This paper investigates the outage performance of simultaneous wireless information and power transfer (SWIPT) in networkcoded\ntwo-way relay systems, where a relay first harvests energy from the signals transmitted by two sources and then uses the\nharvested energy to forward the received information to the two sources.We consider two transmission protocols, power splitting\ntwo-way relay (PS-TWR) and time switching two-way relay (TS-TWR) protocols.We present two explicit expressions for the system\noutage probability of the two protocols and further derive approximate expressions for them in high and low SNR cases. To explore\nthe system performance limits, two optimization problems are formulated to minimize the system outage probability. Since the\nproblems are nonconvex and have no known solutionmethods, a genetic algorithm- (GA-) based algorithmis designed. Numerical\nand simulation results validate our theoretical analysis. It is shown that, by jointly optimizing the time assignment and SWIPT\nreceiver parameters, a great performance gain can be achieved for both PS-TWR and TS-TWR.Moreover, the optimized PS-TWR\nalways outperforms the optimized TS-TWR in terms of outage performance. Additionally, the effects of parameters including relay\nlocation and transmit powers are also discussed, which provide some insights for the SWIPT-enabled two-way relay networks.
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