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Open Access

Extended Kalman Filter Channel Estimation for Line-of-Sight Detection in WCDMA Mobile Positioning

  • Abdelmonaem Lakhzouri1Email author,
  • Elena Simona Lohan1,
  • Ridha Hamila2 and
  • Markku Renfors1
EURASIP Journal on Advances in Signal Processing20032003:514932

Received: 21 October 2002

Published: 24 December 2003


In mobile positioning, it is very important to estimate correctly the delay between the transmitter and the receiver. When the receiver is in line-of-sight (LOS) condition with the transmitter, the computation of the mobile position in two dimensions becomes straightforward. In this paper, the problem of LOS detection in WCDMA for mobile positioning is considered, together with joint estimation of the delays and channel coefficients. These are very challenging topics in multipath fading channels because LOS component is not always present, and when it is present, it might be severely affected by interfering paths spaced at less than one chip distance (closely spaced paths). The extended Kalman filter (EKF) is used to estimate jointly the delays and complex channel coefficients. The decision whether the LOS component is present or not is based on statistical tests to determine the distribution of the channel coefficient corresponding to the first path. The statistical test-based techniques are practical, simple, and of low computation complexity, which is suitable for WCDMA receivers. These techniques can provide an accurate decision whether LOS component is present or not.


extended Kalman filterfading statisticsLOS detectionmobile positioningWCDMA systems

Authors’ Affiliations

Institute of Communications Engineering, Tampere University of Technology, Tampere, Finland
Etisalat College of Engineering, Emirates Telecommunications Corporation, Sharjah, United Arab Emirates


© Copyright © 2003 2003

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.