無線射頻訊號比較於定位系統之應用

Comparison with Radio Frequency for Location Positioning

黃合興(Ho-Hsing Huang)

指導教授 ： 林宗男

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.00797

摘要

本論文提出一個以GSM/WiFi/FM和DVB訊號為基礎的定位系統，在使用Location Fingerprinting的技術，經過offline stage(離線狀態)的訊號強度(RSS)收集，存入資料庫，和實際定位時的online stage(線上狀態)資料庫比對，配合maximum likelihood和K-Nearest-Neighbor的使用，做定位的比較。

在GSM訊號部份，因為其訊號強健度(Robustness)較高，且鑑別度也高，所以很適合應用在定位系統。因為這種特性的訊號，在相鄰的兩點(約3m)之間的訊號分隔很明顯，不易混淆、誤判為另一個點的訊號。相對於GSM訊號，DVB訊號的強健度很差，在同一個測量點上的訊號強度分佈很廣，而且相鄰的兩個點的訊號強度分佈重覆性又很高。所以應用DVB做定位訊號源，在提高量測密度在小於3m的狀況，並不會提高其精確度(accuracy)，反而浪費了系統及時間成本。而WiFi和FM訊號的特性，則是介於GSM和DVB之間。

關鍵字

定位 ； 訊號強度 ； 泛歐式數位行動電話系統 ； 無線區域網路 ； 調頻廣播 ； 數位電視廣播

並列摘要

An approach for the location determination by GSM/WiFi/FM and DVB signal strength is proposed in this paper. Location fingerprinting has two stages. The offline stage: RSS is collected at sampling locations to build the database. The online stage: the physical location of client can be estimated by comparing the measured RSS with the stored RSS values in the database.

The GSM signal is robust and easy to be distinguished between two neighbor positions (around 3m). So GSM signal is suitable for location positioning. DVB signal is not robust neither distinguishable in comparison with GSM signal. By reducing the distance of neighbor positions in 3m when doing the site survey, it can not enhance the accuracy of location by using DVB but it spends computing power and times. The characteristics of radio frequency of WiFi and FM signal are between GSM and DVB.

並列關鍵字

location fingerprinting ； RSS ； GSM ； WiFi ； FM ； DVB

參考文獻

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