基于子空间跟踪的DSSS通信系统抗窄带干扰研究

Subspace Tracking-Based Research on Narrowband Interference Suppression in DSSS Communication Systems

对接收信号自相关矩阵分析表明,窄带干扰的能量集中在一个低秩子空间(干扰子空间)内,扩频信号和噪声的能量均匀散布在整个特征空间,通过跟踪接收信号自相关矩阵大特征值对应特征矢量构成的干扰子空间,可实现对窄带干扰的有效抑制。文中采用RRLS算法跟踪干扰子空间,并根据干扰子空间最小特征值与噪声功率的比值自动确定干扰子空间的维数。分析和仿真表明子空间跟踪窄带干扰抑制算法实现复杂度低,数值稳定性好,性能优于传统的自适应横向滤波器。

The analysis of correlation matrix of the received signal proves that the energy of narrowband interference is compressed in the low rank subspace, interference subspace, and the energy of DSSS signal and AWGN uniformly distribute. The narrowband interference suppression can be realized by tracking the interference subspace and projecting the received signal vector to the orthogonal subspace of it. The algorithm proposed here is low complexity, numerical stability and better performance than traditional Adaptive Transversal Filter （ATF）.