Spectrum Sensing Techniques for Cognitive Radio Application:A Review

In the advanced technology, nearly 70 to 80% of the radio spectrum remains UN utilized, while at the same time the other region of the spectrum is overcrowded, so we are approaching the cognitive radio network. The ultimate need for this new approach is to sense the unused spectrum, by avoiding any interference with the primary or licensed user and allocate them to the secondary users, thus by improving effective Spectrum utilization. Spectrum sensing is a key function of Cognitive radio networks. An important achievement of the Cognitive radio network is to utilize the unused spectrum. Detecting the primary users is the most efficient way by detecting the empty spectrum. The various spectrum sensing techniques includes Energy detector, Matched filter, Cyclostationary feature detection. The spectrum sensing depends on the sensing time and the fusion scheme for its performance. In this paper, the different techniques are going to be compared.