基于频谱预留的一类频谱切换改进方法研究

A Study on a Class of Improved Methods on Spectrum Handoff Based on Spectrum Reservation

在认知无线电网络中,认知用户通过择机接入主用户的空闲频谱来进行工作,当主用户出现在授权频谱上时,认知用户必须及时空出该频段。介绍了认知无线电中的频谱切换理论和现有的两类频谱切换方法,在此基础上对现有方法进行了改进及比较,并设计了切换流程。仿真结果表明,改进后的方法在保持较好切换时延性能的基础上,有效地降低了网络中的切换概率。

In cognitive radio networks, secondary users can utilize the idle spectrum of primary users, and these secondary users have to vacate current channel while primary user appears in the occupied spectrum. In this paper, the spectrum handoff theory and the two kinds of existing spectrum handoff mechanism are examined ; after that some improvements and comparisons to the above mechanism are made, and then the handoff flow diagram is designed. Simulation result shows that the improved mechanism can keep a better handoff delays and can effectively reduce the handoff probability.