Capacity of wireless powered communication systems over rician fading channels

This paper investigates the ergodic capacity of a multi-input multi-output (MIMO) wireless powered communication system with partial channel state information at the power beacon (PB). Employing time splitting protocol, the PB first transmit energy-bearing signals to the energy constrained source S through beamforming, and then S uses this energy to transmit information to the destination. Unlike several prior works, we assume that the energy harvesting link is subjected to Rician fading. Base on this, we present a comprehensive analysis of the system achievable ergodic capacity. Specifically, closed-form expressions for the ergodic capacity bounds are derived. Besides, we investigated the capacity performance in both high and low signal-to-noise ratio regimes and the optimal time split that maximizes the capacity performance. Numerical results and simulations are provided to validate the theoretical analysis. The results show that the Rician factor K has a significant impact on the ergodic capacity performance.