Random Access NDMA MAC Protocols for Satellite Networks

Random Access (RA) approaches in satellite networks may limit the achievable energy efficiency due to the random nature of channel access, especially when hand-held terminals must operate with a very low signal-to-noise ratio. This paper shows that Network Diversity Multiple Access (NDMA) principles can be used to provide an energy efficient RA scheme which satisfies some Quality of Service requirements. The paper proposes performance models for the throughput and energy efficiency considering a finite queue at each terminal and multiple packet retransmissions. Optimal parameters are calculated to maximize the energy efficiency while satisfying the throughput and error requirements, taking into account the bit-rate constraint. The proposed system’s performance is evaluated for a Single-Carrier with Frequency Domain Equalization (SC-FDE) scheme at the uplink. Results show that the proposed system is energy efficient and can provide sustained bandwidth.