A survey of spectrum sensing techniques in Cognitive Radio network

There is a huge demand of spectrum now a days, but in conventional system radio spectrum is very scared resource. To avoid interference and improve spectrum saturation, Cognitive Radio (CR) concept was proposed. CR is the greatest mechanism for use spectrum efficiently. The main objective of CR is to use this limited spectrum resources without interfering the primary users (PUs). This paper explains the several spectrum sensing methods that used in CRso far and also deals benefit-drawback of each sensing method. We explained the cooperative spectrum sensing and it´s all forms; and also the multi-dimensional spectrum sensing concept. Cooperative sensing shares its sensing data with others and utilizes the sensing outcomes of others. As a result the probabilities of miss detection and probabilities of false alarm decreased. Finally, we provided an overview of CR for opportunistic spectrum access and future research challenges regarding spectrum sensing issues.