Performance analysis of decode-and-forward partial relay selection in NOMA systems with RF energy harvesting

Abstract

In this paper, we investigate a dual hop communication decode-and-forward scheme relay system where a source node wants to transmit simultaneously two symbols to two desired destinations with the help of one selected energy constraint relay node. The power for operation of relay is come from the ambient radio frequency energy harvesting and the non-orthogonal multiple access technology is applied. We mathematically evaluate the impact of partial relay selection on the system performance by considering the undecodable probability of symbol for which symbols can not be decoded at the relay node or two destinations. Furthermore, the undecodable probability and the ergodic capacity are analyzed under the effect of imperfect and perfect successive interference cancellation (SIC). The results of theoretical analysis is similar to the simulation results, especially in the high region of transmit power. It verifies the correctness of mathmatical closed-form in our analysis. The results also show that the performance of the system are significantly influenced by the efficiency of SIC technology and the number of relay nodes.