LINEAR ADAPTIVE TRANSMITTER-RECEIVE STRUCTURES FOR ASYNCHRONOUS CDMA SYSTEMS

An asynchronous code-division multiple access (CDMA) system with adapt ive transmitters and receivers is considered. It is assumed that the a daptive receiver and transmitter have no knowledge of the signature wa veforms and timing of other users. The concept of adaptive transmitter is based on feedback information from the corresponding receiver. The information obtained from the receiver is used to calculate the optim um transmitter signature. The signatures are adaptively adjusted accor ding to the MSE criterion during the training period as well as during data transmission. CDMA systems employing the adaptive transmitters i n the presence of multiple access interference achieve the matched fil ter bound with no interference. The proposed CDMA system are tested by simulation over a channel with multiple access interference and addit ive white gaussian noise.