基于三次样条插值的GPSC/A码快捕精频算法研究与仿真

提出了基于三次样条插值和缩小多普勒频移步进值相结合快捕精频的新方法。该方法在基于FFT循环相关捕获算法快速粗捕初始码相位和载波频率,以及利用输入信号在短时间内两个不同时刻的相位差的方法得到载波精频的基础上,将三次样条插值和缩小多普勒频移步进值相结合,使捕获得到循环相关峰值更加接近最大值,进一步得到了最终的精细频率值。通过对仿真产生的数据结果进行了分析和验证,结果表明提出的精细频率方法能够使频率精度达到±2Hz,证明了该结合算法的精确性和可行性。

Study and Simulation of GPS C/A Code Fast Acquisition and Fine Frequency Algorithm Based on Cubic Spline Interpolation

A new method of the combination algorithm based on cubic spline interpolation method and decreasing Doppler frequency step was proposed.It adopted circular correlation algorithm based on FFT algorithm to implement fast coarse acquisition of initial phase and the carrier frequency,then through the input signal phase difference between two different times in a short time,obtained higher carrier frequency.Based on the above the fine frequency was obtained,the combination algorithm of cubic spline interpolation method and decreasing Doppler frequency step made the acquired circular correlation peak closer to the maximum and the final fine frequency more accurate.The data results of the simulation were analyzed and verified.The results expatiated that the proposed fine frequency method makes frequency accuracy of ±2 Hz and proved this combination algorithm is of its accuracy and feasibility.