Title :
Highly sensitive weak signal acquisition method for GPS/compass
Author :
Song Li ; Qing-ming Yi ; Min Shi ; Qing Chen
Author_Institution :
Guangdong Univ. Res. Center for Satellite, Navig. Chip & Applic. Technol., DongGuan Techtotop Microelectron. Co., Ltd., Dongguan, China
Abstract :
For high sensitivity and operation efficiency in weak signal acquisition of Global Positioning System (GPS) software receiver, a differential coherent accumulated acquisition algorithm based on Fast Fourier Transform (FFT) is proposed. Limitation of coherent combining time is overcome by block accumulation of demodulated GPS intermediate frequency data. Based on FFT frequency shift characteristics, a Doppler circular frequency search is used to achieve low computation instead of frequency compensation search. Loss in frequency is resolved by different down conversions. Compared to the original non-coherent combining, SNR is improved by differential-coherent combining of coherent results. Weak signal in a -39dB poor SNR environment is successfully acquired in experiments. High sensitivity and operation efficiency of the proposed algorithm are confirmed by experiment results.
Keywords :
Global Positioning System; demodulation; fast Fourier transforms; radio receivers; signal detection; Doppler circular frequency search; FFT frequency shift characteristics; SNR; coherent combining time limitation; compass; demodulated GPS intermediate frequency data; differential coherent accumulated acquisition algorithm; fast Fourier Transform; global positioning system software receiver; highly sensitive weak signal acquisition method; signal-to-noise ratio; Algorithm design and analysis; Compass; Doppler effect; Frequency-domain analysis; Global Positioning System; Satellites; Signal to noise ratio; Acquisition; Compass; GPS; Satellite receiver; Weak signal;
Conference_Titel :
Neural Networks (IJCNN), 2014 International Joint Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4799-6627-1
DOI :
10.1109/IJCNN.2014.6889719
