Comparison of Two Cognitive Radio Spectrum Algorithms

Abstract

Cognitive radio is a new concept aimed at vastly improving the way radio spectrum is utilized. The principle of cognitive radio is geographic reuse of licensed spectrum, the idea is that an unlicensed user is permitted to use licensed spectrum, provided that it transmits with low enough power and that it is so far from any primary user that it does not interfere with these. The motivation for cognitive radio is the various measurements of spectrum utilization that generally shows that the spectrum is underutilized and that there are many holes in the radio spectrum. Cognitive radio exploits these holes hence improve the efficiency of wireless communication (spectral efficiency) by sensing the environment and then filling the gaps (holes) of unused licensed spectrum.In this thesis MATLAB program was used to simulate cognitive radio spectrum sensing algorithms; energy detection and matched filter. The simulation compared their performance under different signal to noise ratio using both BPSK and QPSK modulation techniques.Theresults showed that the energy detector algorithm is more tolerant to noise than the matched filter algorithm.