Simple MAP Detector for Coded MIMO System

Abstract

In 1974, BCJR algorithm[1] was invented for maximum a posteriori (MAP) decoding of error correcting codes defined on trellises. In this paper, we apply BCJR algorithm to the detector for coded multiple-input multiple-output (MIMO) system to achieve high detection performance. With known channel information, coded MIMO detector can compute loglikelihood ratio (LLR) on the channel trellis by BCJR algorithm. We also propose a simple BCJR algorithm with computational cost reduction. Simulation results show that BCJR algorithm achieves higher performance than maximum likelihood (ML), and there is negligible performance difference between proposed simple method and conventional BCJR algorithm.