Spectrum Allocation and Power Control in OFDM Systems for Cognitive Radio Networks

With the dramatic development of communication technology, wireless network-based applications become more and more popular. Accordingly, how to allocate scarce wireless resource becomes an urgent problem. In order to fully utilize spectrum resource and improve the fairness of allocation, a novel resource allocation scheme is investigated in OFDM Systems for cognitive radio networks (CRNs) in this paper, where cognitive small cell base stations (SBSs) are capable of communicating with multiple secondary users (SUs) via the multiple OFDM subcarriers of primary users (PUs). First, we establish the adaptive resource allocation model, and then, a joint problem of spectrum allocation and power control is formulated with the aim of maximizing the total throughput of SUs while taking the fairness issue into consideration. Finally, we introduce a modified genetic algorithm (GA)—Ploy-chromosome hybrid coding genetic algorithm with elite preserving strategy (EPGA). The analysis and simulation results show that EPGA converges rapidly and enhances the fairness requirements of SUs.