直扩系统最佳接收条件下的处理增益研究

Processing Gain of Optimal Receiver of Direct-sequence Spread-spectrum System

目前在计算直扩系统的扩频处理增益时一般都是采用求扩频前后带宽之比的公式,这个公式求出的只是一个近似值,而且近似程度不高。针对这一问题,文章分析了直扩系统的最佳接收机,提出了直扩系统的无信息码元间串扰的条件,并在此基础上推导出在白噪声及窄带干扰下的扩频处理增益的一个较精确的公式,得出了窄带干扰下的扩频处理增益的最大值及达到最大值的条件。

Up to now, the ratio between bandwidth before spreading spectrum and bandwidth after spreading spectrum is commonly used to calculate the processing gain of direct - sequence spread - spectrum System. The value is a approximate one. Therefore,in this paper,optimal receiver and the qualification of eliminating intersymbol interferences are introduced. And then, based on them, an accurate formula on processing gain with white noise or narrow band interference is deduced. Furthermore, with narrow band interference, the maximum of processing gain and how to get it are pointed out.