Research On Underwater Nodes Movement Based On Channel Prediction And Relay Deployment Strategy

With the rapid development of science and technology and the continuous progress of human society,the ocean has gradually become the research object of various countries.China is a big maritime country,and it will also be a maritime power in the future.The party and the government attach great importance to the research and development of the ocean.Underwater wireless sensor network is an important tool for ocean data acquisition and monitoring in recent years,which has high research significance and value.There are many research directions in the network.In this paper,the underwater acoustic channel quality prediction,dynamic node movement strategy and static node relay deployment are intensively studied.The main research contents of this article are:(1)Underwater acoustic communication is the main way of information interaction between nodes in underwater wireless sensor networks,so it is necessary to study the underwater acoustic propagation channel to help the whole network work better.In this paper,path loss and shadow effect,which cause the fading of underwater acoustic signal,are the main research objects.The two phenomena are characterized by mathematical models,and the prediction model of channel quality is constructed based on them.The unknown parameters in the model can be improved by a small number of samples,and then the channel quality of any position within the sample coverage can be predicted by the model.The feasibility of the model is verified by simulation,and the accuracy of prediction is verified by indoor pool experiment and outdoor lake experiment.(2)Underwater wireless sensor networks not only have fixed static nodes,but also deploy a small number of dynamic nodes(such as autonomous underwater vehicles)for movement operations.In the process of moving,dynamic nodes often need to interact with the control center of the network.In this paper,by considering the length of the moving path and the channel quality of the moving path,we use the improved A* algorithm and Q-learning algorithm to formulate a reasonable movement strategy for the dynamic nodes,and give consideration to the communication quality along the way while ensuring the movement distance.On the basis of channel quality related experimental data,the feasibility of the dynamic node movement strategy is verified by simulation.(3)When two static nodes in underwater wireless sensor network cannot interact with each other due to distance problems,communication can be restored by deploying relay nodes.This paper takes the correct rate of receiving information as the index,constructs the target function of information from transmitting node to receiving node through relay node.Through theoretical analysis and derivation,the best relay deployment position is obtained.The correctness of the conclusion is verified by simulation,and the related work in other literatures further confirms the rationality of the relay node deployment location.On this basis,the indoor pool experiment is carried out,and the experimental results also confirm the correctness of the theory.