频谱重叠信号分离的循环平稳算法

Separating cyclostationary signals from spectrally overlapping interference

利用信号的循环平稳性研究了分离频谱重叠信号的算法,并以直接序列扩频系统为例进行了性能分析.该算法在接收端设置了频移滤波器,以便同时利用信号的时间相关性及频谱相关性来实现信号的分离.通过对循环平稳性和频谱相关性的分析,得出了频移滤波器的结构并采用自适应算法确定多个频移分量的最优权值.仿真结果表明,该算法可有效分离频谱重叠信号,在大干扰功率时,误码率与时域滤波器和简单直扩系统比较均低约2个数量级.

An algorithm about separating overlapping signals using the cyclostationary of signals is studied. On the basis of direct sequence spread system, frequency-shift filter is added into the receiver of communication system. Although the structure of frequency-shift filter is more complicated than the time-domain filter, it uses both time correlations and frequency spectrum correlations so it can achieve better performances for separating the overlapping signals. From the analysis of cyclostationary and frequency spectrum correlation, the structure of frequency-shift filter can be gotten. Then the self-adapting algorithm will achieve optimum weighted coefficients of multidimensional frequency-shift components. Simulation results indicate that this algorithm can efficiently separate overlapping signals, and its error rate is lower than time-domain filter and direct sequence spread spectrum (DSSS) by two orders of magnitude when high-power interference is added into the system.