Ergodic Capacity Analysis in an Energy Harvesting Cooperative NOMA Network

Abstract

본 논문에서는 에너지 하베스팅과 복호 후 전달 방식을 사용하 는 중계기가 있는 비직교 비직교 다중접속 시스템에 시스템에 대해 연구한다. 송신 기와 중계기 사이 및 중계기와 수신기 사이의 신호대간섭잡음비의 누적분포함수을 유도하여 시스템의 단대단 에르고딕 전송 용량을 분석한다. 모의 실험을 실험을 통해 시스템의 단대단 단대단 에르고딕 전송 용량 의 분석 결과가 실험 결과와 일치함을 확인한다.

Non-orthogonal multiple access (NOMA) is a promising technology for the fifth generation (5G) wireless communication systems. NOMA improves the system capacity and user fairness compared to the conventional orthogonal multiple access (OMA). Cooperative communication is widely used to extend the communication range and reception reliability. Energy harvesting (EH) is an efficient way to the improve energy efficiency of the network. In this thesis, we investigate a cooperative NOMA network with a decode-and-forward (DF) relay which harvests energy from the received signal using power splitting. A relay deployed in the network helps the transmission from the source to the users. Channel order indicator is adopted to ensure that more power is allocated to the instantaneous weak user. We derive the analytical expressions for the end-to-end ergodic capacities between the source and the users. Simulation results show that the ergodic capacities of the users increase as the source transmit power increases. It is also shown that the end-to-end ergodic capacity from the source to the user closer to the relay decreases as the power allocation coefficient for the weak user increases while that from the source to the user farther to the relay increases.