The Design And Implementation Of Underwater Acoustic Communication Network Node Based On KeyStone ?

With the increasing emphasis on maritime rights and interests,the research of underwater acoustic communication network have become a research hotspot.Underwater acoustic communication network node is very important in underwater acoustic communication network.The underwater environment is quite complex,in which there are serious noise,interference,and multi-path effect.In order to realize the reliable transmission,the physical layer algorithm becomes more and more complicated.corresponding to the processing capacity of communication nodes require more and more.At the same time,the underwater acoustic communication network requires the communication node to be able to handle the complicated network protocols.In this paper,the platform of the underwater acoustic communication node based on the KeyStone ?architecture processor is carried out.It is a high-performance multi-core platform processor from TIcompany,which consists of four Cortex-A15 cores and eight TMS320C66 x high-performance DSP cores.Firstly,according to the characteristics of the underwater acoustic communication networks,the function and technical index of the communication node are designed.The designed scheme for the platform is presented,including digital signal processing,network protocol processing,analog signal transmitting and receiving,data storageand so on.Secondly,the ARM-based embedded Linux system is developed.Between the PC and circuit board,we build an embedded development environment to lay the foundation for system development.And then we carry out the U-boot transplant,Linux kernel transplant,UBI file system migration and network file system(NFS)configuration.We also focus on the transplantation of network simulation software NS2.Finally,the design and realization of the driver and application are completed.DSP core is responsible for the realization of the physical layer algorithm,in which the direct sequence spread spectrum algorithm is selected as the communication algorithm,and the pseudo-random sequence is used to spread the signal,which effectively overcomes the anti-jamming problem and improves the confidentiality of the communication system.The receiver adopts the hypothesis feedback equalization technique based on the chip level,which can reduce the interference of time-varying channel characteristic.And then we execute the design of PWM modulation module and data acquisition module.Finally,for the communication system requirements,the analog aignal transmitting /receiving module is designed and developed.All modules are verified in the wator-pool.The design of the underwater acoustic communication network node on KeyStone ? architecture can complete the basic function of communication node,and lay the foundation for the development of high-performance communication node.