基于信号循环平稳模型的抗单音干扰算法

直接序列扩频通信系统解扩以前采用干扰抑制算法，可以显著增强抗窄带干扰性能，常用的干扰抑制方法为扩频信号建立的是平稳模型，但扩频信号是循环平稳信号，为此，建立了扩频信号的循环平稳模型，较平稳模型能保留更多信息，基于循环平稳模型提出了一种新的抗干扰算法，以研究抗单音干扰性能，实验证明，对于伪随机码长度为1024的扩频系统，在误码率要求为10^-4时，采用该算法扩频通信系统抗单音干扰容限可以提高2.5dB。

Interference Rejection Based on Cyclostationary Model

It is known that the narrowband interference rejection capability of a Direct Sequence (DS) Spread Spectrum (SS) system can be enhanced considerably by an interference rejection algorithm prior to correlting it with the Pseudo Noise (PN) sequence. The most popular suppression methods include NarrowBand Interference (NBI) predicting, excision techniques in frequency domain, zero forcing and adaptive subspace based techniques. All of them assume stationary SS signal, i.e. to analyze signals in average sense. In fact, the periodical characteristic of PN series makes the SS signal not stationary but cyclostationary. So, the SS signal was modeled as cyclostationary. Compared with the stationary model, it can preserve more information. Based on the cyclostationary model, a new interference rejection approach was introduced. The computer simulation shows that for a DSSS system with processing gain 1 024, under a certain Bit of Error (BER) 10 -4 , the tolerant single tone interference is increased by 2.5 dB.