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Gilbert Siy CHING1; Mir GHORAISHI1; Markus LANDMANN1,2; Navarat LERTSIRISOPON1, 高田 潤一 1; 今井 哲朗 3; 鮫田 いとじ 4; 坂本 洋典 5
1東京工業大学 国際開発工学 2Ilmenau University of Technology 3株式会社エヌ・ティ・ティ・ドコモ 4日本道路公団 5道路通信エンジニア
Wideband Directional Measurements in an Arched Tunnel to Determine - - PowerPoint PPT Presentation
Wideband Directional Measurements in an Arched Tunnel to Determine - - PowerPoint PPT Presentation
Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters Gilbert Siy CHING 1 ; Mir GHORAISHI 1 ; Markus LANDMANN 1,2 ; Navarat LERTSIRISOPON 1 , 1 ; 3 ; 4 ;
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3 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Introduction
In the past few years, wideband measurements within the 1-2 GHz frequency range have been done for straight or curved tunnels, with rectangular or slightly arched cross sections. Results showed azimuth delay spectrum & RMS delay spread. Here, we show the azimuth delay spectrum, RMS delay and angular spreads for a tunnel with semi-circular cross section measured at 5.2 Ghz to identify the significant scatterers.
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4 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Channel Sounding
Wideband directional measurements using the RUSK-DoCoMo channel sounder Operating Frequency : 5.2 GHz Bandwidth : 100 MHz Delay (Rayleigh) resolution : 10 ns Maximum delay : 6.4 us Transmitter Antenna : Sleeve Dipole (vertically oriented)
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5 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Channel Sounding
Receiver Array Antenna : 4 rings x 24 dual polarized circular patch elements (to measure 360 degrees) Synchronization : Cesium clocks
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6 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Experiment Scenario
16.6 meters 8.5 meters 16.6 meters 8.5 meters
- Shimizu tunnel, Tomei highway, Shizuoka prefecture
- semi-circular cross section; 3 car lanes
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7 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Experiment Scenario (top view)
Cleaner Parking Cleaner Parking Lights and railing Cable rack Jetfan Lights and railing Lights and railing Cable rack Cable rack Jetfan Jetfan
Tx is mounted near ceiling 8 meters from ground
25 m 400 m Tx Rx1 Rx16 Rx13 Rx7 Rx4 Rx10 Tx Entrance 25 m 400 m Tx Rx1 Rx16 Rx13 Rx7 Rx4 Rx10 Tx Entrance
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8 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Experiment Scenario
2λ= 11cm 17 points
・・・
2λ= 11cm 17 points
・・・
2.5 meters
Around 200 snapshots were taken for each Rx location For each Rx location
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9 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Parameter Estimation
RIMAX - a multidimensional gradient based maximum likelihood parameter estimator was used. Signal model is composed of
- specular-like paths
- diffuse components (modeled as rise of the floor above
noise, using an exponential function) Used to estimate
- Angle of arrival (azimuth and co-elevation)
- Time of arrival
- Complex path weights (vv and vh)
- diffuse components
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10 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Diffuse Components
Shows CDF of specular power / power of diffuse components When the ratio is large, channel is represented more by specular-like paths, when ratio is small, diffuse components are significant
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11 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Analysis
Considering first the middle point on the rail Middle point Middle point
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12 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Azimuth Delay Spectrum (Rx1)
160 m 135 m 300 m 275 m
Tx ce Tx ce
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13 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Azimuth Co-elevation Spectrum (Rx1)
Considering a few delay bins (40 ns after LOS delay) and upto 20dBm below LOS power to check the significant scatterers Co-elevation
Tx Tx
+ Az
- Az
LOS
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14 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Azimuth Co-elevation Spectrum (Rx1)
Tx Rx Tx Rx
Paths of Wall scatterers Paths of Roof and Ground scatterers
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15 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
RMS Spread
The following formula is used to calculate the RMS spreads is the corresponding path power of the ith received path.
2 1 1
( )
N i m i i RMS N i i
P P ζ ζ ζ
= =
− = ∑
∑
1 1 N i i i m N i i
P P ζ ζ
= =
= ∑
∑
i
P
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16 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
RMS Delay Spread
Trend initially increases and then decreases Jetfan acts like a reflecting wall. Spread will be maximum in the middle of Tx and reflecting object.
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Tx ce Tx ce
17 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Azimuth Delay Spectrum (Rx4)
Wider 160 m 60 m 300 m 200 m
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18 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Azimuth Co-elevation Spectrum (Rx4)
Angle of arrivals of incoming waves are closer, because distance between Rx and Tx is much larger than the width of the tunnel. Considering a few delay bins (40 ns after LOS delay) and upto 20dBm below LOS power to check the significant scatterers
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19 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
RMS Azimuth Spread, for Az = [-90 to 90] deg
RMS azimuth spread for the front scatterers are in the range of 2 to 10 degrees.
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20 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
RMS Azimuth Spread, for Az = [90 to 270] deg
RMS azimuth spread for the back scatterers are in the range of 5 to 50 degrees.
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21 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
RMS Co-elevation Spread
RMS co-elevation spread are in the range
- f 2 to 12 degrees.
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22 Wideband Directional Measurements in an Arched Tunnel to Determine the Spread Parameters
Summary and Future Works
- Wideband directional measurements inside an arched tunnel
were discussed
- spatial and temporal parameters were jointly estimated
together with the diffuse components
- RMS delay, azimuth and co-elevation spreads were
calculated and the median values were plotted
- identification of scatterers, clusters
- compute ratio of cluster power to total power
- relate intra and inter cluster properties