UBC Telematics Test Bed

John Wang, Vanness Shen, Lawrence Penkar, Charles Lo and David G. MichelsonUniversity of British Columbia, Dept. of Electrical and Computer Engineering,

Vancouver, BC, Canada

Why is drive testing essential to verifying vehicular propagation models?

• Ray tracing methods such as those implemented by Wireless InSite allow us to predict both the strength and the time and angular dispersion of a received signal with unprecedented accuracy.

• Importantly, we can directly relate specific channel impairments to specific objects or structures in the physical environment.

• However, the geometric models upon which ray tracing simulations are based can never capture all the detail present in the actual environment.

• Drive testing allows us to validate both the ray tracing method’s predictions and our assumptions concerning the factors that should be captured by the geometric model.

• Drive testing also provides the raw data required to formulate measurement-based models.

Drive Test Vehicle 1 – 2002 Chevy Astro Van

• uBlox dead reckoning GPS

• rooftop rack for mounting antennas

• 10-m antenna mast (stationary use only)

• 25U 19” benchtop rack with shock absorbing mount for securing equipment

• laptop mount

• 2000 W true sine wave inverter

• 440 A-h deep cycle storage batteries

Drive Test Vehicle 2 – 2007 Honda Fit.

• Ublox GPS

• rooftop rack for mounting antennas

• 10U 19” benchtop rack with shock absorbing foam base for securing equipment

• 2000 W true sine wave inverter

• 220 A-h deep cycle storage batteries

What drive test capabilities has UBC RSL developed?

Common Hardware Platform• A common hardware platform supports both a

Multicarrier Channel Sounder Mode and a Stepping Correlator Channel Sounder Mode.

• The transmitter is based upon an Agilent E8267D Vector Signal Generator.

• The receiver is based upon an Agilent N9030A PXA Signal Analyzer.

• The system can operate over a frequency range from 150 MHz to 20 GHz and bandwidths of up to 140 MHz depending upon on the needs of the study.

• Conventional DSRC or similar radios can be substituted if required for performance testing.

Multicarrier Channel Sounder (MCCS) Mode• The centre frequency, number and spacing of the

carriers can be chosen to mimic the pilot tones of a DSRC signal or specified by the operator.

• The results can be used to accurately estimate both received signal strength and the stress that the channel places on the V2V or V2I system’s adaptive equalizer.

Stepping Correlator Channel Sounder (SCCS) Mode• Transmitting a BPSK-modulated pseudo random

binary sequence (PN9) and implementing a correlator-based receiver allows the channel impulse response to be estimated with a dynamic range > 50dB and temporal resolution > 10ns.

Vehicle-to-vehicle measurement scenarios• Car-to-car (LOS and NLOS) • Car-to-van (LOS and NLOS)

Vehicle-to-infrastructure measurement scenarios• Car-to-van with the van at roadside and mast

extended.• Car/van to fixed infrastructure

Vector Signal

AnalyzerLaptop

Rb Freq Std

Vector Signal

GeneratorLaptop

Rb Freq Std

PA

GPS Rcvr

Vehicle Unit

GPS Rcvr

Example:Vehicle to Infrastructure Testing

Van Unit