A Novel Channel Model for 3-D HAP-MIMO Communication Systems

This paper proposes a novel channel model for three-dimensional (3-D) High Altitude Platform (HAP) multipleinput multiple-output (MIMO) communication systems. Due to the movement of HAP and receiver, the “disappeared” scatterers could “appear” again after a certain time. A birth and death process is used to model the non-stationary properties that scatterers “appear” and “disappear” relative to the transmit or receive antenna elements on the time axes. In this paper, we consider that the same scatterer could “appear” again after its “disappearance”. The space-time correlation function of the proposed 3-D HAP-MIMO channel is derived in this paper. Numerical results show that the proposed model is able to capture characteristics as observed in measurements.