Two-way relaying networks in green communications for 5G: Optimal throughput and tradeoff between relay distance on power splitting-based and time switching-based relaying SWIPT

In this paper, we systematically study the performance of two and three time slot transmission schemes (2TS and 3TS) for bidirectional amplify-and-forward (AF) relaying channels, which are deployed by simultaneous wireless information and power transfer (SWIPT). In particular, in SWIPT, there are two protocols, namely power time splitting-based two-slot (PTSTW) and power time splitting-based three-slot (PTSTH) relaying protocol. We also derive closed-form expressions of throughput for both delay-limited and delay-tolerant transmission mode. Moreover, the proposed protocols will be evaluated in terms of the large scale path loss and the distance allocation to achieve the optimal throughput. In addition, numerical results prove that the throughput of PTSTW outperforms PTSTH. Furthermore, the throughput of delay-tolerant transmission mode is greatly better than delay-limited transmission mode. Other numerical results are also provided to verify the validity of theoretical analysis.