Title
New Closed-Form Joint Localization and Synchronization Using Sequential One-Way TOAs
Abstract
It is an essential technique for the moving user nodes (UNs) with clock offset and clock skew to resolve the joint localization and synchronization (JLAS) problem. Existing iterative maximum likelihood methods using sequential one-way time-of-arrival (TOA) measurements from the anchor nodes' (AN) broadcast signals require a good initial guess and have a computational complexity that grows with the number of iterations, given the size of the problem. In this paper, we propose a new closed-form JLAS approach, namely CFJLAS, which achieves the asymptotically optimal solution in one shot without initialization when the noise is small, and has a low computational complexity. After squaring and differencing the sequential TOA measurement equations, we devise two intermediate variables to reparameterize the non-linear problem, and convert it to a simpler one of solving two simultaneous quadratic equations. We then solve the equations analytically to obtain a raw closed-form JLAS estimation. Finally, we apply a weighted least squares (WLS) step to optimize the estimation. We derive the Cramer-Rao lower bound (CRLB), analyze the estimation error, and show that the estimation accuracy of the CFJLAS reaches the CRLB under the small noise condition. The complexity of the new CFJLAS is only determined by the size of the problem, unlike the conventional iterative method, whose complexity is additionally multiplied by the number of iterations. Simulations in a 2D scene verify that the estimation accuracies of the new CFJLAS method all reach the CRLB under the small noise condition. Compared with the conventional iterative method, the proposed new CFJLAS method does not require initialization, obtains the optimal solution under the small noise condition, and has a low computational complexity.
Year
DOI
Venue
2022
10.1109/TSP.2022.3168363
IEEE TRANSACTIONS ON SIGNAL PROCESSING
Keywords
DocType
Volume
Location awareness, Clocks, Synchronization, Iterative methods, Mathematical models, Noise measurement, Time measurement, Sequential one-way time-of-arrival (TOA), joint localization and synchronization (JLAS), closed-form method
Journal
70
ISSN
Citations 
PageRank 
1053-587X
0
0.34
References 
Authors
0
6
Name
Order
Citations
PageRank
Ningyan Guo101.01
Sihao Zhao263.09
Xiao-Ping Zhang35612.72
Zheng Yao44915.33
X. W. Cui521926.61
Mingquan Lu612230.09