Joint spatial modulation and beamforming based on statistical channel state information for hybrid massive MIMO communication systems

Spatial modulation is a promising transmission scheme for massive multiple-input multiple-output (MIMO) systems to improve energy efficiency. In this study, considering the low-complexity hybrid structure, the authors propose a joint spatial modulation and beamforming scheme for a hybrid massive MIMO system in both single user and multi-user scenarios. Specifically, a design criterion of the channel control parameter is provided to reduce the high correlation among different channel coefficients in the hybrid massive MIMO system. In addition, with the statistical channel state information acquired at the base station, the optimum analogue beamforming vectors are designed with the goal of maximising the signal to leakage and noise ratio in the multi-user scenario. Furthermore, the upper bound, the lower bound as well as the closed form approximation of achievable spectral efficiency of the proposed scheme are derived for both single user and multi-user scenarios. Numerical simulation results demonstrate that the proposed scheme outperforms the conventional MIMO scheme.