A Design Of General Digital Signal Proceeding System Of Soft Radio

In 1922, Jeo Mitola of MILTRE cooperation first gave the conception of soft radio. The main idea of soft radio is to build an open,standard,module platform, to make the A/D converter close to the antenna, and to realize the function of modulation,demodulation,communicating protocol ,etc with software. Soft radio is an economic scheme to solve the problem of compatibility of different radios, and it's one of the key technique of the future communications. At present, the theory of soft radio is mature, and all kinds of applications have been tried. In this paper a new design for soft radio, the general signal proceeding machine for soft radio, is introduced, and the design can process the intermediate frequency and base band signal. This system has a plenty of interfaces, including USB1.1, RS232, Ethernet, CODEC, and all these interfaces have been realized through ARM. The signal proceeding part is based on TigerSHARC dsp, with accustomed up converter and down converter interfacing to median frequency signal. A whole design including source scheme and PCB is given,and hardware has been made. Based on this system, amplitude modulation of sine wave,down converting of sine wave,D-QPSK modulation have been realized, and at the end, a design for demodulation of D-QPSK is given. This system can process the digital signal of 3 Mbis/s, and the highest sampling of intermediate frequency is 65 MSPS. It can realize the duplex communications on a single board. It is a powerful tool for research of modulation,coding,Spread Spectrum, etc, and is a talent platform for future.