窄带干扰抑制技术在直接序列扩频通信系统中的应用

The Application of Narrowband Interference Suppression in Direct Sequence Spread Spectrum

直接序列扩频通信系统的扩频增益受限,强功率的窄带干扰对其性能影响较大,为了提高系统的通信效果,需要采取信号处理技术来抑制干扰。笔者对可调谐数字外差滤波器进行了改进,提出了应用于直接序列扩频通信系统中的可调谐数字外差自适应陷波窄带干扰抑制技术,它是一种新的滤波器结构,能够自适应精确跟踪干扰频率,并能控制陷波的带宽及深度,具有较高的灵活性和实用性。通过仿真实验,该滤波器克服了其它处理方法的一些不足,具有滤波系数简单,稳定性好,适应性强,对系统性能影响较小,能跟踪快变的干扰等优点。

In order to improve the system effect, it is necessary take the technique of digital signal process to suppress interference, because of the finite gain and the narrow-band interference in system of direct sequence spread spectrum. The authors design a new filter structure improving on tunable digital heterodyne adaptive notch filters. This filter can adaptively track the interference frequency and control the bandwidth and depth of notch, which has the excellent agility and utility. The experiment proves this method overcomes limitation of other interference suppressions, hardly weaken the system performances, enhances the stability of the filter system, and can quickly track the interference frequency.