Information Harvesting for Far-Field Wireless Power Transfer

In today's smart world, the Internet of Things (IoT) offers a very large scale of technologies and use cases. An IoT system comprises a huge amount of low-power IoT network elements, sensors, and smart devices connected to each other. For these devices, it is important to have a sufficient level of energy resource for communication and to receive software/firmware updates periodically. In this aspect, wireless power transfer is a popular paradigm to tackle energy limitations. Therein, the battery of IoT devices can be remotely replenished by means of radio-frequency-radiated signaling, referred to as far-field wireless power transfer. Furthermore, harvesting energy from ambient communication signals available in the environment introduces simultaneous wireless information and power transfer technology. These systems face the trade-off between information capacity and energy harvesting efficiency. Accordingly, various signaling design frameworks have been proposed to comply with different system preferences between power and information. In this work, aside from existing trends, we propose a novel concept, information harvesting (IH), which introduces a novel protocol that lies in transmitting information on top of the existing wireless power transfer mechanism. Considering the diversity of IoT networks and the availability of wireless power transfer infrastructure, the proposed IH principle may turn out to be a pivotal methodology that combines physical layer security with wireless power transfer, particularly for cases where a large number of IoT devices require software/firmware updates along with periodical battery recharging needs.