Research Of Software-defined Radio Modem Technology Based On The DSP Hardware Design

Software defined radio(SDR )is determined by the software, that is, software defined radio is a software design on the physical layer of wireless communication connection. The core of software radio is A / D, D / A as close as possible to the antenna, with software functions as much as possible; its central idea is a standardized, modular, common hardware platform, software programming, the realization of a multi-channel, multi-level and multi-mode wireless communication open architecture. Application of software radio technology makes a mobile terminal use in different systems.After ten years the rapid development of software radio has become the cornerstone of modern mobile communication (especially the third generation mobile communication). The basic idea of software radio is based on a common, standard, modular hardware platform. Software radio can be programmed to achieve a variety of functions, which make hardware design method is liberated. Function of a single, Poor flexibility hardware is reduce by software radio, especially to reduce the Analog circuit design, the digital processing (A / D and D / A conversion) as close as possible to the antenna. The architecture of software-defined radio which is emphasizing the openness and full programmability, through software updates to change new features. The architecture of software-defined radio has the hardware module that is high-performance and open-bus, in order to facilitate the continued upgrading and expansion.In this paper, based on the software defined radio as a guide, complete the design of software radio hardware platform and the basis of the hardware platform design QAM, GMSK modulation and demodulation methods. Circuit board hardware development tools is protel99se, the process of hardware development, including needs analysis, the choice of chips, the production of schematic and PCB, the debug of hardware board. Make use of the DSP development environment CCS2.0 and C language to complete the modulation and demodulation of QAM and GMSK. DSP is the core of the hardware platform; CPLD is used to coordinate and control. The system has a powerful digital signal processing capabilities, flexibility, so that a variety of communication systems can be used.