Impact of the Receive Antenna Arrays on Spatio-Temporal Availability in Satellite-to-Indoor Broadcasting

This contribution presents the results of our study on spatio-temporal availability in satellite-to-indoor broadcasting. We compare the performance of single and multiple antenna arrays consisting of theoretical and measured antennas with various polarimetric radiation patterns and coupling effects for different satellite elevation angles. The spatial satellite to indoor channels are obtained by a 3D ray tracing engine and by a geometry-based channel modeling tool. The temporal fluctuations of the channels are modeled by the PDF of a truncated normal distribution and are based on satellite-to-indoor measurements. The additional antennas at the receiver reduce both the spatial and the temporal variability of the received power, leading to a significant reduction of the transmit power required to achieve the same target availability. The simulation results suggest that the spatial correlation in the line-of-sight room area is higher than in the non-line-of-sight room area. In the line-of-sight areas, the best performance is achieved by multiple circularly polarized receive antennas. For elevations higher than 50 in the non-line-of-sight areas, a combination of horizontally and vertically (orthogonal) polarized antennas shows the best performance, especially if high availabilities are considered. Furthermore, the influence of coupling effects between closely spaced receive antennas on the availability is studied. In general, antenna coupling effects should be handled by increasing the required link margin. The influence of the temporal changes due to a person movement on the availability is found to be not very significant.