Study On Experiment System Of Multi-Modulation And Demodulation

In the age of universal of the mobile communication and communication product, the principle of communication experiment has become a required course in the major of the university for electronic information engineering,communication engineering Etc. Experiment can verify theoretical knowledge of the student and change theoretical knowledge into practical circuits, it also can train the students' innovative thinking. As the core of the mobile communication technology, the modulation and demodulation is the key to achieve high speed, highly efficient mobile communication system. In order to accommodate various of modulating, different communication protocol and standards and to update and upgrade the system, the software radio technique emerges with the tide of the times. Software radio which applied in the experimental becomes a new experimental model. It focus on designing the satisfied universal hardware platform, to expanding of function and upgrading of performance by software's designing and optimization. It has good versatility,flexibility and development prospects.According consulting related literature, analysis existing experimental system of modulation and demodulation's principles and characteristics after improveing quadrature mathematical model of modem, design a open, standardized, modular, multi-modulation and demodulation hardware experimental platform with the key points and function entities base on FPGA. The platform can set the way of modulation and demodulation, universal filter and parameter of synchronization. The system is helpful for students to learn the theory and control the techniques because each module not only include open, standard input interfaces and output interfaces, but also contains the test points of key signal, which facilitate the achievement of designative, comprehensive, systematic and innovative experiment. This not only accord with development needs of modern communication, but cooperate a better experimental teaching and enhance students' innovative ability. The design of software is finished based on the completed design of universal hardware platform, including signal source module, terminal module, modulation module, demodulation module, controller module and LCD/keyboard module. In this paper, it adopt a new experiment pattern, present controlling universal filter method and realize. It save resources in FPGA by improving arithmetic Last, the module of the system are simulated, tested and analysis. The result shows that the functions satisfied the design requirements and system was steady and reliably.