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 , 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 2 Ilmenau 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 IEICE AP Technical Report, Chiba, Nov. 2005

Outline Introduction Channel Sounding Equipment Scenario Parameter Estimation Diffuse Components Azimuth Delay Spectrum Azimuth Co-elevation Spectrum RMS Spreads Summary and Future Works Wideband Directional Measurements in an Arched 2 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. Wideband Directional Measurements in an Arched 3 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) Wideband Directional Measurements in an Arched 4 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 Wideband Directional Measurements in an Arched 5 Tunnel to Determine the Spread Parameters

Experiment Scenario - Shimizu tunnel, Tomei highway, Shizuoka prefecture - semi-circular cross section; 3 car lanes 8.5 meters 8.5 meters 16.6 meters 16.6 meters Wideband Directional Measurements in an Arched 6 Tunnel to Determine the Spread Parameters

Experiment Scenario (top view) Tx is mounted Tx Tx Tx Tx near ceiling 25 m 25 m Rx1 Rx1 8 meters from Rx4 Rx4 ground Rx7 Rx7 400 m 400 m Rx10 Rx10 Lights and Lights and Lights and Jetfan Jetfan Jetfan railing railing railing Rx13 Rx13 Cleaner Cleaner Cable rack Cable rack Cable rack Parking Parking Rx16 Rx16 Entrance Entrance Wideband Directional Measurements in an Arched 7 Tunnel to Determine the Spread Parameters

Experiment Scenario For each Rx location 2 λ = 11cm 2 λ = 11cm ・・・ ・・・ 2.5 meters 17 points 17 points Around 200 snapshots were taken for each Rx location Wideband Directional Measurements in an Arched 8 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 Wideband Directional Measurements in an Arched 9 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 Wideband Directional Measurements in an Arched 10 Tunnel to Determine the Spread Parameters

Analysis Considering first the middle point on the rail Middle point Middle point Wideband Directional Measurements in an Arched 11 Tunnel to Determine the Spread Parameters

Azimuth Delay Spectrum (Rx1) Tx Tx 160 135 m m 300 275 m m ce ce Wideband Directional Measurements in an Arched 12 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 Tx Tx Co-elevation + Az - Az LOS Wideband Directional Measurements in an Arched 13 Tunnel to Determine the Spread Parameters

Azimuth Co-elevation Spectrum (Rx1) Tx Rx Paths of Wall scatterers Tx Rx Paths of Roof and Ground scatterers Wideband Directional Measurements in an Arched 14 Tunnel to Determine the Spread Parameters

RMS Spread The following formula is used to calculate the RMS spreads N N = ∑ = ∑ ζ P ζ − ζ 2 ( ) P i i i m i ζ = i 1 ζ = i 1 m RMS N N ∑ ∑ P P i i = i 1 = i 1 P is the corresponding path power of the i th received path. i Wideband Directional Measurements in an Arched 15 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. Wideband Directional Measurements in an Arched 16 Tunnel to Determine the Spread Parameters

Azimuth Delay Spectrum (Rx4) Tx Tx 160 60 m m Wider 300 200 m m ce ce Wideband Directional Measurements in an Arched 17 Tunnel to Determine the Spread Parameters

Azimuth Co-elevation Spectrum (Rx4) Considering a few delay bins (40 ns after LOS delay) and upto 20dBm below LOS power to check the significant scatterers Angle of arrivals of incoming waves are closer, because distance between Rx and Tx is much larger than the width of the tunnel. Wideband Directional Measurements in an Arched 18 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. Wideband Directional Measurements in an Arched 19 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. Wideband Directional Measurements in an Arched 20 Tunnel to Determine the Spread Parameters

RMS Co-elevation Spread RMS co-elevation spread are in the range of 2 to 12 degrees. Wideband Directional Measurements in an Arched 21 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 Wideband Directional Measurements in an Arched 22 Tunnel to Determine the Spread Parameters