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Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/35704

Title: 應用希爾伯特-黃轉換於GPS訊號抗干擾之研究
Research on GPS signal anti-jamming using the Hilbert-Huang Transform
Authors: Cheng-Zuo Jheng
Contributors: NTOU:Department of Communications Navigation and Control Engineering
Keywords: 全球定位系統;希爾伯特-黃轉換;經驗模態分解法;本質模態函數;抗干擾
GPS;HHT;EMD;intrinsic mode functions;anti-jamming
Date: 2012
Issue Date: 2013-10-07T02:58:04Z
Abstract: GPS衛星距離地表約20,000公里並且發射輸出功率約為30瓦之訊號,透過長距離傳送至GPS接收機時的強度約-120dbm(1x10-15W),故衛星訊號已非常的微弱。GPS訊號會由於非刻意的干擾而造成失鎖,其來源為日常的電器與電子設備所產生的大量雜訊,這些雜訊將會掩蓋了衛星訊號,另外干擾源甚至也會來自於一般的消費性電子設備,例如隨身聽撥放器、行動電話以及車用電子等。故於GPS的應用之中,如何達到抗干擾是一項很重要的研究課題。 本論文提出利用希爾伯特-黃轉換(HHT)來達成抗干擾之目的,其中的演算法(HHT)為Huang et al. 所提出,其先透過經驗模態分解法(EMD)將訊號分解成數個本質模態函數(IMF),再利用希爾伯特頻譜分析(HSA)法以得到能量─頻率─時間之分佈,接著藉由分析GPS訊號與干擾訊號之間振幅及頻率的差異來達成兩種訊號之分離。經由實驗成果證實本文所提出的方法用於降低干擾的影響有良好之效果。
GPS Satellites transmit with a power output of roughly 30 W and are 20,000 km above earth surface. The signals traveling that distance and acquired by GPS receiver is in the range of –120 dBm (1 x 10–15W), the signals coming from the satellites are very weak. The GPS signal may lose of lock due to unintentional jamming–signals from everyday electrical and electronic devices that create so much noise that they mask the satellite signals. These jamming signals can even come from ordinary battery-operated consumer devices such as portable music players or mobile phones as well as automobile electronics. Hence, anti-jamming is an important research topic in application of GPS. In this thesis, an HHT-based anti-jamming method is proposed to solve this problem. The HHT was proposed by Huang et al. . It uses the EMD method to decompose a signal into intrinsic mode function (IMF), and uses the Hilbert spectral analysis (HSA) method to obtain energy- frequency-time distribution. Analysis the differences of amplitude and frequency between the GPS signal and the jamming signal. The jamming signal and GPS signal can be separated. The experimental results show that the proposed method has great capability to reduce the effect of interference.
URI: http://ethesys.lib.ntou.edu.tw/cdrfb3/record/#G0019967025
Appears in Collections:[通訊與導航工程學系] 博碩士論文

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