直扩码分多址DS-CDMA是利用高速的WALSH正交码序列作为地址码，与多用户信息数据相乘得到信息数据的直接扩频信号，再经过BPSK调制后发送出去，经过AWGN无线信道的传输后，在接收端与本地产生的地址码进行相关检测，从中将地址码与本地码一致的用户数据选出，把不一致的用户数据删除。-DS-CDMA DS-CDMA is the use of high-speed WALSH orthogonal code sequences as address code, with multi-user in

This m file generates a DS BPSK transmitter(spread spectrum) using PRBS s which are modulus 2 added(exclusive ored)with the message and then used to BPSK modulate a carrier.

一个简单的直扩系统，包含卷积编译码，BPSK调制，M序列扩频-A simple DS system, including the convolution coding and decoding, BPSK modulation, M-sequence spread spectrum