Sensing-Throughput Tradeoff in Cognitive Radio With Random Arrivals and Departures of Multiple Primary Users

TL;DR

This paper investigates the sensing-throughput tradeoff in cognitive radio systems considering multiple primary users with random arrivals and departures, analyzing how PU activity impacts secondary user performance.

Contribution

It introduces a comprehensive analysis of the sensing-throughput tradeoff accounting for dynamic PU activity and compares different PU status change scenarios.

Findings

Increasing number of PUs reduces optimal sensing time.

More PUs decrease the chance of finding a vacant channel.

Monte Carlo simulations validate the analytical results.

Abstract

This letter analyzes the sensing-throughput tradeoff for a secondary user (SU) under random arrivals and departures of multiple primary users (PUs). We first study the case where PUs change their status only during SU's sensing period. We then generalize to a case where PUs change status anytime during SU frame, and compare the latter case with the former in terms of the optimal sensing time and SU throughput. We also investigate the effects of PU traffic parameters and the number of PUs on the sensing-throughput tradeoff for SU. Results show that, though the increase in the number of PUs reduces the optimal sensing time for SU, the opportunity to find a vacant PU channel reduces simultaneously, in turn, reducing SU throughput. Finally, we validate the analysis by Monte Carlo simulations.