关键词: 非协作通信, 数字调制信号, 码元速率估计, 包络平方谱, Chirp-Z变换, 相位差, 频谱校正, 高精度

Abstract:

In view of the problem of accurate estimation of symbol rate in non-collaborative communication, a high-precision symbol rate estimation algorithm based on the improved phase difference correction method is proposed on the basis of the envelope-square method. The algorithm compares the positions of the peaks of the envelope squared spectra of two sequences with the minimum shift relationship, discards the sequences that are seriously disturbed by noise, and selects the two sequences with the same peak positions to accurately estimate the symbol rate of the signal by the phase-difference correction method. Compared with the envelope-leveling method, this algorithm breaks the limitation that the estimation accuracy of the symbol rate depends on the number of sampling points of the signal, and has a very high estimation accuracy. Simulation experiment results show that the proposed algorithm can achieve accurate estimation of MPSK (Multiple Phase Shift Keying), MPAM (Multiple Pulse Amplitude Modulation) and MQAM (Multiple Quadrature Amplitude Modulation) signal element rates at low signal-to-noise ratios, and the complexity of the proposed algorithm is lower than that of existing high-precision estimation algorithms, making it suitable for application in engineering practice.

Key words: non-collaborative communications, digitally modulated signals, symbol rate estimation, envelope squared spectrum, Chirp-Z transform, phase difference, spectral correction, high accuracy