A MIMO Radio Channel Model for Low-Altitude Air-to-Ground Communication Systems

Air-to-Ground (A-G) communication networks play an important role providing wireless access to areas that lack cellular or satellite infrastructure. The use of Multiple-Input Multiple-Output (MIMO) technology has been considered to increase the data rate and range of these systems, and over-the-air experiments have shown promising results, however, they lack a detailed characterization of the A-G channel. In this paper an extension to the Geometric Air-to- Ground Ellipsoidal (GAGE) radio channel model is proposed to predict the performance of MIMO for low- altitude A-G systems. The geometry and propagation loss characteristics of the model are defined, and example results for a hilly rural environment are shown for 2x2 Spatial Multiplexing (SMX) and Space-Time Block Coding (STBC). The results predict that an uncoded multi-carrier system can use STBC for gains up to 16 dB or use SMX to increase the throughput by a factor of two.