New paradigm shift in wireless communication networks - Cognitive radio

Cognitive Radios have been proposed as an effective and an efficient solution for the problem of underutilization of spectrum by licensed user. Non cooperative and cooperative detection methods are mentioned under which proper channelization of non cooperative technique is discussed. Different data compression techniques are also indexed in the literature. The presented paper emphasizes mainly on minimizing the detection time by the use of dedicated sensing receiver, using the concept of FFT for calculating the variation in spectrum sensing time with number of antennas and resolution frequency.