摘要：

当认知无线电网络中的主用户活动时,网络连通性较差。针对该问题,结合功率控制和信道分配技术,提出使用最小数目信道构造双信道连通无冲突拓扑的方案。生成基本拓扑,使用图着色理论为每个次级用户分配信道。在此基础上,考虑到删除节点后局部冲突图可能不连通,利用改进MPH算法给最短路径密集经过的节点分配路径权值。同时为避免删除节点后拓扑被分为两部分,取切割部分点间最短距离的一半位置添加节点,从而实现双信道连通。理论分析和仿真结果表明,在任意主用户引起的单信道中断情况下,该方案能够保持网络连通,同时减少所需信道数和网络花费。

关键词: 认知无线电网络, 拓扑控制, 双信道连通, 改进MPH算法, 信道分配

Abstract:

It is difficult to maintain the connectivity when Primary User(PU) is active in Cognitive Radio Network(CRN).To solve the above problem,this paper presents an efficient scheme to build a bi-channel connected network with the minimum number of required channels combining power control and channel assignment.Firstly,basic topology is generated by using graph coloring to assign channels to every secondary user to achieve bi-channel connectivity.Secondly,considering local spanning tree is not connected after deleting nodes,it applies the improved MPH algorithm to give priority to link on these nodes which have the large path weights,which means they are passing by shortest paths.Then,aiming at the problem that the topology is divided into two parts after deleting the nodes,it adds node at the middle of the shortest link between all these edges,which can connect the two parts.Theoretical analysis and simulation results show that,the proposed scheme can maintain the connectivity of network,meanwhile reducing the mumber of required channels and network costs.

Key words: Cognitive Radio Network(CRN), topology control, bi-channel connection, improved MPH algorithm, channel assignment

中图分类号: 

• TP393