Frequency offset compensation method and system in high-speed wireless communication scene and related product

Abstract

The invention provides a frequency offset compensation method and system in a high-speed wireless communication scene and a related product, and relates to the technical field of wireless transmission, and the method comprises the steps: obtaining ephemeris information, GNSS information of a receiving end and an initial digital signal, firstly determining a time scaling factor caused by a radial speed and a relative motion between a transmitting end and the receiving end, and carrying out the calculation of the time scaling factor; a Doppler frequency offset component and a crystal oscillator offset component are separated in combination with total carrier frequency offset, and then frequency compensation and resampling compensation are executed respectively, so that the coupling influence caused by the Doppler effect, the time scaling effect and the crystal oscillator offset can be processed at the same time in a high-speed wireless communication scene, the accuracy of frequency offset estimation and compensation is improved, and the accuracy of frequency offset estimation and compensation is improved. Constellation rotation, sampling dislocation and demodulation errors are reduced, and the synchronization performance and demodulation performance of received signals are improved; moreover, the scheme does not need to depend on a transmitting end or a base station to participate in joint calibration, and compensation processing is independently completed only by a receiving end, thereby facilitating reduction of system interaction overhead and implementation complexity.

Description

Technical Field

[0001] This application relates to the field of wireless transmission technology, and in particular to a frequency offset compensation method, system and related products for high-speed wireless communication scenarios. Background Technology

[0002] In high-speed wireless communication scenarios such as satellite communication and airborne communication, the receiving end is usually affected by a variety of synchronization errors due to the high relative speed between the two communicating parties.

[0003] Specifically, high-speed motion can induce the Doppler effect, causing frequency shifts in the received signal and leading to carrier mismatch. This can result in constellation point rotation and degraded demodulation performance. Furthermore, under high-speed motion conditions, signal propagation may also exhibit time-scale compression or stretching, causing the actual sampling position at the receiver to deviate from the ideal sampling position. This introduces sampling clock skew, affecting symbol synchronization and data recovery. In addition, the receiver's local oscillator is typically provided by a crystal oscillator, whose output frequency is affected by factors such as temperature variations, device aging, and device precision. Consequently, it may deviate from the ideal frequency, further introducing additional frequency errors.

[0004] Traditional techniques typically compensate for only a single frequency offset, failing to adequately consider the coupled effects of Doppler frequency offset, sampling deviations caused by time scaling, and crystal oscillator deviations in high-speed mobile scenarios, making accurate separation and effective compensation difficult. Furthermore, some solutions rely on interactive calibration between the terminal and the base station, resulting in significant system complexity and communication overhead.

[0005] Therefore, how to separate, estimate, and compensate for the aforementioned multiple errors on the user terminal side without the participation of the base station has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this application is to provide a frequency offset compensation method, system and related products for high-speed wireless communication scenarios, so as to overcome the shortcomings of traditional technology in separating and compensating for the coupling effects of Doppler frequency offset, time scaling effect and crystal oscillator deviation, and the complex calibration process and large system overhead.

[0007] In a first aspect, this application proposes a frequency offset compensation method for high-speed wireless communication scenarios, applicable to a receiver, wherein the receiver receives an initial digital signal from a transmitter; the method includes:

[0008] Acquire ephemeris information and GNSS information from the receiver; The radial velocity between the transmitter and the receiver is determined based on the ephemeris information and the GNSS information. The time scaling factor caused by the relative motion between the transmitter and receiver is determined based on the radial velocity; The total carrier frequency offset is determined based on the reference signal in the initial digital signal; Based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset, the Doppler frequency offset component and the crystal oscillator deviation component are separated. The baseband signal is frequency compensated based on the Doppler frequency offset component, and the initial digital signal is resampled and compensated based on the crystal oscillator deviation component and the time scaling factor to obtain the target digital signal; the baseband signal is the baseband representation of the initial digital signal.

[0009] In one embodiment, determining the radial velocity between the transmitter and the receiver based on the ephemeris information and the GNSS information includes: Based on the ephemeris information, determine the first position and first velocity information of the transmitter at the target time; The second position information and second velocity information of the receiving end at the target time are determined based on the GNSS information; The direction of the connection between the transmitter and receiver is determined based on the first location information and the second location information. Calculate the vector difference between the first velocity information and the second velocity information to obtain the relative velocity information of the transmitter relative to the receiver; The projection of the relative velocity information onto the direction of the line is determined as the radial velocity.

[0010] In one embodiment, determining the time scaling factor caused by the relative motion between the transmitter and the receiver based on the radial velocity includes: The time scaling factor is obtained by calculating the ratio of the radial velocity to the speed of light.

[0011] In one embodiment, determining the total carrier frequency offset based on a reference signal in the initial digital signal includes: Extract reference signal segments from the reference signal at two different times, calculate the phase difference between the two reference signal segments, and calculate the total carrier frequency offset based on the phase difference and the corresponding time interval. The expression is as follows:

[0012] in, and These represent reference signal segments at two different times. It represents the time interval between two different moments.

[0013] In one embodiment, the step of separating the Doppler frequency offset component and the crystal oscillator deviation component based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset includes: The Doppler frequency offset component is determined based on the radial velocity and the target carrier frequency, and its expression is as follows:

[0014] in, Indicates radial velocity; Represents the speed of light; Indicates the target carrier frequency; Based on the total carrier frequency offset, the Doppler frequency offset component, and the target carrier frequency, the crystal oscillator deviation component is determined, and its expression is as follows:

[0015] in, This indicates the total carrier frequency offset.

[0016] In one embodiment, the step of frequency compensation of the baseband signal based on the Doppler frequency offset component includes: A digitally controlled oscillator is used to generate a corresponding frequency compensation signal based on the Doppler frequency offset component; The baseband signal is rotated in reverse phase based on the frequency compensation signal to compensate for the frequency shift caused by the Doppler effect.

[0017] In one embodiment, the resampling compensation of the initial digital signal based on the crystal oscillator deviation component and the time scaling factor includes: By combining the crystal oscillator deviation component and the time scaling factor, the resampling compensation parameters are obtained; A fractional resampling filter is configured according to the resampling compensation parameters to resample and compensate the initial digital signal. In one embodiment, Secondly, this application proposes a frequency offset compensation system for high-speed wireless communication scenarios, which is installed at the receiving end. The system includes: The acquisition module is used to acquire ephemeris information and GNSS information from the receiver. The calculation module is configured to determine the radial velocity between the transmitter and the receiver based on the ephemeris information and the GNSS information; determine the time scaling factor caused by the relative motion between the transmitter and the receiver based on the radial velocity; and determine the total carrier frequency offset based on the reference signal in the initial digital signal. The separation module is used to separate the Doppler frequency offset component and the crystal oscillator deviation component based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset. The compensation module is used to perform frequency compensation on the baseband signal based on the Doppler frequency offset component, and to perform resampling compensation on the initial digital signal based on the crystal oscillator deviation component and the time scaling factor, to obtain the target digital signal; the baseband signal is the baseband representation of the initial digital signal.

[0018] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method steps in the first aspect.

[0019] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the method steps of the first aspect.

[0020] The frequency offset compensation methods, systems, and related products for the above-mentioned high-speed wireless communication scenarios have at least the following advantages: This application acquires ephemeris information, GNSS information from the receiver, and initial digital signals. It first determines the radial velocity and time scaling factor caused by relative motion between the transmitter and receiver. Then, it separates the Doppler frequency offset component and crystal oscillator deviation component based on the total carrier frequency offset. Subsequently, it performs frequency compensation and resampling compensation separately. This enables the simultaneous handling of the coupling effects of Doppler effect, time scaling effect, and crystal oscillator deviation in high-speed wireless communication scenarios, improving the accuracy of frequency offset estimation and compensation, reducing constellation rotation, sampling misalignment, and demodulation errors, and enhancing the synchronization and demodulation performance of the received signal. Furthermore, this scheme does not require joint calibration by the transmitter or base station; the compensation process is completed autonomously by the receiver, which helps reduce system interaction overhead and implementation complexity. Attached Figure Description

[0021] Figure 1 This is an application environment diagram of a frequency offset compensation method in a high-speed wireless communication scenario in one embodiment. Figure 2 This is a flowchart illustrating a frequency offset compensation method in a high-speed wireless communication scenario in one embodiment. Figure 3 This is a flowchart illustrating the step of determining the radial velocity in one embodiment; Figure 4 This is a block diagram of a frequency offset compensation system in a high-speed wireless communication scenario in one embodiment. Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0022] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0023] Some exemplary embodiments of this application have been described for illustrative purposes. It should be understood that this application may be implemented in other ways not specifically shown in the accompanying drawings.

[0024] The frequency offset compensation method for high-speed wireless communication scenarios provided in this application embodiment can be applied to, for example... Figure 1 The application environment shown depicts a high-speed wireless communication environment between the transmitter and receiver. The transmitter can be a high-speed moving platform, such as a satellite, airplane, or other high-speed aircraft; the receiver can be a modern communication user terminal (UE), such as a vehicle-mounted terminal, handheld terminal, airborne terminal, or other terminal equipment with wireless receiving capabilities.

[0025] The aforementioned high-speed wireless communication typically has the following three types of problems, which are coupled together at the receiving end, leading to frequency offset issues.

[0026] like Figure 1 As shown, the transmitting end has a velocity v relative to the receiving end, and the angle between its direction of movement and the line connecting the transmitting end and the receiving end is θ. If the carrier frequency of the wireless transmission signal is Therefore, the frequency shift caused by the Doppler effect is:

[0027] The problem this causes is that the Doppler frequency offset effect can cause the constellation points of the signal to rotate, leading to demodulation errors.

[0028] Furthermore, in low-speed terrestrial communication, Doppler is generally considered to be simply a frequency shift, and its expression is: However, in high-speed motion scenarios, the Doppler effect on time scaling cannot be ignored.

[0029] Assuming the sender is at Send signals at all times The time it takes for the signal to reach the receiver is The relationship between the two is as follows:

[0030] in The physical distance between the satellite and the terminal when the signal is transmitted; It is the speed of light.

[0031] Assuming the satellite travels at a radial velocity Approaching the receiver, the initial distance is Then the distance changes with time as follows:

[0032] Substituting the distance formula into the time formula:

[0033] Therefore, we can obtain:

[0034]

[0035] Due to the received signal In essence, it's sending a signal. Therefore, the following condition is met:

[0036] Let the scaling factor It can be obtained from the Taylor series expansion. .

[0037] This leads to the following problem: when the satellite is close, if α > 0, a sine wave of length T will appear to have a different length at the receiver. If the sampling pulse interval at the receiving end does not change accordingly, sampling misalignment will occur, resulting in sampling clock offset (SCO).

[0038] Furthermore, in wireless communication, the UE, as the receiving end, needs to use the same carrier frequency as the transmitting end. The frequency offset is shifted to 0 IF before demodulation. The carrier frequency is generated by the crystal oscillation in the UE receiver. However, due to temperature changes, crystal aging, and other reasons, the carrier frequency generated by the crystal oscillator may not be consistent with the desired ideal carrier frequency, which will lead to an additional frequency offset introduced on the receiving side.

[0039] The problem this causes is that frequency offset can cause the constellation points of the signal to rotate, leading to demodulation errors.

[0040] Based on this, this application provides a frequency offset compensation method for high-speed wireless communication scenarios. By establishing a correlation model between carrier frequency offset and sampling rate offset at the physical layer of the receiver, the frequency offset components caused by the Doppler effect and those caused by hardware crystal oscillator deviation are separated using a reference signal. Combined with the sampling rate offset caused by the time scaling effect, time-frequency domain joint compensation is performed, thereby achieving comprehensive compensation for Doppler frequency offset, sampling clock deviation caused by time scaling, and frequency offset caused by crystal oscillator deviation in high-speed wireless communication scenarios.

[0041] Please see Figure 2 In one exemplary embodiment, this application provides a frequency offset compensation method for high-speed wireless communication scenarios, applicable to a receiver that receives an initial digital signal from a transmitter; specifically including the following steps: Step 202: Obtain ephemeris information and GNSS information from the receiver.

[0042] Specifically, ephemeris information is used to characterize the position, velocity, trajectory, and orbital parameters of a transmitter within a predetermined time range. When the transmitter is a satellite, the ephemeris information can be broadcast ephemeris, precise ephemeris, or orbital parameters pre-stored based on an orbital model, used to determine the satellite's spatial position and motion state at the target time. When the transmitter is an aircraft or other high-speed moving platform, the ephemeris information can also characterize the transmitter's flight trajectory, position changes, and velocity changes. The receiving end can obtain the aforementioned ephemeris information through pre-stored ephemeris, network downloads, broadcast message reception, or navigation aid information.

[0043] GNSS information is state-related information obtained by a receiver through a global navigation satellite system, used to characterize the receiver's position and motion at a target time. Typically, GNSS information includes at least one of the receiver's latitude, longitude, altitude, velocity, heading, and time information. Specifically, the receiver can receive navigation satellite signals through a GNSS receiving module, analyze them to obtain its own position coordinates, velocity vector, and current time information, thus providing basic data for subsequently determining the relative geometric and motion relationships between the transmitter and receiver.

[0044] In this embodiment, the receiving end also receives an initial digital signal from the transmitting end. The initial digital signal refers to the digital signal obtained by the receiving end after performing radio frequency reception, down-conversion, and analog-to-digital conversion on the wireless signal sent by the transmitting end. The initial digital signal includes a synchronization signal, a reference signal, and a service data signal. The reference signal may be a downlink synchronization signal block (SSB), a demodulation reference signal (DMRS), or other known structure signals used for frequency offset estimation.

[0045] Step 204: Determine the radial velocity between the transmitter and receiver based on the ephemeris information and GNSS information; determine the time scaling factor caused by the relative motion between the transmitter and receiver based on the radial velocity; determine the total carrier frequency offset based on the reference signal in the initial digital signal.

[0046] Specifically, radial velocity characterizes the degree of proximity or distance between the transmitter and receiver along the line-of-sight direction. Based on ephemeris and GNSS information, the position and velocity information of the transmitter and receiver can be determined, and thus the radial velocity between them can be determined. Radial velocity can be positive or negative, with a positive sign indicating that the transmitter and receiver are moving away from each other, and vice versa for moving closer.

[0047] The time scaling factor is a parameter used to characterize the degree of compression or stretching of the received signal on the time axis, caused by the relative motion between the transmitter and receiver. Since wireless signals require a certain propagation delay from transmitter to receiver, and in high-speed wireless communication scenarios, the distance between the transmitter and receiver dynamically changes over time, the time scale of the signal observed at the receiver will change relative to the original time scale at the transmitter. The time scaling factor is related to radial velocity; the greater the radial velocity, the more pronounced the time scaling effect. Furthermore, when the transmitter is closer to the receiver, the received signal appears compressed on the time axis; when the transmitter is farther away from the receiver, the received signal appears stretched on the time axis. Therefore, the time scaling factor can be used to reflect the degree of sampling timing offset caused by high-speed relative motion and provide a parameter basis for subsequent resampling compensation.

[0048] Total carrier frequency offset refers to the total actual frequency deviation currently observed at the receiver, used to characterize the overall degree of deviation of the received signal relative to the preset target carrier frequency. Since the reference signal is a known or reconfigurable signal at the receiver, the total carrier frequency offset can be determined by analyzing the measurable phase rotation or frequency shift produced by this known signal at the receiver.

[0049] Furthermore, radial velocity reflects the relative motion between the transmitter and receiver along the line-of-sight direction, and is a fundamental physical quantity for generating the Doppler effect and time scaling effect. The time scaling factor is further determined by radial velocity and is used to characterize the impact of relative motion on the signal time scale. The total carrier frequency offset reflects the overall frequency deviation observed at the receiver, which includes both the Doppler frequency offset component caused by radial velocity and the frequency offset component caused by the local crystal oscillator deviation at the receiver. Therefore, radial velocity provides the basis for subsequent determination of the Doppler frequency offset component, the time scaling factor provides the basis for subsequent resampling compensation, and the total carrier frequency offset provides the observational basis for subsequent separation of the Doppler frequency offset component and the crystal oscillator deviation component.

[0050] Step 206: Based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset, the Doppler frequency offset component and the crystal oscillator deviation component are separated.

[0051] Specifically, the preset target carrier frequency refers to the ideal carrier frequency corresponding to the communication system protocol, network configuration, or terminal preset, that is, the target local oscillator frequency that the receiver should use when there is no crystal oscillator deviation.

[0052] In high-speed wireless communication scenarios, the total carrier frequency offset observed by the receiver is not formed from a single source, but includes at least the Doppler frequency offset caused by the relative motion between the transmitter and receiver, and the additional frequency offset caused by the local crystal oscillator deviation at the receiver. Therefore, this application separates the Doppler frequency offset component and the crystal oscillator deviation component based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset.

[0053] The Doppler frequency offset component refers to the frequency deviation caused by the relative motion between the transmitter and receiver along the line-of-sight direction. It can be calculated based on the radial velocity and the target carrier frequency. Since the Doppler frequency offset component corresponds to the frequency offset caused solely by motion under ideal carrier frequency conditions, it can serve as a fundamental quantity for separating the effects of motion from the total carrier frequency offset.

[0054] The crystal oscillator deviation component is used to characterize the degree of deviation between the actual local carrier frequency at the receiver and the target carrier frequency. In the embodiments of this application, the crystal oscillator deviation component is preferably a dimensionless deviation parameter, used to reflect the relative deviation between the local crystal oscillator output frequency at the receiver and the ideal frequency. Since the total carrier frequency offset includes not only the Doppler frequency offset component but also the crystal oscillator deviation and its coupling effect, the crystal oscillator deviation component can be further obtained after deducting the Doppler frequency offset effect determined by the radial velocity and the target carrier frequency.

[0055] Step 208: Perform frequency compensation on the baseband signal based on the Doppler frequency offset component, and perform resampling compensation on the initial digital signal based on the crystal oscillator deviation component and the time scaling factor to obtain the target digital signal; the baseband signal is the baseband representation of the initial digital signal.

[0056] Specifically, after obtaining the Doppler frequency offset component, crystal oscillator offset component, and time scaling factor, the receiver performs joint compensation processing on the received signal. On the one hand, frequency compensation is performed on the baseband signal based on the Doppler frequency offset component to reduce the frequency offset effect caused by relative motion; on the other hand, resampling compensation is performed on the initial digital signal based on the crystal oscillator offset component and time scaling factor to correct the sampling deviation caused by crystal oscillator offset and time scaling effect. After frequency compensation and resampling compensation, the target digital signal is obtained for subsequent synchronization processing, channel estimation, demodulation, or data recovery.

[0057] The baseband signal is the representation of the initial digital signal in the baseband domain. In other words, both frequency compensation and resampling compensation can be applied to the corresponding signals in the receiver's digital processing link, thereby achieving comprehensive correction of various error effects in high-speed wireless communication scenarios, improving the quality of the target digital signal and the accuracy of subsequent processing.

[0058] The frequency offset compensation method described above for high-speed wireless communication scenarios acquires ephemeris information, GNSS information from the receiver, and initial digital signals. It first determines the radial velocity and time scaling factor caused by relative motion between the transmitter and receiver. Then, it separates the Doppler frequency offset component and the crystal oscillator deviation component based on the total carrier frequency offset, and performs frequency compensation and resampling compensation separately. This allows for the simultaneous handling of the coupling effects of Doppler effect, time scaling effect, and crystal oscillator deviation in high-speed wireless communication scenarios, improving the accuracy of frequency offset estimation and compensation, reducing constellation rotation, sampling misalignment, and demodulation errors, and enhancing the synchronization and demodulation performance of the received signal. Furthermore, this scheme does not require joint calibration by the transmitter or base station; the compensation process is completed autonomously by the receiver, which helps reduce system interaction overhead and implementation complexity.

[0059] Please see Figure 3 Optionally, the radial velocity between the transmitter and receiver is determined based on ephemeris information and GNSS information, including: Step 302: Determine the first position and first velocity information of the transmitter at the target time based on the ephemeris information.

[0060] Step 304: Determine the second position information and second velocity information of the receiver at the target time based on the GNSS information.

[0061] Step 306: Determine the connection direction between the transmitter and receiver based on the first position information and the second position information.

[0062] Step 308: Calculate the vector difference between the first velocity information and the second velocity information to obtain the relative velocity information between the transmitter and the receiver; determine the projection of the relative velocity information onto the connecting line as the radial velocity.

[0063] Specifically, ephemeris information is used to characterize the position changes and motion state of the transmitter within a predetermined time range. By parsing the ephemeris information, first position information and first velocity information are obtained. The first position information is used to characterize the spatial position of the transmitter at the target time, and the first velocity information is used to characterize the velocity and direction of motion of the transmitter at the target time.

[0064] The second position information and the second velocity information are obtained by parsing its own GNSS information. The second position information is used to characterize the spatial position of the receiver at the target time, and the second velocity information is used to characterize the speed and direction of motion of the receiver at the target time.

[0065] Based on the first and second position information, the spatial relative position relationship between the transmitter and receiver at the target time is determined, and the direction of the line connecting the two is determined accordingly. Then, the relative velocity information is projected along the direction of the line to obtain the radial velocity of the transmitter relative to the receiver.

[0066] Optionally, the time scaling factor caused by the relative motion between the transmitter and receiver is determined based on the radial velocity, including: calculating the ratio of the radial velocity to the speed of light to obtain the time scaling factor.

[0067] Specifically, let the transmitting end have a velocity v relative to the receiving end, and let the angle between the direction of its movement and the line connecting the receiving end be denoted as . Then the radial velocity satisfies The time scaling factor satisfies ; It is the speed of light.

[0068] Optionally, the total carrier frequency offset is determined based on a reference signal in the initial digital signal, including: Extract reference signal segments from the reference signal at two different times, calculate the phase difference between the two reference signal segments, and calculate the total carrier frequency offset based on the phase difference and the corresponding time interval. The expression is as follows:

[0069] in, and These represent reference signal segments at two different times. It represents the time interval between two different moments.

[0070] Optionally, based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset, the Doppler frequency offset component and the crystal oscillator deviation component are separated, including: The Doppler frequency offset component is determined based on the radial velocity and the target carrier frequency, and its expression is as follows:

[0071] in, Indicates radial velocity; Represents the speed of light; Indicates the target carrier frequency; Based on the total carrier frequency offset, Doppler frequency offset components, and the target carrier frequency, the crystal oscillator deviation components are determined, and their expression is as follows:

[0072] in, This indicates the total carrier frequency offset.

[0073] Specifically, in high-speed wireless communication scenarios, the total carrier frequency offset observed by the receiver is usually composed of two parts: one part is the Doppler frequency offset caused by the relative motion between the transmitter and receiver. The other part is the frequency deviation caused by the local crystal oscillator deviation at the receiving end. To separate the two, the embodiments of this application first introduce the actual carrier frequency generated when there is a deviation in the local crystal oscillator at the receiving end. Let the crystal oscillator deviation component be . The actual carrier frequency With the target carrier frequency The following conditions must be met: Based on this, the expression for the total carrier frequency offset observed at the receiver is: .

[0074] Because the Doppler effect actually affects the actual carrier frequency when there is crystal oscillator deviation at the receiving end. Therefore, we have: ,Will Substituting into the above equation, we get: This leads to the expression;

[0075] Optionally, frequency compensation of the baseband signal is performed based on the Doppler frequency offset component, including: A digitally controlled oscillator is used to generate a corresponding frequency compensation signal based on the Doppler frequency offset component; The baseband signal is reverse-phase rotated based on the frequency compensation signal to compensate for the frequency shift caused by the Doppler effect.

[0076] Specifically, a digitally controlled oscillator is used to generate a frequency compensation signal corresponding to the aforementioned Doppler frequency offset component. This frequency compensation signal characterizes the compensation amount opposite to the direction of the Doppler frequency offset. By performing a reverse phase rotation on the baseband signal, the phase accumulation change introduced by the Doppler effect in the baseband signal can be canceled. For example, the digitally controlled oscillator can be combined with the CORDIC algorithm to support the reverse rotation compensation process.

[0077] Optionally, the initial digital signal is resampled and compensated based on the crystal oscillator deviation component and the time scaling factor, including: By combining the crystal oscillator deviation component and the time scaling factor, the resampling compensation parameters are obtained; Configure a fractional resampling filter based on the resampling compensation parameters to resample and compensate the initial digital signal.

[0078] Specifically, the resampling compensation parameters are obtained by combining the crystal oscillator deviation component and the time scaling factor, and their expression is as follows: This resampling compensation parameter comprehensively reflects the degree of sampling timing offset caused by both crystal oscillator deviation and time scaling effect, and can be used as the basis for configuring subsequent resampling compensation.

[0079] Furthermore, the fractional resampling filter is configured according to the resampling compensation parameters, and the initial digital signal is resampled and compensated using the fractional resampling filter to adjust the sampling point distribution of the initial digital signal, so that the sampling position of the compensated digital signal on the time axis is closer to the ideal sampling position. For example, the fractional resampling filter in this embodiment is a Farrow filter.

[0080] By employing the combined compensation method of frequency compensation and resampling compensation, on the one hand, frequency compensation of the baseband signal based on the Doppler frequency offset component can reduce frequency shift and constellation rotation caused by relative motion; on the other hand, resampling compensation of the initial digital signal based on the crystal oscillator deviation component and time scaling factor can correct sampling timing deviations caused by both crystal oscillator deviation and time scaling effects. Therefore, this application can not only coordinately correct frequency domain errors and time domain errors in high-speed wireless communication scenarios, but also avoid the problem of insufficient compensation caused by treating multiple coupling errors as a single frequency offset, thereby improving the recovery quality of the target digital signal, enhancing synchronization accuracy, demodulation accuracy, and communication link stability.

[0081] The frequency offset compensation method described above for high-speed wireless communication scenarios acquires ephemeris information, GNSS information from the receiver, and initial digital signals. It first determines the radial velocity and time scaling factor caused by relative motion between the transmitter and receiver. Then, it separates the Doppler frequency offset component and the crystal oscillator deviation component based on the total carrier frequency offset, and performs frequency compensation and resampling compensation separately. This allows for the simultaneous handling of the coupling effects of Doppler effect, time scaling effect, and crystal oscillator deviation in high-speed wireless communication scenarios, improving the accuracy of frequency offset estimation and compensation, reducing constellation rotation, sampling misalignment, and demodulation errors, and enhancing the synchronization and demodulation performance of the received signal. Furthermore, this scheme does not require joint calibration by the transmitter or base station; the compensation process is completed autonomously by the receiver, which helps reduce system interaction overhead and implementation complexity.

[0082] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0083] Based on the same inventive concept, this application also provides a frequency offset compensation system for high-speed wireless communication scenarios. This system is applicable to the frequency offset compensation method for the above-mentioned high-speed wireless communication scenarios. The solution provided by this system is similar to the solution described in the above-mentioned method. Therefore, the specific limitations of one or more system embodiments provided below can be found in the limitations of the method above, and will not be repeated here.

[0084] Please see Figure 4 In one embodiment, the frequency offset compensation system for high-speed wireless communication scenarios includes: an acquisition module, a calculation module, a separation module, and a compensation module.

[0085] The acquisition module is used to acquire ephemeris information and GNSS information from the receiver.

[0086] The calculation module is used to determine the radial velocity between the transmitter and receiver based on ephemeris information and GNSS information; determine the time scaling factor caused by the relative motion between the transmitter and receiver based on the radial velocity; and determine the total carrier frequency offset based on the reference signal in the initial digital signal.

[0087] The separation module is used to separate the Doppler frequency offset component and the crystal oscillator deviation component based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset.

[0088] The compensation module is used to perform frequency compensation on the baseband signal based on the Doppler frequency offset component, and to perform resampling compensation on the initial digital signal based on the crystal oscillator deviation component and the time scaling factor, so as to obtain the target digital signal; the baseband signal is the baseband representation of the initial digital signal.

[0089] Optionally, the calculation module determines the radial velocity between the transmitter and receiver based on ephemeris information and GNSS information, including: determining the first position information and first velocity information of the transmitter at the target time based on ephemeris information; determining the second position information and second velocity information of the receiver at the target time based on GNSS information; determining the direction of the line connecting the transmitter and receiver based on the first position information and the second position information; calculating the vector difference between the first velocity information and the second velocity information to obtain the relative velocity information of the transmitter relative to the receiver; and determining the projection of the relative velocity information onto the direction of the line as the radial velocity.

[0090] Optionally, the calculation module determines the time scaling factor caused by the relative motion between the transmitter and receiver based on the radial velocity, including: calculating the ratio of the radial velocity to the speed of light to obtain the time scaling factor.

[0091] Optionally, the calculation module determines the total carrier frequency offset based on the reference signal in the initial digital signal, including: extracting reference signal segments at two different times from the reference signal, calculating the phase difference between the two reference signal segments, and calculating the total carrier frequency offset based on the phase difference and the corresponding time interval, the expression of which is:

[0092] in, and These represent reference signal segments at two different times. It represents the time interval between two different moments.

[0093] Optionally, the calculation module separates the Doppler frequency offset component and the crystal oscillator deviation component based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset. This includes determining the Doppler frequency offset component based on the radial velocity and the target carrier frequency, with the following expression:

[0094] in, Indicates radial velocity; Represents the speed of light; Indicates the target carrier frequency; Based on the total carrier frequency offset, Doppler frequency offset components, and the target carrier frequency, the crystal oscillator deviation components are determined, and their expression is as follows:

[0095] in, This indicates the total carrier frequency offset.

[0096] Optionally, the compensation module performs frequency compensation on the baseband signal based on the Doppler frequency offset component, including: using a digitally controlled oscillator to generate a corresponding frequency compensation signal based on the Doppler frequency offset component; and performing a reverse phase rotation on the baseband signal based on the frequency compensation signal to compensate for the frequency offset caused by the Doppler effect.

[0097] Optionally, the compensation module performs resampling compensation on the initial digital signal based on the crystal oscillator deviation component and the time scaling factor, including: combining the crystal oscillator deviation component and the time scaling factor to obtain resampling compensation parameters; and configuring a fractional resampling filter based on the resampling compensation parameters to perform resampling compensation on the initial digital signal.

[0098] The frequency offset compensation system in the aforementioned high-speed wireless communication scenario acquires ephemeris information, GNSS information from the receiver, and initial digital signals. It first determines the radial velocity and time scaling factor caused by relative motion between the transmitter and receiver. Then, it separates the Doppler frequency offset component and the crystal oscillator deviation component based on the total carrier frequency offset, and performs frequency compensation and resampling compensation respectively. This allows for the simultaneous handling of the coupling effects of Doppler effect, time scaling effect, and crystal oscillator deviation in high-speed wireless communication scenarios, improving the accuracy of frequency offset estimation and compensation, reducing constellation rotation, sampling misalignment, and demodulation errors, and enhancing the synchronization and demodulation performance of the received signal. Furthermore, this scheme does not require joint calibration by the transmitter or base station; the compensation process is completed autonomously by the receiver, which helps reduce system interaction overhead and implementation complexity.

[0099] The modules in the frequency offset compensation system for the aforementioned high-speed wireless communication scenarios can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0100] In one feasible embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements the frequency offset compensation method in the aforementioned high-speed wireless communication scenario. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0101] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0102] In one feasible embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the method steps in the frequency offset compensation method for the high-speed wireless communication scenario described above.

[0103] In one feasible embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the method steps in the frequency offset compensation method for the high-speed wireless communication scenario described above.

[0104] In one feasible embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the method steps in the frequency offset compensation method for the high-speed wireless communication scenario described above.

[0105] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0106] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0107] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A frequency offset compensation method for high-speed wireless communication scenarios, characterized in that, Applicable to a receiving end, the receiving end receives an initial digital signal from a transmitting end; the method includes: Acquire ephemeris information and GNSS information from the receiver; The radial velocity between the transmitter and the receiver is determined based on the ephemeris information and the GNSS information. The time scaling factor caused by the relative motion between the transmitter and receiver is determined based on the radial velocity; The total carrier frequency offset is determined based on the reference signal in the initial digital signal; Based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset, the Doppler frequency offset component and the crystal oscillator deviation component are separated. The baseband signal is frequency compensated based on the Doppler frequency offset component, and the initial digital signal is resampled and compensated based on the crystal oscillator deviation component and the time scaling factor to obtain the target digital signal; the baseband signal is the baseband representation of the initial digital signal.

2. The method according to claim 1, characterized in that, Determining the radial velocity between the transmitter and the receiver based on the ephemeris information and the GNSS information includes: Based on the ephemeris information, determine the first position and first velocity information of the transmitter at the target time; The second position information and second velocity information of the receiving end at the target time are determined based on the GNSS information; The direction of the connection between the transmitter and receiver is determined based on the first location information and the second location information. Calculate the vector difference between the first velocity information and the second velocity information to obtain the relative velocity information of the transmitter relative to the receiver; The projection of the relative velocity information onto the direction of the line is determined as the radial velocity.

3. The method according to claim 1, characterized in that, Determining the time scaling factor caused by the relative motion between the transmitter and the receiver based on the radial velocity includes: The time scaling factor is obtained by calculating the ratio of the radial velocity to the speed of light.

4. The method according to claim 1, characterized in that, Determining the total carrier frequency offset based on the reference signal in the initial digital signal includes: Extract reference signal segments from the reference signal at two different times, calculate the phase difference between the two reference signal segments, and calculate the total carrier frequency offset based on the phase difference and the corresponding time interval. The expression is as follows: in, and These represent reference signal segments at two different times. It represents the time interval between two different moments.

5. The method according to claim 4, characterized in that, The step of separating the Doppler frequency offset component and the crystal oscillator deviation component based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset includes: The Doppler frequency offset component is determined based on the radial velocity and the target carrier frequency, and its expression is as follows: in, Indicates radial velocity; Represents the speed of light; Indicates the target carrier frequency; Based on the total carrier frequency offset, the Doppler frequency offset component, and the target carrier frequency, the crystal oscillator deviation component is determined, and its expression is as follows: in, This indicates the total carrier frequency offset.

6. The method according to claim 1, characterized in that, The step of frequency compensation of the baseband signal based on the Doppler frequency offset component includes: A digitally controlled oscillator is used to generate a corresponding frequency compensation signal based on the Doppler frequency offset component; The baseband signal is rotated in reverse phase based on the frequency compensation signal to compensate for the frequency shift caused by the Doppler effect.

7. The method according to claim 1, characterized in that, The resampling compensation of the initial digital signal based on the crystal oscillator deviation component and the time scaling factor includes: By combining the crystal oscillator deviation component and the time scaling factor, the resampling compensation parameters are obtained; Configure a fractional resampling filter according to the resampling compensation parameters to resample and compensate the initial digital signal.

8. A frequency offset compensation system for high-speed wireless communication scenarios, characterized in that, The system, located at the receiving end, includes: The acquisition module is used to acquire ephemeris information and GNSS information from the receiver. The calculation module is configured to determine the radial velocity between the transmitter and the receiver based on the ephemeris information and the GNSS information; determine the time scaling factor caused by the relative motion between the transmitter and the receiver based on the radial velocity; and determine the total carrier frequency offset based on the reference signal in the initial digital signal. The separation module is used to separate the Doppler frequency offset component and the crystal oscillator deviation component based on the radial velocity, the preset target carrier frequency, and the total carrier frequency offset. The compensation module is used to perform frequency compensation on the baseband signal based on the Doppler frequency offset component, and to perform resampling compensation on the initial digital signal based on the crystal oscillator deviation component and the time scaling factor, to obtain the target digital signal; the baseband signal is the baseband representation of the initial digital signal.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1-7.

10. A computer-readable 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 1-7.

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