大气波导中多径衰落信道参数的定量计算  

Numerical computation of parameters of multipath fading channel in the atmospheric duct

作　　者：陈绍贺[1] 郑辉[1] 黄兴忠[1] 

机构地区：[1]西南电子电信技术研究所,四川成都610041

出　　处：《电波科学学报》2010年第4期638-645,共8页Chinese Journal of Radio Science

基　　金：国家自然科学基金(NO.60927002;NO.60728101)

摘　　要：利用Snell定律,给出了球面分层大气中确定两点之间电磁波多径传输幅度和时延的定量计算方法,建立了大气波导条件下多径传输模型,数值地分析了大气折射指数分布、收发天线高度和距离等参数对多径传输的影响。数值模拟结果表明:大气波导强度对多径信道的相对时延和幅度有显著的影响;随着大气波导强度的增加,相对时延越来越大,相对幅度越来越小。另外,信号多径传输使信号在一定带宽信道内出现周期性频率选择性衰落现象;衰落周期和衰落深度与大气波导强度成反比,而且衰落最深处频点随大气波导强度有规律地变化。By using Snell＇s law, numerical methods are presented to determine the amplitudes and time delays of the multipath propagation in the spherical layered atmosphere, and a model of multipath propagation in the atmospheric duct is developed to analyze the effect of the parameters, such as refractive index gradient, transmitter height, receiver height and ground range, on the multipath propagation. Numerical results show that the relative delays and amplitudes of multipath channel are strongly influenced by the atmospheric duct. The multipath propagation incurs the periodical frequency selective fading that the fading period and depth are inversely proportional to the strength of the duct.

关 键 词：大气波导 多径衰落信道 多径传输幅度和时延 

分 类 号：TN011.3[电子电信—物理电子学]