基于小波变换的移相键控信号符号速率估计

Symbol Rate Estimation of Phase Shift Keying Signals Based on Wavelet Transform

研究基于小波变换有效提取信号瞬变特性的功能,对数字调制移相键控(PSK)信号进行符号速率估计.通过对信号作固定尺度下的小波变换,提取PSK信号符号间的相位瞬变信息.然后通过对小波变换幅值求自相关运算及其他处理,实现对PSK信号符号速率的准确估计.该方法的优点是无需任何PSK信号的先验知识,在低信噪比下仍能准确估计.对BPSK,QPSK和8PSK信号在Matlab环境下的仿真结果表明,信噪比≥8dB时能准确估计其符号速率.

Studies the function of wavelet transform (WT) that can effectively distill the transient characteristics of digital signals to estimate the symbol rate of PSK signals. Through obtaining WT's coefficient of PSK signals, the phase changes between different symbols can be effectively extracted. By means of the autocorrelation operation of the WT's coefficient and other processes the symbol rate of PSK signals is then estimated accurately. The advantages of this method include no need of any prior knowledge of the modulated signals and accurate estimation even at low signaltonoise ratio (SNR). Simulation in Matlab environment with BPSK,QPSK and 8PSK signals shows that the symbol rate estimation is accurate at SNR≥8 dB.