An iterative receiver for groupwise bit-interleaved coded QAM STBC OFDM

A groupwise bit-interleaved coded quadrature amplitude modulated (BICQAM) space-time block coded (STBC) orthogonal frequency division multiplexing (OFDM) system is studied in this paper, to exploit both the capacity and transmit diversity gains in wideband frequency selective channels. A "turbo" receiver is deployed to further exploit the diversity gains from receive antennas. Through iteratively exchanging soft information between the detector and the decoder, the receiver can achieve the performance of a single-group BICQAM STBC OFDM system after four to five iterations. Simplified interference estimation is then proposed to reduce the computational complexity. Simulation results show that only marginal performance degradation is introduced by this simplification.