Impact of Quality of Service Constraints on the Performance of Spectrum Sharing Cognitive Users

Abstract

This article investigates the impact of choosing a specific quality of service constraint on the performance of the cognitive users in a spectrum sharing cognitive environment. To communicate over a wireless channel reserved to a primary user, the cognitive user has to satisfy the primary user's quality of service constraint. Cognitive systems under interference temperature and outage probability constraints are investigated in this work. The outage probability of the primary user in an interference temperature-constraint environment is analyzed, and the performance measures of the cognitive users are developed. A comparative study of the cognitive user's performance under equivalent outage probability and interference temperature constraints is conducted as well. Numerical results are presented to verify the theoretical analysis and compare the performance measures under these constraints. Results of this work illustrate the effects of the communication environment parameters on the cognitive users and detail the performance differences between the equivalent outage probability-constraint and interference temperature-constraint cognitive systems.