Feedback Bits Allocation for Guaranteed Bit Rate Services in Cooperative Cognitive Radio Networks As the number of users using multimedia sharing services increases, the need to ensure the minimum data rate of wireless users increases. Meanwhile, in the cooperative cognitive radio (CR) network, it is important to provide the qualityofservices for secondary users (SUs) while satisfying the internetwork interference constraint from secondary transmitters to primary users (PUs). Under the limited feedback resource constraint, this paper proposes a feedback bits allocation scheme for the guaranteed bit rate services of SUs while satisfying the internetwork interference constraint. This paper investigates how many feedback bits between the ST and PUs are required to guarantee the minimum data rate of SUs and then proposes a feedback bits allocation scheme that maximizes the average sum rate of SUs while reducing the outage probability of SUs.

A Joint Design of User Modeling and Resource Management in Cognitive Radio Networks The limited available spectrum and inefficient spectrum utilization make it necessary to employ dynamic spectrum access techniques. The key enabling technology for dynamic spectrum access is cognitive radio (CR), which exploits the existing wireless spectrum opportunistically and utilizes the licensed spectrum when primary users are passive. Thus, the activities of primary radio (PR) and cognitive radio (CR) users play a major role in the performance of cognitive radio networks. In this paper, a joint solution for user modeling and spectrum management is offered. The activities of PR and CR users are modeled through threestate Markov chain as the spectrum resource blocks are utilized with help of servicelevel overbooking strategy. Simulation results show the performance of the booking limit with respect to the channel release ratio of CR users and consequently the improved revenue of the network.