Performance requirements update 26/08/2014

Overview

Time-to-first-fix (PAR#5) New values for other receiver classes (stand-alone GNSS and A-GNSS) New user dynamics (pedestrian) for indoor environments according to 5.1.2.1 (table 5.1 to be amended with a column for indoor/outdoor) Tables updated

Robustness to Interference (PAR#8) Jammer scenarios definition Identification of applicable classes of positioning terminals for simulations Performance parameters definition Post-processing of the results and minimum performance requirements derivation for the applicable classes

Jammer scenarios Based on PPDs (Personal Privacy Devices) surveys available on literature D. Borio, J. Fortuny-Gausch and C. O’Driscoll "Characterization of GNSS Jammers", Coordinates, Vol. XI, Issue 5, May 2013, pp. 8-16 T. Kraus et al., Survey of In-Car Jammers — Analysis and Modeling of the RF Signals and IF Samples (Suitable for Active Signal Cancelation), Proceedings of ION-GNSS 2011 September 2011 Mitch, R. H., Dougherty, R. C., Psiaki, M. L., Powell, S. P., O’Hanlon, B. W., Bhatti, B. W. and Humphreys T. E. (2011). Signal characteristics of civil GPS jammers. Proceedings of the 24th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION/GNSS), pages 1907-1919, Portland, OR. Pullen, S. and Gao G. (2012). GNSS jamming in the name of privacy. Inside GNSS, pages 34-43. Chirp signals with different characteristics   No. Class Center frequency Bandwidth Sweep time(s) PPeak [dBm] 1 I 1.5747594 GHz 0.92 kHz - -12.1 dBm 2 II 1.57507 GHz 11.82 MHz TSW = 11.71µs -14.4 dBm 3 1.58824 GHz 44.9 MHz TSW = 18.97µs -9.6 dBm 4 1.5744400 GHz -25.6 dBm 5 III 1.57130 GHz 10.02 MHz TSW1 = 8.7 µs (TSW1,up = 6.8µs, TSW1,down = 1.9µs) TSW2 = 34.8µs -19.3 dBm 6 IV 1.57317 GHz (1.57723 GHz) 11.31 MHz (– 19.43 MHz) TSW1 = 8,7408µs TSW4,1 = 1.1215 ms TSW2 = 43.78µs TSW4,2 = 1.3557 ms TSW3 = 139.9– 183.7µs TSW4,3 = 2.2825 ms -9.5 dBm 7 1.57194 GHz 10.72 MHz TSW = 8.62µs -30.8 dBm

Jammer position and relative power Testing scenario defined as a repetition of N successive overtaking of the jammer Relative power accounts for free space propagation losses and the initial jammer power relative Doppler is negligible if compared to the frequency range swept by the jammer DoA of the jammer considered for Beam-forming antenna Class Center Frequency Bandwidth Sweep time(s) Peak [dBm] Chirp signal with one saw-tooth function – case 1 1575.42 MHz 11.82 MHz 11.71µs -14.4 Chirp signal with one saw-tooth function – case 2 44.9 MHz 18.97 µs -9.6

Performance parameter definitions Availability of the position fix Accuracy degradation of the position fix in dependence of the interference power level (jammer distance and J/S) Loss of lock and reacquisition probability according to the interference power level (jammer distance and J/S)

Test results Test results with different high sensitivity receivers (only GPS L1) -160 dBm trk. Sensitivity and narrowband (can filter out part of the jammer power) UBLOX: Ublox 5H, 5T Mediatek MT3329 (Fastrax IT500) STM TeseoII (Fastrax IT600) with notch filter NOKIA N8 GPS NovAtel OEM4

Single frequency position accuracy The solution availability when the maximum J/S was around 25 dB was only 16%

Applicable classes of terminals Standard GNSS receiver single constellation Standard GNSS receiver multiple constellation (the impact of the jammer is not the same at the same time on all the satellites – different instantaneous spectral separation coefficients. It depends on the sweeping time of the jammer and on its bandwidth) Standard GNSS receiver multiple constellation + Notch filters (expected gain of 5 dB) Standard GNSS receiver multiple constellation + Notch filters + beam-forming antenna

Notch filter analysis – based on STM Teseo II Multi-constellation receiver (GPS + Galileo + GLONASS) notch filter to track and eliminate narrow-band interferers from the GPS/Galileo and GLONASS RF paths Command to enable / disable notch proprietary message that reports the current status of the notch filter indicating the intermediate frequency value tracked by the notch filter and estimated power of the interferer

Beam forming antenna Antenna Solutions: CRPA (Controlled Radiation Pattern Antenna) - null steering or sidelobe cancellation Adaptive Beamforming - beamforming the receiver antenna towards GPS satellites Example (military applications) for Controlled Reception Pattern Antenna: Novatel GAJT (Anti-Jam Antenna) 7 antenna elements (Maximal 6 interferers simultaneous) Interference suppression 40 dB (typical) Way-forward for simulation: definition of a beam-nulling or forming algorithm Computation of the beam and reduction of the Jammer and SV signals

GNSS Sensitivity (PAR#10) Defined scenarios based on AWGN channel with decreased GNSS SV signal power Simulation to be finished

Position Integrity Protection Level and Position Integrity Time-to-Alert (TTA) and (PAR#11 & 12) To be completed (not yet started)