Turbo joint detection algorithm for multiple-input multiple-output code division multiple access system

A new uplink encoding multiple-input multiple-output code division multiple access based on random layered space-time (RLST) is proposed. A spatial-time interleaver between each transmitting antennas is inserted in RLST, so that the encoded bits can be transmitted on random layers. At node B, by applying the Turbo principle to the receiver, a new Turbo joint detection (Turbo-JD) receiver is proposed, which is composed of a soft-in soft-out space time multi-user joint detector and some soft-in soft-out decoders. The partner's external information is used by detectors and decoders as their prior information through the feedback encoding bit, and the bit error rate (BER) of the system is gradually depressed by iterative method. The simulation shows that the Turbo-JD algorithm is able to acquire approximate 3.4 dB gain after 3 iterations when BER is 10^-4.