A SINR Guaranteed Power and Spectrum Allocation Algorithm for Cognitive Networks

Cognitive network is now regarded as a promising approach to solve the spectrum underutilization problem. To protect the primary user, interference temperature has been promoted as a threshold under which the secondary user must control its transmitting power. As the traditional contention graph based model can´t actually depict this interference character, we proposed a geometric SINR model which can jointly solve the interference temperature requirement and optimal spectrum assignment problem. Differing from other research works, this paper considers both primary and secondary users´ SINR requirement. As finding the optimal results of power control and spectrum allocation is proved to be NP complete, we proposed a novel heuristic power and spectrum allocation algorithm (HPSA) to solve this problem efficiently. Based on the HPSA algorithm´s result, an intensive iterative power and spectrum allocation (IPSA) algorithm is designed to find a more excellent result. By detailed simulation, the results demonstrated that this algorithm can quickly be converged within 10 iterations. IPSA also has the average performance improvement about 60% comparing to the maximum coloring scheme.