Resource allocation scheme based on weighted power control in cognitive radio systems

Opportunistic spectrum access (OSA) is a promising method to improve the spectrum utilization. In this paper, we propose a weighted power control approach to further exploit the flexibility of OSA. We first give the definition and basic idea of confidence level of sub-channel idle (CLSI), then two schemes are raised to enhance the system performance considering the time-variance of channels, the accuracy of spectrum sensing and mutual interference (MI) in power-constrained cognitive radio systems. The first scheme is to maximize the system capacity, and the second one is a multi-objective optimization model for maximizing both the system capacity and the user satisfaction. Both theoretical analysis and simulation results demonstrate that scheme 1 can achieve optimal system capacity, and scheme 2 can obtain sub-optimal system capacity with optimal user satisfaction compared to the conventional algorithm.