Instrumentation Development for the Measurement and Characterisation of Indoor and Urban Canyon Ambient Noise Floor in the Galileo Frequency Bands

M. Junered and D. Akos, Luleå University of Technology, SwedenM. Adjrad, L. E. Aguado, M. Daly, and A. H. Kemp, The University of Leeds, UK

NAVITEC '2006, 11-13 December 2006

The QGN project is managed by the Galileo Joint Undertaking through EU 6FP funds

GNSS Research GroupEIS Laboratory

I3S InstituteCAA ISN Research Group

Technical Features:RF switches: Mechanical relay

Low insertion loss ~0.2 dB.VSWR 1.2:1.Isolation 80 dB (min).Actuating current ~0.15 A@28V.TTL Control.Indicator circuitry.

Triplexer: Custom order from Delta Microwave

Passbands: -1559 to 1591 MHz. -1260 to 1300 MHz. -1164 to 1214 MHz.Insertion Loss 0.75dB.VSWR1.3:1.40 dB Bandwidth +/- 100 MHz Max.Connectors: -1 SMA Female (in). -3 SMA Female (out).

LNA: Minicircuits XHL-1217HLNFrequency 1.2 GHz –1.7 GHz.Noise Figure 1.5 dB.Gain 30 dB (min).VSWR 2.4:1.Power consumption 725 mA @ 15V. Case style NN92 = big heatsink.

Front-End4

EMC Chamber Test5

Technical Features:Frequency range 100 kHz to 3 GHz.Internal preamplifier (frequency range 100 kHz - 3 GHz).Displayed average noise level -135 dBm typical (RBW 100 Hz).High level accuracy 0.5 dB typical.Resolution bandwidths 100Hz to1MHz.Wide range of detectors:

Sample.Max/Min Peak.Auto Peak.RMS.

3 Spectrum Analyzer

1 Measurement InstrumentMajor Components:Wideband antenna. 5 metre low-loss cable.Front-end.Spectrum Analyzer.Notebook Computer:

Runs Matlab® software.Controls the switches.Configures/Controls the

spectrum analyzer.Data Acquisition Card.

REFERENCES[1] Galileo Open Service, Signal In Space Interface Control Document (OS SIS ICD), Draft 0, European Space Agency/ Galileo Joint Undertaking, 2006.[2] G. Brodin, A. Kemp, D. Akos, J. Cooper, “Quantification of the potential threat to Galileo from Man-made Noise sources (QGN),” Technical proposal, in response to GJU call 2423, September 2004.[3] J. Do, D. M. Akos, and P. K. Enge, “L and S Bands Spectrum Survey in the San Francisco Bay Area,” Position Location and Navigation Symposium, PLANS 2004, 26-29 April 2004.[4] M. O’Donnell, T. Watson, J. Fisher, S. Simpson, G. Brodin, E. Bryant, and D. Walsh, “GPS Interoperability and Discriminators for Urban and Indoor Environments,” GPS World (invited article), Advanstar Communications, June 2003.[5] “Quantification of the potential threat to Galileo from man-made Noise sources (QGN), Deliverable D1a – System requirements,” GJU Research & Development, 2nd Call, Area 3, July 2006.

MOTIVATIONGalileo system will offer new frequency bands as well as share existing spectrum with parallel systems. Development of the Galileo system will significantly improve on existing accuracy, availability, reliability and integrity. Indoors and urban canyons are typical environment for emergency services, GNSS for caller location, etc.Significant performance loss in urban canyon and indoor locations due to high levels of attenuation, signal masking and multipath. Great impact of accurate characterization of signal and noise environments on receiver design. The effect on the noise floor in the sensitive Galileo bands from the proliferation of electronic devices is largely unknown.

PROJECTUnintentional man-made noise measuring receiver design utilizing commercially available equipment to characterise the indoor and urban canyon existing interferences in the various frequency bands in which Galileo will operate.Presentation of design trade-offs and initial instrument testing. A joint measurements campaign between Luleå Technical University and the University of Leeds.

MEASUREMENTSSpectrum Analyzer Configuration/ Measurement Scheme:

Measurement Example: Location/Duration: The university of Leeds computing laboratory / 48 hours test, Friday-Saturday.Spectrum analyzer settings: 1 kHz resolution bandwidth, Detector: RMS, Trace mode: Clear/Write.

CONCLUSIONSGalileo E5, E6, and L1 band monitoring.Instrument:

Sensitivity of -143 dBm at the instrument antenna port using 1 kHz resolution bandwidth.Automatic control/configuration of the spectrum analyzer and the front-end.Components carefully selected in particular with respect to minimize the noise figure of the front-end.Theoretical and measured noise floor levels match.Noise Figure 3.6 dB for the front-end and 2 dB from the antenna port to the LNA input.

Interference characterization:Characterize interference as a function of time and location.Correlation between interference and activity (specific for each location).

Updates on the instrument and measurement campaign will be available on: http://www.engineering.leeds.ac.uk/i3s/research/Sat_Nav_wire/qgn_project.shtml

Technical Features:Passive antenna.3 dB passband 1.15 GHz – 1.65 GHz.Gain at zenith (90°):

L1 + 6.0 dBic (minimum).L5, E5a + 2.0 dBic (minimum).E6 + 3.0 dBic (minimum).

VSWR ≤ 2.0 : 1.Pinwheel technology:

Multipath rejection.Phase stability.

Novatel GPS704X Antenna2

L1 L5/E5a