المجلة الدولية للعلوم والتقنية

This paper investigates the potential of increasing spectrum efficiency and minimizing the increased demand for unlicensed spectrum emerged by the growth of modern technologies. It have shown that cognitive radios capable to achieve such demand. In a smart and rapid fashion, cognitive radios have to jump in and out of unused spaces to increase spectrum efficiency and provide wideband services for several application domains. The proposed scenario suggests that a cognitive radio user can sense the licensed spectrum and make autonomous decisions about how it accesses the unoccupied spaces. However, meeting this huge demand for extra frequency bands is a challenge. The main challenge is the interference caused by the unlicensed users due to the error sensing outcomes when the most spectrum bands have been allocated. In this concern, I develop a mechanism that based on multichannel scenario and makes efficient decisions to mitigate the interference and maximize the spectrum efficiency. The simulation results have demonstrated that high spectrum efficiency can be achieved when a threshold level is adapted according to the ratio of the licensed user’s signal power to noise power