SLIDE 1
Outline
2 Directional Measurements Inside Tunnel
- Introduction and Scenario
- Channel Sounding
- Measurement Positions
- Parameter Estimation Algorithm
- Results and Discussions
- Conclusion
Directional Measurements Inside Tunnel Gilbert Siy CHING 1 , Mir - - PowerPoint PPT Presentation
Directional Measurements Inside Tunnel Gilbert Siy CHING 1 , Mir - - PowerPoint PPT Presentation
Directional Measurements Inside Tunnel Gilbert Siy CHING 1 , Mir GHORAISHI 1 , Markus LANDMANN 1 , Navarat LERTSIRISOPON 1 , 1 , 2 , 3 , 4 1 2 NTT
SLIDE 2
SLIDE 3
Introduction
3 Directional Measurements Inside Tunnel
Kinds of communication in tunnels
- for frequencies up to hundreds of MHz, leaky feeders or
radiating cables are used
- in the GHz range, natural propagation results in low loss
Communication inside tunnel is part of a wide range of roadside-to-vehicle and vehicle-to-vehicle communication for traffic management and public safety. Objective : To determine the dominant scatterers to know tunnel propagation behavior
SLIDE 4
Scenario
4 Directional Measurements Inside Tunnel
Shimizu 3rd tunnel, 2nd Tomei highway (3 lanes, arched ) 16.6 meters 8.5 meters
SLIDE 5
Channel Sounding
5 Directional Measurements Inside Tunnel
Wideband directional measurements using RUSK-DoCoMo channel sounder
Frequency 5.2 Ghz Bandwidth 100 Mhz Delay resolution 10 ns TX Signal Multitone TX Antenna Vertically Polarized Dipole TX Power 40 dBm TX Height 7.95 meters (placed just below ceiling)
SLIDE 6
Channel Sounding
6 Directional Measurements Inside Tunnel RX Antenna 24 dual polarized patch x 4 rings (to measure 360 degrees) Rayleigh Resolution 15 degrees (horizontal); 25 degrees (vertical) RX Height 2.53 meters (placed on top of car)
SLIDE 7
Measurement Positions
7 Directional Measurements Inside Tunnel
Co-Elevation RX TX Co-Elevation RX TX
40m TX
RX1 RX2 RX3 TX Jetfan 35m 40m 3.75m 3.75m 3.75m + azimuth
40m TX
RX1 RX2 RX3 TX Jetfan 35m 40m 3.75m 3.75m 3.75m + azimuth
SLIDE 8
Parameter Estimation Algorithm
8 Directional Measurements Inside Tunnel
RIMAX
- a maximum likelihood based parameter estimator for
multidimensional channel sounding Signal model is composed of
- specular scattering
- dense multipath components (distributed diffuse
components) Used to estimate
- Angle of arrival (azimuth and co-elevation)
- Time of arrival
- Complex path weights (vv and vh)
SLIDE 9
Delay spread [ns] Az spread [deg] Co-ele spread [deg] 74 27 16
Azimuth Delay Spectrum of RX1
9 Directional Measurements Inside Tunnel
- figure plots the normalized azimuth delay spectrum
averaged over co-elevation angle
- scatterers with short and long delay exists
- spread parameters of the estimated paths are computed
SLIDE 10
Path Gain relative to LOS [dB] Delay[ns] Az [deg] Co- Ele [deg] 0 (LOS) 135
- 3
83
- 5
138
- 2
82
- 6.5
143 15 103
- 7
138
- 3
105
- 9.5
138 10 76
Azimuth Delay Spectrum of RX1
10 Directional Measurements Inside Tunnel
- table shows the parameter of dominant scatterers
- the dominant scatterers are plotted on the tunnel
- paths does not necessary obey Snell's law.
- measurement system can detect single bounce scatterers
SLIDE 11
Path Gain relative to LOS [dB] Delay[ns] Az [deg] Co- Ele [deg] 0 (LOS) 135 3 83
- 9
140 17 81
- 12
143
- 18
84
- 12
137 4 110
Delay spread [ns] Az spread [deg] Co-ele spread [deg] 54 28 11
Azimuth Delay Spectrum of RX2
11 Directional Measurements Inside Tunnel
SLIDE 12
Path Gain relative to LOS [dB] Delay[ns] Az [deg] Co- Ele [deg] 0 (LOS) 135 6 83
- 5
136 5 82
- 6
150 22 107
- 7
150 23 105
- 13
138
- 11
76
Delay spread [ns] Az spread [deg] Co-ele spread [deg] 35 22 19
Azimuth Delay Spectrum of RX3
12 Directional Measurements Inside Tunnel
SLIDE 13
Scatterers
13 Directional Measurements Inside Tunnel
SLIDE 14
Conclusion
14 Directional Measurements Inside Tunnel
- initial report of wideband directional measurements
inside tunnel
- reflections from environment vary with position of
receiver
- reflections can cause undesired multipath that can
degrade performance of communication systems
- can reduce effect by properly designing radiation