使用訊號場強及延遲擴展之無線定位機制

本論文提出通道狀態對應法之射頻定位技術，其方法利用訊號衰減的特性與通道狀態相似性的觀念，先記錄參考點的通道狀態然後將這些通道狀態與待定位點的通道狀態做比較，進而利用來自每個基站的接收場強之機率密度函數求得待定點位於該參考點的機率做為權重值，對於手機位置做調整，以上定位方法應用於台北環境實際量測資料之情況下，證明當事先記錄參考點的通道狀態規劃適當時，實測數據分析結果，說明本論文提出之修正型通道狀態相似性之定位機制，可實現於GSM網路系統中，其最佳的參考點間距的選取大約是160公尺。另外一方面隨著無線通訊系統頻寬不斷的增加，例如：WLAN、CDMA、WCDMA..等等，故在寬頻系統中的定位機制顯的格外的重要，本論文利用上述之定位方法運用於寬頻系統中、上述GSM系統中通道狀態是使用場強來描述，但在寬頻系統中因其頻寬較大故其對於時間上訊號的解析度較高，因此在寬頻系統通道狀態是使用訊號延遲擴展以及接收場強來描述待定位點與參考點上的通道狀態，之後將待定位點之通道狀態與每個參考點來做比較進而找出相似度最大的參考點，在此也可使用接收場強的相似度來做權重值，本論文將此定位方法應用於室內環境中且發現隨著系統頻寬的增加定位的準確度也會隨之提高，參考點間距選取以10公尺最為恰當。

關鍵字

訊號衰減；通道狀態；射頻定位；無線通訊系統

並列摘要

This thesis proposes a mobile location based on channel status mapping .The proposed method utilizes signal attenuation and the channel status of mobile. First , we record the channel status of reference points , then compared the channel status of reference points with the channel status of mobile. The signal strength utilizes probability density function of received signal strength from each base station to obtain the weightings value. The weightings are the probabilities of mobile lies in the reference points . The modificatory channel status mapping method that applies to actual measurement in Taipei city environment . when it is proper to plan the reference points. According to analysis real measurement .The proposed radio location mechanism using modificatory channel status mapping method is validate for predicting mobile location and can be implement in GSM systems , the best distance between reference points approximates 160 meters. On the other hand, with wireless communication systems such as: WLAN、CDMA、WCDMA. , increase bandwidth . The mobile location of wideband system is very important and we can use the modificatory channel status mapping method to locate the mobile . In GSM system , the signal strength is used for modificatory channel status mapping . In wideband system , it’s bandwidth is bigger than narrow system , so the signal resolution in time is much better . Therefore the mobile can receive the signal delay profile and the signal strength in wideband system. Then we utilize these data to modificatory channel status mapping and find the mobile location. In this thesis, this algorithm applies to locate the mobile in indoor environment. The location accuracy is higher when the bandwidth is increased. The best distance between reference points in indoor environment approximates 10 meters.

並列關鍵字

signal attenuation ； channel status ； radio location ； wireless communication system

參考文獻

[1] J. J. Caffery, Wireless Location in CDMA Cellular Radio Systems, Kluwer Academic, 2000.

[2] Sirin Tekinay, Ed Chao, and Robert Richton, “Performance Benchmarkingfor Wireless Location Systems,” IEEE Communications Magazine,Vol. 36, pp. 72-76, April 1998.

[3] James M. Zagami, Steen A. Parl, Julian J. Bussgang, and KarenDevereaux, “Providing Universal Location Services Using a WirelessE911 Location Network,” IEEE Communications Magazine, Vol. 36,pp. 66-71, April 1998.

[4] Yilin Zhao, “Mobile Phone Location Determination and Its Impact on Intelligent Transportation Systems,” IEEE Transactions on Intelligent Transportation Systems, Vol. 1, pp. 55-64, March 2000

[6] G. D. Ott, “Vehicle location in cellular mobile radio system,” IEEE Trans. Veh. Technol., vol. VT-26, pp. 43–46, Feb. 1977.

國際替代計量

使用訊號場強及延遲擴展之無線定位機制

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