Design and analysis of novel Ka band NOMA uplink relay system for Lunar farside exploration

Abstract

This paper proposes a novel Ka band non-orthogonal multiple access (NOMA) uplink relay system for Lunar farside exploration, where a satellite relay node with the help of NOMA scheme, amplifies and forwards the signal from the Earth Base Station (EBS) to a Lunar rover and a lander. We assume that the signal undergoes shadowed-Rician fading for the source-relay link and Rayleigh fading for the relay-destination link. Then, the analytical expressions for the outage probability (OP) and ergodic capacity are derived for the satellite relay node equipped with single and multiple antennas, respectively. In addition, we obtain the optimal power allocation coefficients by maximizing the sum ergodic capacity of the system, and we calculate the power consumption of the NOMA uplink relay system to achieve the same OP performance of OMA system and provide some useful guides for the design of the Earth-to-Lunar communication system. Simulations are provided to confirm the reliability of our analytical results and show the impact of various parameters on the system performance.