Power Splitting and Power Allocation for Energy Harvesting Multi-antenna Relay Networks in the Presence of CSI Errors

Adaptive power splitting and power allocation can provide a substantial performance gain in energy-hungry multi-antenna relay wireless networks when perfect channel state information (CSI) is available at relay. In the case when only imperfect CSI is available, the performance may significantly degrade, and robust power-splitting and power-allocation schemes are developed to save this kind of degradation. In this paper, we investigate the energy-constrained multi-antenna relay system, in which one source communicates with one destination (S-D) with the aid of an energy constrained relay. We focus on power splitting (PS) protocol to enable simultaneous energy harvesting and information forwarding, and power allocation (PA) to support both the battery power and harvested energy. The optimization problem is established under partial CSI conditions. The objective is to maximize the transmission rate of S-D pair by jointly optimizing PS and PA. Through mathematical analysis, the PS and PA are obtained.