On MIMO-OFDM with Coding and Loading

Orthogonal frequency-division multiplexing (OFDM) with multiple transmit and multiple receive antennas (MIMO-OFDM) is considered a candidate for high-data rate communication in various existing and forthcoming system standards. To achieve the usually desired low frame and bit error rates, MIMO-OFDM should be combined with adaptive bit loading (ABL) and forward error correction (FEC) coding, where the former is particularly apt for moderate mobility as considered in, for example, IEEE 802.16e OFDM systems. In this paper, we investigate "simple" coding schemes and their combination with ABL for MIMO-OFDM. In particular, we consider wrapped space-frequency coding (WSFC) and coded V-BLAST with ABL and optimize both schemes to mitigate error propagation inherent in the detection process. Simulation results show that bit-loaded WSFC and V-BLAST optimized for coded MIMO-OFDM achieve excellent error rate performances, close to that of quasioptimal MIMO-OFDM based on singular value decomposition of the channel, while their feedback requirements for loading are low.