ESTEC Postbus NL2200 AG Noordwijk - Keplerlaan - NL 2201 AZ Noordwijk ZH - Tel. (31) Fax (31)

Transcription

1 Galileo Transportation - DLR - Oberpfaffenhofen, 28.Mar.2006 European Space Agency A g ence spatiale européenne ESTEC Postbus NL2200 AG Noordwijk - Keplerlaan - NL 2201 AZ Noordwijk ZH - Tel. (31) Fax (31) Dr. Martin Hollreiser GALILEO User and Ground Receiver Manager GALILEO Project Office Tel Martin.Hollreiser@esa.int

2 Receiver Development in the Galileo Project Galileo Test User Segment (TUS) Sensor Station Receiver (GRC) in the GJU MassMarket, Professional, SoL Galileo Signal-In-Space (SIS) TUS Requirements: Functional & Performance Galileo / GPS Differences GIOVE-A First Results Conclusion

3 TUS (NonPRS TUR, PRS TUR, ConstellationSimulator, SAR Beacon) support to system validation and signal experimentation ( characterization of SIS, UERE, PVT, Clocks, P/L, OD&TS (UERE contrib. and SISA confidence level) Highly flexible & reconfigurable platform Most of Rx parameters are configurable (LoopBW, PreDetectionBW, BumpJump, PulseBlanking, ) Access to large number of observables & detailed internal measurements Measurement & IF Sample stored on mass-storage-media Analysis Subsystem on LapTop allows analyses and replay of measurements and IF samples Emulation of different user classes (Antenna, RF-FE, Bandwidth, clocks) GRC (NonPRS GRC, PRS GRC, Constellation Simulator) Acquisition of accurate measurements in the sensor station for Processing (ODTS & IPF & PTF) Very stringent specs wrt absolute group delay calibration (GRC in PTF) Very stringent specs wrt group, phase delay & CCC stability (also vs. GPS Rx) Good performance (code and carrier phase measurements) under interference, multipath and iono scintillation Very stringent RAMS requirements + SW Development to DAL C

4 50% funding Rx Project Company MassM Rx GAMMA FhG D MassM Rx GR - Poster STMicroelectronics I MassM Rx GREAT PA Consulting (DLR, QualComm, u-blox ) UK Prof. Rx ARTUS IfEN D Prof. Rx SWIRLS Septentrio B SoL Rx GiraSol AAS-I (Train, Avionics, Maritime) I

5 ARNS Bands Three Frequency Bands are are part part of of the the ARNS allocated bands ARNS Bands RNSS Bands RNSS Bands E5a/L5 E5b L2 E6 E2 L1 SAR E MHz (*) MHz (*) MHz 214 M1Hz 1215 MHz 1237 MHz 1260 MHz MHz 1300 MHz 1544 MHz 1545 MHz 1559 MHz 1563 MHz MHz 1587 MHz 1591 MHz GALILEO Bands (Navigation) GALILEO SAR Downlink GPS Bands E2-L1-E1 and and E5a/L5 are are common to to The The GPS Frequency bands for for interoperability

6 F/Nav Signal: Data+Pilot BPSK mod. Rc=10.23 Mcps Rs=50 sps I/Nav Signal: Data+Pilot BPSK mod. Rc=10.23 Mcps Rs=250 sps G/Nav Signal: BOC(10,5) mod. Rc=5.115 Mcps C/Nav Signal: Data + Pilot BPSK mod. Rc=5.115 Mcps Rs=1000 sps G/Nav Signal: BOC(n,m) mod. I/Nav Signal: Data + Pilot BOC(1,1) BOC(2,2) mod. Rc=2.046 Mcps Rs=250 sps L5/E5a E5b E6 E2 L1 E1 DATA CHANNELS PILOT CHANNELS Frequency (MHz) MHz MHz CDMA Transmission RHCP Polarization MHz MHz AltBOC Modulation Interplex Multiplexing Scheme Interplex Multiplexing Scheme

7 Structure Generic Receiver Definitions Signal in Space Definition User Environment Definition and Requirements Fixed Environment Rural Pedestrian Environment Rural Vehicle Environment Aeronautical Environment The different environments are given in terms of: satellite visibility through masking angles valid User Location across the earth User Dynamics Tropospheric and Ionospheric effects (incl scintillation) Multipath and Interference (in-band, out of band,,as continuous & pulsed) TUR Common Requirements including the baseline algorithms to meet the minimum navigation end-to-end performance Specific Requirements for each of the 15 specific TUR Configurations TUR Analysis Tool Security Related Requirements as well as the PRS TUR configurations are specified in a classified annex.

8 Galileo/GPS/ EGNOS (SIS) Correction Antenna Radio Frequency Front-End Signal Processing Navigation & Application Processing MMI Analysis Subsystem User Positioning RF/IF Downconversion Signal Processor User Integrity MMI Command/ Control Navigation Processor Sensors

9 Receiver Functional Tree Baseline is a software defined Rx Concept Software defined receiver in this context means that the functionality of the receiver can be flexibly defined by downloading different configuration files into FPGAs operating configurable code on DSPs and CPUs NOT to be mistaken with Software Radio Rx

10 Analysis Subsystem Signalprocessing Performance Analysis Visibility Analysis Coverage and Dilution of Precision Analysis Geometry Analysis User Navigation Performance User Integrity Analysis Link Budget Analysis (to support C/No evaluation from the data provided by the receiver and from a link budget calculator) Error Budget Analysis (UERE) Navigation Message Analysis Use Cases Integration of system simulator to calibrate system models relying on real receiver data (navigation message, measurements) Derivation of statistics (max value, min value, mean and std, ) on any data set Replay of Rx algorithms on stored IF-samples and measurements

11 Galileo Only 1. Single Freq w/o Integrity Satellite-Only Configuration 2. Dual Freq w/o Integrity Satellite-Only Configuration 3. Single Freq w Integrity Satellite-Only Configuration 4. Dual Freq w Integrity Satellite-Only Configuration 5. Timing/Calibration Laboratory Satellite-Only Configuration Galileo / GPS Combined 6. Single Freq Galileo + GPS Satellite-Only Configuration 7. Dual Freq Galileo + GPS Satellite-Only Configuration Galileo Local Precision and Local High Precision 8. Precision Sat.-plus-Local Reference Configuration, differential code 9. Precision Sat.-plus-Rover Configuration, single frequency, differential code 10. Precision Sat.-plus-Rover Configuration, dual frequency, differential code 11. High Precision Sat.-plus-Local Reference Configuration, differential carrier 12. High Precision Sat.-plus-Local Reference Configuration, multicarrier (TCAR)

12 Specified in range domain in terms of UERE / UERRE PVT domain with related mean availability For different user environments over elevation (5-90 ) - rural pedestrian, rural vehicle, Aeronautical (final approach), fixed For different service definitions - Single & Dual frequency, receiver classes, Open, CS, SoL and PRS UERE Typical Residual Errors (1-sigma) due to Contributions from - Orbit Determination and Time Synchronisation Error or SISA (Integrity) - Tropospheric Residual Error - Ionospheric Residual Error (single/dual frequency) - Thermal Noise / Interference / Multipath (bias and random components) - Satellite Broadcast Group Delay (BGD) uncertainty (single freq) - Code-Carrier ionospheric divergence error (single freq) 10% margin on top single element margins Values include improvement factors due to carrier smoothing

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14 single frequency service horizontal accuracy is specified to 15m vertical accuracy is specified to 35m dual frequency service horizontal accuracy is specified to 4m vertical accuracy is specified to 8m velocity velocity accuracy is specified to 20cm/sec Time transfer velocity accuracy is specified to 4.3ns 95% confidence availability the percentage of time, in any constellation repeat period in any place within the service volume (5 x 5 resolution) 100%, when operating in nominal SIS constellation state mean availability of 99.5%.

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17 Larger number of signals increase of hardware complexity and processor load New modulation and multiplexing schemes little processing know how before, better accuracy, larger HW complexity Signal Acquisition: Codes ~10x longer, Multiple correlation peaks (BOC) parallel processing required (matched filter or corr.bank) different acquisition techniques and strategies investigated bump jumping or SSB acquisition and switching to BOC tracking Signal Tracking: larger BW (extreme AltBOC) better accuracy, higher processing gain, higher sampling frequencies Pilot improved sensitivity (pre-detection and PLL discriminator) Multipath Mitigation intrinsically better performance (larger BW, BOC) / however danger of false acquisition and tracking due to BOC SW / HW Boundary large number of channels / Higher data rates / Viterbi decoding / Deinterleaver, leads to very high burst CPU load, complicates SW (load-balancing), multi-processor systems and/or dedicated HW required

18 GIOVE-A First Results Constellation Simulator GSVF Overview Receiver Overview Receiver Measurement Results Correlation Functions and Power Spectra Code Measurement Error MultiPath Envelopes First Multipath Results with Stochastic Model First GIOVE-A Results

19 GSVF-2 Overview The Galileo Signal Validation Facility is capable of generating at RF, simultaneously and in real-time, each of the three Galileo satellite signals for up to 16 satellites. The signal is generated taking into account: satellites orbital motion incl. earth gravitational harmonics, third-body gravitation and solar flux satellite clock offsets and drift, including relativistic effects HPA non-linearities antenna gain and phase characteristics propagation path ionospheric and troposheric effects fading, shadowing and multipath environment of the receiver User receiver antenna pattern user trajectory

20 GETR is a first output of Galileo Test User Receiver development by Septentrio All-In-View dual-frequency PolaRx 2 GPS Receiver + simulaneously tracks the GIOVE-A and GIOVE-B 6 GIOVE-A channels 1 AltBOC channel 9 GPS CA channels Channels for tracking all the modulation, except AltBOC Dedicated AltBOC Channel Channels for CA-code (L1) Real-Time Monitoring of the Correlation Fct Output Measurements Logging Capability IF Samples Logging Capability Carrier Aiding PreDetect, PLL & DLL BW user select Correlator Spacing d=35ns Bump Jumping & Pulse Blanking Parallel Acquisition (Matched Filt + FFT)

21 Code Measurement Error Scenario N.1 Goal: compare the GETR code tracking error with the theoretical curves L1BC (SV1) Code Noise Stdev vs C/No Pilot 1 SV PRN 1 Signal Path set to Fixed C/N0 Mode C/N0: dbhz Fixed User Model is applied Satellite Motion (apart from C/No) enabled Stdev (cm) Data Pilot-Data Theoret. Data Theoret. Pilot GPS CA-Code L1 B&C channels BOC(1,1) C/No E5 - AltBOC - (SV1) Code Noise Stdev vs C/No Stdev (cm) Data Theoretica 1.00 E5 AltBOC(15,10) C/No

22 Multipath Envelope Scenario N.2 Goal: compare GETR Multipath Envelopes with theoretical curves 2 SV in GEO, both PRN 1 SV 2 cloned, same PRN, clock slowly swept Signal Path is set to Fixed C/N0 Mode 4 C/N0:50 dbhz, SMR 6dB 3 2 Multipath Error Envelope for SMR = 6dB BOC(1,1) BPSK(5) BPSK(10) AltBOC(15,10) BOC(2,2) Code Phase Error [m] Delay [m]

23 Stoch. Multipath Analysis Scenario N.3 Goal: compare GETR Multipath Results with the TUSREQ UERE Allocations std: standard deviation of the Code-Carrier Phase measurements bias: difference between mean of two Code Phase measurements: Simulation Duration 1.5h (RV, RP) 3.5h (Fixed) 2 SV, PRN 1 & PRN 2 SV 2 (PRN 2) cloned, stochastic MP model C/N0: 32 / 50 dbhz; SMR=7.2dB Different User Models (Rural Ped., Rural Vehic, Fixed) Rural Pedestrian C/No = ~ 34.7 dbhz Rural Pedestrian C/No = ~ 49.8 dbhz SV 1 PRN 1 No MP Model std = 19.59cm SV 1 PRN 1 No MP Model std = 3.85 cm SV 2 PRN 2 Yes MP Model std = cm SV 2 PRN 2 Yes MP Model std = cm bias = 50cm bias = 51 cm Rural Vehicle C/No = ~ 32.7 dbhz Rural Vehicle C/No = ~ 49.5 dbhz SV 1 PRN 1 No MP Model std = cm SV 1 PRN 1 No MP Model std = 5.98 cm SV 2 PRN 2 Yes MP Model std = cm SV 2 PRN 2 Yes MP Model std = 6.96 cm bias = 1 cm bias = 2 cm Fixed C/No = ~ 35.5 dbhz Fixed C/No = ~ 50.2 dbhz SV 1 PRN 1 No MP Model std = 17.5 cm SV 1 PRN 1 No MP Model std = 3.27 cm SV 2 PRN 2 Yes MP Model std = cm SV 2 PRN 2 Yes MP Model std = cm bias = 41 cm bias = 42 cm

24 Giove-A E5 CodeErr & E6 C/No CodeMeasErr E5 AltBOC(15,10) C/No E6C Pilot and E6A CodeMeasErr = PR i L i i j 2 2 f L i f L j 1 PRi: Li: Lj: Code Measurement at carrier frequency fi Code Measurement at carrier frequency fi Code Measurement at carrier frequency fj

25 Correlation Functions & Spectra Correlation Function per Signal Component for each carrier Power Spectra derived through post processing from the Correlation Functions

26 Conclusion An Overview of the TUS has been presented with functional and performance specification First Test Results with a Galileo Receiver have been presented Code Measurement Errors agree very well with theoretical analyses Multipath Envelopes agree very well with theoretical analyses First MP tests based on stochastic MP models have been performed and already show good performance even without Carrier Smoothing First results from Giove-A have been presented and show very good performance Currently detailed investigations and analyses are continuing for the different signals under MP and Interference environment on the simulator as well as in the field

27 Further Information