Open Access

Autonomous Positioning Techniques Based on Cramér-Rao Lower Bound Analysis

  • Mats Rydström1Email author,
  • Andreu Urruela2,
  • Erik G. Ström1 and
  • Arne Svensson1
EURASIP Journal on Advances in Signal Processing20062006:093043

https://doi.org/10.1155/ASP/2006/93043

Received: 31 May 2005

Accepted: 11 October 2005

Published: 12 March 2006

Abstract

We consider the problem of autonomously locating a number of asynchronous sensor nodes in a wireless network. A strong focus lies on reducing the processing resources needed to solve the relative positioning problem, an issue of great interest in resource-constrained wireless sensor networks. In the first part of the paper, based on a well-known derivation of the Cramér-Rao lower bound for the asynchronous sensor positioning problem, we are able to construct optimal preprocessing methods for sensor clock-offset cancellation. A cancellation of unknown clock-offsets from the asynchronous positioning problem reduces processing requirements, and, under certain reasonable assumptions, allows for statistically efficient distributed positioning algorithms. Cramér-Rao lower bound theory may also be used for estimating the performance of a positioning algorithm. In the second part of this paper, we exploit this property in developing a distributed algorithm, where the global positioning problem is solved suboptimally, using a divide-and-conquer approach of low complexity. The performance of this suboptimal algorithm is evaluated through computer simulation, and compared to previously published algorithms.

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Authors’ Affiliations

(1)
Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
(2)
Department of Signals and Systems, Chalmers University of Technology

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Copyright

© Rydström et al. 2006