Spectrum Access and Sharing for Cognitive Radio

Abstract

Cognitive radio (CR) has emerged as a smart solution to spectrum bottleneck faced by current wireless services, under which licensed spectrum is made available to intelligent and reconfigurable secondary users. CR technology enables these unlicensed secondary users to exploit any spectrum usage opportunity by adapting their transmission parameters on the run. In this chapter, the authors discuss the characteristic features and main functionality of CR oriented technology. Central to this chapter is Spectrum sensing (SS), which has been identified as a fundamental enabling technology for next generation wireless networks based on CR. The authors compare different SS techniques in terms of their sensing accuracy and implementation and computational complexities along with merits and demerits of these approaches. Various challenges facing SS have been investigated, and possible solutions are proposed.