Sphere-Packing Modulated Space-Time Coding Using Non-Binary LDPC-Coded Iterative-Detection

A recently proposed Space-Time Block Coding (STBC) signal construction method that combines orthogonal design with sphere packing, referred to here as (STBC-SP), has shown useful performance improvements over Alamouti’s conventional orthogonal design. In this contribution, we propose a purely symbol-based LDPC-coded scheme, demonstrating that the performance of STBC-SP systems can be further improved by concatenating sphere packing aided modulation with non-binary LDPC and by performing symbol-based turbo detection between the non-binary LDPC decoder and a rate-1 non-binary inner precoder. We also investigate the convergence behaviour of this symbolbased concatenated scheme with the aid of novel nonbinary Extrinsic Information Transfer (EXIT) charts. Finally, we demonstrate that in the investigated scenarios it requires 1-2dB lower power in comparison to equivalent effective throughput 0.5, 0.75 and 1 bit/symbol systems employing bit-based turbo detection