Ultra Wideband UK Test Results Presented by John Mettrop UK CAA (Press)

What is Ultra WideBand? Short Duration Pulse Occupies significant Bandwidth (Normally >500MHz) High Instantaneous Power Low average Power Flux Density Intended to Operate Below Noise Floor

Ultra Wideband Applications (1) Communications 3.1 – 10.6 GHz Range <30 Metres Bandwidth 480 MBits/Sec Replacement of USB, Video Streaming Ground/Wall Penetrating Radar < 3 GHz Range <2 cm to contact face Road/Runway/Wall Assessment Licensed and Co-ordinated

Ultra Wideband Applications (2) Building Material Analysis < 4 GHz Range <1 Metre through Wall Location of Pipes/Cables/ Imperfections Intended to Be Unlicensed

Theoretical Studies ITU ECC TG1/8 Established in 2002 Completed it’s work in 2005 Produce 1 report and 4 Recommendations ECC PT 3 Report 64 ECC Decision Further Consultation on PFD Limits 3.1 – 4.4 GHz On-going Work on GPR/WPR/BMA Due to Complete June 2006

Practical Testing in the UK

Aggregate Effects? Decreasing antenna gain UWB Devices ~300m Radar Antenna 4° 2° Sidelobes Azimuth beamwidth ~2 to 4 degrees

Antenna Elevation Difference in antenna gain < 1dB One storey Two building Two storey building Handheld External? Shielding Glass 0 dB Brick ~10 dB dB

Antenna Elevation Difference in antenna gain < 1dB More important is number of devices rather than height e.g. departure lounge. Eastleigh? Shielding Glass 0 dB Brick ~10 dB dB

I/N versus UWB EIRP Radar IF Filter Response Single UWB spike e.g. 50 MHz PRF Multiple UWB spikes e.g. 1.5 MHz PRF Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

1.5 MHz Undithered, 1 MHz bandwidth Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Dithered UWB Undithered Dithered Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Dithered UWB Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

OFDM UWB 1 MHz measurement bandwidth Bandwidth correction factor channel width 1 MHz measurement bandwidth Bandwidth correction factor for noise-like signals: C = 10log10(BW ratio) C = 10log10(5) = 7 dB BW Ratio = Radar IF BW/1 MHz Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Effect of Radar Processing on Interference Type Radar return pulse 20 dB 20 dB 50 MHz undithered spike Frequency 20 dB Radar return pulse 30 dB OFDM Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

False Targets: Early Warning Mode Targets start at 40 nm Target spacing 2.5 nm Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Determining Pd: 100% 5 targets, no interference Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Determining Pd: 80% 4 targets Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Determining Pd: 60% 3 targets Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Determining Pd: 40% 2 targets Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Determining Pd: 3 faint targets 1 2 3 Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Pd vs EIRP: Radar B Uncorrected Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Pd vs EIRP: Radar A Uncorrected Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Correcting for wrong Pd Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Correcting for wrong Pd Measured at 90% +9.6 dB Perform correction Curve Fit Model for 90% + 9.6 dB At 50% point Model Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Pd vs EIRP: Radar B Corrected -90 dBm/MHz at 358m -70 dBm/MHz at 358m -56 dBm/MHz at 358m ~20 dB Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Pd vs EIRP: Radar A Corrected -53 dBm/MHz at 358m -84 dBm/MHz at 358m ~30 dB Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Distance correction Antenna near field effects ~ 100m? First Fresnel Zone At 3 GHz > 2 km Field strength ITU Propagation Models 20 Log D1/D2 40 Log D1/D2 Distance Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

UWB Allowable Field strength vs Distance

UWB Allowable Field strength vs Distance

I/N versus EIRP: UWB to Radar B Shows how decreasing PRF or dithering can increase the I/N for a 20 MHz bandwidth

Propagation: Onset of UWB interference

Key factors Setting of targets to 90% Pd Determining when a target is visible IF measurement bandwidth Location of IF measurement in radar chain

Faulty Baby Alarms Purpose Potentially Affect Services Monitoring baby activity during sleep Potentially Affect Services VHF Communications Documented Cases of Interference Numerous in the UK Solution Supply replacement unit Studies None

Industrial/Scientific/Medical 5th Harmonic of 27 MHz Purpose Various including RF drying ovens for biscuits etc Potentially Affect Services VHF Communications Documented Cases of Interference Numerous within the UK Solution Retune centre frequency of the RF unit Better RF Shielding Studies None

Cable TV Purpose Potentially Affect Services Provision of television and internet services Potentially Affect Services ILS, VOR, VHF Communications Documented Cases of Interference Numerous in Germany and Belgium Initial Problems in the UK Solution Improved termination of cables Frequency avoidance Studies ECC Report 24 May 2003 http://www.ero.dk/documentation/docs/docfiles.asp?docid=1941&wd=N

Wireless Cameras Purpose Potentially Affect Services Wireless CCTV cameras Potentially Affect Services DME, SSR, GNSS Documented Cases of Interference See WG F Working Paper 9 Solution Confiscation Prosecution Studies None

GSM On-board Aircraft Purpose Potential Impact Studies Provide mobile phone communications in flight Potential Impact Interference to Aircraft Systems Passenger Behaviour (Air Rage) Interference to Ground Non-Aeronautical Services Studies RTCA 202 (on-going) Eurocae WG58 (on-going) CEPT SE 7 Technical Report (on-going)

Windfarms 1 Purpose Potentially Affect Services Renewable Energy Provision Potentially Affect Services Radar (ILS, MLS, VHF Communications) Documented Cases of Interference See next slide Solution Objection to Development Studies None published Work on-going

Windfarms 2

Questions