https://scholars.lib.ntu.edu.tw/handle/123456789/122595
標題: | 應用於寬頻CDMA通訊系統下各種波束合成演算法之效能比較 Performance Comparison with Different Beamforming Technoques for WCDMA Communication Systems |
作者: | 劉水元 Liu, Shui-Yuan |
關鍵字: | 智慧型天線;寬頻分碼多工;最大比例結合;耙式接收機;共軛複數法;二維耙式接收機;入射角法;最小平均平方法;遞回最小平方法;陣列圖案;波束合成技巧;GTVVC 模型;WCDMA;Beamforming technique;Recursive-Least-Squares method;RAKE receiver;2D Rake receiver;Direction-of-Arrival method;maximum ratio combining;Smart antenna;Least-Mean-Squares method;Array pattern;Complex-Conjugate method | 公開日期: | 2004 | 摘要: | 本論文討論在寬頻CDMA通訊系統中,用戶端的訊號經過多重路徑及多用戶干擾信號(MAI)環境因素下,在基地台的效能比較。寬頻CDMA是使用分頻雙工(FDD)來提供用戶端在上傳通道傳輸資料給基地台的同時,基地台也可以利用不同頻帶的下傳通道回傳資料給用戶端。在基地台端,我們可以利用智慧型天線(Smart antenna)中波束合成(Beamforming)演算法的訊號處理技巧,來將干擾信號消除進而區別出用戶端資料。在本論文中,我們提出一種可以模擬戶外通道環境的時空通道模型,此模型簡稱GTVVC模型。藉由GTVVC模擬通道,我們利用遞回最小平方法(RLS method)、最小平均平方法(LMS method)、共軛複數法(CC method)及入射角法(DOA method) 等四種常用波束合成演算法,來比較上傳及下傳通道的信號干擾雜訊比(SINR)的效能。另外,我們觀察如果基地台利用所估測到的上傳波束合成權值當作下傳波束合成權值,傳輸信號給用戶端的情況下,基地台天線傳輸能量經過通道效應的衰減狀態。最後,我們利用通道量測(channel sounder)儀器所量測到的通道資料來做模擬,以比較系統效能與之前用GTVVC模型下的系統效能的差異。 In this thesis, we discuss the effect of multiple access interference (MAI) in a WCDMA communication system. In uplink, there are more than two users share the same frequency band in a WCDMA/FDD system, and signals from all users arrive at the base station asynchronously. We extract desired user’s signals from received signals by employing beamforming techniques in smart antenna systems. Here, we propose a new channel model as our outdoor environment channel, which is called the GTVVC model. We compare the uplink SINR performance and downlink SINR performance respectively with different channels by employing several beamforming methods, which are the Recursive Least Squares (RLS) method, the Least Mean Squares (LMS) method, the Complex Conjugate (CC) method and the Direction of Arrival (DOA) method. We also observe the power degradation when applying uplink beamforming weights to downlink beamforming weights. Finally, we compare the system performance by using different channel models, which are the measured data from an outdoor wireless channel and the GTVVC channel. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/58935 | 其他識別: | en-US |
顯示於: | 電信工程學研究所 |
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ntu-93-R91942092-1.pdf | 23.31 kB | Adobe PDF | 檢視/開啟 |
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