基于FPGA的NAVTEX数字下变频系统设计

发布时间：2018-04-22 14:11

本文选题：可编程逻辑器件 + 软件无线电　；参考：《东华理工大学》2017年硕士论文

【摘要】：随着国际海洋运输行业的快速发展,海洋运输行业对海上通信设备提出了更高的要求。为满足设备要求,需要采用新的技术实现手段。软件无线电技术作为通信技术的未来发展方向,其理论的发展和应用为海上通信设备的研制提供了一种更加高效的技术实现途径。以FPGA为代表的可编程逻辑器件的快速发展,为软件无线电技术提供了更好的实现平台。FPGA可编程器件的出现使得软件无线电技术的灵活性和开放性扩展到系统硬件设计级别。本文详细介绍了NAVTEX系统的发展现状并对国内外NAVTEX系统的技术实现方案进行了分析。在此基础上提出了采用软件无线电技术实现的基于FPGA的NAVTEX系统数字下变频系统的设计,用以替代通用的基于专用硬件设计的下变频系统。本文对数字下变频系统的整体方案进行设计并对系统中的数控振荡器、积分梳状滤波器、有限单位脉冲响应滤波器、正交解调模块进行了理论分析和介绍。根据系统功能要求对数字下变频系统各组成部分进行了详细的理论分析以及具体的设计过程。利用Simulink仿真软件对设计的系统进行整体系统模型和简化系统模型的建模以验证算法的正确性。根据系统理论设计在FPGA平台上对各组成部分进行硬件实现。利用modelsim软件对各个组成模块进行功能仿真并对部分仿真结果进行MATLAB分析。最后,在FPGA平台上对数字下变频系统进行整体实现,通过在实验室搭建硬件测试平台对数字下变频系统的各项性能进行测试。通过对数字下变频系统的硬件测试表明系统能够实现对518KHZ的中频调制信号进行正确的解调且各项性能测试条件下系统对中频信号的解调输出误码率低于4%,符合国际标准对NAVTEX系统的性能要求。同时,系统可以进行在线升级和功能扩展,极大的增加了系统的设计的灵活性和可扩展性。
[Abstract]:With the rapid development of the international marine transportation industry, the marine transportation industry has put forward higher requirements for the marine communications equipment. In order to meet the requirements of the equipment, the new technology is needed to implement the technology. The software radio technology is the future development direction of the communication technology. The development and Application of its theory provide one of the development of maritime communication equipment. A more efficient approach to technical implementation. The rapid development of programmable logic devices, represented by FPGA, provides a better implementation platform for software radio technology, the emergence of.FPGA programmable devices, which extends the flexibility and openness of software radio to the system hardware design level. This paper introduces the NAVTEX system in detail. The development status and the technical implementation of the NAVTEX system at home and abroad are analyzed. On this basis, the design of the FPGA based NAVTEX system digital down conversion system based on the software radio technology is proposed to replace the general-purpose down conversion system based on the special hardware design. This paper is the whole side of the digital down conversion system. The case is designed and the numerical control oscillator, the integrated comb filter, the finite unit pulse response filter and the orthogonal demodulation module are analyzed and introduced. According to the function requirements of the system, the detailed analysis of the components of the digital down conversion system and the specific design process are carried out. The Simulink simulation software is used. The whole system model and simplified system model are modeled to verify the correctness of the algorithm. Based on the system theory, the hardware implementation of each component is carried out on the FPGA platform. The function simulation of each module is simulated with the Modelsim software and the MATLAB analysis is carried out for some of the real results. Finally, the FPGA level is flat. On the platform, the digital down conversion system is realized, and the performance of the digital down conversion system is tested by building the hardware test platform in the laboratory. The hardware test of the digital down conversion system shows that the system can realize the positive demodulation of the 518KHZ intermediate frequency modulation signal and the system under various performance testing conditions. The error rate of the demodulation output of the intermediate frequency signal is less than 4%, which is in line with the performance requirements of the international standard for NAVTEX system. At the same time, the system can upgrade and expand the function online, which greatly increases the flexibility and extensibility of the system design.

【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN773

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