Selective Detection for Coded MIMO-OFDM Transmission

We present a novel technique for the detection of spatially multiplexed transmitted symbols in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. The method, termed Selective Detection, observes errors caused by a simple zero-forcing (ZF) on different OFDM sub-carriers, and selectively performs list sphere detection (LSD) on sub-carriers with larger errors. Compared with the full-complexity LSD, the proposed algorithms could significantly reduce the receiver complexity at a small signal-to-noise ratio (SNR) loss. For example, simulation results for a coded MIMO- OFDM system using four transmitters and four receivers with 16 quadrature amplitude modulation (16-QAM) and low density parity check (LDPC) coding show that more than 90% of SNR gain that can be achieved by the use of LSD over ZF can be achieved if only 20% of sub-carriers are intelligently selected for LSD.