MIMO-OFDM optimal decoding and achievable information rates under imperfect channel estimation

Abstract

Optimal decoding of bit interleaved coded modulation (BICM) MIMO-OFDM where an imperfect channel estimate is available at the receiver is investigated. First, by using a Bayesian approach in- volving the channel a posteriori destiny, we derive a practical de- coding metric for general memoryless channels that is robust to the presence of channel estimation errors. Then, we evaluate the out- age rates achieved by a decoder that uses our proposed metric. The performance of the proposed decoder is compared to the classical mismatched decoder and a theoretical decoder defined as the best de- coder in the presence of imperfect channel estimation. Numerical re- sults over Rayleigh block fading MIMO-OFDM channels show that the proposed decoder outperforms mismatched decoding in terms of bit error rate and outrage capacity without intorducing any additional complexity.