A 3-D Channel Model for Distributed MIMO Satellite Systems

This paper proposes a three dimensional channel model for the study of distributed MIMO communication systems, where the transmit antennas may be at different directions when viewed from the receiver. Examples of such systems include cooperative satellites and air based base stations. Both line of sight and multipath signal components are considered. A common difficulty of such channel models is that there are too many geometric parameters to produce analytical correlation functions of the antennas in order to gain insight on how the channel depends on those parameters. The difficulty is solved here by identifying a single key parameter, the projected distance, to summarize the effect of all the geometric parameters, and thus, the model is simple enough to be useful for system designers. Analytical correlation functions are provided, which is used to compare the rate of the MIMO and SIMO systems in order to demonstrate that with high probability, significant rate gain can be obtained by the distributed MIMO systems.