Building entry loss and capacity evaluation of a UAV‐to‐indoor dual‐polarised MIMO channel

Abstract

This study presents building entry loss and capacity results obtained from an unmanned aerial vehicle (UAV)‐to‐indoor narrowband dual‐polarised multiple‐input–multiple‐output (MIMO) channel measurement campaign. Six different measurement scenarios were carried out with the transmitter (Tx) located on a low altitude platform (LAP) and the receiver (Rx) at various floors and distances from the external windows of a multi‐storey building. An analytic and simple procedure is proposed for the calculation of entry loss. The results reveal that there is a strong dependence on the propagation geometry and the orientation of the receiver with respect to the moving LAP transmitter. The processed data for both entry loss and capacity indicate a two‐state process that is closely related to the Tx–Rx relative azimuth and elevation angle. The average entry loss levels vary from 33 to 50 dB. The overall ergodic capacity varies between 3.1 and 4.1 b/s/Hz with insignificant variations with the floor level and the distance from the window. Finally, the K‐factor of the channel lies below 6 dB tending to decrease with higher elevation angles.