Description

The increasing demand of wireless applications has put a lot of limitations on the use of available radio spectrum is limited and precious resource. Some of the frequency bands in the spectrum are unoccupied, some of the frequency bands less occupied and few bands are over utilized. Cognitive radio system is a technique which overcomes that spectrum underutilization. There are mainly two tiers of users in the cognitive radio model . Primary Users (PU) are licensed users, have the rights of priority in using certain stable frequency band for communications, Secondary Users (SU ) are allowed to use the frequency spectra momentarily only if they do not interfere with the PU. A function of cognitive radio is called Spectrum sensing which enables to search for the free bands. In the proposed work, cognitive radio system is a technique which overcomes that spectrum underutilization. By using the spectrum sensing algorithms, the Bit Error Rate (BER) is considered for Cognitive radio users. The proposed modified algorithm shows the improvement in BER for high data rate applications of CR. The Welche’s power spectral density and Probability of detection and probability of false alarm are being compared using FFT/NFFT conventional Periodogram and then the BER is compared with the Welch’s Periodogram. Finally, the BER performance analysis has been evaluated, simulations are done by using MATLAB R2013a