Reducing RF resource for 5G communication networks: A spatial modulation motivated approach

Multiple-input multiple-output (MIMO) techniques have constituted a key approach to facilitate the rapid data traffic growth in future 5G communication networks. However, the high cost and low efficiency nature of radio frequency (RF) resource has unfortunately reduced the benefit of MIMO. While spatial modulation (SM) technique has recently been proposed to reduce the RF resource for conventional small-scale MIMO systems, it is unclear if future 5G communication network, where conventional MIMOs encounter much different challenges, still embraces the benefits of SM. In order to address this issue, in this paper the application of SM in 5G communications is discussed, where we propose to incorporate SM into i) massive MIMO systems, and ii) millimeter wave (mmWave) MIMO systems, to strike a better tradeoff between energy efficiency and spectral efficiency for future wireless communications. It is revealed in this paper that SM is capable of improving the transmission data rates for 5G communication networks while maintaining an equal scale of RF resource occupancy, which therefore motivates the fruitful application of SM in 5G communications.