分析切换合并系统LCR和AOD的新方法  

An alternative method for analyzing level crossing rate and average outage duration in switched combining systems

作　　者：郭冬梅[1] 张曙[1] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001

出　　处：《哈尔滨工程大学学报》2010年第8期1087-1092,共6页Journal of Harbin Engineering University

基　　金：国防科学技术工业委员会基础研究基金资助项目(40106030503)

摘　　要：平均电平交叉率(LCR)是研究快衰落信道的重要性能指标.该文提出了一种分析各分支相互独立切换合并系统LCR的方法.该方法基于全概率公式,并作为莱斯公式的扩展具有良好的通用性,适用于任意衰落信道下的双分支切换驻留合并(DB-SSC)、切换检测合并(SEC)和后选择切换检测合并(SECps)系统.应用该方法,得到了各分支独立情况下切换合并系统LCR的通用表达式,给出了各分支独立同分布(i.i.d.)情况下切换合并系统平均中断时间(AOD)的通用表达式.相对于传统的直接应用莱斯公式的方法,该文的方法不仅简单、具有更好的通用性,并且首次给出了SEC和SECps的LCR和AOD的闭合表达式.The average level crossing rate（LCR） is an important performance measure for a fast fading channel,yet the current method has drawbacks.In response,an alternative method for calculating an average LCR was developed.It was applied to switched combining systems operating over multiple independent generalized fading paths which are not necessarily identically distributed.This alternative method was based on the total probability theorem,and was an extension of the Rice formula.It can be applied to dual-branch switch-and-stay combining（DB-SSC）,switch-and-examine combining（SEC） and switch-and-examine combining with post-selection（SECps） systems over any type of fading channels.The general closed-form expressions for the LCRs of these systems with independent branches were obtained using this alternative method.When all branches were independent and identically distributed（i.i.d.）,average outage duration（AOD） was also given in general closed-form.Compared with the traditional method which uses the Rice formula directly,this alternative method is simpler and has better generalization.Closed-form expressions of the LCR and AOD for SEC and SECps were obtained for the first time using this alternative method.

关 键 词：电平交叉率 平均中断时间 双分支切换驻留合并 切换检测合并 后选择切换检测合并 

分 类 号：TN929.5[电子电信—通信与信息系统]