Low-Complexity Improved-Rate Generalised Spatial Modulation: Bit-to-Symbol Mapping, Detection and Performance Analysis

Low-complexity improved-rate generalised spatial modulation (LCIR-GSM) is proposed to mitigate the high complexity of the mapping book design and demodulation of variable-${N_a}$ GSM. Specifically, first of all, we propose two efficient schemes for mapping the information bits to the transmit antenna activation patterns, which can be readily scaled to massive MIMO setups. Secondly, we derive a pair of low-complexity near-optimal detectors, one of which has a reduced search scope, while the other benefits from a decoupled single-stream based signal detection algorithm. Finally, the performance of the proposed LCIR-GSM system is characterised by the improved error probability upper bound. Our simulation results confirm the improved error performance of our proposed scheme, despite its reduced signal detection complexity.