Capacity Analysis of Terrestrial Antenna Array in Distributed Satellite MIMO Communication System
Cong Li, Hongpeng Zhu, Jun Cai, Jing Hu, Guang Li, Guangxia Li
Abstract
Multiple-Input Multiple-Output (MIMO) techniques are able to enhance the channel capacity by multiplexing the space dimension resources. By constructing distributed satellite MIMO scenarios, MIMO techniques can be potentially employed to satellite communication networks. In this paper, we study the capacity performance of a distributed satellite communication network with the MIMO scheme that contains two geostationary earth orbit (GEO) satellites and a terrestrial antenna array. Specifically, the model of two kinds of terrestrial antenna array, uniform linear array (ULA) and uniform circular array (UCA), are proposed and the coordinate representation of the array elements is provided by coordinate system transformation. Then, the analytical expressions of the system capacity with different antenna arrays are derived considering the rotation angle of the antenna array. The Min-Max ratio is investigated for both ULA and UCA to gain further insights of the system capacity performance. Finally, numerical simulations are provided to validate the analytical expressions, show the impact of the rotation angle and other system parameters on the capacity performance. The research results show that ULA is preferred for terrestrial users with fixed locations and the maximum channel capacity can be obtained through adjusting the rotation angle while UCA is not only suitable for fixed locations, but can also be used in mobile scenarios such as vehicles, ships to ensure the stability of the system capacity.