler shift deviation change rate and the time interval of the SSB period, the first frequency shift value of the wave position center is updated by interpolation to obtain the second frequency shift value generated by the wave position center in the time interval.

10. A Doppler shift compensation device, characterized by The device is applied to a terminal and includes: A basic frequency shift compensation unit is configured to receive a pre-compensated SSB sent by a first cell, and the first cell is a cell whose signal quality meets an evaluation standard; Based on the pre-compensated SSB, a basic frequency shift value of the terminal relative to a wave position center is estimated, and the basic frequency shift value is used to compensate the Doppler shift of a first downlink signal; A dynamic frequency shift compensation unit is configured to compensate the Doppler shift of a second downlink signal based on the first downlink signal compensated by the basic frequency shift compensation unit, and estimate a dynamic frequency shift value generated by the terminal in a time interval of an SSB period based on a pre-compensated downlink signal sent by the first cell, and the dynamic frequency shift value is used to compensate the Doppler shift of the second downlink signal.

11. The apparatus of claim 10, wherein, The basic frequency shift compensation unit is configured to: Detect a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in the pre-compensated SSB; Receive a first reference signal in a physical broadcast channel (PBCH), and the channel position of the PBCH is determined based on the time domain position of the PSS and the frequency domain position of the SSS; Estimate the basic frequency shift value of the terminal relative to the wave position center based on the phase difference between the received first reference signal and a local first reference signal.

12. The apparatus of claim 10, wherein, The dynamic frequency shift compensation unit is configured to: The downlink signal obtains a second reference signal based on the pre-compensated downlink signal sent by the first cell, and estimates the dynamic frequency shift value of the terminal relative to the wave position center based on the phase difference between the received second reference signal and a local second reference signal.

13. A computer device, comprising: It comprises a processor and a memory, wherein the memory stores program codes, which, when executed by the processor, cause the processor to perform the steps of the method of any one of claims 1-6.

14. A computer-readable storage medium, characterized in that, It comprises program codes, which, when the program product is run on a computer device, are used to cause the computer device to perform the steps of the method of any one of claims 1-6.

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