System Capacity Limits Introduced by Data Fusion on Cooperative Spectrum Sensing under Correlated Environments

Abstract

Spectrum sensing, the cornerstone of the Cognitive Radioparadigm, has been the focus of intensive research, from which the mainconclusion was that its performance can be greatly enhanced throughthe use of cooperative sensing schemes. Nevertheless, if a proper designof the cooperative scheme is not followed, then the use of cooperativeschemes will introduce some limitations in the network perceivedcapacity. In this paper, we analyze the performance of a cooperativespectrum sensing scheme based on Data Fusion, by measuring theperceived capacity limits introduced by the use of Data Fusion oncooperative sensing schemes. The analysis is supported by evaluationmetrics which accounts for the perceived capacity limits. The analysis isperformed along the data fusion chain, comparing several scenariosencompassing different degrees of environment correlation between thecluster nodes, number of cluster nodes, and sensed channel occupationstatistics. Through this study, we motivate that to maximize the perceivedcapacity by the cooperative spectrum sensing, the use of data fusionneeds to be performed in a fractioned way, i.e., that the fusion must bedone between subsets of the nodes in a cluster