Various Optimization Algorithm used in CRN

Cognitive radio is a next generation technology of wireless communication system and the limitations of conventional wireless networks are overcome by cognitive techniques. The main objective behind CR was to improve the management and utilization of spectrum resources. Software defined Radios (SDR) use cognitive radio and enhances optimization algorithm that can modify radio transmission parameters as per conditions of environment parameter Number of researchers has used various optimization algorithms in CR for improving its results. In this paper, we have given review on work done on various optimization algorithms in Cognitive radio network for different purpose. The main algorithms covered in this paper are Firefly algorithm, Particle swarm optimization, Genetic algorithm, Ant colony optimization and Support vector machine. All these algorithms were used in CRN for different purposes like to solve NP-hard problem, to tune transmission parameters in multicarrier cognitive systems, to propose a routing algorithm, to optimize the weighted coefficient vector and global decision threshold assigned to each cognitive users, used for centralized CRN, to solve the optimization problem of channel assignment as a linear programming, etc.