摘要
对于采用选择合并方案的分布式天线系统,当各分集支路经受独立且不等同分布的复合衰落时,分析了系统合并输出包络的平均电平交叉率和平均衰落持续时间,得到这些二阶统计量的精确表达式.该方法对于任意分集支路数目下的Rayleigh-lognormal,Ricean-lognormal和Nakagami-lognormal三种复合衰落环境均是有效的.仿真结果验证了所得表达式的正确性.
In the selection of combining distributed antenna systems, exact expressions for the average level crossing rate (LCR) and average fade duration (AFD) of the output signal envelope are derived. The diversity branches are assumed to be independent but non-identical composite fading channels. The results are valid for arbitrary diversity order and the amount of fading, and are obtained for Rayleigh-lognonnal, Ricean-lognormal and Nakagami-lognormal composite fadings. Numerical results validate the derived expressions.
出处
《山东大学学报(工学版)》
CAS
2007年第5期83-88,共6页
Journal of Shandong University(Engineering Science)
基金
This workis partially supported by the China 863 Project (2005AA123510)
关键词
分布式天线系统
复合衰落信道
选择分集
平均电平交叉率
平均衰落持续时间
distributed antenna access system
composite fading channel
selection diversity
average level crossing rate
average fade duration