IJSTR

International Journal of Scientific & Technology Research

IJSTR@Facebook IJSTR@Twitter IJSTR@Linkedin
Home About Us Scope Editorial Board Blog/Latest News Contact Us
CALL FOR PAPERS
AUTHORS
DOWNLOADS
CONTACT
QR CODE
IJSTR-QR Code

IJSTR >> Volume 4 - Issue 6, June 2015 Edition



International Journal of Scientific & Technology Research  
International Journal of Scientific & Technology Research

Website: http://www.ijstr.org

ISSN 2277-8616



Implementation Of Code And Carrier Tracking Loops For Software GPS Receivers

[Full Text]

 

AUTHOR(S)

Win Kay Khaing, Zaw Min Naing, Su Su Yi Mon, Aung Soe Khaing, Hla Myo Tun, Sao Hone Pha

 

KEYWORDS

Keywords: code tracking, carrier tracking, discriminator function, software GPS receiver, N-FUELS simulator

 

ABSTRACT

Abstract: GPS is playing in very important role in our modern mobile societies. Software approach is very flexible rather than the traditional hardware receivers. The soft-GPS receiver includes two portions: hardware and software. In hardware portion, an antenna, filter, down-converter from RF (Radio Frequency) to IF (Intermediate Frequency), and an ADC (Analog to Digital Converter) are included. In software portion, signal processing such as acquisition, tracking and navigation that runs on general purpose processor is included. The GPS signal is taken from N-FUELS (Full Educational Library of Signals for Navigation) signal simulator. The heart of soft-GPS receiver is the synchronization processes such as acquisition and tracking. In tracking, there are two main loops for code and carrier tracking. The objective of this paper is to analyse and find the optimum discriminator function for the code tracking loop in soft-GPS receivers. The delay lock loop (DLL) is a well-known technique to track the codes for GNSS spread spectrum systems. This paper also presents non-coherent square law DLLs and the impacts of some parameters on DLL discriminators such as number of samples per chip, early-late spacing, different C/ No values where C denotes the signal power and No is the noise spectral density, and the impact of with or without front-end device. The results of discriminator outputs are illustrated by using S-curves. Testing results with the real GPS signal are also described. This optimized discriminator functions can be implemented in any soft-GPS receivers.

 

REFERENCES

[1] “Digital Satellite Navigation and Geophysics”, A Practical Guide with GNSS Signal Simulator and Receiver Laboratory by IVAN G. PETROVSKI, IP-Solutions, Japan TOSHIAKI TSUJII Japan, Aerospace Exploration Agency (JAXA).

[2] “Introduction to Global Navigation Satellite Systems” edited by: Fabio Dovis, Paolo Mulassano.

[3] “Theoretical Analysis of S-Curve for GNSS System,” by Maristella Musso, Gianluca Gera, Carlo S. Regazzoni, Department of Biophysical and Electronic Engineering (DIBE), University of Genoa Italy and CNIT-DIBE Unit University of Genova.

[4] “A Software-Defined GPS and Galileo Receiver: Single-Frequency Approach,” by Kai Borre, Aalborg University and Dennis Akos, University of Colorado.

[5] “The GPS Code Software Receiver at Aalborg University,” by Nicolaj Bertelsen, Kai Borre, Peter Rinder, at Danish GPS Center, Aalborg University, Niels Jernes Vej 14, DK-9220 Aalborg Ř, Denmark, {nb,borre,rinder}@gps.aau.dk.

[6] “Implementation of a Software GPS Receiver,” by C. Ma, G. Lachapelle, and M.E. Cannon, Position, Location And Navigation (PLAN) Group, Department of Geomatics Engineering, University of Calgary, Calgary, Alberta, Canada, T2N 1N4.

[7] Dinesh MANANDHAR, Yongcheol SUH and Ryosuke SHIBASAKI, “GPS Signal Acquisition and Tracking: An Approach towards Development of Software-based GPS Receiver,” Center for Spatial Information Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 Japan.

[8] R. Arsinte, “A Software Model for GPS Receiver Signal Processing Blocks Used in Educational Environment,” Technical University of Cluj-Napoca, Communications Department, 26-28 Baritiu Str, Cluj-Napoca, Romania, Radu.Arsinte@com.utcluj.ro.

[9] “Simulation of Code Tracking Error Variance with Early Late DLL for GALILEO/GPS Bandlimited Receivers,” by Ondrej Daniel, Martin Ernesto Orejas, Juraj Gazda, Honeywell Advanced Space Technology, Tuřanka 100, Brno, Czech Republic, Dept. of Multimedia Comm., Technical University of Košice, Letná 9, Košice, Slovakia,

[10] Hui Hu, and Lian Fang, “Signal Search and Acquisition Algorithms for Software GPS Receiver,” Proceedings of the 2009 International Symposium on Information Processing (ISIP’09), Huangshan, P.R. China, August 21-23, 2009, pp. 013-016.

[11] “GPS Satellite Signal Acquisition and Tracking,” by Fredrik Johansson, Rahman Mollaei, Jonas Thor, Jorgen Uusitalo, August 21, 1998.

[12] “Fundamentals of Global Positioning System Receivers: A Software Approach,” by James Bao-Yen Tsui, Copyright @ 2000, John Wiley & Sons, Inc. Print ISBN0-471-38154-3, Electronic ISBN0-471-20054-9.

[13] “IF GPS Signal Simulator Development and Verification,” (URL: http://www.geomatics.ucalgary.ca/links/GradTheses.html) by Lei Dong, December 2003.

[14] “Signal Acquisition and Tracking for a Software GPS Receiver,” by Sophia Y. Zheng, February, 2005, Blacksburg, Virginiaa.

[15] J.A. Starzyk and Z. Zhu, “Averaging Correlation for C/A Code Acquisition and Tracking in Frequency Domain,” School of Electrical Engineering and Computer Science, Ohio University, Athems, Ohio 45701, USA.