室內超寬頻無線電通道頻寬效應之研究

Abstract

本論文主要是研究室內環境超寬頻無線電傅播之頻寬效應，在此論文中，吾人是以隨機節拍-延遲-線模型，描述室內超寬頻通道的特性，在此模型是以兩種參數：功率比值r以及衰減常數ε來描述平均功率延遲曲線圖，而這些參數可經由在大樓內進行大量的量測之後計算得到，而所量測頻段為3 GHz至5 GHz。由計算結果發現以下之現象：（1）衰減常數僅稍微與訊號頻寬有關；（2）功率比值會隨著頻寬增加而變小；（3）衰減常數會隨著區域散射體愈靠近接收端而變小；（4）功率比值會隨著區域散射體愈靠近接收端而變大；（5）在視線內環境，Rician 因子會隨著頻寬增加而變小；（6）在非視線內環境，Rician 因子會隨著頻寬增加而變大。

Effects of bandwidth on Ultra-Wideband (UWB) radio propagation in indoor environments are investigated. To characterize the indoor UWB channels, the stochastic tapped-delay-line (STDL) model is employed. With the STDL model, the power delay profile (PDP) can be described by using power ratio r and decay constantεas described. Those parameters can be calculated with a large number of measurement data carried out at an education building. The measured frequencies are ranged from 3 GHz to 5GHz. It is found that (1) The decay constant of the PDP is only slightly dependent on the signal bandwidth; (2) The power ratio of the PDP is decreased when the signal bandwidth is increased; (3) The decay constant is decreased as the local scatterers move closer to receiver; (4) The power ratio is increased as the local scatterers move closer to receiver; (5) The Rician factor is decreased when radio bandwidth is increased of LOS condition; (6) The Rician factor is increased when radio bandwidth is increased of NLOS condition.