Sensing-Throughput Tradeoff for Interweave Cognitive Radio System: A Deployment-Centric Viewpoint

TL;DR

This paper investigates the sensing-throughput tradeoff in interweave cognitive radio systems, emphasizing the impact of imperfect channel estimation and proposing constraints to optimize secondary throughput while protecting primary users.

Contribution

It introduces a novel model incorporating channel estimation into the sensing-throughput analysis, addressing practical limitations and proposing methods to mitigate performance degradation.

Findings

Imperfect channel estimation affects detection probability and system performance.

Proper estimation time selection can control performance degradation.

Secondary throughput can be significantly improved with the proposed approach.

Abstract

Secondary access to the licensed spectrum is viable only if interference is avoided at the primary system. In this regard, different paradigms have been conceptualized in the existing literature. Of these, Interweave Systems (ISs) that employ spectrum sensing have been widely investigated. Baseline models investigated in the literature characterize the performance of IS in terms of a sensing-throughput tradeoff, however, this characterization assumes the knowledge of the involved channels at the secondary transmitter, which is unavailable in practice. Motivated by this fact, we establish a novel approach that incorporates channel estimation in the system model, and consequently investigate the impact of imperfect channel estimation on the performance of the IS. More particularly, the variation induced in the detection probability affects the detector's performance at the secondary transmitter, which may result in severe interference at the primary users. In this view, we propose to employ average and outage constraints on the detection probability, in order to capture the performance of the IS. Our analysis reveals that with an appropriate choice of the estimation time determined by the proposed model, the degradation in performance of the IS can be effectively controlled, and subsequently the achievable secondary throughput can be significantly enhanced.