直扩通信系统窄带干扰的抑制技术研究

该文先给出直接序列扩频通信系统的一般模型，然后应用SYSTEMVIEW对其进行系统仿真，认识到系统本身因其扩频增益具有较强的抗窄带干扰能力，比较了不同地址码接收端的输出，系统同样具有抗多址干扰的能力。考虑到因带宽限制，仅仅依赖系统本身的扩频增益抑制干扰是不够的，因而在接收端解扩之前加人一个自适应滤波器。该文证明了该自适应滤波器对窄带干扰抑制的有效性，分析了LMS算法。最后应用MATLAB仿真了自适应滤波的整个过程，结论是应用基于LMS算法的自适应滤波器能极大地降低误码率，能抑制掉单音／窄带干扰的绝大部分能量。

Suppression Techniques against Narrow-Band Interference in DS/SS Communications System

This paper first introduces a model of Spread-Spectrum communications system, then applies the software SYSTEMVIEW to the system simulation, and it gets to realize that the system owns a powerful anti-interference property by itself. It compares the output signals of receivers with different 'address codes', and indicates that the system can suppress interference caused by multiple access. Because of limited bandwidth, only relying on its spread-spectrum gain is not enough, therefore it is essential to add an adaptive filter before despreading. The paper testifies the availability of suppression against narrow-band interference, and analyzes the LMS algorithm. At last it simulates the whole course of filtering with MATLAB. The conclusion is that application of adaptive filter based on LMS algorithm can decrease Bit Error Rate near to zero, and suppress a majority of energy of jammer.