Generic Modem System Based On Dsp Design And Implementation

Along with the development of technology, various wireless systems have been designed to meet different needs appeared. However, for historical and some other reasons, the radio stations are designed for some specific purpose, such that though there are many common functions, it is quite difficult to integrate their common features together due to their poor compatibility design. In 1990s, Joe Mitola proposed "Software Radio (SA)", a new technology concept for radio system design, which aims at building software re-configurable information system on general or common hardware platform, so that various functions can be easily configured by software updating for more versatile communication function or for interoperation requirements.To our main concern here, current wireless communication systems are quite different, though they are operating on the same frequency / channel and/or being fed with data from the same source, i.e. the same unit– which leads to severe incompatibility and high costs. Based upon Joe Mitola's SA concept, the best solution should be that design a common channel device platform or a software configurable channel module which can be configured by software to different operating modes to replace channel modules in use.Therefore, the Software Radio can solve the existing problems, improve system cost and usability. The purpose of this thesis is to develop a test system, to incorporate several types of digital signal modulation and demodulation functions, to meet the design requirements. The demand is consistent with the concept of Software Radio.We design a universal modem system, which can be regarded as a DSP-centered solution with A/D front-end and a D/A back-end. Through research, we chose TI's high-performance 6000 DSP, XILINX's FPGA and ADI's high-speed A/D, D/A converter.In this thesis, we start with technique background including the concept and theory of software radio, and then the software radio based modulation and demodulation system design is given including its system structure, signal flow, test bed and system performance evaluation. Finally, a summary of the designed system is presented.