直接序列扩频通信系统的仿真，信道中加入高斯白噪声，扩频比为512，调制方式为BPSK。扩频序列可选m序列或者Gold序列，编码方式可选不编码或者卷积编码。-Simulation of direct sequence spread spectrum communication system, the channel joined the Gaussian white noise, the spreading ratio is 512, the modulation scheme is BPSK.