A Two-Step Power Distribution Algorithm Based on Game Theory in Cognitive Radio Networks

The power distribution problem in cognitive radio networks is analyzed, the correct transmission probability per frame and consumed power levels of the cognitive users are used to establish the utility function. The power distribution that maximizes the utility functions of the cognitive users is selected as the target power strategy. In order to avoid the computational complexity of calculating the desired power strategy, a two-step power distribution scheme is proposed. The optimal signal to noise ratio (SIR) that maximizes the utility function is first calculated iteratively. With the acknowledgement of the optimal SIR and channel state information, the cognitive users are divided into two groups: the cognitive users reach the maximum transmission power constraints and the cognitive users achieve the optimal SIR, and then the power strategies of the cognitive users are achieved iteratively through power balancing scheme. Simulation results show that the proposed two-step power distribution scheme can achieve the power strategies that maximize the utility function, and it can maintain the system utility with lower consumed power levels