Science & Engineering Research Support soCiety (SERSC)
Traditional beamforming and power control algorithms in Cognitive Radio (CR) are based on the assumption of perfect Channel State Information (CSI) however; this may lead to performance degradation in realistic systems. In this paper, the problem of joint beamforming and power control is investigated in underlay CR networks with imperfect CSI. The authors' objective is to maximize the sum utility of Secondary Users (SUs) under the Primary Users (PUs) interference power constraints and the transmission power constraint of SUs. First, the joint beamforming and power control problem is formulated under game theory framework, where the SUs compete with each other over the beamforming vectors and transmission power level made available by the PUs.