Performance Degradation of Shared Spectrum Systems from Interference Misclassification

Alan J. Coulson

Australian Communications Theory Workshop (AusCTW) 2009 

Abstract-Cognitive radio technologies are being developed which allow heterogeneous systems to share spectrum access while minimizing interference to improve the overall efficiency of spectrum usage. Interference minimization requires cognitive radio receivers to be able to detect the presence of all other systems competing for spectrum usage, a process often termed "spectrum sensing". However, the performance of spectrum sensing algorithms depends on the statistics of a number of stochastic processes and even the most robust algorithms have finite probabilities of misclassification of interference, through either false detection or missed detection. This paper focuses on the impact of misclassification through missed detection of interference on the performance of shared spectrum systems, both primary and secondary. It is shown that interference misclassification in any part of the shared spectrum produces significant degradation on the performance of both primary and secondary systems. It is also shown that the incremental performance degradation due to interference from additional misclassified spectrum is significant for both primary and secondary systems.