认知无线电网络中一种改进的广播调度算法

Improved broadcasting scheduling algorithm in cognitive radio networks

当前CRN广播问题的解决方案主要为近似方案,要么性能没有保证,要么方案性能与最优解方案差距太大。对CRN最小延时广播调度问题展开了研究,提出了基于单位圆盘图模型(UDG)的混合广播调度算法MBS-UDG,该算法通过在两个阶段混合使用单播和广播通信模式完成广播任务。同时证明了,当ΔT≤1/p时,该算法的延时性能为O(n+ΔT);当ΔT>1/p时,延时性能为O+log1-p+1pΔT,其中和ΔT分别为与广播树SU用户相连的叶节点高度和最大数量,p为次要用户通信的频谱机会。在协议干扰模型下,将MBS-UDG算法扩展至通用性更强的MBS算法,并分析了新算法的延时和冗余性能,通过仿真实验验证了MBS算法的有效性,相对当前其他算法在延时和冗余方面的性能有显著提高。

Existing works for the broadcast issue in CRNs were either heuristic solution without performance guarantee or with performance far from the optimal solution. This paper studied the minimum-latency broadcast scheduling issue for CRNs. This contributions were threefold. Firstly, it proposed a mixed broadcasting scheduling algorithm under the unit disk graph model, denoted by MBS-UDG. MBS-UDG finished a broadcasted task by employing mixed unicast and broadcast communication modes in two phases. It showed that the latency performance of MBS-UDG was O（n＋ΔT） , when ΔT） 〉 1/p orO（n＋log1-p＋1/pΔT/）, where h and Ar were the height and the maximum number of leaf nodes connected by a SU of the broad- casting tree, respectively, and p was the spectrum opportunity for a secondary communication. Secondly, it extended MBS- UDG to a more general MBS algorithm under the protocol interference model and analyzed its latency and redundancy perfor- mance. Finally, simulations are conducted to validate MBS, which indicate that MBS significantly improves existing algorithms with respect to both latency and redundancy.