Optimal Spectrum Access for a Rechargeable Cognitive Radio User Based on Energy Buffer State

TL;DR

This paper proposes an energy-aware spectrum access strategy for rechargeable cognitive radio users, optimizing throughput by considering energy buffer states and harvesting dynamics in fading channels.

Contribution

It introduces a probabilistic access scheme based on energy queue state, accounting for energy harvesting and buffer capacity, to improve secondary user throughput.

Findings

The strategy enhances SU throughput compared to non-adaptive methods.

Energy arrival rate and buffer size significantly impact performance.

Optimal parameters depend on channel fading and energy harvesting conditions.

Abstract

This paper investigates the maximum throughput for a rechargeable secondary user (SU) sharing the spectrum with a primary user (PU) plugged to a reliable power supply. The SU maintains a finite energy queue and harvests energy from natural resources, e.g., solar, wind and acoustic noise. We propose a probabilistic access strategy by the SU based on the number of packets at its energy queue. We investigate the effect of the energy arrival rate, the amount of energy per energy packet, and the capacity of the energy queue on the SU throughput under fading channels. Results reveal that the proposed access strategy can enhance the performance of the SU.