Low complexity iterative receiver for multiuser STBC block transmission systems

In this paper, a low complexity space-frequency iterative detection and decoding scheme is developed for multiuser space-time block-coded (STBC) block transmission systems, such as the cyclic prefix based single-carrier block transmission (CP-SCBT) system and OFDM system. Using the algebraic properties of such systems, the MMSE-based turbo detection algorithm can be implemented in the frequency domain and then the complexity of the matrix inversion can be reduced greatly. The performance of the iterative receiver for multiuser STBC block transmission systems with bit-interleaved coded modulation (BICM) is evaluated in mobile multipath frequency selective channels through computer simulations. It has been shown that the proposed receiver significantly outperforms the conventional noniterative receiver. Moreover, at high signal-to-noise ratio, the detrimental effects of multiple-access interference (MAI) and intersymbol interference (ISI) in the channel can almost be completely overcome by the turbo processing, and the performance is very close to that of BICM in a Gaussian channel.