Research On Intermediate Frequency Module In Software Radio Mobile Communication Systems

As communications technology continues its rapid transition from analog to digital, more functions of contemporary radio systems are implemented in software, leading toward the software radio.As a promising novel concept and system to realize mobile communications, Software Radio's core theory is to put the Analog to Digital Converter and Digital to Analog converter as closely as possible to the antenna, and all the function is defined as software, while the hardware is treated just as a basic platform in software radio. Thus, good performance in generality and flexibility can be met easily in such mobile communications. And It is also very convenient to inter-system connect and update.This liberation is accomplished through a combination of techniques that includes multi-band antennas and Radio Frequency (RF) conversion; wideband Analog to Digital (A/D) and Digital to Analog (D/A) conversion (A/D/A conversion); and the implementation of Intermediate Frequency (IF), baseband, and bit-stream processing functions in general-purpose programmable processors. The resulting software-defined radio (or "software radio") in part extends the evolution of programmable hardware, increasing flexibility via increased programmability.This paper introduces the general architecture and the key technologies of software radio, studies feasible implementation of software radio for digital intermediate frequency, discusses its hardware properties and finally indicates its application foreground in next generational mobile communication system. A hardware testbed platform is designed and verified in the paper.In this dissertation, studying of intermediate frequency field of Software Radio is focused. Still, some new ideas are introduced on the intermediate frequency hardware platform, which can implemented in a general mobile communication systems. In addition, some part of the testbed was verified.