一种基于循环谱的时频混叠信号参数估计方法

Parameter Estimation of Time-Frequency Overlapped Signals Based on Cyclic Spectrum

基于时频混叠信号的循环平稳特性,计算其循环谱并用形态学滤波的思想提取含有载频与码元信息的截面的谱峰,而后进行搜索从而实现估计。解决了参数配对的问题,并且由形态学滤波在提取谱线时有效降低背景色噪声。同时探究了多径与多普勒频移信道下该算法对估计精度的影响。经仿真验证,该算法能实现BPSK与8QAM任意混合后的载频与码元速率估计,具有抗噪声性能好、精确度高等优点。

A parameter estimation algorithm of time-frequency overlapped signals is presented based on cyclostationary of time-frequency signals. In the algorithm, the cyclic spectrum is calculated and the discrect spectrum-line is picked up making use of mathematic morphology, then modulation parameters are estimated, including carrier frequency and chip rate. The algorithm solves the problem of parameter pairs, and the use of mathematic morphology can reduce the background noise effectively. At the same time, the effect of the algorithm on the accuracy in the multipath fading ＆ Doppler effect channel is considered. The simulation proves that the algorithm is effective and accurate after overlapping BPSK and 8QAM, and it is robust to the noise with a high accuracy.