Multiuser receiver scheme for the CDMA system based on full-rate space-time coding
YU Xiang-bin · Journal of Xidian University · 2007
A full-rate space-time coding based CDMA system model is firstly given.Considering that the existing space-time coded CDMA system has high decoding complexity,a low-complexity multiuser receiver scheme is proposed.In this scheme,each user employs the multiuser detection method to achieve the single user receiver signal form,which benefits the application of complex orthogonality of space-time coding.After maximum ratio combination,the decoding computation is only simple linear combination,and thus the exponential decoding complexity of the existing scheme is effectively decreased.On the condition of the same system throughput,the given system can adopt the low-order modulation scheme,and utilize more spatial redundant information.As a result,the concatenation of channel coding significantly strengthens the transmission reliability of the system in the fading channel.Simulation results also show that the system has a lower bit error rate than corresponding full-diversity space-time coded CDMA systems.