Outage Performance for Multiuser Threshold-Based DF Satellite Relaying

Satellite communication plays an important role in future seamless wireless network. In this paper, we investigate the system outage performance of a multiuser threshold-based decode-and-forward (DF) satellite relaying network, where the satellite employing spot beam technology is used as an aerial relay to assist the signal transmission between the terrestrial equipments with multi-antenna. Assuming that maximum ratio transmission (MRT) and maximum ratio combining (MRC) are utilized to achieve the optimal performance, we first obtain the equivalent output signal-to-noise ratio (SNR) expression of the considered system, where frequency division multiplexing access (FDMA) scheme is exploited in the uplink. Then, we derive the closed-form system outage probability (SOP) expression for the considered system, where both uplink and downlink are subject to shadowed-Rician (SR) fading with path loss and antenna gain being considered. The main advantage of our theoretical formula is that it can be used in the case of integer and rational Nakagami- $m$ fading parameters. Furthermore, asymptotic SOP formula at high SNR is also presented to show the diversity order and coding gain of the considered system. Finally, simulation results are provided to verify the correctness of the exact and asymptotic SOP expressions and reveal the effects of representative parameters on the system outage performance of the satellite relaying system with threshold-based DF protocol.