Exact Statistical Characterization of RF-Energy Harvesting over Rice Fading Channel

RF-energy harvesting has been one of the hottest research topics in wireless communications for the past few years. It found applications in cognitive radio networks, wireless sensor networks, personal area networks, device-to-device communications and a host of other wireless technologies. However, fundamental characteristics of the RF-energy harvesting process have been widely overlooked, often for mathematical convenience. These are i) the harvested energy is a statistical process, ii) the harvesting circuit has a sensitivity level that has to be met for harvesting to happen. In [1], we have shown that the amount of harvested energy is a linear function of the amount of incident energy, which can be statistically modeled using the Sampling Theorem. In this article, we capitalize on that result and derive the statistical characteristics of the harvested energy over a sequence of N harvesting blocks. The findings of this article give researchers a useful mathematical tool to design realistic RF-energy harvesting protocols.