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Outline
- Introduction
- UWB double-directional channel
sounding system
- Experiment in an office environment
- Data processing and analysis
- Conclusion
UWB Double-Directional Channel Sounding based on Deterministic - - PowerPoint PPT Presentation
UWB Double-Directional Channel Sounding based on Deterministic - - PowerPoint PPT Presentation
UWB Double-Directional Channel Sounding based on Deterministic Components Clusterization Hiroaki TSUCHIYA, Katsuyuki HANEDA, and Jun-ichi TAKADA Tokyo Institute of Technology Outline Introduction UWB double-directional channel
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Introduction (1)
New wireless communication systems (wideband) What kind of antenna is better ?
- UWB system performance can suffer from
dense multipath propagation.
- To evaluate the antenna, a propagation
channel model which is independent on the antenna system is necessary.
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- Removing the antenna characteristics from
every ray-path.
- DoD & DoA of the path are also important
in a multipath environment.
- So to deconvolve the antenna effects, double
directional measurement is necessary.
Introduction (2)
Propagation channel (DoD, DoA, ToA, Spectrum) Tx antenna Rx antenna Radio channel
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- Double-directional channel measurements
UWB double-directional channel sounding system (1)
VNA Tx Rx Laptop GPIB Positioner Controller X-Y-Z Positioner GPIB
3D array
X-Y-Z Positioner
3D array
Positioner Controller
LNA Channel
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- Two single-directional channel measurements
are used.
UWB double-directional channel sounding system (2)
Tx Rx
3D array
Tx Rx
Fixed 3D array Fixed
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Experiment in an office environment (1)
- Empty office room
- Top view of the room
Tx Rx
- The view from the position of Tx to Rx
- Four windows and doors, some pillars
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Experiment in an office environment (2)
- Specifications of the experiment
3.0 GHz Bandwidth of each subband 100 Hz IF bandwidth of VNA Function of VNA and back-to-back Calibration Vertical-Vertical (V-V), Polarization Biconical Type of antennas DoD and DoA azimuth, elevation angle, ToA delay time and spectrum. Estimated parameters 10 × 10 ×7 points in X-Y-Z whose element spacing is 48 mm (less than half wavelength in 3.1 GHz) Spatial sampling in the Rx and Tx position 751 Frequency sweeping points 3.1 to 10.6 [GHz] Bandwidth
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Data processing and analysis
- SAGE algorithm
- Extension of the SAGE for an UWB signal
- SAGE Algorithm [1]
Widely adopted for wideband channel estimation
- To detect paths, Successive Interference
Cancellation (SIC) type procedure is used
- Remove the reconstructed signal peak from
- riginal data
[1] SAGE : Space-alternating generalized expectation-maximization algorithm
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Data processing and analysis
- DoDs and DoAs are estimated separately by
using two single-directional channel measurements, and they are related by ToA and ray tracing.
- 120 waves are detected each at Tx and Rx
- position. (above noise floor level)
- Specular reflections are the dominant
phenomena of propagation.
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Data processing and analysis
- Azimuth-delay power spectrum (1)
- Power spectrum before detecting wave
- Tx position
- Rx position
sidelobe sidelobe
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Data processing and analysis
- Clusterization of deterministic components
- Tx position
- Rx position
Above －80 [dB] ◇ －80 to －90 [dB] □ －90 to －100 [dB] ○ －100 to －110 [dB] ☓ Below －110 [dB] *
○ : Single bounce cluster ○ : Multi-bounce cluster
- 15 clusters are found each at Tx and Rx position.
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Data processing and analysis
- Azimuth-delay power spectrum (2)
- Residual spectrum after detecting 120 waves
- Tx position
- Rx position
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Data processing and analysis
- Identification of the clusters between the Tx and Rx position (1)
- Tx position
- Rx position
- 79.50
0.59 33.38 1.10
- 0.10
2.44 325.97 A-Rx
- 80.17
0.71 33.73 0.88
- 0.19
3.09 323.81 A-Tx Sum Spread Mean Spread Mean Spread Mean Power [dB] Delay [nsec]
- El. [deg]
- Az. [deg]
Cluster
- Single bounce cluster
- The clusters both at the Tx and Rx
position have the same ToA and identical scatterers.
Rx Tx
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Data processing and analysis
- Identification of the clusters between the Tx and Rx position (2)
- Tx position
- Rx position
- Multi-bounce cluster
- The clusters both at the Tx and Rx
position have the same ToA but different scatterers.
Rx Tx
- 109.30
0.90 56.13 0.85 0.20 11.38 159.95 G-Rx
- 106.05
1.02 57.01 1.22 0.97 1.93 22.63 G-Tx Sum Spread Mean Spread Mean Spread Mean Power [dB] Delay [nsec]
- El. [deg]
- Az. [deg]
Cluster
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Data processing and analysis
- Sum of power for each cluster
- 66.85
Total 34.11
- 71.52
Residual ： ： ： 0.11
- 96.56
J 0.14
- 95.32
F 0.18
- 94.26
B 0.19
- 94.05
C 0.24
- 92.99
E 0.46
- 90.26
P 3.47
- 81.45
N 4.66
- 80.17
A 5.01
- 79.86
D 43.70
- 70.45
LOS Percentage
- f power
Sum of power [dB] Cluster at Tx
- 66.38
Total 25.02
- 72.40
Residual ： ： ： 0.13
- 95.12
J 0.19
- 93.54
B 0.21
- 93.26
I 0.23
- 92.83
E 0.23
- 92.67
C 0.45
- 89.87
P 4.06
- 80.29
N 4.87
- 79.50
A 4.98
- 79.41
D 51.64
- 69.25
LOS Percentage
- f power
Sum of power [dB] Cluster at Rx
- Tx position
- Rx position
A D N P CI F E J B
- Clusters in the real environment.
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CDF of angular and delay spread within one cluster
5 10 15 20 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Azimuth angular spread [deg] CDF
0.5 1 1.5 2 2.5 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Delay spread [nsec] CDF
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Conclusion
- UWB double-directional measurement in an empty
- ffice room
- Double-directional channel models are needed for
separating the antenna transfer function.
- Clusters can be determined by physical structures of
the environment.
- Sum of power for each cluster
- Intra-cluster properties (Mean, spread, CDF)
Future work
- Antenna deconvolution
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