A new spatial modulation scheme based on quasi-orthogonal sequences

In this paper, we propose a new spatial modulation (SM) scheme based on quaternary quasi-orthogonal sequences (Q-QOSs), referred to as Q-QOS-SM. Unlike an original SM scheme, the proposed scheme uses the indices of the Q-QOSs for mapping of input bits, resulting in two times more bits to be allocated to an antenna-selection part compared to the original SM. From simulation results, the Q-QOS-SM is shown to achieve much higher bit throughput than the existing SM and generalized SM schemes for all simulation cases.