CFE条件下基于循环维纳滤波的单通道分离算法

在航天测控数传（C＆T）信号中,频谱混叠的现象非常普遍,因此对频谱严重混叠的信号进行单通道盲分离成为信号处理领域中研究的热点和难点。基于线性-共轭-线性频移（LCL-FRESH）滤波的基本概念,考虑到在实际非合作通信应用中基于循环平稳的LCL-FRESH滤波依赖于较高的循环频率精度,然而循环频率误差（CFE）总是无可避免,提出了一种改进的CFE校正算法,简单分析了误差条件下滤波器性能下降的原因。仿真表明,所研究的算法可以有效分离存在CFE下时频重叠的数传通信信号。

Single Channel Signals Separation Algorithm Based on Cyclostationary Filtering Under CFE Correction

In Aeronautical Data Transmission Signals,signals spectral overlapping interference is very common. Some of the theoretical concepts underlying Linear-Conjugate-Linear Frequence-Shift（ LCLFRESH） filtering are proposed,which are generalization of Wiener filtering called cyclic Wiener filtering. However,severe performance degration of FRESH filtering are unavoidable,when there is a small mismatch in the cyclic frequency error of the desired signal. The truly measured aeronautical data transmission signals are given,the feasibility of cyclostationary filtering applying in the single channel signal separation problem for the spectrally overlapping signals is analyzed,and an improved CFE correction algorithm is proposed. The results from theoretical analysis and numerical simulations indicate that the performance of FRESH filter is very sensitive to CFE,and the proposed algorithm can correrct CEF effectively.