The Hidden Node Time Synchronization Algorithm With Passive Localization Used In Underwater Acoustic Networks

Clock synchronization and node localization are two important basic technologies,which are the object of this research.Under the restriction of complicated underwater conditions,the original land wireless sensor technology cannot be applied underwater,making it more difficult in underwater application.In addition,there are exposed networks in the ocean,but there are mobile nodes that cannot be exposed.It is a challenge to complete its clock synchronization and localization without exposing the nodes.Then,to solve the current dilemma of these two technologies,based on underwater scenes and application demand,the hidden mobile node clock synchronization algorithm with passive TDOA localization is proposed.In the case of underwater high latency,the location trajectory of the underwater mobile node in the motion process is solved to reduce the harmful influence of the clock drift problem and to locate the node location accurately.Algorithm is divided into the node movement direction of known and unknown.And the noise interference errors caused by underwater environment can also be filtered by combining Kalman filtering,and thus continue to synchronize the clock of the nodes and realize its localization.The value contribution and innovation of this algorithm is as follows:(1)Time synchronization and node localization are usually solved independently,but they are coordinated to complete tasks in this research work in order to realize the node localization as well as clock synchronization,in which situation,the need to exchange information amount is significantly reduced,the energy consumption is saved,while the two solutions are both improved.(2)In this algorithm,nodes need not to send information to the outside,so that the nodes would not be exposed to the network,and their concealment and security can also be guaranteed.In the process of clock synchronization,the one-way information transmission is different from the existing algorithm,which is a highlight.(3)In the current mainstream algorithm,the nodes need to complete the clock synchronization in the case of being static.However,most of the underwater nodes need to be in motion in order to be used in suitable applications.The algorithm in thispaper can realize the clock synchronization during the movement of the nodes,which creates a new application scenario for underwater applications making it more possible.(4)In the OPNET platform,the algorithm is simulated in this paper,and the results of simulation is showed.And the performance of the algorithm in this paper and other representative algorithms are compared and analyzed,verifying the algorithm in this paper are superior.