扩展频谱通信系统是指待传输信息的频谱用某个特定的扩频函数扩展后成为宽频带信号，送入信道中传输，再利用一定手段将其压缩，从而获取传输信息的通信系统。

在传输同样信息时所需的射频带宽，远比我们已熟知的各种调制方式要求的带宽要宽得多。扩频带宽至少是信息带宽的几十至 几万倍。-spread spectrum communication systems refer to the transmission of information with a particular spectrum of spreading function expansion into broadband signal into Channel Tunnel, and then use some of its means of compression, thus acquiring the transmission of information communication systems. In the same transmission of information necessary for RF bandwidth than we have been familiar with the various requirements of the modulation bandwidth to a much wider. Spreading information bandwidth is the bandwidth of at least a few dozen to several tens of thousands of times.