Optimization of power and data rate in cognitive radio networks

Cognitive radio networks are adaptive intelligent radio devices and associated network entities allowed to share the same allocated spectrum band for the licensed systems. We aim in this scheme to Maximizing the total throughput of cognitive radio networks under the power and interference constraints that assure the quality of service of the licensed systems considering new optimal power optimization algorithms aim to find the best and the optimum values of transmitted powers for all cognitive users that allow Cognitive system to operate in the presence of licensed users while keeping their quality of service unaffected. Moreover the Multi-Carrier modulation techniques like Orthogonal Frequency Division Multiplexing and Generalized Frequency Division Multiplexing systems and multiple-input-multiple-output system are proposed as a motivated and promising modulation and transmission techniques aiming to maximize the system throughput. Also this scheme is used to maximize the minimal throughput among all cognitive users to achieve the fairness between the cognitive users.