Power allocation with max-min fairness for cognitive radio networks

In this paper, we study power allocation strategy of the cognitive radio (CR) system. In a CR system the user has different channel condition. So, different amount of power resource is required to meets the QoS request. In order to guarantee the fairness of each CR user and limit the interference that is caused by CR users within the range into the level that primary user can tolerate, we proposed a new power allocation scheme. The target is to maximize the minimum signal-to-interference-plus-noise ratio (SINR) among all CR users. This power allocation scheme can be formulated using Geometric Programming (GP). Since GP problem is equivalent to the convex optimization problem, we can obtain the optimal solutions for the allocation scheme. Simulation results shows that proposed scheme can efficiently guarantee the fairness of CR users under the QoS constraint of the primary user.