Abstract: In recent years wireless communication industry has grown enormously. Every individual is behind in getting a share of spectrum. Day by day wireless electronic gadgets are demanding more spectrum for their applications and so the scarcity roused. To address such type of situation where a spectrum can be offered spatially and temporally cognitive radio comes up as an effective solution. This can be accomplished without disturbing the operation of primary users. However in practical situations performance is degraded by multipath fading and shadowing. To overcome with these issues cooperative sensing is used. For a practical scenario of cognitive radio where secondary users deals with multiple channel instead of single channel the study of dealing with a multiple channel becomes necessary and hence this survey has been done. The open research challenges related to multichannel cooperative sensing are also discussed in this paper

Keywords: Cognitive Radio, Spectrum sensing, Multichannel Cognitive Radio, Cooperative sensing