Conference Paper

Positioning Algorithms for Cellular Networks Using TDOA

Inst. of Commun. & Navigation, German Aerosp. Center, Wessling
DOI: 10.1109/ICASSP.2006.1661018 Conference: Acoustics, Speech and Signal Processing, 2006. ICASSP 2006 Proceedings. 2006 IEEE International Conference on, Volume: 4
Source: IEEE Xplore

ABSTRACT In this paper, we investigate the performance of positioning algorithms in wireless cellular networks based on time difference of arrival (TDoA) measurements provided by the base stations. The localization process of the mobile station results in a non-linear least squares estimation problem which cannot be solved analytically. Therefore, we use iterative algorithms to determine an estimate of the mobile station position. The well-known Gauss-Newton method fails to converge for certain geometric constellations, and thus, it is not suitable for a general solution in cellular networks. Another algorithm is the steepest descent method which has a slow convergence in the final iteration steps. Hence, we apply the Levenberg-Marquardt algorithm as a new approach in the cellular network localization framework. We show that this method meets the best trade-off between accuracy and computational complexity

0 Bookmarks
 · 
109 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper gives an introduction to a generic OFDM based testbed for positioning using time difference of arrival (TDoA) measurements. An overview of the transmitter system and receiver system is given. Furthermore an inital access algorithm with interference mitigation for subsample delay estimation is presented and simulation results are shown. The influence of the geographic base station mapping and the used synchronization codes is discussed. First measurement results reveal perliminary figures for the expected performance leading to further algorithm investigations.
    8th International Workshop on Multi-Carrier Systems & Solutions, MC-SS 2011; 01/2011
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A conventional approach for passive source localization is to utilize signal strength measurements of the emitted source received at an array of spatially separated sensors. The received signal strength (RSS) in- formation can be converted to distance estimates for constructing a set of circular equations, from which the target position is determined. Never- theless, a major challenge in this approach lies in the shadow fading effect which corresponds to multiplicative measurement errors. By utilizing the mean and variance of the squared distance estimates, we devise two linear leastsquares (LLS)estimators forRSS-based positioning inthis paper. The first one is a best linear unbiased estimator while the second is its improved version by exploiting the known relation between the parameter estimates. The variances of the position estimates are derived and confirmed by com- puter simulations. In particular, it is proved that the performance of the improved LLS estimator achieves Cramér-Rao lower bound at sufficiently small noise conditions.
    IEEE Transactions on Signal Processing 01/2011; 59:4035-4040. · 2.81 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Recently, Impulse Radio Ultra Wideband (IR-UWB) signaling has become popular for providing precise location accuracy for mobile and wireless sensor node localization in the indoor environment due to its large bandwidth and high time resolution while providing ultra-high transmission capacity. However, the Non-line-of-sight (NLOS) error mitigation has considerable importance in localization of wireless nodes. In order to mitigate NLOS errors in indoor localization this paper proposes and investigates a novel approach which creates a hybrid combination of channel impulse response (CIR)-based fingerprinting (FP) positioning and an iterative Time of Arrival (TOA) real time positioning method using Ultra Wideband (UWB) signaling. Besides, to reduce the calculation complexities in FP method, this paper also introduces a unique idea for the arrangement of reference nodes (or tags) to create a fingerprinting database. The simulation results confirm that the proposed hybrid method yields better positioning accuracies and is much more robust in NLOS error mitigation than TOA only and FP only and a conventional iterative positioning method.
    Sensors 01/2012; 12(8):11187-204. · 1.95 Impact Factor