Energy-harvesting irregular repetition slotted ALOHA with unit-sized battery

Abstract

We propose an irregular repetition slotted ALOHA (IRSA) based uncoordinated random access scheme for energy harvesting (EH) nodes. Specifically, we consider the case in which each user has a unit- sized battery that is recharged with energy harvested from the environment in a probabilistic manner. We analyze this scheme by deriving asymptotic throughput expressions, and obtain optimized probability distributions for the number of packet replicas for each user. We demonstrate that for the case of IRSA with EH nodes, these optimized distributions perform considerably better than those of slotted ALOHA (SA), contention resolution diversity slotted ALOHA (CRDSA) and IRSA, which do not take into account the EH process, for both asymptotic and finite frame length scenarios.