建構都會區無線通道多重路徑生成與消失模型

Abstract

本論文以建構都會區無線通道多重路徑生成與消失模型為目標 該模型合併GBSBCM模型( Geometrically Based Single Bounce Circular Model)以及GWSSUS模型(Gaussian Wide Sense Stationary Uncorrelated Scattering Model )模型之概念，建構散射體分布模型，並且將因行動台移動所造成之通道時變效應加入該模型，此外，並利用寬頻向量通道響應量測系統在台北市進行多重路徑生成與消失率之量測，該量測結果顯示：1.多重路徑生成與消失的變化量與取樣間距成正相關性；2.多重路徑平均生成率與平均消失率幾乎相同，此點發現與3GPP的規格相仿；3.多重路徑存在時間之機率密度，呈現一指數衰減(exponential decay)分布，由分析發現，多重路徑約有80%的機率將在25秒內消失。最後。這些量測結果同時驗證了本論文發展之生成與消失模型的預估準確性。經由驗證，發現在都會區合理的遠端散射體密度約為67( )。

The thesis develops a stochastic model to predict the variation of multipath in urban environment.The model is a combination of two statistical channel models, the geometrically-based single bounce circular model (GBSBCM) and Gaussian wide-sense stationary uncorrelated scattering (GWSSUS) channel model and is extended to include time-varying effect caused by the movement of mobile station. Furthermore, for measurement of the time-varying mobile radio channels, RUSK vector channel sounder is employed. The measurement data shows that : 1. The quantity of variation of multipath birth and death is positive correlation with sampled distance. 2. The multipath averaged birth rate and death rate are almost the same, and are similar to the standard of 3GPP. 3. The probability density of multipath life-time shows a kind of exponential decay distribution. In addition, from the measurement analysis multipath life-time got a probability of 80% disappearing within 25 seconds. Finally, these mesurement results also validate the accuracy of the multipath birth and death model. Besides, this thesis also validates the reasonable distant scatterer density is about 67( ).