一种基于小波变换和循环自相关的波特率估计方法

Symbol Rate Estimation Method Based on Wavelet Transform and Cyclic Autocorrelation

在循环平稳理论的基础上,给出了一种小波变换和循环自相关相结合的PSK信号波特率估计方法。首先通过恒模和延迟复共轭相乘将中频信号变为基带信号,再利用此基带信号小波变换系数模值,搜索其傅立叶变换系数除直流分量外的第一个峰值对波特率进行粗略估计;最后利用PSK信号的循环自相关同循环频率和延时的关系对码元速率进行细估计。理论分析和仿真结果表明:新方法计算量小,估计精度高,对滚降系数的变化不敏感,具有良好的性能。

A symbol rate estimation method of PSK signals which combines wavelet transform and cyclic autocorrelation based on the cyclostationary is given. First the preprocessing of constant amplitude and delayed complex conjugated multiplication is used to move intermediate frequency signal to baseband, then the wavelet transform coefficients are computed to search the first peak value of Fourier transform in order to give rough symbol rate estimation; at last the relation of cyclic autocorrelation and delay is analyzed to give accurate estimation. Theoretical analysis and practical signal processing justify the effectiveness of the new algorithm.