High speed radio communication technology using parallel combinatory CDMA under multipath Rayleigh-fading interference environment
M. Watanabe, Osamu Kato, Eiji Katsura, Koichi Homma · 2002
The CDMA system is a next generation access technique that holds the promise of greatly increased capacity for cellular systems. We propose a convolutional coding and soft decision Viterbi decoding method applicable to a parallel combinatory CDMA (PC-CDMA) system. In the proposed method, branch metric is calculated for every four bits by weighting the output levels of the PC-CDMA correlators to introduce bit interleaving and soft decision to the system. The result of our simulation using this method under a multipath Rayleigh-fading interference environment shows a BER of 10/sup -5/ or less for the transmission of a 1.92 Mbps data stream at a chip rate of 7.68 Mcps.