Hybrid, SWIPT-Based, Green Cooperative Wireless System Design and Performance Analysis

We consider a two-hop, hybrid collaborative radio communication system having regenerative and non-regenerative energy harvesting (EH) relays. The regenerative or non-regenerative relay harvests energy from its received radio frequency (RF) signals transmitted by the collaborative EH radio system's source node. We employ simultaneous wireless information and power transfer (SWIPT) with the time-switching EH protocol. We propose an insightful hybrid cooperative relaying protocol and its performance analysis. Specifically, we formulate an ergodic capacity optimization problem with average power constraint on relay transmissions. The proposed hybrid relaying protocol analysis and numerical results provide valuable insights into the effect of various hybrid EH collaborative radio system parameters. These parameters include EH time and non-regenerative relay's amplification factor on system performance in terms of normalized capacity. Furthermore, a comparison between multiple relaying protocols shows that hybrid relaying provides better fading-averaged capacity performance.