认知无线网络动态权值调整的频谱切换策略

认知无线网络中，次用户的目标信道选择受次用户传输功率、信道衰落因子、信道带宽、信道可用率等因素影响。针对基于多属性判决的频谱切换没有充分考虑各因素的重要程度和动态变化问题，本文提出了基于动态权值调整的频谱切换策略。根据主观经验和网络环境变化动态调整权值，采用多属性简单加权法计算各信道目标函数值，根据目标函数值降序排列结果选择切换的目标信道。仿真结果表明，本文所提出的算法能够减少次用户的切换次数，提高有效数据传输速率。 

Spectrum handoff based on dynamic weight's adjustment in Cognitive Radio Network

In cognitive radio network, some factors affect secondary users′ selection of target channel to switch which are its transmission power, fading factor, bandwidth, and channel availability on the authorized channel, etc. In this paper, a spectrum handoff strategy based on dynamic weights′ adjustment is presented, considering the degree of each factor’s importance and dynamics which are not fully considered in multi-attribute decision of spectrum handoff in the past. The proposed method sets the dynamic weights by the change of environment and the subjective experience. Then the value of utility function is obtained by multiple attribute of simple weighted algorithm. The target channel to switch is determined according to its descending order. The simulation results show that the proposed algorithm can reduce the switching times of secondary users, and improve the effective transmission rate of data.