Optimization of a QoS-aware channel assignment for cognitive radio networks

The channel assignment problem is an important issue in cognitive radio networks because the conventional fixed spectrum allocation mechanism leads to significant spectrum underutilization. In this paper, the QoS-aware channel assignment is formulated as an optimization problem. The objective is to maximize the utilization of spectrum opportunities and fairness among secondary users (SUs) subject to constraints of different SUs demands, spectrum levels of the QoS and channel availabilities for each SU. Designing the QoS-Aware channel assignment scheme is based on genetic algorithm (GA) and quantum genetic algorithm (QGA). Two different objective functions are proposed as the network utilization and fairness indexes. Simulation results are provided to show the efficiency of the proposed method.