Adaptive Coherent/Non-Coherent Spatial Modulation Aided Unmanned Aircraft Systems

UAVs are envisioned to be an important part of the device-centric IoT. These bespoke Unmanned Aircraft Systems (UASs) that support UAVs significantly differ from traditional terrestrial and aeronautical networks, both of which are evolving toward their next-generation forms. The major challenges of the UAS include augmented interference due to strong LoS, the dynamic shadowing effects owing to 3-D aerial maneuvering, the excessive Doppler shift owing to high UAV mobility, and the SWAP constraints. Against this background, we propose to invoke the recently developed coherent/non-coherent SM and its diversity-oriented counterpart of STBC-ISK. These arrangements employ multiple TAs in order to improve the network's QoS, but they only use a single RF chain. Furthermore, based on the throughput, delay and power-efficiency, we conceive a novel three-fold adaptivity design, where the UAS may adaptively switch between coherent and non-coherent schemes, switch between single- and multiple-TA based arrangements, as well as switch between high-diversity and high-spectral-efficiency multiple-TA based schemes.