直接序列扩频利用与信息无关的伪随机码，以调制方法将已调制信号的频谱宽度扩展得比原调制信号的带宽宽得多的过程。-Direct sequence spread spectrum has nothing to do with the information of pseudo-random code modulated signal spectrum width modulation method will be extended than the original modulation signal bandwidth is much wider process.