Title
To Retransmit or Not: Real-Time Remote Estimation in Wireless Networked Control.
Abstract
Real-time remote estimation is critical for mission-critical applications including industrial automation, smart grid, and the tactile Internet. In this paper, we propose a hybrid automatic repeat request (HARQ)-based real-time remote estimation framework for linear time-invariant (LTI) dynamic systems. Considering the estimation quality of such a system, there is a fundamental tradeoff between the reliability and freshness of the sensor's measurement transmission. When a failed transmission occurs, the sensor can either retransmit the previous old measurement such that the receiver can obtain a more reliable old measurement, or transmit a new but less reliable measurement. To design the optimal decision, we formulate a new problem to optimize the sensor's online decision policy, i.e., to retransmit or not, depending on both the current estimation quality of the remote estimator and the current number of retransmissions of the sensor, so as to minimize the long-term remote estimation mean-squared error (MSE). This problem is non-trivial. In particular, it is not clear what the condition is in terms of the communication channel quality and the LTI system parameters, to ensure that the long-term estimation MSE can be bounded. We give a sufficient condition of the existence of a stationary and deterministic optimal policy that stabilizes the remote estimation system and minimizes the MSE. Also, we prove that the optimal policy has a switching structure, and derive a low-complexity suboptimal policy. Our numerical results show that the proposed optimal policy notably improves the performance of the remote estimation system compared to the conventional non-HARQ policy.
Year
DOI
Venue
2019
10.1109/icc.2019.8761710
IEEE International Conference on Communications
Field
DocType
Volume
Hybrid automatic repeat request,LTI system theory,Mathematical optimization,Wireless,Optimal decision,Smart grid,Communication channel,Real-time computing,Automation,Mathematics,Estimator
Journal
abs/1902.07820
ISSN
Citations 
PageRank 
1550-3607
0
0.34
References 
Authors
11
4
Name
Order
Citations
PageRank
Kang Huang1172.54
Wanchun Liu2727.12
Yonghui Li33393253.70
Branka Vucetic43266352.78