ABSTRACT

The most commonly used method in the time domain is the sliding correlation method. Shen (2012) mention that Circular correlation algorithm, The earliest frequency domain acquisition algorithm, is proposed in 1991, which can acquire GNSS signal quickly, but it requires large amount of computation and a high performance of CPU. Therefore, sun (2011) and Borio et al. (2010) put forward some kind of improvement to it. For example, a paper provided a kind of C/A code acquisition algorithms that combines FFT and circular product. patent No. CN 200910072325.X opened a kind of differential correlation cumulation acquisition algorithm that can acquire feeble signal. Which solve the problems of long acquisition time and square consuming which accompany the semibit method and fullbit method in the acquisition of feeble GNSS signal.