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Improving Time to First Fix For GPS Receivers

Abstract

In the Global Position System (GPS), receivers spend a long time to acquire the signals required for position. A study to determine the factors affecting time to first fix (TTFF) and methods to improve it is being conducted. This paper addresses two key aspects, which are the acquisition process and antenna design. Studies on advance correlation techniques such as FFT, XMC and Sqaured-D are being done over the conventional sliding serial/parallel correlator. At the same time, we also investigate the advantages of CRPA antenna over FRPA antenna as well as other new antenna designs. Simulation and actual data logging of the satellite view at a specific location is being done to study the possibility and feasibility of implementing a look up table for improving cold start. An actual field-test on three different types of receivers coupled with three different antennas with different LNA gain is being done at two different location to simulate clear sky and actual operating conditions, to address the validity of TTFF specifications provided by the manufacturer.

 

Report

Paper

PowerPoint Presentation

Poster

 

 

Papers and Documents

 

Guides to Understanding GPS

 

Papers on Acquisition Algorithm

 

Papers on Antenna

 

Specification Sheets and Pricelist