Rate Splitting in Multi - Pair Energy Harvesting Relaying systems

Rate-splitting (RS) technique has recently been proposed to provide significant performance benefits in multiple users communication systems. In this paper, we investigate the performance benefits of RS in a multi-pair relay network, in which multiple users communicate with multiple destination users through a multiple antennas decode-and-forward (DF) energy-harvesting (EH) relay node. In the first phase, the users transmit their independent signals to the relay. Part of the received signal power will be harvested at the relay node. In the second phase, the relay uses the harvested energy to decode and forward the received signals to their intended users using RS transmission technique. Based on the amount of the harvested power and the availability of the channel state information (CSI) at the relay node, different RS transmission strategies are investigated. New closed-form analytical expressions for the ergodic spectral efficiency is derived and Monte-Carlo simulations are provided to confirm the derivations. In addition, the impacts of the main system parameters on the proposed strategies are investigated.