DSSS系统中自适应时变小波包干扰抑制

提出了一种基于自适应时变小波包变换实现直接序列扩频通信系统时变窄带干扰抑制的方法。该方法在自适应时域分解的基础上，利用小波包变换多分辨分析能力和良好的时频特性进行频率分解，将有用信号和干扰分离，然后将受扰频带置零后进行小波包合成，达到滤除时变窄带干扰的目的。计算机仿真结果表明，该方法与非时变自适应小波包抑制技术相比较，以计算复杂度为代价，能更灵活有效地跟踪和定位时变干扰，提供较好的误码率性能。
关 键 词 时域分解; 自适应小波包变换; 时变干扰; 扩频通信

Abstract In this paper, an adaptive time-varying wavelet packet transform (WPT) excision algorithm is proposed for time-varying narrowband interference (TVNBI) in DSSS communication. Based on time decomposition, this method takes advantage of multi-resolution capability and favorable time-frequency character of WPT to perform frequency decomposition, separate desirable signal from jamming signal, the DS signal is recovered by wavelet reconstruction after setting zeros to polluted frequency sub-band. Computer simulation results show that compared with the non-time-varying WPT technique, this method could efficiently search and locate the TVNBI, provide satisfied bit error rate (BER) performance at the cost of increasing computation.
Key words time decomposition; adaptive wavelet packet transform; time-varying interference; spread spectrum