认知无线网Underlay模式下频谱资源优化分配

Optimal Spectrum Allocation of Cognitive Wireless Network under Underlay Mode

为了实现对频谱资源最大限度再利用,有效缓解无线频谱资源紧缺的问题,通过分析无线认知网络共享方式下的物理连接和图论模型,建立了具有不同干扰强度频谱分配数学模型,并将此模型转换为以信道干扰系数最小化、次网络效益最大化和主用户最大干扰最小化的多目标优化问题,进而采用多目标改进遗传算法对认知无线网络进行频谱共享方案设计,且对其有效性进行了仿真分析.仿真结果表明,采用所提出的优化算法进行频谱分配与图论K-最大割方法相比,能更好地实现网络效益最大化,同时能减少对主系统的干扰.

Cognitive radio is regarded as a promising technology to improve spectrum utilization significantly.Studies are put to discuss underlay spectrum sharing and power control,but issues such as the interference of the primary system are also considered as the constraint.The article builds up a spectrum allocation mathematical model which considers different interference intensity according to relative geographic locations between two SLs in the spectrum-sharing mode of cognitive radio network.Then it is converted into multi-objective optimization problem.To solve the spectrum sharing problem,the multiobjective improved genetic algorithm was adopted.Simulation shows that the proposed methods greatly outperform the commonly used K-max-cut in graph theory.It can realize the network benefit maximization and reduce the disturbance to the primary system by using the multi-objective optimization algorithm.