Optimal Random Access and Random Spectrum Sensing for an Energy Harvesting Cognitive Radio

TL;DR

This paper develops optimal random access and spectrum sensing strategies for an energy-harvesting secondary user in cognitive radio, maximizing throughput while ensuring primary QoS, considering sensing errors and primary feedback.

Contribution

It introduces a novel scheme combining random spectrum sensing, access, and primary feedback to optimize secondary throughput under stability and delay constraints.

Findings

Enhanced secondary throughput compared to random access

Leveraging primary feedback improves system performance

Effective handling of spectrum sensing errors and MPR capabilities

Abstract

We consider a secondary user with energy harvesting capability. We design access schemes for the secondary user which incorporate random spectrum sensing and random access, and which make use of the primary automatic repeat request (ARQ) feedback. The sensing and access probabilities are obtained such that the secondary throughput is maximized under the constraints that both the primary and secondary queues are stable and that the primary queueing delay is kept lower than a specified value needed to guarantee a certain quality of service (QoS) for the primary user. We consider spectrum sensing errors and assume multipacket reception (MPR) capabilities. Numerical results are presented to show the enhanced performance of our proposed system over a random access system, and to demonstrate the benefit of leveraging the primary feedback.