Date Added: May 2013
Cognitive radio is an attractive result to the spectral congestion tricky by presenting the resourceful procedure of frequency band channels that cannot be greatly captured by users who holds the license. They cannot be exploited by others except license holders at the moment. Orthogonal Frequency Division Multiplexing is the most widely used technique in recent wireless communication systems which has the latent of satisfying the necessities of cognitive radios intrinsically otherwise minority changes will be held. With it interoperability among the different protocols becomes easier which is one of the significant necessities in Cognitive radio.