Broadband satellite terminal Doppler compensation method and device

Abstract

The invention relates to a broadband satellite terminal Doppler compensation method and device, and the method comprises the steps: calculating each search point according to the preset Doppler boundary range and frequency search interval of a receiver terminal, and carrying out the compensation of a received time domain signal through employing each search point; performing correlation operation on the time domain signal of the local pilot frequency and each compensated time domain signal of the corresponding pilot frequency to obtain a plurality of correlation values; taking the search point corresponding to the correlation value with the maximum amplitude in the plurality of obtained correlation values as a Doppler frequency shift value of the receiver terminal, and compensating the received time domain signal by adopting the Doppler frequency shift value of the receiver terminal; and based on the Doppler frequency shift value of the receiver terminal, carrying out fine Doppler frequency shift estimation and compensation on the received time-domain signal after compensating the received time-domain signal. The performance of the terminal receiver can be improved.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and particularly to a method and device for Doppler compensation of a broadband satellite terminal. Background Art

[0002] The LEO satellite system consists of network elements such as low-earth orbit satellites and gateway stations. Each gateway station can be connected to multiple satellites, while each satellite can only be connected to one gateway station at the same time. Figure 1 As shown in the schematic diagram of a transparent transponder mode satellite communication system, the radio link between the gateway station and the satellite is called the feeder link, and the radio link between the user equipment and the satellite is called the service link.

[0003] Generally, the satellite altitude is about 600 - more than 1000 kilometers. The launch is divided into multiple beams. In a typical scenario, the time for a ground fixed point to be covered by one beam is about 8 - 10 seconds, and the time for being covered by one satellite is 2 - 3 minutes. Due to the satellite altitude, compared with the ground air interface transmission technology, the satellite channel has a longer signal transmission delay and a greater signal attenuation. The particularly serious impact is the Doppler frequency shift caused by the high-speed movement of the satellite, which makes the frequency of the signal received by the terminal deviate from the frequency of the transmitted signal.

[0004] The Doppler frequency shift in the satellite channel will bring common phase rotation and interference to the OFDM system in the frequency domain. For the terminal OFDM receiver, the relative frequency offset caused by the Doppler frequency offset is ε f , for the target sub-carrier in the frequency domain of the receiver, the amplitude of the receiver target sub-carrier signal will attenuate, and the phase also increases by a rotation factor. The phase of the rotation factor linearly increases with the increase of OFDM symbols. On the basis of noise, inter-carrier interference is also increased, and this interference power is proportional to the sub-carrier spacing and the magnitude of the frequency offset. It can be seen that the Doppler frequency offset caused by the high-speed movement of the satellite causes the leakage energy of each sub-carrier to interfere with adjacent sub-carriers, thus having an adverse impact on channel estimation and equalization.

[0005] In the low-earth orbit satellite system, in order to overcome the damage caused by the Doppler frequency shift to the communication performance, it is necessary to estimate the Doppler frequency shift and perform compensation. However, the low-earth orbit satellite system usually consists of satellites with different carrier frequencies and different orbital altitudes, and the resulting Doppler variation range is very large, as shown in Table 1.

[0006] Table 1

[0007]

[0008]

[0009] As can be seen from Table 1, under the influence of various factors, the range difference of Doppler frequency shift varies from dozens to hundreds of kHz, which requires that the Doppler estimation ability of the communication system should be able to meet the requirements of large estimation range and high estimation accuracy.

[0010] In the prior art, the processing of Doppler frequency offset of satellite terminals is mostly limited to compensating the terminals using the estimated ephemeris value. However, the value estimated by the ephemeris is the average Doppler frequency offset of all terminals within the satellite coverage area. For different terminals within this satellite coverage area, their relative motion directions with respect to the satellite are different, resulting in Doppler frequency shifts with different signs. If the average value of all terminals estimated by the ephemeris is used for compensation, for some terminals, the compensation values will be opposite. For example, a terminal with a positive frequency offset may be compensated with a negative value, which will cause a double deviation and a relatively serious loss of the performance of the terminal receiver. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a broadband satellite terminal Doppler compensation method and device, which can improve the performance of the terminal receiver.

[0012] The technical solution adopted by the present invention to solve its technical problem is: to provide a broadband satellite terminal Doppler compensation method, including the following steps:

[0013] Calculate each search point according to the preset Doppler boundary range and frequency search interval of the receiver terminal, and use each search point to compensate the received time-domain signal;

[0014] Perform a correlation operation on the time-domain signal of the local pilot and the time-domain signal of each corresponding compensated pilot to obtain multiple correlation values;

[0015] Use the search point corresponding to the correlation value with the largest amplitude among the obtained multiple correlation values as the Doppler frequency shift value of the receiver terminal, and use the Doppler frequency shift value of the receiver terminal to compensate the received time-domain signal;

[0016] Based on the signal after compensating the received time-domain signal using the Doppler frequency shift value of the receiver terminal, perform precise Doppler frequency shift estimation and compensation.

[0017] The search point is calculated by f test,i =-f max +Δf interval *i, where f test,i is the i-th search point, f max is the maximum value of the Doppler boundary range; Δf interval is the frequency search interval.

[0018] The method of estimating and compensating the signal after compensating the received time domain signal based on the Doppler frequency shift value of the receiver terminal specifically includes:

[0019] The time domain signal after the Doppler frequency shift value of the receiver terminal is used to compensate the received time domain signal is transformed into the frequency domain, and the phase difference is performed according to the LS channel estimation value on two adjacent columns of pilot signals in a time slot to obtain the phase difference value;

[0020] Calculating a phase change value at a unit symbol interval for the phase difference value;

[0021] Calculating a phase change value at a unit symbol interval for the phase difference value;

[0022] Performing inter-symbol averaging processing on the phase change value, and calculating a current filtering value in combination with a filtering value of a previous time slot;

[0023] When no longer scheduling, the current filtering value is used as the precise Doppler frequency shift estimation value;

[0024] The precise Doppler frequency shift estimation value is used to perform frequency offset compensation on different symbols, and phase calibration is performed according to the pilot symbol index.

[0025] The phase difference value is obtained by Calculated, where B Δl is the phase difference value at intervals of Δl OFDM symbols, H[k] is the LS channel estimation value on the kth subcarrier of the pilot symbol obtained by compensating the received time domain signal with the Doppler frequency shift value of the receiver terminal and performing FFT transformation to the frequency domain, and H * [k] is the conjugate of H[k], Indicates the total number of all pilot subcarriers on the allocated bandwidth RB.

[0026] The phase change value under the unit symbol interval is obtained by Calculated, where Δθ l is the phase change value under unit symbol interval, B Δl It is the phase difference value separated by Δl symbol intervals, Im() extracts the imaginary part operation, and Re() extracts the real part operation.

[0027] The current filter value is passed through Δθ average =α·Δθ ave +(1-α)·Δθ history Calculated, where Δθ average is the current filter value, Δθ ave is the average processing value between symbols, expressed as: Δθ lis the phase change value under the unit symbol interval, NSym DMRS is the number of columns of pilot symbols, Δθ history is the filtering value of the previous time slot, and α is the weight coefficient.

[0028] The technical solution adopted by the present invention to solve its technical problems is: to provide a broadband satellite terminal Doppler compensation device, including:

[0029] A calculation compensation module, configured to calculate each search point according to a preset Doppler boundary range and frequency search interval of a receiver terminal, and compensate the received time-domain signal with each search point;

[0030] A correlation operation module, configured to perform a correlation operation on the time-domain signal of a local pilot and the time-domain signal of each corresponding compensated pilot to obtain a plurality of correlation values;

[0031] A coarse Doppler frequency shift compensation module, configured to use the search point corresponding to the correlation value with the largest amplitude among the obtained plurality of correlation values as the Doppler frequency shift value of the receiver terminal, and compensate the received time-domain signal with the Doppler frequency shift value of the receiver terminal;

[0032] A fine Doppler frequency shift compensation module, configured to perform fine Doppler frequency shift estimation and compensation on the signal after compensating the received time-domain signal with the Doppler frequency shift value of the receiver terminal.

[0033] The fine Doppler frequency shift compensation module includes:

[0034] A phase difference calculation unit, configured to transform the time-domain signal after compensating the received time-domain signal with the Doppler frequency shift value of the receiver terminal into the frequency domain, and perform a phase difference on the LS channel estimation values on two adjacent columns of pilots within one time slot to obtain a phase difference value;

[0035] A phase change calculation unit, configured to calculate the phase change value under the unit symbol interval for the phase difference value;

[0036] A current filtering value calculation unit, configured to perform inter-symbol averaging processing on the phase change value, and calculate the current filtering value in combination with the filtering value of the previous time slot;

[0037] A determination unit, configured to use the current filtering value as the fine Doppler frequency shift estimation value when no longer scheduling;

[0038] A compensation unit, configured to perform frequency offset compensation on different symbols using the fine Doppler frequency shift estimation value, and perform phase calibration according to the pilot symbol index.

[0039] The technical solution adopted by the present invention to solve its technical problems is: to provide an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the steps of the above-mentioned broadband satellite terminal Doppler compensation method are implemented.

[0040] The technical solution adopted by the present invention to solve its technical problems is: to provide a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned broadband satellite terminal Doppler compensation method are implemented.

[0041] Beneficial effects

[0042] Due to the adoption of the above technical solution, compared with the prior art, the present invention has the following advantages and positive effects: The present invention uses its own receiver signal to perform coarse Doppler frequency offset estimation and fine Doppler frequency offset estimation. Compared with the average value obtained from the ephemeris, the estimation accuracy is high and more accurate, thereby obtaining better terminal receiver performance. Brief description of the drawings

[0043] Figure 1 It is a flowchart of the broadband satellite terminal Doppler compensation method according to an embodiment of the present invention. Specific embodiments

[0044] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0045] The first embodiment of the present invention relates to a broadband satellite terminal Doppler compensation method, as Figure 1 shown, including the following steps:

[0046] Step 1, calculate each search point according to the preset Doppler boundary range and frequency search interval of the receiver terminal, and use each search point to compensate the received time-domain signal.

[0047] Assume that in this embodiment, the Doppler boundary range of the receiver terminal is [-f max , f max , and the frequency search interval is Δf interval , then the i-th search point can be calculated by the following calculation formula:

[0048] f test,i = -f max + Δf interval * i

[0049] By performing blind detection on each search point, the received time-domain signal rx is compensated, i.e.:

[0050] rxcomp = rx * exp(j * 2π * (-f test ) * T s )

[0051] where rxcomp is the signal after compensating the received time-domain signal rx, and T s is the system sampling rate.

[0052] Step 2: Perform a correlation operation on the time-domain signal of the local pilot and the time-domain signals of the corresponding compensated pilots to obtain multiple correlation values.

[0053] In this step, for the compensated signal, calculate its time-domain correspondence according to the pilot index DMRSID, extract the corresponding time-domain signal values, and perform a correlation operation with the signal localDMRS obtained by transforming the known local pilot into the time domain, which can be expressed as:

[0054] refCorr = xcorr(rxcomp(DMRSID), localDMRS)

[0055] where refCorr is the obtained correlation value, and xcorr() represents the sequence correlation operation. Through this operation, the signals compensated for each search point can be correlated to obtain multiple correlation values.

[0056] Step 3: Use the search point corresponding to the correlation value with the largest amplitude among the obtained multiple correlation values as the Doppler frequency shift value of the receiver terminal, and use the Doppler frequency shift value of the receiver terminal to compensate the received time-domain signal.

[0057] In this step, take the search point f maxtest corresponding to the value with the largest amplitude among the multiple correlation values as the Doppler frequency offset value of the receiver, and then use this search point f maxtest for time-domain compensation, which can be expressed as:

[0058] rxcomp max = rx * exp(j * 2π * (-f maxtest ) * T s )

[0059] For example, for a low-earth orbit satellite system with a distance of 600 km and a carrier frequency of 2 GHz, when f max is set to 48 Hz, the Doppler boundary range searched by the terminal is [-48, 48], the frequency search interval is Δf interval = 1 KHz, and for each search point, according to f test,i = -f max + Δfinterval *i performs blind detection. At this time, after the initial estimated Doppler frequency offset value, the remaining Doppler is 1 kHz. It can be seen that in this embodiment, by adjusting the maximum value f of the Doppler boundary range max , the Doppler frequency shift values in different intervals can be searched, and by changing the frequency search interval Δf interval the residual error after the initial search can be changed.

[0060] Because the accuracy of the search point f of the Doppler frequency offset test is limited by the size of the frequency search interval Δf interval If the frequency search interval Δf interval is too small, the search interval is too large. If the frequency search interval Δf interval is too large, the estimated f maxtest error is relatively large. Usually, considering the balance between implementation overhead and estimation accuracy, a fine Doppler estimation is performed on the signal after rxcomp max compensation.

[0061] Step 4, perform a fine Doppler frequency shift estimation and compensation on the signal obtained by compensating the received time-domain signal based on the Doppler frequency shift value of the receiver terminal.

[0062] Because the accuracy of the search point f of the Doppler frequency offset test is limited by the size of the frequency search interval Δf interval If the frequency search interval Δf interval is too small, the search interval is too large. If the frequency search interval Δf interval is too large, the estimated f maxtest error is relatively large. Usually, considering the balance between implementation overhead and estimation accuracy, a fine Doppler estimation is performed on the signal after rxcomp max compensation, and the specific steps are as follows:

[0063] First, transform the time-domain signal obtained by compensating the received time-domain signal based on the Doppler frequency shift value of the receiver terminal into the frequency domain, and perform phase difference on the LS channel estimation values on two adjacent columns of pilots within a time slot to obtain the phase difference value. Among them, the calculation formula of the phase difference value is:

[0064]

[0065] In the formula, B Δl is the phase difference value at an interval of Δl OFDM symbol intervals, H[k] is the LS channel estimation value on the k-th subcarrier of the pilot symbol obtained by transforming the time-domain signal obtained by compensating the received time-domain signal based on the Doppler frequency shift value of the receiver terminal into the frequency domain through FFT, and H *[k] is the conjugate of H[k]. Indicates the total number of all pilot subcarriers on the allocated bandwidth RB.

[0066] Next, calculate the phase change value under the unit symbol interval for the phase difference value, where the calculation formula for the phase change value is:

[0067]

[0068] In the formula, Δθ l is the phase change value under the unit symbol interval, Im() extracts the imaginary part operation, and Re() extracts the real part operation.

[0069] Then, perform inter-symbol averaging processing on the phase change value, and calculate the current filtering value in combination with the filtering value of the previous time slot. In this embodiment, when multiple columns of pilot symbols are configured, it is necessary to perform inter-symbol averaging processing on the phase change value. The specific processing method is:

[0070]

[0071] Among them, Δθ ave is the inter-symbol averaging processing value, and NSym DMRS is the number of columns of pilot symbols.

[0072] Perform α filtering on the obtained inter-symbol averaging processing value. When performing α filtering, it is also necessary to combine the filtering value Δθ history of the previous time slot. Then, α filtering can be expressed as:

[0073] Δθ average = α·Δθ ave +(1 - α)·Δθ history

[0074] Among them, Δθ average is the current filtering value, and α is the weight coefficient.

[0075] After filtering is completed, mark the filtering value Δθ history of the previous time slot as the current filtering value Δθ average for α filtering in the next time slot.

[0076] When no longer scheduled, use the current filtering value Δθ average as the fine Doppler frequency shift estimation value, and clear the filtering value Δθ history of the previous time slot.

[0077] Finally, use the fine Doppler frequency shift estimation value to perform frequency offset compensation on different symbols, and perform phase calibration according to the pilot symbol index, that is, multiply the pilot subcarrier by exp(-j*Δθ average *l DMRS)。

[0078] It is not difficult to find that this embodiment uses the signal of its own receiver to perform coarse Doppler frequency offset estimation and fine Doppler frequency offset estimation. Compared with the average value obtained from the ephemeris, the estimation accuracy is high and more accurate, thereby obtaining better terminal receiver performance.

[0079] The second embodiment of the present invention relates to a broadband satellite terminal Doppler compensation device, including:

[0080] A calculation compensation module, configured to calculate each search point according to a preset Doppler boundary range and frequency search interval of the receiver terminal, and compensate the received time-domain signal with each search point;

[0081] A correlation operation module, configured to perform a correlation operation on the time-domain signal of the local pilot and the time-domain signal of each corresponding compensated pilot to obtain a plurality of correlation values;

[0082] A coarse Doppler frequency shift compensation module, configured to use the search point corresponding to the correlation value with the largest amplitude among the obtained plurality of correlation values as the Doppler frequency shift value of the receiver terminal, and compensate the received time-domain signal with the Doppler frequency shift value of the receiver terminal;

[0083] A fine Doppler frequency shift compensation module, configured to perform fine Doppler frequency shift estimation and compensation on the signal after compensating the received time-domain signal with the Doppler frequency shift value of the receiver terminal.

[0084] The calculation compensation module calculates the search point through f test,i =-f max +Δf interval *i, where f test,i is the i-th search point, f max is the maximum value of the Doppler boundary range; Δf interval is the frequency search interval.

[0085] The fine Doppler frequency shift compensation module includes:

[0086] A phase difference calculation unit, configured to transform the time-domain signal after compensating the received time-domain signal with the Doppler frequency shift value of the receiver terminal into the frequency domain, and perform a phase difference on the LS channel estimation values on two adjacent columns of pilots within one time slot to obtain a phase difference value;

[0087] A phase change calculation unit, configured to calculate the phase change value per unit symbol interval for the phase difference value;

[0088] A current filtering value calculation unit, configured to perform an inter-symbol averaging process on the phase change value and calculate the current filtering value in combination with the filtering value of the previous time slot;

[0089] A determination unit, configured to use the current filtering value as the accurate Doppler frequency shift estimation value when scheduling is no longer performed;

[0090] A compensation unit, configured to perform frequency offset compensation on different symbols by using the accurate Doppler frequency shift estimation value, and perform phase calibration according to a pilot symbol index.

[0091] The phase difference calculation unit passes through to calculate a phase difference value, where B Δl is the phase difference value at an OFDM symbol interval separated by Δl, H[k] represents the LS channel estimation value on the k-th subcarrier of the pilot symbol obtained by compensating the received time-domain signal with the Doppler frequency shift value of the receiver terminal and performing FFT transformation to the frequency domain, and H * [k] represents the conjugate of the LS channel estimation value on the k-th subcarrier of the pilot symbol obtained by compensating the received time-domain signal with the Doppler frequency shift value of the receiver terminal and performing FFT transformation to the frequency domain, represents the total number of all pilot subcarriers on the allocated bandwidth RB.

[0092] The phase change calculation unit passes through to calculate the phase change value per symbol interval, where Δθ l is the phase change value per symbol interval, B Δl is the phase difference value at an interval separated by Δl symbols, Im() is the imaginary part extraction operation, and Re() is the real part extraction operation.

[0093] The current filtering value calculation unit calculates the current filtering value through Δθ average =α·Δθ ave +(1 - α)·Δθ history where Δθ average is the current filtering value, Δθ ave is the inter-symbol average processing value, expressed as: Δθ l is the phase change value per symbol interval, NSym DMRS is the number of columns of pilot symbols, Δθ history is the filtering value of the previous time slot, and α is the weight coefficient.

[0094] The third embodiment of the present invention relates to an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the broadband satellite terminal Doppler compensation method in the first embodiment are implemented.

[0095] The fourth embodiment of the present invention relates to a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the broadband satellite terminal Doppler compensation method of the first embodiment are implemented.

[0096] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0097] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in Figure 1 one or more of the flows Figure 1 or blocks or a combination of multiple blocks.

[0098] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction method that implements the specified functions in Figure 1 one or more of the flows Figure 1 or blocks or a combination of multiple blocks.

[0099] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the specified functions in Figure 1 one or more of the flows Figure 1 or blocks or a combination of multiple blocks.

[0100] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. A broadband satellite terminal Doppler compensation method, characterized in that, It includes the following steps: Calculate each search point according to the preset Doppler boundary range and frequency search interval of the receiver terminal, and use each search point to compensate the received time-domain signal; Perform a correlation operation on the time-domain signal of the local pilot and the time-domain signal of each corresponding compensated pilot to obtain multiple correlation values; Use the search point corresponding to the correlation value with the largest amplitude among the obtained multiple correlation values as the Doppler frequency shift value of the receiver terminal, and use the Doppler frequency shift value of the receiver terminal to compensate the received time-domain signal; Perform fine Doppler frequency shift estimation and compensation based on the signal after compensating the received time-domain signal using the Doppler frequency shift value of the receiver terminal.

2. The broadband satellite terminal Doppler compensation method according to claim 1, wherein The search point is obtained by f test,i =-f max +Δf interval *i, where f test,i is the i-th search point, and f max is the maximum value of the Doppler boundary range; Δf interval is the frequency search interval.

3. The broadband satellite terminal Doppler compensation method according to claim 1, characterized in that The performing fine Doppler frequency shift estimation and compensation based on the signal after compensating the received time-domain signal using the Doppler frequency shift value of the receiver terminal specifically includes: Transform the time-domain signal after compensating the received time-domain signal using the Doppler frequency shift value of the receiver terminal into the frequency domain, and perform phase difference calculation on the LS channel estimation values on two adjacent columns of pilots within one time slot to obtain phase difference values; Calculate the phase change value per symbol interval for the phase difference values; Perform inter-symbol averaging processing on the phase change values, and calculate the current filtering value in combination with the filtering value of the previous time slot; When there is no longer scheduling, use the current filtering value as the fine Doppler frequency shift estimation value; Use the fine Doppler frequency shift estimation value to perform frequency offset compensation on different symbols, and perform phase calibration according to the pilot symbol index.

4. The broadband satellite terminal Doppler compensation method according to claim 3, characterized in that The phase difference value is obtained by calculation, where B Δl is the phase difference value at an interval of Δl OFDM symbol intervals, H[k] is the LS channel estimation value of the k-th subcarrier on the pilot symbol obtained by compensating the received time-domain signal with the Doppler frequency shift value of the receiver terminal and performing FFT transformation to the frequency domain, and H * [k] is the conjugate of H[k], represents the total number of all pilot subcarriers on the allocated bandwidth RB.

5. The broadband satellite terminal Doppler compensation method according to claim 3, characterized in that The phase change value under the unit symbol interval is obtained through calculation, where Δθ l is the phase change value under the unit symbol interval, and B Δl is the phase difference value under the phase difference of Δl symbol intervals. Im() extracts the imaginary part operation. Re() extracts the real part operation.

6. The broadband satellite terminal Doppler compensation method according to claim 3, wherein The current filtering value is obtained through Δθ average = α·Δθ ave + (1 - α)·Δθ history where Δθ average is the current filtering value, and Δθ ave is the average value between symbols, expressed as: Δθ l is the phase change value per unit symbol interval, NSym DMRS is the number of columns of pilot symbols, and Δθ history is the filtering value of the previous time slot, and α is the weight coefficient.

7. A broadband satellite terminal Doppler compensation device, characterized in that, It includes: A calculation compensation module, configured to calculate each search point according to the preset Doppler boundary range and frequency search interval of the receiver terminal, and use each search point to compensate the received time-domain signal; A correlation operation module, configured to perform a correlation operation on the time-domain signal of the local pilot and the time-domain signal of each corresponding compensated pilot to obtain multiple correlation values; A coarse Doppler frequency shift compensation module, configured to use the search point corresponding to the correlation value with the largest amplitude among the obtained multiple correlation values as the Doppler frequency shift value of the receiver terminal, and use the Doppler frequency shift value of the receiver terminal to compensate the received time-domain signal; A fine Doppler frequency shift compensation module, configured to perform fine Doppler frequency shift estimation and compensation based on the signal after compensating the received time-domain signal using the Doppler frequency shift value of the receiver terminal.

8. The broadband satellite terminal Doppler compensation device according to claim 7, characterized in that, The fine Doppler frequency shift compensation module includes: A phase difference calculation unit, configured to transform the time-domain signal after compensating the received time-domain signal using the Doppler frequency shift value of the receiver terminal into the frequency domain, and perform phase difference calculation on the LS channel estimation values on two adjacent columns of pilots within one time slot to obtain phase difference values; A phase change calculation unit, configured to calculate the phase change value per symbol interval for the phase difference values; A current filtering value calculation unit, configured to perform inter-symbol averaging processing on the phase change values, and calculate the current filtering value in combination with the filtering value of the previous time slot; A determination unit, configured to use the current filtering value as the fine Doppler frequency shift estimation value when there is no longer scheduling; A compensation unit is configured to perform frequency offset compensation on different symbols by using the accurate Doppler frequency shift estimation value, and perform phase calibration according to the pilot symbol index.

9. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the broadband satellite terminal Doppler compensation method according to any one of claims 1-6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the steps of the broadband satellite terminal Doppler compensation method according to any one of claims 1-6 are implemented.

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