Hybrid MMSE and SIC for multiuser detection

The near-far problem limits both the system performance and the overall network capacity in the reverse link of a DS-CDMA system. In this paper, we propose a MMSE/SIC hybrid algorithm, which first divides the users into groups, with each group consisting of users with a close power level. The successive interference cancellation (SIC) is then used to distinguish users among different groups, while the MMSE-MUD is used to detect users within each group. As such, the computational complexity of the MMSE-MUD and the latency problem in the SIC can thus be greatly mitigated. Simulation results also show that the new algorithm performs better than both of the MMSE-based MUD and the SIC-based MUD algorithms.