On biased estimators and the unbiased Crame´r-Rao lower bound
Signal Processing
Fundamentals of statistical signal processing: estimation theory
Fundamentals of statistical signal processing: estimation theory
Signal Processing
Fine-grained network time synchronization using reference broadcasts
ACM SIGOPS Operating Systems Review - OSDI '02: Proceedings of the 5th symposium on Operating systems design and implementation
Lightweight time synchronization for sensor networks
WSNA '03 Proceedings of the 2nd ACM international conference on Wireless sensor networks and applications
Timing-sync protocol for sensor networks
Proceedings of the 1st international conference on Embedded networked sensor systems
TSync: a lightweight bidirectional time synchronization service for wireless sensor networks
ACM SIGMOBILE Mobile Computing and Communications Review - Special issue on wireless pan & sensor networks
The flooding time synchronization protocol
SenSys '04 Proceedings of the 2nd international conference on Embedded networked sensor systems
Secure time synchronization service for sensor networks
Proceedings of the 4th ACM workshop on Wireless security
Localization in underwater sensor networks: survey and challenges
WUWNet '06 Proceedings of the 1st ACM international workshop on Underwater networks
Clock Offset Estimation in Wireless Sensor Networks Using Bootstrap Bias Correction
WASA '08 Proceedings of the Third International Conference on Wireless Algorithms, Systems, and Applications
A study on the optimal time synchronization accuracy in wireless sensor networks
Computer Networks: The International Journal of Computer and Telecommunications Networking
EURASIP Journal on Wireless Communications and Networking - Special issue on synchronization in wireless communications
Maximum likelihood trend estimation in exponential noise
IEEE Transactions on Signal Processing
On Maximum Likelihood Estimation of Clock Offset and Skew in Networks With Exponential Delays
IEEE Transactions on Signal Processing
IEEE Transactions on Wireless Communications
Time synchronization in sensor networks: a survey
IEEE Network: The Magazine of Global Internetworking
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Accurate clock synchronization is vital to many applications of wireless sensor networks (WSNs). The availability of a mathematical tool that at an early design stage can provide insight into the theoretically achievable performance of the clock synchronization may accordingly be valuable in the initial design phase of the network. Therefore, the achievable clock synchronization accuracy is examined in a WSN employing a two-way message exchange model under a Gaussian assumption. The Cramér-Rao bound for the estimation of the clock parameters is derived for four different parameterizations (i.e., different nuisance parameters), reflecting different levels of prior knowledge concerning the system parameters. The results on the Cramér-Rao bound are transformed into a lower bound on the mean square error of the clock offset, a figure of merit often more relevant, characterizing the system performance. Further, by introducing a set of artificial observations through a linear combination of the observations originally obtained in the two-way message exchange, an approximate maximum likelihood estimator for the clock parameters is proposed. The estimator is shown to be of low complexity and it obeys near-optimal performance, that is, a mean square error in the vicinity of the Cramér-Rao bound. The applicability of the derived results is shown through a simulation study of an offshore engineering scenario, where a remotely operated underwater vehicle is used for operations at the seabed. The position of the vehicle is tracked using a WSN.