A Virtual MIMO Relay System with Unmanned Aircraft and Multiple Ground Stations

This paper proposes a virtual MIMO system model for the unmanned aircraft system (UAS) that consists of a small unmanned aircraft (UA) and multiple ground stations (GSs). Since it is difficult to equip a small UA with multiple antennas due to the limitation of its payload, the proposed system exploits a mobility of the single-antenna UA to realize virtual MIMO channels. The channel is assumed to be either Rayleigh or Rician fading, and in the case of Rician, we also investigate the case where the UA fails to receive the line-of-sight (LOS) path due to some turbulence as a probabilistic event. The comparison of the bit error rate (BER) performance through computer simulations shows that when the channel fading is severe or the LOS path is lost with non-negligible probability, a significant improvement of BER performance can be achieved by the diversity gain through the proposed virtual MIMO approach.