Analysis and Software implementation of a Cognitive Radio to maximize the detection at lowest sensing time

Communication system witnessed dramatic changes and great developments due the huge increases if the number of users that require many services and new applications for them. These circumstances restricted and made the frequency spectrum more crowded and not enough to provide the user with the service that required. The cognitive radio (CR) is one best solution that can solve or reduce the traffic jam of the frequency spectrum by allowing the users to share the locations between them without interference. The basic idea behind the CR is to allow an unlicensed user known as the secondary user (SU) to utilize a channel of the Authorized user known as the primary user (PU) for a limited time. In this paper, the proposed CR system at low SNR with the shortest sensing time (Ts), this system will produce a high probability of detection (Pd) at low false alarm probability (Pf) selected as 0.1 that produce Pd= 100% at SNR equal to −20dB. The noisy channel was selected to be AWGN and fading channel to test the quality of the system.