BER Performance of Convolutionally Encoded MIMO-CDMA Employing Permutation Spreading and Soft Decision Decoding

In this paper we propose a soft output detector for the MIMO-CDMA systems with permutation spreading. In such systems, the spreading waveforms of each transmit antennas are dependent on the data to be transmitted. In the proposed system, information bits are convolutionally encoded prior to being used in a MIMO-CDMA system with permutation spreading. Reliability of the detected bits in the receiver is calculated in the form of LLRs and then used as the input of a soft input Viterbi decoder. The performance of the proposed system is compared to conventional coded MIMO-CDMA systems.