Time switching based relaying for coordinated transmission using NOMA

Simultaneous Wireless Information and Power transfer (SWIPT) is a technique that allows energy harvesting and processing of the received data at the same time. If these two tasks are done one-by-one, SWIPT is said to be using time switching (TS) mechanism. TS is a unique way of mutually scavenging energy and transferring information by slicing the time into two slots for achieving the energy harvesting and information transmission goals together. This paper examines the performance of TS-based SWIPT in a wireless network, where an out-of-coverage user is served utilising Non-Orthogonal Multiple Access (NOMA) technique. NOMA is an evolving power domain multiplexing scheme which combines signals within same frequency/time band by varying power levels for transmission. We consider a relaying environment, where a NOMA based near user is incentivised with energy for transferring the data to a remote user. The performance of our proposed system is evaluated by deriving the expressions for the outage probabilities of all users and the system throughput. The results which are also validated by Monte Carlo simulations, show that the proposed system performs well along and provides additional coverage to a far-located user.