Abstract: With regard to the low operation efficiency of Global Positioning System (GPS) weak signal high-sensitive acquisition algorithm, a new acquisition method applying wavelet transform and synchronized data blocks accumulation was proposed. The sampled Intermediate Frequency (IF) signal was processed using discrete wavelet transform and Signal-to-Noise Ratio (SNR) was improved by the different characteristics of useful signal and noise during wavelet transform. Meanwhile the quantity of baseband data was decreased. Frequency compensation and synchronized data blocks accumulation method were adopted to reduce the Doppler search range and improve SNR effectively. The simulation results show that compared with traditional high-sensitive acquisition method, the proposed method can obviously reduce the acquisition time and improve the performance of weak signal acquisition.

Key words: Global Positioning System (GPS), weak signal, wavelet transform, frequency compensation, data blocks accumulation, high-sensitive

摘要： 针对传统全球定位系统（GPS）弱信号高灵敏度捕获算法运算效率低的问题，提出了一种经过小波滤波预处理的同步数据块累加捕获方法。通过对采样的中频信号进行小波滤波预处理，根据有用信号与噪声在小波变换时所具有的不同特性来提高信噪比，同时降低基带处理的数据量；采用经过频率补偿后的同步数据块累加方法，减小多普勒频移搜索空间，提高运算效率，并能显著提高信噪比。仿真结果表明，与传统的高灵敏度捕获方法相比，该方法在捕获同样指标的微弱信号时，可以有效缩短捕获时间，改善微弱信号的捕获性能。

关键词: 全球定位系统, 弱信号, 小波变换, 频率补偿, 数据块累加, 高灵敏度