CN-122027429-A - High-order modulation signal carrier synchronization rapid acquisition method based on phase rotation

Abstract

The application relates to a high-order modulation signal carrier synchronization rapid capturing method based on phase rotation. The method comprises the steps of performing instantaneous phase calculation on a 32APSK signal after symbol synchronization by adopting a coordinate rotation digital calculation method to obtain an instantaneous phase, performing phase expansion on the instantaneous phase to enable the modulation phase of each symbol to rotate to a zero phase to obtain a target phase, performing cosine operation and sine operation on the target phase to obtain an in-phase component and a quadrature component respectively, performing fast Fourier transformation on the in-phase component and the quadrature component to obtain a signal spectrum, performing peak value search on the signal spectrum, determining a frequency value corresponding to the peak value, performing inverse scaling operation on the frequency value through multiple frequencies to obtain a carrier frequency offset estimation value, generating a compensation carrier signal according to the carrier frequency offset estimation value based on a direct digital frequency synthesizer, performing frequency mixing operation on the compensation carrier signal and an original received signal to offset the carrier frequency offset influence, and completing carrier synchronization acquisition.

Inventors

• LIN XINGPENG
• WU YUEHUI

Assignees

• 湖南斯北图科技有限公司

Dates

Publication Date

20260512

Application Date

20260331

Claims (10)

1. 1. A method for fast capturing carrier synchronization of a high-order modulated signal based on phase rotation, the method comprising: Performing instantaneous phase calculation on the 32APSK signals after symbol synchronization by adopting a coordinate rotation digital calculation method to obtain instantaneous phases, performing phase expansion on the instantaneous phases, and rotating the modulation phase of each symbol to zero phase to obtain a target phase; Performing cosine operation and sine operation on the target phase to obtain an in-phase component and a quadrature component, and performing fast Fourier transformation on the in-phase component and the quadrature component to obtain a signal spectrum; Performing peak search on the signal spectrum, determining a frequency value corresponding to the peak, and obtaining a carrier frequency offset estimation value through multiple frequency inverse scaling operation; and generating a compensation carrier signal based on the direct digital frequency synthesizer according to the carrier frequency offset estimation value, and carrying out frequency mixing operation on the compensation carrier signal and an original receiving signal to offset the carrier frequency offset influence so as to complete carrier synchronous capturing.
2. 2. The method of claim 1, wherein performing instantaneous phase calculation on the symbol-synchronized 32APSK signal by using a coordinate rotation digital calculation method to obtain an instantaneous phase, comprises: Carrying out instantaneous phase calculation on the 32APSK signals after symbol synchronization by adopting a coordinate rotation digital calculation method to obtain instantaneous phases as follows: Wherein, the In order to modulate the phase of the light, For the phase caused by the carrier frequency offset, For the initial phase position, For the carrier frequency offset, For the time index of the time index, Is the symbol period.
3. 3. The method of claim 1, wherein phase expanding the instantaneous phase to rotate the modulation phase of each symbol to zero phase to obtain a target phase, comprising: The instantaneous phase is subjected to phase expansion, so that the modulation phase of each symbol is rotated to a zero phase, and the target phase is obtained as follows: Wherein, the For the instantaneous phase position, In order to modulate the phase of the light, For the phase caused by the carrier frequency offset, For the initial phase position, For the carrier frequency offset, For the time index of the time index, Is the symbol period.
4. 4. The method of claim 1, wherein performing cosine and sine operations on the target phase to obtain an in-phase component and a quadrature component, respectively, comprises: Cosine operation is respectively carried out on the target phases, and the obtained in-phase components are as follows: Wherein, the For the phase of the object to be achieved, For the initial phase position, For the carrier frequency offset, For the time index of the time index, Is the symbol period.
5. 5. The method according to claim 4, wherein the method further comprises: And respectively carrying out sine operation on the target phases to obtain quadrature components: Wherein, the For the phase of the object to be achieved, For the initial phase position, For the carrier frequency offset, For the time index of the time index, Is the symbol period.
6. 6. The method of claim 5, wherein performing a fast fourier transform on the in-phase component and quadrature component to obtain a signal spectrum comprises: Performing fast fourier transform on the in-phase component and the quadrature component to obtain a signal spectrum as follows: 。
7. 7. The method of claim 1, wherein performing a peak search on the signal spectrum comprises: for signal spectrum Searching peak value to find index value corresponding to peak value Setting the sampling rate 2GSps, then the frequency resolution of the FFT The method comprises the following steps: 。
8. 8. The method of claim 7, wherein determining the frequency value corresponding to the peak value comprises: Peak corresponding frequency value The method comprises the following steps: 。
9. 9. the method of claim 8 wherein obtaining the carrier frequency offset estimate by a multiple frequency inverse scaling operation comprises: Due to Carrier frequency offset estimation value The method comprises the following steps: 。
10. 10. the method of claim 1 wherein generating a compensated carrier signal based on the carrier frequency offset estimate by a direct digital frequency synthesizer, performing a mixing operation on the compensated carrier signal and an original received signal to cancel carrier frequency offset effects, and performing carrier synchronization acquisition comprises: estimating value according to carrier frequency offset by using direct digital frequency synthesizer Generating a compensation carrier signal, and mixing with the input signal to obtain a real part of the signal after frequency offset correction Sum signal imaginary part : Wherein, the And The in-phase and quadrature components of the signal after symbol synchronization respectively, For the time index of the time index, Is the symbol period.

Description

High-order modulation signal carrier synchronization rapid acquisition method based on phase rotation Technical Field The application relates to the technical field of digital communication, in particular to a high-order modulation signal carrier synchronization rapid acquisition method based on phase rotation. Background In modern digital communication systems, such as satellite communication, 5G and future mobile communication, high-speed data transmission, etc., the receiving end needs to accurately recover the original data from the signal contaminated by frequency offset and phase noise, a process called carrier synchronization. Carrier synchronization is a precondition for the normal operation of the receiver. The received signal may have an unknown carrier frequency offset due to the transmitter and receiver local oscillator bias, and doppler effects. If this frequency offset is not corrected, it may lead to a dramatic deterioration in demodulation performance and even incomplete communication. In high dynamic environments, a large doppler shift or frequency switch requires that the receiver must complete synchronization and establish a connection in a very short time, otherwise it may cause communication interruption, connection failure, or loss of critical data. The traditional slow frequency offset searching method can bring long handshake time, the communication delay can be obviously reduced by quick capture, and the system efficiency and the user experience are directly improved. The high-order modulation technology (such as 32 APSK) is widely applied to satellite communication, deep space communication and new generation broadcasting standard DVB-S2, can bear more bits in one symbol, thereby improving the spectrum efficiency, is more robust to nonlinearity, has constellation points concentrated on a plurality of limited amplitude levels, has low peak-to-average ratio of signals and smaller amplitude fluctuation, and causes the distortion generated by the nonlinear amplifier to be smaller. However, the existing carrier synchronization acquisition technology has obvious defects in coping with high-order modulation signals, on one hand, the traditional method mainly adopts a mode of carrying out high-order operation on time complex signals to eliminate modulation information, so that the calculation complexity is extremely high, the occupation amount of hardware resources (especially Digital Signal Processors (DSPs)) is large, the application of the carrier synchronization acquisition technology in resource-limited equipment is limited, on the other hand, the carrier acquisition range and the acquisition time have inherent contradiction, the requirements of large frequency offset acquisition and quick synchronization are difficult to meet at the same time, and the severe requirements of high-dynamic communication scenes cannot be adapted. These problems severely limit the application performance of high-order modulation techniques in modern communication systems, and an efficient carrier synchronization fast acquisition scheme is needed. Disclosure of Invention Based on this, it is necessary to provide a fast capturing method for carrier synchronization of a high-order modulation signal based on phase rotation, which can reduce the computational complexity and the hardware resource consumption of carrier synchronization of a high-order modulation signal, and simultaneously achieve carrier capturing in a large frequency offset range, fast and reliably. A method for fast acquisition of carrier synchronization of a high-order modulated signal based on phase rotation, the method comprising: Performing instantaneous phase calculation on the 32APSK signals after symbol synchronization by adopting a coordinate rotation digital calculation method to obtain instantaneous phases, performing phase expansion on the instantaneous phases, and rotating the modulation phase of each symbol to zero phase to obtain a target phase; Performing cosine operation and sine operation on the target phase to obtain an in-phase component and a quadrature component, and performing fast Fourier transformation on the in-phase component and the quadrature component to obtain a signal frequency spectrum; carrying out peak search on the signal spectrum, determining a frequency value corresponding to the peak, and obtaining a carrier frequency offset estimation value through multiple frequency inverse scaling operation; and generating a compensation carrier signal based on the direct digital frequency synthesizer according to the carrier frequency offset estimation value, carrying out frequency mixing operation on the compensation carrier signal and an original receiving signal to offset the carrier frequency offset influence, and completing carrier synchronization acquisition. According to the high-order modulated signal carrier synchronization rapid capturing method based on phase rotation, the coordinate rotation digital computi