Non-binary and concatenated LDPC codes for multiple-antenna systems

Coded multiple-antenna systems are a promising solution to the provision of high data rate and bandwidth efficient wireless communications. Low-density parity-check (LDPC) codes achieve excellent coding gains in AWGN channels. LDPC codes applied to multiple antenna systems have been considered by a number of authors where good results have been achieved. In this paper, the performance of non-binary LDPC codes is investigated in a LDPC modulated system, whereby the output of the LDPC encoder is modulated and mapped to multiple transmit antennas. Furthermore a serially concatenated system, employing an outer non-binary LDPC code and an inner space-time trellis code, is proposed. Simulation results show that non-binary LDPC codes outperform binary LDPC codes in the LDPC modulated system and that the concatenated system outperforms the LDPC modulated system