Method and system for global position system (GPS) signal capture

Abstract

The invention discloses a method and a system for global position system (GPS) signal capture, which organically combine fast Fourier transformation (FFT), double block zero padding (DBZP), differential coherence, frequency difference correction and other techniques, can achieve efficient and fast GPS signal capture and can reduce related power loss caused by chip speed change due to large doppler frequency shift in a fast Fourier transformation calculating process. In addition, power loss caused by residual doppler frequency shift errors can be reduced through the frequency difference correction technique, and efficient and fast capture is achieved.

Description

technical field [0001] The invention relates to the field of GPS (Global Position System, Global Positioning System) weak signal capture, in particular to a GPS signal capture method and system. Background technique [0002] At present, GPS has been widely used all over the world, but most of them are in environments with ideal signal conditions. When the signal conditions are not ideal, such as indoors, forests, and cities, where phenomena such as occlusion, multipath, and interference are serious, GPS cannot be used well. And these environments are the main places of human activities. There are many important GPS application requirements in these environments. High-performance GPS satellite navigation receivers are produced to meet this requirement, and have become the main research direction in the navigation field. The high-sensitivity acquisition algorithm of GPS signals is at the forefront of GPS receiver baseband signal processing, and is the key to improving the per...

AI Technical Summary

Problems solved by technology

However, when the relative speed between the receiver and the GPS satellite is high, the GPS signal received by the receiver will produce a large Doppler frequency shift, and under long-time integration, the Doppler frequency shift will have a great impact on the chip rate , causing the code period to be inaccurate, and there is a related power loss when using FFT for circular convolution; differential coherent acquisition will also cause a related power loss at the residual carrier Doppler frequency

Ziedan N I, Jiao Ruixiang et al. used DBZP technology to reduce the relative power loss caused by the chip rate change caused by the Doppler frequency shift in the FFT calculation process. However, in the acquisition process, it is necessary to Estimate the most reliable combination of data bits and use it to remove the previous data bits, which requires a large computational overhead

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