直接序列扩频系统中的窄带干扰抑制

Suppression of Narrow-band Interference in Direct-sequence Spread-spectrum Systems

扩频技术在新兴的个人无线通信中得到了广泛的应用。由于可用频带的限制,扩频通信系统要与现有的窄带通信系统共享相同的频带,而且扩频信号的幅度相对于窄带信号的幅度要小很多。尽管扩频通信系统自身具有抗窄带干扰的能力,但当存在窄带干扰的时候,有效的窄带干扰抑制技术可以提高系统性能。该文主要对最小均方误差检测技术抑制窄带干扰进行了研究,分析了其性能及自适应算法的实现。仿真结果证明,应用最小均方误差检测可以有效地对抗数字窄带干扰。

Spread- spectrum technique has been widely used in the burgeoning individual wireless communication. Because the practicable frequency bands are limited, spread - spectrum system shares the same frequency bands with narrowband system, and the altitude of spread - spectrum signals is much lower than that of narrowband signals. Although spread - spectrum systems enjoy a natural immunity to narrowband interference （NBI）, their performance in the presence of such interference can be enhanced by active NBI suppression techniques. In this paper, we focus our attention on MMSE detector to suppress NBI, analyse its performance and its adaptation algorithm. The simulation results show that MMSE detector can suppress the NBI effectively.