Differential Full Diversity Spatial Modulation using Amplitude Phase Shift Keying

Diversity is a fundamental concept used to reduce the adverse effects of fading in wireless communications. Differential full diversity spatial modulation (DFD-SM) is a differential spatial modulation (DSM) scheme that makes use of a cyclic signaling phase shift keying (PSK) constellation to achieve transmit diversity. In this paper, firstly, we extend the work of DFD-SM to improve its throughput and/or error performance, by making use of an amplitude phase shift keying (APSK) constellation. Next, a power allocation concept (PAC) based on generalized differential modulation (GDM) is applied to DFD-SM using APSK. Finally we derive a theoretical upper bound on the average bit error probability (ABEP) for DFD-SM using APSK. It is shown through Monte Carlo simulations that the proposed DFD-SM using APSK scheme outperforms conventional DFD-SM by approximately 1 dB at the same throughput, and that the proposed power allocation scheme provides an approximate 3 dB gain over the conventional scheme.