Performance Analysis of Underlay Cognitive Radio Systems: Estimation-Throughput Tradeoff

TL;DR

This paper investigates the performance of underlay cognitive radio systems with power control, focusing on the tradeoff between channel estimation time and secondary throughput under realistic imperfect channel knowledge conditions.

Contribution

It introduces a novel channel estimation approach at the secondary transmitter and analyzes the estimation-throughput tradeoff considering outage and power constraints.

Findings

Optimal estimation time improves secondary throughput.

Imperfect channel knowledge impacts interference management.

Tradeoff analysis guides system parameter optimization.

Abstract

In this letter, we study the performance of cognitive Underlay Systems (USs) that employ power control mechanism at the Secondary Transmitter (ST). Existing baseline models considered for the performance analysis either assume the knowledge of involved channels at the ST or retrieve this information by means of a feedback channel, however, such situations hardly exist in practice. Motivated by this fact, we propose a novel approach that incorporates the estimation of the involved channels at the ST, in order to characterize the performance of USs under realistic scenarios. Moreover, we apply an outage constraint that captures the impact of imperfect channel knowledge, particularly on the interference power received at the primary receiver. Besides this, we employ a transmit power constraint at the ST to determine an operating regime for the US. Finally, we analyze an interesting tradeoff between the estimation time and the secondary throughput allowing an optimized performance of the US.