Clock offset estimation in wireless sensor networks using robust M-estimation

Jaehan Lee, Jangsub Kim, Khalid Qaraqe, Erchin Serpedin

Research output: Contribution to journalArticle

Abstract

Clock synchronization plays a crucial role in Wireless Sensor Networks (WSNs). Assuming that there is no clock skew between sensor nodes, the Maximum Likelihood Estimate (MLE) of clock offset was derived by [1] for clock synchronization protocols assuming exponential random delays and a two-way message exchange mechanism as in TPSN (Timing-sync Protocol for Sensor Networks [2]) or NTP (Network Time Protocol). The MLE is appropriate for the case that the random delays in WSNs are exponentially distributed. However, the performance of the MLE is deteriorated considerably in the case that the underlying distribution is contaminated by or mixed with other distributions. Hence, a robust estimator is needed. In this paper, clock offset estimators based on the robust M-estimation method are proposed and it is shown that the proposed estimators present excellent performance in the mean squared error (MSE) sense under the condition that the underlying distribution is mixed with other distribution.

Original languageEnglish
Article number729726
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume7297
DOIs
Publication statusPublished - 2009
Externally publishedYes

Fingerprint

M-estimation
clocks
Wireless Sensor Networks
Clocks
Wireless sensor networks
maximum likelihood estimates
Maximum Likelihood Estimate
Clock Synchronization
estimators
sensors
Maximum likelihood
Network protocols
synchronism
Synchronization
Estimator
Robust Estimators
Mean Squared Error
Skew
Sensor Networks
Timing

Keywords

  • Clock Synchronization
  • Robust M-estimation
  • Wireless Sensor Networks

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

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