Polarization Diversity Performance for UMTS

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Polarization Diversity Performance for UMTS

• L. Lukama, K. Konstantinou, D.J. Edwards.
• Department of Engineering Science
• University of Oxford,U.K

April 2001
BT VURI on Mobility
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Polarization Diversity Performance for UMTS

• Poster layout
• Introduction
• Wideband measurement system
• Measurement environment
• Diversity processing
• Correlation coefficients
• Cross polarization discrimination
• Selection diversity
• Equal Gain combining
• Conclusions

April 2001
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Polarization Diversity Performance for UMTS

• Introduction
• Polarization diversity at handset explored
• Lack of line of sight in microcells leads to
  multipaths
• UMTS uses a RAKE receiver to counteract
  multipaths
• In microcells, paths are closely spaced
  warranting extra diversity
• Antennas in polarization can be co-located
• Can therefore be applied to handsets of limited
  size
• Relies on the scatterers to rotate the
  transmitted polarization

April 2001
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Polarization Diversity Performance for UMTS
Vector Network Analyser based measurement System
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Polarization Diversity Performance for UMTS
Measurement environment and set up

• Transmitter outdoor
• Vertically polarized
• Horizontally polarized
• Receiver indoor
• Vertical-Horizontal
• 45 slant
• Made to scan an 1X1m area

April 2001
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Polarization Diversity Performance for UMTS
Distribution of cross-correlation coefficients
Over 90 of correlation coefficients lt0.7
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Polarization Diversity Performance for UMTS
Distribution of cross-correlation discrimination
For V/H-45 and V/H-45-NLOS Majority of XPD lt5dB
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Polarization Diversity Performance for UMTS
Polarization diversity performance for VP-HP
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Polarization Diversity Performance for UMTS

• Polarization diversity performance for V/H-45 LOS
•  

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Polarization Diversity Performance for UMTS
Polarization diversity performance for
V/H-45-NLOS
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Polarization Diversity Performance for UMTS

• Conclusions
• The diversity branches are uncorrelated
• Over 90 of measurements have values lt0.7
• EGC performs better than Selection combining
• Vp-Hp-45 configuration has a better performance
  compared to Vp-Hp.
• Has lower cross-correlation discrimination
  leading to better diversity performance

April 2001
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