基于CME算法的数字窄带干扰抑制及改进

Rejection of Digital NBI in DSSS Systems Based on CME Algorithm and Its Improvement

用连续均值剔除干扰(Consecutive mean excision,CME)算法可以抑制直扩系统中的数字窄带干扰,通过迭代更新门限值,可抑制50%带宽的数字窄带干扰。针对CME算法计算量大的缺点,利用FFT幅度谱的中心对称特性,提出了一种改进的更易于工程实现的CME算法。与常规的CME算法相比,改进的CME算法仅对部分幅度谱进行迭代更新,在减少运算量和节省存储空间的同时,能够保持良好的抑制性能。理论分析和数字仿真表明,改进算法可有效地抑制直扩通信系统中的数字窄带干扰,且实现简单。

A consecutive mean excision （CME） algorithm is used to suppress digital narrowband interference （NBI） in direct sequence spread spectrum （DSSS） systems. The algorithm can offer remarkable interference suppression and its bandwidth is up to 50% of the bandwidth of the desired signal. Based on centrosymmetry of FFT, an improved CME algorithm is proposed. The algorithm can reduce the iterative times and the storage space, and keep the system performance. Both theoretical analysis and numerical simulation show that the proposed algorithm can effectively suppress digital NBI.