基于改进相位差校正法的高精度码元速率估计

High-Precision Symbol Rate Estimation Based on Improved Phase Difference Correction Method

针对非协作通信中的码元速率精确估计等问题,文中在包络平方法的基础上,提出基于改进相位差校正法的高精度码元速率估计算法。该算法通过对比具有最小时移关系的两段序列包络平方谱峰位置一致情况,舍弃受噪声干扰严重导致谱峰位置不一致的序列,并选取谱峰位置一致的两段序列,通过相位差校正法精确估计信号的码元速率。相较于包络平方法,所提算法突破了码元速率估计精度依赖信号采样点数的限制,具有较高的估计精度。仿真实验结果表明,所提算法可在较低信噪比条件下对MPSK(Multiple Phase Shift Keying)、MPAM(Multiple Pulse Amplitude Modulation)和MQAM(Multiple Quadrature Amplitude Modulation)信号码元速率进行精确估计,且相较于现有高精度估计算法,该算法复杂度更低,适合应用于工程实践。

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.