GPS capture unit design method based on matched filter

Abstract

The invention discloses a GPS (Global Positioning System) capture unit design method based on a matched filter. The GPS capture unit design method comprises the following steps: a GPS signal is changed into a mid-frequency digital signal after being subject to RF (Radio Frequency) front-end processing, and then the mid-frequency digital signal is re-quantified into a digital signal by a data quantification unit; the digital signal is changed into an orthogonal signal I and an orthogonal signal Q by a data orthogonal transformation unit; the orthogonal signal I and an orthogonal signal Q are further subjected to carrier stripping through a carrier NCO (Numerical Controlled Oscillator) and a complex multiplier to be changed into baseband signals close to zero frequency; a C / A code encoder generates a local C / A code; the locally generated C / A code is utilized to strip pseudo-codes in the orthogonal signal I and the orthogonal signal Q in MF (Medium Frequency) to complete coherent integration; and an FFT (Fast Fourier Transform) module transforms the coherent integration value to the frequency domain, outputs the frequency-domain amplitude values at 32 frequency points, then conduct noncoherent integration, and after that, outputs the maximum value, as well as a frequency point and a code phase, which correspond to the maximum value. The GPS capture unit design method increases the signal capture speed of a GPS receiver.

Description

technical field [0001] The invention belongs to the technical field of GPS communication, in particular to a method for capturing a GPS receiver, in particular to a method for designing a GPS capturing unit based on a matched filter (MF, Matched Filter). Background technique [0002] The new GPS, Galileo, and BD-2 signals have longer code lengths than GPS C / A codes, which help reduce cross-correlation between satellites and make satellite signals more robust against jamming. However, as the length of the code lengthens, the range of the search is also increasing when capturing. For these new pseudocodes, the traditional sequential capture algorithm is no longer applicable, because it will bring unbearable capture time. [0003] Parallel capture units that can greatly improve capture performance have been proposed in the past few years for military and indoor applications. These acquisition units are usually designed to only capture specific pseudo-codes and cannot capture ...

AI Technical Summary

Problems solved by technology

[0004] Purpose of the invention: for the problems and deficiencies in the above-mentioned prior art, the purpose of the invention is to provide a GPS acquisition unit design method based on a matched filter, which solves the problems that the existing GPS receiving and capturing time is long and the acquisition code mode is single, and speeds up the acquisition process. The GPS receiver captures the signal speed, improves the dynamic performance of the receiver, and can realize the capture of different satellite signals

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