Energy efficiency optimization of simultaneous wireless information and power transfer system with power splitting receiver

In this paper, an algorithm for energy efficiency optimization is designed in a point-to-point narrowband Multiple-Input Single-Output (MISO) system with Simultaneous Wireless Information and Power Transfer (SWIPT). Power splitting architecture is assumed for the receiver, which would split the received Radio Frequency (RF) signals into two independent streams for information decoding and energy harvesting, respectively. Taking both the Quality of Service (QoS) requirement and the constraint of harvested power requested into consideration, the energy efficiency optimization problem is formulated as a two-dimension non-convex problem. Nonlinear fractional programming, one-dimension searching and convex optimization are involved to develop the “EE-Max algorithm” to resolve the problem. The channel capacity optimization problem and the corresponding algorithm, “Capacity-Max algorithm”, are also studied for comparison. Numerical results demonstrate the excellent performance of energy efficiency for the EE-Max algorithm and reveal the influence of the searching interval, channel fading, the maximum transmission power and the QoS requirement.