On Dual-Path Energy-Harvesting Receivers for IoT With Batteries Having Internal Resistance

Internet of Things (IoT) systems will increasingly rely on energy harvested from their environment, and energy harvesting (EH) techniques necessitate a rethinking of how we design and optimize IoT systems. The performance of EH IoT systems is affected by the battery nonidealities and the energy consumption for transmitting and receiving. While EH considerations at the transmitter have been widely studied, the EH receiver has received relatively much less attention. Motivated by this, we investigate, in this paper, the performance of EH receivers in IoT systems with batteries having non-negligible internal resistance. We first consider a receiver with a dual-path architecture and give an optimal battery management scheme. Then, based on this management scheme, we maximize the amount of information decoded at the receiver for single and multiple block scenarios. In the multiple block scenario, we transform the nonconvex problem into a series of convex problems by exploiting certain structural properties of the nonconvex constraints. Additionally, we present extensive numerical results to validate our analysis and to study the impact of the internal resistance. This paper suggests that the internal resistance significantly impacts the design and performance of EH IoT systems. However, the dual-path architecture can be an efficient way to reduce the performance loss caused by internal resistance. Finally, we discuss implementation considerations.