I. Introduction
The fast development of the Internet of Things (IOT) enables the interconnection of mobile devices, sensors, agents, users, machines and vehicles in a large scale, and the location awareness enables the networked agents to be operated and managed efficiently and accurately [1], [2], [3]. The localization of networked agents is a hot research topic due to its wide range of applications. For the cooperative planning and control of multi-agents [4], [5], [6] operating in a network, each agent should obtain its own location information so that the formation control or cooperative task can be fulfilled. Moreover, the localization technology of sensor networks is also applied in many other fields, such as enterprise attendance [7], worker location acquisition in mines [8], monitoring of expensive equipment in factories [9], etc.