Performance Analysis of Cognitive Two-Way Relay Networks with Multi-Rate SWIPT

This paper analyses the performance of an analog network coding (ANC) based underlay cognitive two-way relay (TWR) network with energy harvesting (EH) relay, in which the secondary users have adaptive multi-rate (MR) selection capability depending on the channel state information (CSI). We consider an ANC-based cognitive TWR network with amplify-and-forward (AF) EH relay, in which the transmission power of secondary nodes is limited by the primary receiver’s interference temperature limit (ITL). In this simultaneous wireless information and power transfer (SWIPT) network, the AF-EH relay adopts power-splitting relaying (PSR) protocol for energy harvesting. In particular, we derived closed-form expression for throughput (τ) of cognitive TWR networks with an adaptive multi-rate selection scheme at secondary nodes. Further, the ergodic sum-rate (R) is analyzed to show the effectiveness of multi-rate transmission scheme. The results establish that multi-rate transmission scheme improves performance significantly over the single-rate transmission in the considered cognitive network scenario. Simulation results validate the mathematical analysis and verify the correctness of obtained expressions.