A Review of Cognitive Radio Spectrum Sensing Methods in Communication Networks

The evolving technologies in wireless communication have put a lot of conditions on the use of radio frequency spectrum. Cognitive radio is playing a wide role in wireless communication system and it is an efficient technique to overcome the spectrum underutilization. In Cognitive networks, unlicensed users are allowed [Non-serviced/secondary users' (SUs)] to utilize licensed frequency bands when the licensed users [Serviced/Primary users' (PUs)] are not present. Spectrum insufficiency is a strong motivation for research. Ongoing research is been focusing on developing new techniques to utilize the available frequency spectrum to full extent. In this paper, different sensing techniques are reviewed that includes Signal Processing, Cooperative and Machine learning techniques. Finally, the pros and cons of the mentioned techniques are discussed.