Key Laboratory of Broadband Wireless Communication and Sensor Network Technology;
Nanjing University of Posts and Telecommunications;
Nanjing;
210003;
China;
YuanTong Express Co.LTD;
Shanghai;
201705;
China;
Department of Computer Science;
Tuskegee University;
Tuskegee;
AL;
36088;
USA;
College of Information Engineering;
Nanjing University of Finance and Economics;
Nanjing;
210023;
China;
Time synchronization; particle filter; expectation maximization; wireless sensor networks(WSNs);