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) was proposed. The limitation of coherent integration time was overcome by block accumulation of demodulated GPS intermediate frequency data. Based on FFT frequency shift characteristics, a Doppler circular frequency search was used to achieve low computation instead of frequency compensation search. The loss in frequency was resolved by different down conversions. Compared to the original incoherent accumulation, Signal-to-Noise Ratio (SNR) was improved by differential coherent accumulation of coherent results. The weak signal in a -39dB poor SNR environment was successfully acquired in experiments. High sensitivity and operation efficiency of the proposed algorithm were confirmed by the experimental results.
黎山 易清明 陈庆 石敏. 适用于GPS软件接收机的弱信号捕获方法[J]. 计算机应用, 2012, 32(03): 816-818.
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2012, Vol. 32 
