Generalised spatial modulation for large-scale MIMO

In this paper, the performance of generalised spatial modulation (GSM) and spatial modulation (SM) is studied assuming channel estimation errors (CSEs) and correlated Rayleigh and Rician fading channels. A new, simple, accurate and general analytical closed-form upper bound for the average bit error ratio (ABER) performance of both systems is derived. The analytical bound is shown to be applicable to correlated and uncorrelated channels, as well as to small and large scale multiple-input multiple-output (MIMO) systems. The results demonstrate that GSM is more suitable for large-scale MIMO systems than SM. The performance gain of GSM over SM is about 5 dB. The results also show that SM is very robust to CSEs. Specifically, the performance degradation of SM in the presence of CSEs are 0.7 dB and 0.3 dB for Rayleigh and Rician fading channels respectively. Lastly, the findings in this paper underpin the suitability of both GSM and SM for future large-scale MIMO systems.