Design of a turbo coded OFDM/CDMA transmitter-receiver with QPSK signal mapping

In this paper the performance of a turbo coded OFDM/CDMA system with QPSK signal mapping under additive white Gaussian noise (AWGN) with no fading and with multipath fading channel is analyzed and simulated. For turbo codes, the max-log-MAP algorithm is employed because it is a less complex sub-optimal algorithm for iterative decoding. Evaluation of the proposed receiver by means of computer simulation has shown substantial performance improvement for both non-fading and multipath fading environments under AWGN.