Sampling frequency offset phase compensation method and device under QPSK (Quadrature Phase Shift Keying) modulation

Abstract

The invention discloses a sampling frequency offset phase compensation method and device under QPSK modulation, and relates to the technical field of phase compensation methods, and the method comprises the steps: collecting each load frame, and carrying out the QPSK modulation of the load frames; configuring a corresponding phase twiddle factor for each OFDM symbol based on the QPSK modulation of each load frame; in the calculation process of the phase twiddle factor, determining a corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each load frame have corresponding phase compensation values; according to the method, corresponding diversity combining is triggered according to each OFDM symbol, at the moment, a sampling frequency offset estimation value does not need to be directly estimated, approximate sampling frequency offset phase deflection information is obtained after multiple pieces of subcarrier information are combined and noise is reduced, correction is carried out according to the approximate sampling frequency offset phase deflection information, and a good correction effect can also be obtained under the low signal-to-noise ratio. Phase compensation is carried out on corresponding data before demodulation and decoding, and the receiving performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of phase compensation methods, and in particular to a sampling frequency offset phase compensation method and device under QPSK modulation. Background Art

[0002] With the development of technology, communication systems have been gradually applied to people's lives for data communication. In the prior art, in the case of multiple diversity combining modes, each OFDM symbol has a residual phase deflection. The longer the time difference between symbols, the greater the phase deflection. For a communication system with too narrow a bandwidth, more OFDM symbols are required to transmit the same original information. From the simulation and actual test results, the performance without phase compensation will drop sharply at this time. The fundamental reason is that there is still a large phase deviation remaining in each diversity after channel equalization in diversity combining, and corresponding phase compensation cannot be achieved. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art, and the present invention provides a sampling frequency offset phase compensation method and device under QPSK modulation.

[0004] An embodiment of the present invention provides a sampling frequency offset phase compensation method under QPSK modulation, including: before demodulating and decoding the data, collecting each payload frame and performing QPSK modulation on the payload frame;

[0005] Configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; in the process of calculating the phase rotation factor, determining a corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values;

[0006] Triggering corresponding diversity combining according to each OFDM symbol.

[0007] An embodiment of the present invention provides a sampling frequency offset phase compensation device under QPSK modulation. The sampling frequency offset phase compensation device under QPSK modulation is applied to the above sampling frequency offset phase compensation method under QPSK modulation, and the sampling frequency offset phase compensation device under QPSK modulation includes:

[0008] A modulation module for collecting each payload frame and performing QPSK modulation on the payload frame before demodulating and decoding the data;

[0009] A phase compensation module for configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; in the process of calculating the phase rotation factor, determining a corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values;

[0010] The diversity combining module is used to trigger corresponding diversity combining according to each OFDM symbol.

[0011] The present invention has the following beneficial effects:

[0012] Before demodulating and decoding the data, collect each payload frame and perform QPSK modulation on the payload frame; configure a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; in the process of calculating the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values; trigger corresponding diversity combining according to each OFDM symbol. At this time, instead of directly estimating the sampling frequency offset estimation value, multiple subcarrier information is used for combining to reduce noise and then an approximate sampling frequency offset phase deflection information is obtained and corrected accordingly, and a good correction effect can also be obtained under low signal-to-noise ratio, realizing phase compensation for the corresponding data before demodulating and decoding and improving the receiving performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the application scenario of the sampling frequency offset phase compensation method under QPSK modulation in an embodiment;

[0014] Figure 2 It is a schematic flow chart of the sampling frequency offset phase compensation method under QPSK modulation in an embodiment of the present invention;

[0015] Figure 3 It is a schematic diagram of the structural composition of the sampling frequency offset phase compensation device under QPSK modulation in an embodiment of the present invention;

[0016] Figure 4 It is a schematic diagram of the sampling frequency offset phase compensation method under QPSK modulation in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0018] The sampling frequency offset phase compensation method under QPSK modulation provided by the present application is applied to an application environment as Figure 1 shown. Among them, the computer 102 communicates with the server 104 through the network. Among them, the computer 102 is not limited to various personal computers, servers, and communication systems, and the server 104 is implemented by an independent server or a server cluster composed of servers.

[0019] Please refer to Figures 1 to 4, A sampling frequency offset phase compensation method under QPSK modulation, which is applied to the sampling frequency offset phase compensation scenario under QPSK modulation; The sampling frequency offset phase compensation method under QPSK modulation includes:

[0020] Step S11: Before demodulating and decoding the data, collect each payload frame and perform QPSK modulation on the payload frame;

[0021] Step S12: Configure a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; In the calculation process of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values;

[0022] Step S13: Trigger corresponding diversity combining according to each OFDM symbol;

[0023] In step S11, before demodulating and decoding the data, collect each payload frame and perform QPSK modulation on the payload frame;

[0024] In the specific implementation process of the present invention, the specific steps are as follows:

[0025] S111: Collect the data in the communication process and trigger the corresponding demodulation and decoding for the data;

[0026] S112: Before demodulating and decoding the data, collect each payload frame; Match the corresponding digital modulation method based on each payload frame. At this time, perform the corresponding QPSK modulation on the payload frame.

[0027] In the embodiment of the present application, collecting the data in the communication process and triggering the corresponding demodulation and decoding for the data realizes the demodulation and decoding of the data.

[0028] At this time, collecting the data in the communication process means that the receiving end receives the signal from the sending end. At the same time, in the communication system, the data is usually first collected by the receiving end, but the demodulation and decoding are usually performed after the identification and processing of the digital modulation method of the data. Therefore, performing the demodulation and decoding immediately after the data collection may not be accurate. In addition, the demodulation and decoding are performed on the already modulated signal, so mentioning the demodulation and decoding in this step may be misunderstood as directly processing the original data.

[0029] Therefore, before demodulating and decoding the data, collect each payload frame; Match the corresponding digital modulation method based on each payload frame. At this time, perform the corresponding QPSK modulation on the payload frame, which introduces the matching of each payload frame and the digital modulation method, ensuring the digital modulation effect of each payload frame.

[0030] At this time, the data is demodulated and decoded, and the demodulation and decoding of the data are controlled in real time. Before the demodulation and decoding of the data, each payload frame is collected. Optionally, in a communication system, a payload frame is an information unit containing data to be transmitted. At the receiving end, this step involves receiving a wireless signal through an antenna and converting it into a digital signal through an analog-to-digital converter (ADC). Then, these digital signals are segmented into different payload frames, and each payload frame may contain multiple symbols or data bits.

[0031] In an actual communication system, the transmitting end and the receiving end usually pre-agree on the modulation method to be used (such as QPSK, 16-QAM, etc.). After receiving the data, the receiving end needs to determine the modulation method used by analyzing the characteristics of the received signal (such as amplitude, phase, or frequency). This step may involve technologies such as signal detection, synchronization, and parameter estimation. Based on each payload frame, the corresponding digital modulation method is matched to facilitate the QPSK modulation of the payload frame.

[0032] In step S12, a corresponding phase rotation factor is configured for each OFDM symbol based on the QPSK modulation of each payload frame; in the process of calculating the phase rotation factor, the corresponding phase compensation value is determined based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values;

[0033] In the specific implementation process of the present invention, the specific steps are as follows:

[0034] S121: Monitor the QPSK modulation of each payload frame in real time;

[0035] S122: In the equalized reception under the QPSK modulation of the payload frame, collect each OFDM symbol l; configure the corresponding phase rotation factor φ for each OFDM symbol l l (when l is 0, φ0 is 0);

[0036] S123: For the phase rotation factor φ l (when l is 0, φ0 is 0), and monitor the calculation of the phase rotation factor;

[0037] S124: In the process of calculating the phase rotation factor, the processing unit is the time-domain signal of an OFDM symbol, and each OFDM symbol is subjected to FFT transformation, that is, the frequency-domain data z0(k, l), where k refers to the subcarrier index and l refers to the OFDM symbol index;

[0038] S125: Collect all subcarrier k ranges under the OFDM symbol l, that is, k ∈ [K start K end ; for each subcarrier k, obtain a rotation compensation angle according to its carrier position Each sub - carrier corresponds to a value after phase compensation, that is

[0039] S126: Perform channel equalization on all the rotated sub - carrier signals to obtain z(k); Rotate z(k) clockwise by 45 degrees, that is z(k) = z(k)*e -jπ / 4 ; When k ≤ K end Compare the absolute value of z(k).re and the absolute value of z(k).im;

[0040] S127: If the absolute value of z(k).re is greater than the absolute value of z(k).im, let the real part z1(k).re = z(k).re*k 2 , and the imaginary part z1(k).im = z(k).im*k; If z(k).re is greater than or equal to 0, accumulate z1(k) to z I ; If z(k).re is less than 0, subtract z1(k) from z I ;

[0041] S128: If the absolute value of z(k).re is less than or equal to the absolute value of z(k).im, let the imaginary part z1(k).im = z(k).im*k 2 , and the real part z1(k).re = z(k).re*k; If z(k).im is greater than or equal to 0, accumulate z1(k) to z Q ; If z(k).re is less than 0, subtract z1(k) from z Q ;

[0042] S129: Calculate the complex accumulated value S(l), that is the real part S(l).re = z I .re + z Q .im and the imaginary part S(l).im = z I .im - z Q .re; Obtain the complex parameter S(l) of the phase deflection information for the current OFDM symbol l; Calculate the phase angle Δφ of S(l) l , and represent the phase reference deviation of the current OFDM symbol l;

[0043] S1210: Let φ l+1 = φ l +Δφ l , then the phase compensation value corresponding to the sub - carrier k of the OFDM symbol l + 1 is

[0044] In the embodiments of the present application, the QPSK modulation of each payload frame is monitored in real - time; In the equalized reception under the QPSK modulation of the payload frame, each OFDM symbol l is collected; Based on each OFDM symbol l, the corresponding phase rotation factor φ is configured l(When l is 0, φ0 is 0), a phase rotation factor φ is introduced. l (When l is 0, φ0 is 0), and through the phase rotation factor φ l (When l is 0, φ0 is 0), gradually control the phase compensation.

[0045] Furthermore, for the phase rotation factor φ l (When l is 0, φ0 is 0), and monitor the calculation of the phase rotation factor; during the calculation of the phase rotation factor, the processing unit is the time-domain signal of one OFDM symbol, and each OFDM symbol undergoes an FFT transformation, that is, the frequency-domain data z0(k, l), where k refers to the subcarrier index and l refers to the OFDM symbol index.

[0046] At this time, the FFT transformation of each OFDM symbol is introduced, corresponding transformation is performed on each OFDM symbol, and the frequency-domain data z0(k, l) is output to facilitate further control of the frequency-domain data z0(k, l).

[0047] Furthermore, collect all subcarrier k ranges under OFDM symbol l, that is, k ∈ [K start K end ; for each subcarrier k, obtain a rotation compensation angle according to its carrier position The value after phase compensation corresponding to each subcarrier is obtained, that is

[0048] At this time, a rotation compensation angle is obtained according to its carrier position, and the rotation compensation angle is introduced to facilitate the phase compensation of each subcarrier, ensuring the value after phase compensation corresponding to each subcarrier.

[0049] Furthermore, perform channel equalization on all the rotated subcarrier signals to obtain z(k); rotate z(k) clockwise by 45 degrees, that is, z(k) = z(k) * e -jπ / 4 ; when k ≤ K end , compare the absolute value sizes of z(k).re and z(k).im. If the absolute value of z(k).re is greater than the absolute value of z(k).im, let the real part z1(k).re = z(k).re * k 2 , and the imaginary part z1(k).im = z(k).im * k; if z(k).re is greater than or equal to 0, accumulate z1(k) to z I ; if z(k).re is less than 0, subtract z1(k) from z I .

[0050] Furthermore, if the absolute value of z(k).re is less than or equal to the absolute value of z(k).im, let the imaginary part z1(k).im = z(k).im * k 2, the real part z1(k).re = z(k).re * k; if z(k).im is greater than or equal to 0, accumulate z1(k) to z Q ; if z(k).re is less than 0, subtract z1(k) from z Q .

[0051] Furthermore, calculate the complex accumulation value S(l), that is, the real part S(l).re = z I .re + z Q .im and the imaginary part S(l).im = z I .im - z Q .re; obtain the complex parameter S(l) of the phase deflection information for the current OFDM symbol l; obtain the phase angle Δφ of S(l) l , and represent the phase reference deviation of the current OFDM symbol l, ensuring the accuracy of the phase reference deviation.

[0052] Therefore, let φ l+1 = φ l + Δφ l , then the phase compensation value corresponding to the subcarrier k of the OFDM symbol l + 1 is The phase compensation value is introduced, realizing the phase compensation of each subcarrier. After combining multiple subcarrier information to reduce noise, an approximate sampling frequency offset phase deflection information is obtained and corrected accordingly, and a good correction effect can also be obtained under low signal-to-noise ratio, realizing the phase compensation of the corresponding data before demodulation and decoding, and improving the receiving performance.

[0053] In step S13, trigger the corresponding diversity combining according to each OFDM symbol;

[0054] In the specific implementation process of the present invention, the specific steps are as follows:

[0055] S131: Collect each OFDM symbol, and each OFDM symbol has been subjected to corresponding phase compensation; trigger the corresponding diversity combining based on each OFDM symbol;

[0056] In the embodiment of the present application, collect each OFDM symbol, and each OFDM symbol has been subjected to corresponding phase compensation; trigger the corresponding diversity combining based on each OFDM symbol.

[0057] At this time, OFDM is a multi-carrier modulation technology widely used in wireless communication systems such as 4G LTE, 5G NR, and Wi-Fi. In an OFDM system, data is split into multiple narrower sub-carriers for transmission, and the signals on each sub-carrier are orthogonal, allowing multiple data streams to be transmitted in parallel within the same spectrum. Due to phase distortion in the wireless channel (such as phase rotation caused by multipath effects), the received OFDM symbols may need to be phase-compensated to recover the original signal. Phase compensation is typically achieved through channel estimation and equalization techniques to ensure accurate signal reception.

[0058] Diversity combining is a technique to improve the reliability and performance of wireless communication systems. It utilizes the signals received on multiple receiving paths (or antennas) to enhance the signal quality and reduce the impact of fading effects. In an OFDM system, diversity combining can be applied in the time, frequency, or spatial domain. For example, spatial diversity uses multiple antennas to receive signals and combines these signals to improve the reception quality. In this step, the system triggers the diversity combining process based on the collected OFDM symbols. This typically involves weighting and combining the signals on multiple receiving paths to maximize the signal quality or minimize the bit error rate.

[0059] Embodiment 1

[0060] In high-speed carrier power line communication, after preamble synchronization, frequency offset estimation, and channel estimation, it is necessary to equalize each sub-carrier signal in each OFDM symbol of the PSDU to restore it as much as possible to the initial phase at the original transmitting end. There is usually a certain time difference between the preamble position where the pilots are located and the data area. As long as there is a certain frequency offset error, there will inevitably be a certain phase difference after equalization compensation for different OFDM symbols.

[0061] Therefore, specific technical processing needs to be carried out for this problem to make up for the performance impact caused by the phase difference. Assume that the modulation method of the current PSDU is QPSK, as Figure 1 shown, the specific steps of the method proposed by the present invention are as follows:

[0062] Let the phase rotation value required for OFDM symbol l be φ l , and it is usually assumed that when l = 0, φ0 = 0.

[0063] Perform FFT transformation on the time-domain data of OFDM symbol l to obtain the frequency-domain information z0(k, l) of symbol l. Here, k represents the sub-carrier index, and according to the protocol, k belongs to the valid sub-carriers, that is, k ∈ [K start , K end , which is used to carry the data of the PSDU. Each sub-carrier will be randomly phase-rotated by θ at the transmitting end according to the protocol itself k, if there is no channel fading, noise, and frequency offset at the receiving end, z0(k, l) should be a number of 1 or -1 after being rotated by the solution of θ k The solution of

[0064] Here, a new rotation angle is calculated for symbol l And the phase of each subcarrier k of each symbol is compensated accordingly To obtain the subcarrier data z(k, l) after phase compensation correction

[0065] Rotate z(k, l) clockwise by 45 degrees, that is, z(k, l) = z(k, l) * e -jπ / 4 .

[0066] When k ≤ K end , compare the absolute values of z(k, l).re and z(k, l).im

[0067] a) If |z(k, l).re| ≥ |z(k, l).im|, let the real part z1(k, l).re = z(k, l).re * k 2 , and the imaginary part z1(k, l).im = z(k, l).im * k. If z(k, l).re ≥ 0, accumulate z1(k, l) to z I ; if

[0068] z(k, l).re < 0, subtract zl(k, l) from z I .

[0069] If |z(k, l).re| < |z(k, l).im|, let the imaginary part z1(k, l).im = z(k, l).im * k 2 , and the real part z1(k, l).re = z(k, l).re * k. If z(k, l).im ≥ 0, accumulate z1(k, l) to z Q ; if z(k, l).re < 0, subtract z1(k, l) from z Q .

[0070] Calculate the complex accumulated value S(l), that is, the real part S(l).re = z I .re + z Q .im and S(l).im = z I .im - z Q .re. Obtain the complex signal S(l) for the phase deflection information of the current OFDM symbol

[0071] By calculating That is, obtaining the phase angle Δφ of S(l) l To obtain the phase reference deviation of the current OFDM symbol l

[0072] Let φ l+1 = φ l + Δφ l , then the phase compensation value corresponding to the sub - carrier k of the next OFDM symbol l + 1 is

[0073] Repeat the above steps until after all OFDM symbols of the PSDU in a frame have undergone dynamic phase estimation and compensation processing, enter the diversity combining process.

[0074] The present invention has the following beneficial effects:

[0075] Before data demodulation and decoding, collect each payload frame and perform QPSK modulation on the payload frame; configure corresponding phase rotation factors for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each sub - carrier until all sub - carriers in each payload frame have corresponding phase compensation values; trigger corresponding diversity combining according to each OFDM symbol. At this time, instead of directly estimating the sampling frequency offset estimation value, use the information of multiple sub - carriers for combination to reduce noise and then obtain an approximate sampling frequency offset phase deflection information and correct accordingly, and a good correction effect can also be obtained under low signal - to - noise ratio, realizing phase compensation for the corresponding data before demodulation and decoding and improving the receiving performance.

[0076] Please refer to Figure 3 , Figure 3 which is a schematic structural composition diagram of the sampling frequency offset phase compensation device under QPSK modulation in an embodiment of the present invention. The sampling frequency offset phase compensation device under QPSK modulation includes:

[0077] A modulation module 21, configured to collect each payload frame and perform QPSK modulation on the payload frame before data demodulation and decoding;

[0078] A phase compensation module 22, configured to configure corresponding phase rotation factors for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each sub - carrier until all sub - carriers in each payload frame have corresponding phase compensation values;

[0079] A diversity combining module 23, configured to trigger corresponding diversity combining according to each OFDM symbol.

[0080] For any combination of the technical features of the above embodiments, for the sake of concise description, not all combinations of the technical features in the above embodiments are described. However, as long as these combinations of technical features do not conflict, they should all be considered as the scope recorded in this specification.

Claims

1. A sampling frequency offset phase compensation method under QPSK modulation, characterized in that, Including: Before demodulating and decoding the data, collect each payload frame and perform QPSK modulation on the payload frame; Configure a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values; Trigger corresponding diversity combining according to each OFDM symbol.

2. The sampling frequency offset phase compensation method under QPSK modulation according to claim 1, characterized in that, The step of, before demodulating and decoding the data, collecting each payload frame and performing QPSK modulation on the payload frame includes: Collect the data during the communication process and trigger corresponding demodulation and decoding for the data; Before demodulating and decoding the data, collect each payload frame; match the corresponding digital modulation method based on each payload frame, and at this time, perform corresponding QPSK modulation on the payload frame.

3. The sampling frequency offset phase compensation method under QPSK modulation according to claim 1, characterized in that The step of configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values includes: Monitor the QPSK modulation of each payload frame in real time; In the equalized reception under QPSK modulation of the payload frame, each OFDM symbol l is acquired; a corresponding phase rotation factor φ is configured based on each OFDM symbol l l (when l is 0, φ0 is 0).

4. The sampling frequency offset phase compensation method under QPSK modulation according to claim 3, wherein The step of configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values further includes: For the phase rotation factor φ l (when l is 0, φ0 is 0), and monitor the calculation of the phase rotation factor; During the calculation of the phase rotation factor, the processing unit is the time-domain signal of one OFDM symbol, and each OFDM symbol performs FFT transformation, that is, the frequency-domain data z0(k, l), where k refers to the subcarrier index and l refers to the OFDM symbol index.

5. The sampling frequency offset phase compensation method under QPSK modulation according to claim 4, wherein The step of configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values further includes: Collect all subcarriers k in the range of OFDM symbol l, i.e., k ∈ [K start K end ; for each subcarrier k, obtain a rotation compensation angle according to its carrier position After phase compensation, the value corresponding to each subcarrier is obtained, i.e., 6. The sampling frequency offset phase compensation method under QPSK modulation according to claim 5, wherein The step of configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values further includes: Perform channel equalization on all the subcarrier signals after rotation to obtain z(k); rotate z(k) clockwise by 45 degrees, i.e., z(k) = z(k) * e -jπ / 4 ; when k ≤ K end , compare the absolute value magnitudes of z(k).re and z(k).im; If the absolute value of z(k).re is greater than the absolute value of z(k).im, let the real part z1(k).re = z(k).re * k 2 , and the imaginary part z1(k).im = z(k).im * k; if z(k).re is greater than or equal to 0, accumulate z1(k) to z I ; if z(k).re is less than 0, subtract z1(k) from z I ; If the absolute value of z(k).re is less than or equal to the absolute value of z(k).im, let the imaginary part z1(k).im = z(k).im * k 2 , and the real part z1(k).re = z(k).re * k; if z(k).im is greater than or equal to 0, accumulate z1(k) to z Q ; if z(k).re is less than 0, subtract z1(k) from z Q .

7. The sampling frequency offset phase compensation method under QPSK modulation according to claim 6, characterized in that The step of configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; during the calculation of the phase rotation factor, determine the corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values further includes: Calculate the cumulative complex value S(l), that is, the real part S(l).re = z I .re + z Q .im and the imaginary part S(l).im = z I .im - z Q .re; obtain the complex parameter S(l) of the phase deflection information for the current OFDM symbol l; obtain the phase angle Δφ of S(l) l , and represent the phase reference deviation of the current OFDM symbol l.

8. The sampling frequency offset phase compensation method under QPSK modulation according to claim 7, characterized in that, Configuring a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; in the process of calculating the phase rotation factor, determining a corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values, further including: Let φ l+1 = φ l + Δφ l , then the phase compensation value corresponding to sub - carrier k of OFDM symbol l + 1 is 9. The sampling frequency offset phase compensation method under QPSK modulation according to claim 8, characterized in that, The triggering of corresponding diversity combining according to each OFDM symbol includes: Collecting each OFDM symbol, where each OFDM symbol has undergone corresponding phase compensation; triggering corresponding diversity combining based on each OFDM symbol.

10. A sampling frequency offset phase compensation device under QPSK modulation, characterized in that The sampling frequency offset phase compensation device under QPSK modulation is applied to the sampling frequency offset phase compensation method under QPSK modulation as described in any one of claims 1-9. The sampling frequency offset phase compensation device under QPSK modulation includes: A modulation module, configured to collect each payload frame before demodulating and decoding the data and perform QPSK modulation on the payload frame; A phase compensation module, configured to configure a corresponding phase rotation factor for each OFDM symbol based on the QPSK modulation of each payload frame; in the process of calculating the phase rotation factor, determining a corresponding phase compensation value based on the rotation compensation of each subcarrier until all subcarriers in each payload frame have corresponding phase compensation values; A diversity combining module, configured to trigger corresponding diversity combining according to each OFDM symbol.

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