An Algorithm for Accurate Distributed Time Synchronization in Mobile Wireless Sensor Networks from Noisy Difference Measurements

Abstract

We propose a distributed algorithm for time synchronization in mobile wireless sensor networks. The problem of time synchronization is formulated as nodes estimating their skews and offsets from noisy difference measurements of offsets and logarithm of skews; the measurements acquired by time-stamped message exchanges between neighbors. The algorithm ensures that the estimation error is mean square convergent (variance converging to 0) under certain conditions. A sequence of scheduled update instants is used to meet the requirement of decreasing time-varying gains that need to be synchronized across nodes with unsynchronized clocks. Moreover, a modification on the algorithm is also presented to improve the initial convergence speed. Simulations indicate that highly accurate global time estimates can be achieved with the proposed algorithm for long time durations, while the errors in competing algorithms increase over time.where the scalar parameters u , u are called its skew (the relative speed of the clock with respect to t) and offset Manuscript

Further Results on Quasi‐Synchronization of Delayed Chaotic Systems with Parameter Mismatches Via Intermittent Control

“…For given admissible intermittent time sequences (h 11 , h 12 , h 21 , h 22 ), suppose that  = {x ∈ R n | ‖x‖ ≤ 1 } contains the attractor of the drive system (1) and the mismatched parameters satisfy ‖ΔA‖ + L f ‖ΔB‖ + L g ‖ΔC‖ ≤ 2 . Consider the drive system (1) and the response system (2) satisfying A1, for the given n × m matrix K, positive scalars , 1 , 2 , there exist n × n matrices P ij > 0, Q i > 0 i, j = 1, 2, n × n diagonal matrices D ijl > 0, i, j = 1, 2, l = 0, 1, positive scalars i , , i = 1, 2, such that (7) and the following LMIs hold:…”

“…In recent decades, synchronization has received considerable attention from various fields, such as a fascinating behavior in signal processing, secure communication, biology, automatic control engineering, pattern recognition and artificial intelligence (for example, and the reference therein). Based on the chaotic True Random Bits Generator, investigated synchronization phenomena between two mutually coupled identical nonlinear circuits.…”