CN-122027424-A - Multi-carrier 4096QAM signal coordination synchronization method and system

CN122027424ACN 122027424 ACN122027424 ACN 122027424ACN-122027424-A

Abstract

The invention provides a multi-carrier 4096QAM signal coordination synchronization method and system, and relates to the technical field of digital communication. The method comprises the steps of performing down-conversion and analog-to-digital conversion on a multi-carrier 4096QAM signal to obtain a digital baseband signal, extracting a time-frequency spectrogram and a pilot symbol sequence of the multi-carrier 4096QAM signal, performing forward reasoning by taking the time-frequency spectrogram and the pilot symbol sequence as joint characteristics to obtain a multi-dimensional estimation vector, performing time-domain interpolation adjustment on the digital baseband signal to obtain a preliminary pair Ji Shiyu signal, performing pre-compensation on the preliminary aligned time-domain signal according to a preliminary estimation value of the multi-dimensional estimation vector to obtain a frequency offset compensation signal, performing state prediction on a phase track of the frequency offset compensation signal, applying a reverse phase rotation on the frequency offset compensation signal according to an output value of the state prediction to obtain a synchronized signal, and performing equalization and 4096QAM demodulation on the synchronized signal to obtain a data bit stream. The invention can improve the efficiency of the coordination and synchronization of the multi-carrier 4096QAM signals.

Inventors

CHANG YINGHUI
ZHAO PEI
WU WEIKANG
LI BIN

Assignees

中国电子科技集团公司第五十四研究所

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (10)

1. A method for coordinated synchronization of multicarrier 4096QAM signals, comprising the steps of: Step 1, performing down-conversion and analog-to-digital conversion on a received multi-carrier 4096QAM signal to obtain a digital baseband signal of the multi-carrier 4096QAM signal; step 2, extracting a time-frequency spectrogram and a pilot frequency symbol sequence of the multi-carrier 4096QAM signal, and carrying out forward reasoning by taking the time-frequency spectrogram and the pilot frequency symbol sequence as joint characteristics to obtain a multi-dimensional estimation vector of the multi-carrier 4096QAM signal; Step 3, according to the preliminary estimated value of the symbol timing error in the multidimensional estimated vector, carrying out time domain interpolation adjustment on the digital baseband signal to obtain a preliminary pair Ji Shiyu signal of the multicarrier 4096QAM signal; step 4, according to the preliminary estimated value of the carrier frequency deviation in the multidimensional estimated vector, performing frequency deviation pre-compensation on the preliminary alignment time domain signal to obtain a frequency deviation compensation signal of the multicarrier 4096QAM signal; Step 5, carrying out state prediction on the phase track of the frequency offset compensation signal, and applying a reverse phase rotation to the frequency offset compensation signal according to the output value of the state prediction to obtain a synchronized signal of the multi-carrier 4096QAM signal; and 6, carrying out equalization and 4096QAM demodulation on the synchronized signals to obtain a data bit stream of the multi-carrier 4096QAM signal.
2. The method for coordinated synchronization of multicarrier 4096QAM signals according to claim 1, wherein the multicarrier 4096QAM signals received in step 1 are radio frequency signals, and the specific manner of step 1 is: Step 101, mixing a received radio frequency signal with a local oscillator signal generated by a local oscillator through a mixer, so as to down-convert the radio frequency signal to an intermediate frequency signal; step 102, filtering the intermediate frequency signal by using an anti-aliasing filter, and inhibiting out-of-band noise and image frequency interference to obtain a filtered intermediate frequency signal; Step 103, sampling and quantizing the filtered intermediate frequency signal to obtain a digital intermediate frequency signal; Step 104, converting the digital intermediate frequency signal into baseband frequency, and separating out in-phase component and quadrature component to obtain digital baseband signal of multi-carrier 4096QAM signal.
3. The method for coordinated synchronization of a multi-carrier 4096QAM signal according to claim 1, wherein in step 2, a time-frequency spectrum diagram and a pilot symbol sequence of the multi-carrier 4096QAM signal are extracted by: Step 201, dividing the digital baseband signal into continuous signal frames; Step 202, performing short-time Fourier transform on each signal frame to obtain a time-frequency unit corresponding to the signal frame; step 203, time-frequency units are combined in time sequence to form a time-frequency spectrogram of the multi-carrier 4096QAM signal; Step 204, positioning and extracting pilot symbols from the frequency domain resource of the digital baseband signal according to the pilot pattern predefined by the communication protocol, so as to obtain the pilot symbol sequence of the multi-carrier 4096QAM signal.
4. The method for coordinated synchronization of a multi-carrier 4096QAM signal as claimed in claim 3, wherein in step 2, forward reasoning is performed using a time-frequency spectrogram and a pilot symbol sequence as joint features to obtain a multi-dimensional estimated vector of the multi-carrier 4096QAM signal, specifically by: Step 205, performing channel normalization processing on the time-frequency spectrogram, and performing phase unwrapping on the pilot symbol sequence to obtain normalized time-frequency characteristics and normalized pilot characteristics; step 206, carrying out feature cascade on the normalized time-frequency features and the normalized pilot frequency features to obtain a joint feature vector of the multi-carrier 4096QAM signal; Step 207, performing nonlinear transformation on the multicarrier 4096QAM signal according to the joint feature vector to obtain a multidimensional estimation vector of the multicarrier 4096QAM signal.
5. The method for coordinated synchronization of a multicarrier 4096QAM signal of claim 4, wherein step 207 is performed by: ; In the formula, For a multi-dimensional estimation of the vector, The function is activated for Sigmoid, For the hyperbolic tangent activation function, Is the dominant weight matrix in the nonlinear transformation, In order to combine the feature vectors, Is the dominant bias vector in the nonlinear transformation, Is a gating weight matrix in a nonlinear transformation, Is a gating bias vector in a nonlinear transformation, Is Hadamard product.
6. The method for coordinated synchronization of multicarrier 4096QAM signals according to claim 1, wherein the specific manner of step 3 is: step 301, resolving a preliminary estimation value of the symbol timing error from the multidimensional estimation vector; step 302, determining the direction of time domain interpolation operation and a reference sampling point according to the initial estimated value of the symbol timing error and the symbol; Step 303, resampling a sampling sequence of the digital baseband signal based on the reference sampling point to obtain an interpolated sampling point, and performing a choice on the original sampling point; Step 304, the interpolated sampling points and the original sampling points subjected to the rounding are recombined according to the time sequence, so as to obtain the preliminary alignment time domain signal of the multicarrier 4096QAM signal.
7. The method for coordinated synchronization of multicarrier 4096QAM signals according to claim 1, wherein the specific manner of step 4 is: step 401, resolving a preliminary estimated value of carrier frequency deviation from the multidimensional estimated vector; Step 402, determining the angular velocity of the multi-carrier 4096QAM signal according to the preliminary estimated value of the carrier frequency deviation and the sampling period; step 403, taking the product of the proportional ratio of the phase value of each element in the multicarrier 4096QAM signal and the angular velocity as a phase rotation sequence; in step 404, in the time domain, the initially aligned time domain signal is phase-rotated based on the phase rotation sequence, so as to obtain a frequency offset compensation signal of the multicarrier 4096QAM signal.
8. The method for coordinated synchronization of multicarrier 4096QAM signals according to claim 1, wherein in step 5, the phase trajectory of the frequency offset compensation signal is predicted in a state, specifically by: step 501, extracting a historical phase track sequence containing at least one symbol period length from a memory unit of a nonlinear phase tracker; Step 502, capturing a local fluctuation mode and a global variation trend in a historical phase track sequence to obtain a phase dynamic feature vector; Step 503, splicing the optimal estimated state vector and the phase dynamic feature vector at the previous moment to obtain an enhanced state vector of the multi-carrier 4096QAM signal; step 504, under the influence of the phase dynamic characteristics, performing nonlinear evolution on the enhanced state vector to obtain a predicted state vector of the multicarrier 4096QAM signal.
9. The method for coordinated synchronization of a multicarrier 4096QAM signal of claim 8, wherein said predictive state vector is calculated as follows: ; In the formula, Is that The predicted state vector of the moment in time, For a linear state transfer function based on a classical state space model, Is that The best estimated state vector for the moment in time, As a function of the time factor, As a function of the non-linear mapping, As the phase dynamic feature vector, Is a historical phase trajectory sequence.
10. A multi-carrier 4096QAM signal coordinated synchronization system, comprising: The signal processing module is used for carrying out down-conversion and analog-to-digital conversion on the received multi-carrier 4096QAM signal to obtain a digital baseband signal of the multi-carrier 4096QAM signal; the multi-dimensional estimation vector extraction module is used for extracting a time-frequency spectrogram and a pilot frequency symbol sequence of the multi-carrier 4096QAM signal, and carrying out forward reasoning by taking the time-frequency spectrogram and the pilot frequency symbol sequence as joint characteristics to obtain a multi-dimensional estimation vector of the multi-carrier 4096QAM signal; The time domain interpolation module is used for performing time domain interpolation adjustment on the digital baseband signal according to the preliminary estimation value of the symbol timing error in the multidimensional estimation vector to obtain a preliminary pair Ji Shiyu signal of the multicarrier 4096QAM signal; the frequency offset pre-compensation module is used for carrying out frequency offset pre-compensation on the preliminarily aligned time domain signals according to the preliminary estimated value of the carrier frequency deviation in the multidimensional estimated vector to obtain frequency offset compensation signals of the multicarrier 4096QAM signals; The signal synchronization module is used for carrying out state prediction on the phase track of the frequency offset compensation signal, and applying a reverse phase rotation to the frequency offset compensation signal according to the output value of the state prediction to obtain a synchronized signal of the multi-carrier 4096QAM signal; and the signal demodulation module is used for carrying out equalization and 4096QAM demodulation on the synchronized signals to obtain a data bit stream of the multi-carrier 4096QAM signal.

Description

Multi-carrier 4096QAM signal coordination synchronization method and system Technical Field The invention relates to the technical field of digital communication, in particular to a method and a system for coordinating and synchronizing multicarrier 4096QAM signals. Background In the prior art, in the parameter estimation link of a multi-carrier 4096QAM signal, a time-frequency spectrogram and a pilot frequency symbol sequence are not combined to be used as joint features for carrying out analysis, parameter estimation is carried out only by means of a single feature, complementary information among different features cannot be fully utilized, and therefore estimation accuracy of key synchronous parameters such as symbol timing errors, carrier frequency deviations and the like is low. Meanwhile, the characteristics are not standardized in the parameter estimation process, the characteristic mapping relation is not optimized through nonlinear transformation, the generated estimated vector is poor in accuracy and insufficient in robustness, the high requirement of a 4096QAM high-order modulation signal on the precision of synchronous parameters is difficult to meet, and hidden danger is buried for subsequent synchronous adjustment. In addition, the prior art has defects in the synchronous correction and phase compensation links of the multi-carrier 4096QAM signal. When time domain alignment is carried out, the interpolation direction and the reference sampling point are not dynamically determined according to the accurate estimated value of the symbol timing error, and the digital baseband signal is adjusted only by adopting a fixed interpolation strategy, so that the problems of unreasonable sampling point selection and low alignment precision are easy to occur. When the frequency offset is compensated, the phase rotation sequence is not accurately calculated by combining the sampling period, and the offset is offset only through rough frequency adjustment, so that the influence caused by carrier frequency offset cannot be thoroughly eliminated. The phase correction stage does not predict the dynamic state of the phase track of the frequency offset compensation signal, and only relies on static phase adjustment or a simple feedback mechanism to correct the phase, so that the phase correction stage cannot adapt to the local fluctuation and global change trend of the phase track, and the synchronous signal still has phase deviation, finally affects the equalization and demodulation effects, and is difficult to output high-quality data bit stream. Disclosure of Invention In view of the above, the present invention provides a method and a system for coordinated synchronization of multi-carrier 4096QAM signals, so as to solve the above-mentioned problems in the prior art. The invention can improve the efficiency of the coordination and synchronization of the multi-carrier 4096QAM signals. In order to achieve the above purpose, the technical scheme provided by the invention is as follows: a multi-carrier 4096QAM signal coordination synchronization method comprises the following steps: Step 1, performing down-conversion and analog-to-digital conversion on a received multi-carrier 4096QAM signal to obtain a digital baseband signal of the multi-carrier 4096QAM signal; step 2, extracting a time-frequency spectrogram and a pilot frequency symbol sequence of the multi-carrier 4096QAM signal, and carrying out forward reasoning by taking the time-frequency spectrogram and the pilot frequency symbol sequence as joint characteristics to obtain a multi-dimensional estimation vector of the multi-carrier 4096QAM signal; Step 3, according to the preliminary estimated value of the symbol timing error in the multidimensional estimated vector, carrying out time domain interpolation adjustment on the digital baseband signal to obtain a preliminary pair Ji Shiyu signal of the multicarrier 4096QAM signal; step 4, according to the preliminary estimated value of the carrier frequency deviation in the multidimensional estimated vector, performing frequency deviation pre-compensation on the preliminary alignment time domain signal to obtain a frequency deviation compensation signal of the multicarrier 4096QAM signal; Step 5, carrying out state prediction on the phase track of the frequency offset compensation signal, and applying a reverse phase rotation to the frequency offset compensation signal according to the output value of the state prediction to obtain a synchronized signal of the multi-carrier 4096QAM signal; and 6, carrying out equalization and 4096QAM demodulation on the synchronized signals to obtain a data bit stream of the multi-carrier 4096QAM signal. Further, the multicarrier 4096QAM signal received in step 1 is a radio frequency signal, and the specific manner of step 1 is: Step 101, mixing a received radio frequency signal with a local oscillator signal generated by a local oscillator through a mixer, so as to down-conv