A Design And Implementation Of A Digital-IF Transmitter Module Based On Software Radio In Communication System

Conventional transmitter depends on hardware much more. The emergence of Software Radio (SDR) results in transmitter's renovation. The basic theory of SDR is to sample RF signal, process the digital signal by installing different software to implement different functions on a high-speed DSP platform. Due to the limitation of device level, it is impossible to sample RF signal in direct now and have to choose the mid project---sampling IF signal, using special chips to build the intermediate frequency module.This paper discusses the realization of the digital IF module in SDR transmitter. Firstly it expatiates on the theory on SDR, discussing all modules about SDR transmitter. Then on the basis of those, a scheme of the system is given, and the hardware circuits are built with appropriate chips. Finally, the feasibility of the multi-frequency and multi-module SDR transmitter is analyzed by simulating the system and modulating the signal.