摘要
在认知无线电通信系统中,当主用户出现在授权频谱时,认知用户必须及时空出该频段,这个过程称作频谱切换。衡量频谱切换算法的一项重要指标是切换延时,切换延时越短,认知用户越能快速顺利地进行数据传输。在分析切换机制分类的基础上,提出了一种基于信道空闲概率排序的频谱切换算法,并且通过仿真验证了其理论上的有效性。针对实际的信道模型,对该算法进行了改进,比较了改进前后的切换延时,仿真结果表明,改进后的算法对缩短切换延时效果显著。
In cognitive radio communication system, secondary user has to vacate current channel while primary user appears in the occupied spectrum, which is called spectrum handoff. Handoff delay is one of the key indicators of spectrum handoff algorithm, the shorter the delay is, the faster the cognitive user is able to finish its transmission. After analyse two kinds of handoff machanism,a handoff algorithm based on rank ordering according to leisure possibility of the optional channels is proposed in this paper and confirmed to be theoretically effective through simulation. For practical channel model, make some improvements to the algorithm compare the handoff delays before and after the improvement,simulation result shows that the improved algorithm has markedly decreased handoff delay.
出处
《电子测量技术》
2009年第9期11-14,共4页
Electronic Measurement Technology
基金
上海市电磁兼容检测重点实验室开放课题
关键词
认知无线电
频谱切换
切换延时
空闲概率
cognitive radio
spectrum handoff
handoff delay
leisure possibility
