Evaluation of energy detector based spectrum sensing for OFDM based cognitive radio

With congested wireless spectrum and increasing number of users, cognitive radio serve as a panacea for efficient spectrum utilization. This stands to substantiate the amount of research happening in this area. Spectrum sensing is indubitably a key functionality in cognitive radio, which helps determining the spectral holes and white spaces for the secondary users to communicate. In this paper, the energy detector based spectrum sensing for OFDM based cognitive radio is studied and evaluated for various Signal and Noise conditions. The threshold which is a determining factor in energy detector is computed using a divide and conquer approach which is also a novelty of this paper. The bound for minimum width of the white space that is detectable by an energy detector in the case of real time multiple primary user scenario is well established through convincing simulations. The influence of SNR on the spectrum sensing is also presented with regard to the accuracy of sensing or probability of detection. Certain indispensable conditions for implementation of this detector are also discussed.