Performance improvement of a frequency hopping-CDMA system utilizing memorized prior data

An algorithm for improving the stability and throughput of a frequency hopping code-division multiple-access system (FH-CDMA) is presented. The algorithm includes a multiple block transmission with error-detection block(s) and a logical AND-operation between previously received (erroneous but saved) data, and retransmitted data. The packet success probability of the new algorithm is formulated and the improvement in stability is shown in terms of the proportion of retransmission users in the system under various conditions, including the new packet generation probability, retransmission probability, different signal-to-noise ratio in the channel, and the number of blocks in a packet. The average drift of retransmission users and the analysis of the expected number of retransmissions were used to evaluate the stability performance of the retransmission strategy