Non-Unitary Super Orthogonal Differential Space-Time Trellis Coding and Decoding

In this paper, a non-unitary differential space-time coding scheme is proposed based on the super orthogonal space-time trellis coding scheme (SOSTTC). First, we extend the SOSTTC scheme to support quadrature amplitude modulation (QAM) constellations. Then we present a differential space-time coding scheme based on these power-efficient SOSTTCs. Several low-complexity suboptimal differential decoders are developed based on the per-survivor processing technique (PSP). The performance analysis shows that the proposed PSP decoding schemes only have a 0.4dB performance loss compared with the coherent scheme under slow fading channels. Simulation results demonstrate that the proposed scheme can achieve much higher coding gain compared with the known unitary space time codes in the high data rate region.