Utility-based Joint Power and Admission Control Algorithm in Cognitive Wireless Networks

Resource allocation is one of the major challenges in wireless communications including cognitive radio networks. In these networks secondary users try to coexist with primary ones.We consider a data communication scenario in which utility obtained by a user measures its quality of service (QoS). Thisutility is quantified based on success of the user for correct transmission of information bits. To provide primary users protection, a threshold tolerable interference is determined forthem. Therefore, transmit powers of secondary users should be controlled in a way that the aggregate interferences for primaryusers are not exceeded from the predefined extent. A utilitybased joint power and admission control (U-JPAC) algorithm ispresented for data networks, in order to allocate radio resources in an efficient manner to the requesting links, while the interference constraints are not violated and considering the totalutility of secondary users as the objective. Simulation results show that the proposed algorithm performs efficiently in maximizing total utility of cognitive data networks considering primary users protection compared to the similar previousalgorithm. However, a small outage increment is occurring. It is illustrated by simulation results that U-JPAC algorithm is efficient in both single and multiple primary user scenarios

Keywords:

Cognitive radio , underlay spectrum sharing , power and admission control , game theory , optimization problem