Differential Super-Quasi-Orthogonal Space-Time Trellis Codes

This paper proposes a new differential super-quasi- orthogonal space-time trellis codes (SQOSTTC) with single- symbol maximum-likelihood (ML) decoding. Firstly, a new joint constellation, which can be used to construct a unitary matrix for quasi-orthogonal space-time block code (QOSTBC), is designed. Secondly, based on the joint constellation and criterion of maximizing the coding gain distance (CGD), set-partitioning is done. Finally, we introduce the simple single-symbol maximum- likelihood (ML) decoding. Simulation results show that our differential SQOSTTC can get better performance than the differential super-orthogonal space-time trellis code (SOSTTC) [5] with four transmit antennas at the transmission rate of 1.5 bits/s/Hz and lower decoding complexity than the differential super-pseudo-orthogonal space-time trellis codes (SPOSTTC) [13] and the differential SOSTTC [14] at the transmission rate of 2 bits/s/Hz.