GNSS Receiver - Software Radio Concept František Vejražka Czech Technical University in Prague Faculty of Electrical Engineering

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 2 Why we have developed GNSS Receiver ? Czech economy needs satellite navigation Grant of Ministry of Transport „Implementation of Galileo System in the Czech Republic“

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 3 Receiver concept: 1. Present situation GPS signal available only several GLONASS satellites (14) no Galileo signals in early future –Giove A, Dec no ranging signals –Giove B, June 2007 (?) –first SV 2009 (?) [Hein, Jeju 2006] –full constellation 2011 CR government imperative: to prepare for Galileo

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 4 Receiver concept: 2. Requirements 2006: prepare applications with GPS (&GLONASS) signals use 2009: be able to add Galileo signals even with uncompleted constellation 2011: use full Galileo constellation signals and to support them by GPS & GLONASS and by differential corrections (EGNOS)

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 5 Receiver concept: 3. Decision Receiver should process signals GPS: C/A L1, L2C, L5C GLONASS: L1, L2 GALILEO: L1, E5a, E5b (~ OS service) and later GPS III: L1C GALILEO: E1, E2, E6

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 6 Receiver concept: How to realize it? HW: to do basic processing only on highest frequencies where digital processing is impossible SW: to process signals digitally on as highest frequencies as it is possible SOFTWARE DEFINED RADIO ARCHITECTURE

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 7 Software Defined Radio Architecture Processor only solution Processor & programmable logic RF front end ADCComputer RF front end ADC Programmable logic Computer

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 8 Architectures Comparison Processor only solution Processor & prog. logic Cost +- Bandwidth GNSS performance GPS L1 C/A WAAS/EGNOS Galileo L1 GPS L1, L2, L5 WAAS/EGNOS Galileo L1, E5 GLONASS

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept... 9 Aim of the Experimental GNSS Receiver Signal processing algorithms development tool Algorithms validation in experiments in real environment Requirements High performance High flexibility  Processor & programmable logic receiver architecture

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Experimental GNSS Receiver Development Bandwidth [MHz] nd generation 3rd generation 1st generation

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Experimental GNSS Receiver G3 Features Four RF channels Bandwidth >80 MHz Capability –GPS L1 C/A –GLONASS –WAAS/EGNOS –Galileo L1 –GPS L5 –Galileo E5, E5A, E5B –NON GNSS signals processing Complex signal processing Integration with terrestrial navigation and communication systems Galileo E5 front end

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Correlator Logic schema

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Correlator Results of analysis & simulations

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Correlator structure

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Correlator realization

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Correlator realization 32 bits NCO and PRN generator of GPS and EGNOS codes

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Correlator realization 32 bits NCO and PRN generator of GPS and EGNOS codes 32 bits NCO and complex (IQ) mixer

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Development procedure Program in Simulink Compilation Testing, validation

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Development procedure

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Development procedure Program in Simulink Compilation Testing, validation Compiled program saved in receiver memory Testing

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Development procedure Realization

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 1. GPS EGNOS Receiver for Railway Features Based on Experimental GNSS Receiver G2 L1 & L2 RF channels External EGNOS data input Certified software

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 1. GPS EGNOS Receiver for Railway On Board Unit

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 1. GPS EGNOS Receiver for Railway Control Panel of Locomotive On Board Unit Locomotive On Board Unit Dispatcher Screen

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 2. GIOVE A signal reception

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 3. EGNOS Monitoring Station Features Experimental GNSS Receiver G2 Four L1 RF units: –1x hemisphere antenna for GPS & EGNOS &Galileo –3x directional antenna for EGNOS message reception  Improved SNR & BER for EGNOS message channel Directional antenna prototype Gain 17 dB

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 4. Research of Egnos Signal Availability Investigation of the EGNOS satellite shadowing EGNOS GNSS

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept EGNOS Signal Availability Optimal Processing

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 4. Research of Egnos Signal Availability Country Town Unblocked Blocked Distance [km] 148 Unblocked Blocked Distance [km] 148 PRN 120 IOR, Prague, Czech Republic, elevation 15 

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Application of designed receiver: 4. Research of Egnos Signal Availability position meassurement maximum acceptable age of message FLAG NO FLAG position OK message age

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept EGNOS Service Availability Example: Msg. No. 2 Sparsely built-up townUndulating country Flat country Age [s] Probability Probability that message age exceeds given threshold threshold 18 s (for aircraft enroute navigation!)

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept EGNOS Service Availability – Expert Finding EGNOS signal is not generally available for a land mobile user EGNOS service can be ensured by distribution of the EGNOS messages trough data channel with high availability for a land mobile user  EGNOS monitoring station

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept EGNOS Monitoring Station Reasons Reception of the EGNOS messages for further distribution via highly available channel Monitoring of all EGNOS and GPS satellites in view –Investigation of the GNSS system behavior –Investigation of the receiver problem

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Plans for Future GNSS receiver of the third generation Implementation of the Galileo signal processing including E5 band Integration with terrestrial navigation and communication systems with good indoor availability like DTV Non GNSS signal ranging

Czech Technical University in Prague NavSup 2006 November 14-16, 2006, Gdynia, Poland Vejražka: GNSS Receiver – SW Radio Concept Conclusions Experimental SW receiver is excellent tool for: experiments with GNSS signals prototyping of algorithms for non standard applications non standard GNSS measurements signal reception of early phase Galileo education in GNSS techniques

Thank you for your attention František Vejražka Czech Technical University in Prague, Czech Republic