Time-varying clock offset estimation in two-way timing message exchange in wireless sensor networks using factor graphs

@article{Ahmad2012TimevaryingCO,
  title={Time-varying clock offset estimation in two-way timing message exchange in wireless sensor networks using factor graphs},
  author={Aitzaz Ahmad and Davide Zennaro and Erchin Serpedin and Lorenzo Vangelista},
  journal={2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)},
  year={2012},
  pages={3113-3116}
}
  • A. Ahmad, D. Zennaro, L. Vangelista
  • Published 31 January 2012
  • Computer Science
  • 2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
The problem of clock offset estimation in a two-way timing exchange regime is considered when the likelihood function of the observation time stamps is exponentially distributed. In order to capture the imperfections in node oscillators, which render a time-varying nature to the clock offset, a novel Bayesian approach to the clock offset estimation is proposed using a factor graph representation of the posterior density. Message passing using the max-product algorithm yields a closed form… 

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References

SHOWING 1-9 OF 9 REFERENCES
On maximum-likelihood estimation of clock offset
  • D. Jeske
  • Mathematics
    IEEE Transactions on Communications
  • 2005
TLDR
It is shown that the MLE corresponds to a previously proposed estimator of clock offset, and the ML interpretation of the estimator provides further insight and motivation for its use.
Novel Clock Phase Offset and Skew Estimation Using Two-Way Timing Message Exchanges for Wireless Sensor Networks
TLDR
This paper proposes novel clock skew estimators assuming different delay environments to achieve energy-efficient network-wide synchronization for WSNs and derives the Cramer-Rao lower bounds and the maximum likelihood estimators under different delay models and assumptions.
Analysis of synchronization algorithms with time-out control over networks with exponentially symmetric delays
TLDR
It is shown that the MnLD algorithm achieves the best accuracy over symmetric links without having to impose a strict TO control, which substantially speeds up the algorithm.
Synchronization in Sensor Networks: an Overview
  • B. Sadler, A. Swami
  • Computer Science
    MILCOM 2006 - 2006 IEEE Military Communications conference
  • 2006
TLDR
This paper reviews the problem of wireless sensor network synchronization and associated key issues, including the fundamental signal processing tasks needed, such as estimation of the skew and offset between two clocks, round trip delay estimation, extension of synchronization to multiple nodes, as well as performance analysis and bounds.
CLOCK SYNCHRONIZATION IN WIRELESS SENSOR NETWORKS
Sensor nodes in wireless sensor networks (WSNs) are equipped with cheap hardware clocks which frequently drift apart due to their low-end quartz crystals whose frequencies are not stable and vary
Clock Synchronization of Wireless Sensor Networks
TLDR
This article illustrates that many of the proposed clock synchronization protocols can be interpreted and their performance assessed using common statistical signal processing methods, and shows that advanced signal processing techniques enable the derivation of optimal clock synchronization algorithms under challenging scenarios.
Timing-sync protocol for sensor networks
TLDR
It is argued that TPSN roughly gives a 2x better performance as compared to Reference Broadcast Synchronization (RBS) and verify this by implementing RBS on motes and use simulations to verify its accuracy over large-scale networks.
Timingsync protocol for sensor networks
  • Proc. SenSys, Los Angeles, CA, pp. 138-149, Nov. 2003.
  • 2003
A survey on sensor networks
TLDR
The current state of the art of sensor networks is captured in this article, where solutions are discussed under their related protocol stack layer sections.