Optimal Online Transmission Schedule for Remote State Estimation over a Hidden Markovian Channel⁎This work was supported in part by the National Natural Science Foundation of China under Grants 61573103, 61520106009 and 61921004, in part by the Outstanding Young Scholarship of Jiangsu Province under Grant BK20180012, in part by the Southeast University "Zhongying Young Scholars" Project, and in part by the Key Laboratory of System Control and Information Processing, Ministry of Education, China (Corresponding author: Xianghui Cao). Issue 2 (2020)