Concatenation of LDPC codes with Golden space-time block codes over the block fading MIMO channels: System design and performance analysis

The use of low-density parity-check (LDPC) codes over the multi-input multi-output (MIMO) channels has shown the performance to be achieved to the capacity limit. For the 2 × 2 MIMO system, the Golden codes were recently developed as the optimal space-time codes with a full rate and a full diversity gain. In this paper, we give the detailed system design for the concatenated coding scheme, which consists of the LDPC codes as the outer code and the Golden space-time block codes (STBC) as the inner code. The outer binary block codeword transforms itself onto the sequence of the internal space-time (IST) symbols according to a fixed constellation map. The soft-input soft-output (SISO) message passing decoder of the LDPC codes can be combined with a SISO constellation de-mapper as the Golden STBC decoder. They exchange the extrinsic messages in turbo-iterations. We evaluate the error performance for different block lengths of the proposed system. For the Golden codes concatenated with the LDPC codes, the maximum-likelihood union bound analysis is used for performance benchmarking.