A Review on Modern Spectrum Sensing and Assignment Techniques in CRN

Abstract

Cognitive radio (CR) is ascending as an advanced technology with the aim of utilizing the unused spectrum bands in an opportunistic and dynamic way. Fixed spectrum allocation done by government based agencies leads to underutilization of resources. The segments of spectrum bands that are unused, are called “spectrum holes” or “white spaces”. The solution to this issue is provided by implementing CR technology. It allows users to determine the unused bands in spectrum, choose the suitable one (depending on availability and accessibility of the spectrum) and use them in the best way possible. Spectrum assignment plays a vital role in minimizing any possibility of interference between secondary and primary users. Because of the varying parameters of available spectrum along with the different QoS specifications of various networks, CR technology raise a range of challenges. Spectrum management functions should tackle these problems and ensure that the CR network runs smoothly. This article therefore presents a brief survey on CR networks, its architecture and other relevant functionalities like spectrum sensing, spectrum decision, spectrum sharing, and spectrum mobility.