复接入，B/W双用户使用直接扩频序列 ％ >>>multiple access b/w 2 users using DS CDMA ％ >>>format is : cdmamodem(user1,user2,snr_in_dbs) ％ >>>user1 and user2 are vectors and they should be of equal length ％ >>>e.g. user1=[1 0

功能：CDMA调变 multiple access b/w 2 users using DS CDMA-multiple access b/w 2 users using DS CDMA format is : cdmamodem(user1,user2,snr_in_dbs) user1 and user2 are vectors and they should be of equal length

2个用户的DS CDMA ，2个用户长度必须相等-multiple access b/w 2 users using DS CDMA user1 and user2 are vectors and they should be of equal length

DS-CDMA实现基本过程： <TRANSMITTING END>待传信息--NRZ变换（变成NRZ码）---调制（乘以sqrt(2*eb)*cos(2*w*t)）----扩频（乘以m序列或其他伪随机码） ----信道中传输（有加性噪声）<DURING THE CHANNEL> ---解扩（乘以相同的m序列或其他伪随机码）---解调（乘以sqrt(2*eb)*cos(2*w*t)）----比特判别（sum(i)>0-->1 sum(i)<0-