Performance of turbo coded Space-Time transmit diversity aided IDMA system

Abstract

In this letter, we investigate the bit error rate performance of turbo coded Multiple-input Multiple-output (MIMO) assisted-interleave division multiple access (IDMA) system over correlated frequency-selective channels for down-link (DL) communications. In this contribution, we realize MIMO profile using Alamouti Space-Time transmit diversity (STTD) which offers full rate and full diversity. We implement such STTD architecture by utilizing two transmit antennas at the base station(BS)and two receive antennas at each mobile station(MS).We consider parallel concatenated convolutional encoder as a channel encoder at the transmitter side. We employ Maximum Likelihood (ML) detection algorithm based on non-linear multi-user detection to estimate the desired users' signals at the MS. Further, we exploit the iterative decoding technique based on maximum log-MAP decoding algorithm to achieve necessary coding gain. Our simulation results reveals that our considered coded STTD-IDMA system with ML detection algorithm provides better bit error performance with less signal to noise ratio for DL communications.