基于本地码插值修正的GPS信号捕获方法

A GPS Signal Acquisition Scheme Based on Interpolated Local Code

提出了对GPS信号平均下采样捕获方法的改进.首先描述了平均下采样方法中峰值幅度受CA码起始位置的影响,从而会造成大量的运算时间.由此角度出发,通过FFT变换基插值的方法修改本地码,不仅避免了峰值衰减,而且在无需大量增加硬件资源的情况下,把捕获的时间缩短为原来的1/3.

In this paper,an improved version of Modified-Code Averaging Correlation Method for GPS signal acquisition is presented. Firstly,effect of CA starting point location on magnitude of correlation peak of that method,which leads to a large amount of computation time,is described. Then,a remedy scheme using FFT basic to interpolate local code to prevent attenuation is introduced. With this improved version,performance enhancement can be achieved in terms of execution time reduced to about 1/3 of the original one without great overhead in hardware.