Achievable Rate Maximization in MIMO-BICM Systems: A Unified Transceiver Design

Transceiver designs for multiple-input multiple-output (MIMO) systems have been extensively studied in the past decades. However, in the context of finite constellation inputs, existing transceiver designs do not guarantee optimal performance across all SNR ranges or varying code rates. In this paper, we propose a novel maximum achievable rate transceiver (MART) design for bit-interleaved coded modulation in MIMO (MIMO-BICM) systems. Our proposed MART scheme combines channel matrix decomposition and decision feedback equalization (DFE), decomposing the MIMO channel into multiple parallel subchannels. We establish a tight lower bound for achievable rates in MIMO-BICM, based on which we transform the sophisticated problem to the optimization of the output signal-to-noise ratios (SNRs) of subchannels. We consider the achievable rate maximization under both zero-forcing (ZF) and minimum mean-square error (MMSE) criteria and provide a unified solution framework for both two problems. To simplify the optimization process, we further propose an alternative near-optimal scheme for both ZF and MMSE problems. Numerical results show the optimality of the proposed MART scheme across all SNR ranges, demonstrating its potential in practical MIMO-BICM systems.