Algorithm and architecture for joint detection and decoding for MIMO with LDPC codes

Abstract

With better spectral efficiency, multiple-input and multiple-output (MIMO) systems have drawn increasing attentions. Due to its near-optimal performance, K-best algorithm has been widely adopted for MIMO detection. To the best knowledge of the authors, this paper first proposes a joint detection and decoding (JDD) method for MIMO with low-density parity-check (LDPC) codes. By pruning the searching tree of K-best detection with LDPC coding constraint, the proposed JDD scheme benefits from both reduced tree-search complexity and improved performance compared to its uncoded MIMO counterpart. Numerical results of 16-QAM MIMO with (8, 2) LDPC code and 64-QAM MIMO with (18, 6) LDPC code have shown that, the proposed JDD scheme's performance is evidently superior over separated detection and decoding (SDD) scheme. More specifically, for the latter case with 12 antennas, JDD shows nearly 10 dB performance improvement than SDD when BER = 10−3. Hardware architecture and complexity analysis are also given in this paper to demonstrate JDD's advantages.