부산대학교 도서관

Hybridization of algorithms for optimization of communication systems has always been an interesting field for researchers. Here, a recently introduced hybrid of particle swarm optimization and gravitational search algorithm, named PSOGSA is presented for optimizing cognitive radio system. A new environment of cognitive radio is proposed which allows the spectrum access to multiple secondary users with their channels experiencing Nakagami-m fading. The transmission factors belonging to multiple secondary users relying on IEEE 802.22 WRAN standard are optimized to realize multiple objectives for anticipated quality of service using standard PSO, standard GSA and their hybrid PSOGSA. Modified fitness functions influenced by fading are established for optimization. The optimization results indicate enhanced performance of PSOGSA over other two basic techniques for a cognitive radio system.