摘要
针对如何协调多个认知用户择机接入多段空闲频域信道的问题,提出了一种基于无休止多臂赌博机(RMAB)模型的动态频谱接入机制。首先,考虑到实际环境下认知用户的信道感知误差,推导出能有效处理感知误差的Whittle索引值算法,该算法通过历史经验积累给予每个信道一定的信任值,并综合考虑在当前信任值下选择每个信道的立即收益与未来收益的多少,选择出需要感知接入的信道;其次,对于多个认知用户接入相同信道时产生冲突的问题,提出了基于多标拍卖的协调机制,通过多标拍卖的方式处理认知用户之间的冲突。仿真结果表明,在相同的环境中,所提出的频谱接入机制与未处理误差的或者未采用多标拍卖的接入机制相比,认知用户获得的吞吐量更大。
Based on the theory of Restless Multi-Armed Bandit （RMAB） model, a novel mechanism of dynamic spectrum access was proposed for the problem that how to coordinate multiple user access multiple idle channels. Firstly, concerning the channel sensing error of the cognitive user being existed in the practical network, the Whittle index policy which can deal with sensing error effectively was derived. In this policy, the users achieved one belief value for every channel based on the historical experience accumulation and chose the channel, which was needed to sense and access, by considering the immediate and future rewards based on the belief values. Secondly, this paper used the multi-bid auction algorithm to deal with the collision among secondary users when they selected the channels to improve the spectrum utilization. The simulation results demonstrate that, in the same environment, the cognitive users with the proposed mechanism have higher throughtput than the mechanism without dealing with sensing error or without multi-bid.
出处
《计算机应用》
CSCD
北大核心
2014年第10期2782-2786,共5页
journal of Computer Applications
基金
国家自然科学基金资助项目(61102062)
教育部科学技术研究重点项目(212145)
重庆市科委自然科学基金资助项目(cstc2011jjA1192)
重庆市教委科学技术研究项目(KJ120530)
重庆邮电大学博士启动基金资助项目(A2010-11)
