Design And Implementation Of Underwater Acoustic Communication Networks System And Localization

Underwater wireless communication networks is one of the hottest topics in the world. Based on the study of underwater networks and the characteristics of acoustic channel, this paper designs a hydroacoustic network node system implementation, studies related self-positioning and ranging technology for simulation and related pool experiment, finally completes a self-organizing underwater communication network systems.The main research and innovation of this paper is as follows:(1) Designed and developed a set of six nodes hydroacoustic network systems, including hardware design and development of electronic devices, software and programming, as well as the overall design and development and so on. The network node can achieve distance 2km,information rate 500bit/s underwater acoustic communications, and ranging, TDMA/ALOHA network protocols, self-positioning network protocols and related functions;(2) Propose An adaptive frequency ranging method based on the best frequency. System uses multiple iterations method to find a way to calculate the optimal frequency for different distance, which could improve the receiver SNR and ranging performance. The simulation shows adaptive frequency ranging method based on the best frequency could effectively improve the ranging signal receiving end SNR from about 2 to 20 d B, which could improve the ranging accuracy of about 0.5m-7m in situation that signal band is 6 to 30 KHz and distance range is 0.5 to 10 km.(3) Proposed an effectively method which could improve the efficiency of nodes ranging. Simulation results show that, if system use this ranging method, acoustic system can take full advantage of the delay interval propagation of acoustic signals in the water, and could effectively improve the efficiency of ranging work. According to the number of sending ranging pulses in a single group,ranging system could increase ranging efficiency 1.5 to 4 times.(4) Based on(1) which includes the development of underwater acoustic communication network system,this paper completes a self-organizing network node self-localization methods, including TDMA timing design, software programming based on finite state machine, network communication packet format and design, and the contrast simulation experiments with DV-HOP. Pool experiments show that this method average positioning error ?0.5m, have already reached the application requirements.(5) Based on the development of underwater acoustic communication network system, this paper completes related tests in the pool which includes communications, ranging, TDMA protocol, ALOHA protocol and self-localization. The tests in the pool proved that the underwater acoustic communication system is reliable and stable to provide support for the realization of acoustic networks functions, which has important practical value.