Wireless Energy Harvesting and Communications: Limits and Reliability

Wireless energy harvesting (WEH) technique has emerged as a fascinating solution to extend the lifetime of energy-constrained wireless networks, and has been regarded as a key functional technique for almost perpetual communications. With the WEH technology, wireless devices are enabled to harvest energy from, e.g., ambient light or RF signals broadcast by ambient/dedicated wireless transmitters to support their operation and communications capabilities. The WEH technology has been expected to have even wider range of upcoming applications for, e.g., wireless sensor networks, Machine-to-Machine (M2M) communications, and the Internet of Things (IoT). In this paper, the usability and fundamental limits of solar cell harvesting based M2M communication systems are studied and presented. The theoretical performance is essentially based on the Shannon capacity theorem, combined with selected propagation loss models, assumed additional realistic link nonidealities, as well as the given energy harvesting and storage capabilities of state-of-the-art printed supercapacitor. Fundamental performance and available reliability of the communicating and harvesting functionalities are derived and analyzed, together with extensive numerical results evaluated in different practical scenarios for low power, low bandwidth, and low bitrate sensor type communication applications using organic solar cell harvester model.