Abstract: In this paper, we describe iterative multiuser detection/decoding scheme, which was recently proposed in [8]. The multiuser detector and single-user turbo decoders are coupled such that after each turbo decoding iteration the extrinsic information of the interfering users is passed to the multiuser detector, and after each multiuser iteration, updated a posteriori probabilities are passed to the single-user turbo decoders as the soft input metrics. The impact of imperfect channel state information is taken into account. Simulation results indicate that amplitude estimation error of 1 dB results in performance degradation of 0.4 dB.
Key words: Multiuser detection, turbo codes, CDMA system.