Radio Propagation Channel Measurements for Multi-Antenna Satellite Communication Systems: A Survey

For the terrestrial infrastructure, the multiple-input multiple-output (MIMO) architecture is a key technology that has brought the wireless gigabit vision closer to reality. Satellite communication systems have not been immune from this wave of innovation, and theoretical and experimental efforts have recently been devoted to the investigation of the applicability of multiple-antenna techniques to these systems. This paper intends to highlight and critically present the most important results from measurement campaigns conducted to characterize the radio channel of multi-antenna satellite systems. Emphasis is given on the viability of MIMO technology over satellite, and the potential enhancements in terms of channel capacity and link reliability that can be achieved through spatial and/or polarization diversity. The configurations under investigation range from very simple single-input multiple-output (SIMO) systems, with multiple antennas only at the terrestrial receiver, to quite complex and challenging systems, such as dual-satellite multiple-input single-output (MISO) systems, and single-satellite dual-polarized MIMO systems. The spotlight is on land mobile satellite (LMS) systems in outdoor radio propagation environments. However, satellite-to-indoor reception is also included.