The Research On Software Radio Modulation And Demodulation System And The Realization Based On FPGA

The Software Radio is one of the systems of realization wireless communication which produced in 1990s. It is regarded as the third generation wireless communication technique succeeds to the analog communication and the digital communication. It focuses on constructing an open, standard, modularized and universal hardware flat, and making broadband A/D or D/A converters go near to the antennas as possibly as they can, so that on the hardware flat all kinds of functions are completed through software. The functions include frequency range, modulation mode, data format, encryption mode, communication protocols and so on.The thesis firstly introduces the basic principle of the Software Radio and three kinds of structure form and then expounds several items of key technology and the progress for latest research. The modulation and demodulation module is an essential part of the Software Radio. And this part embody a concentrated reflection of the most remarkable advantage of the Software Radio -Flexibility. The technologies to implement this part are varied at present. With development of Manufacturing engineering of the chip at full speed in recent years, FPGA with high-speed treatment performance, high capacity and flexibility becomes the important means to implement the Software Radio.The thesis chooses representative 16QAM and QPSK as the research object. After using System View software as a system-level tool to emulate 16QAM and QPSK principles on the systematic grade, my research focused on the implementation of digital modulation/demodulation in the Software Radio signal processing based on FPGA, and how to control the modulation/demodulation mode conversion by embedded CPU core. At the same time, design reuse method has been brought to this project by using IP core of Xilinx. Since the logic of FPGA can be reconstructed to implement different functions, debugging and upgrading of system hardware become very easy. The re-configurable ability of hardware and the application of control software with embedded CPU show the flexibility of the Software Radio.The thesis demonstrates the feasibility and flexibility to implement digital modulation/demodulation processing and control in FPGA. Moreover, the thesis has a profound research in the extension of the project and lays a foundation for building up a whole Software Radio system.