The Research Of Some Key Thechnologies On Soft-Defined Radio

"Soft-Defined Radio-SDK." has been a new technology in the world recent years. It has been called another revolution in radio communication after transition from analogue to digital. It has vast military and civil use. As a result, some key technologies of SDR such as modulation, demodulation, DDC and DUG have been hot topics.In this paper, some key technologies of SDR are researched deeply. All is based on software radio frame of IF sampling. First, how to conduct sample and quantification of continuous time signal which is prior condition of SDR is explored in detail, and the comparison and analysis of some sample modes are given in which band pass signal sampling theorem is most important. Second, multi-sample rate signal processing which is an important basis of SDR is studied. Emphasis are put on decimation and interpolation those are the most fundamental process and the realization of decimation and interpolation filter. Then, CIC filter that is applicable to first class decimation and HB filter that is applicable to double decimation are introduced. Moreover, with the consideration of DDC and DUG, orthogonal modulation and demodulation algorithms of AM, FM, FSK, BPSK, QPSK are explored and implemented based on traditional algorithms.HSP50214B and HSP50215 is very important in this paper. The basic characteristics, framework, principles of dominant parts and application of those are studied and illustrated. At the last chapter, by devising a short-wave radio station aforementioned fundamental theories are put into practice especially digital modulation, demodulation, DDC and DUG etc. The implement framework and design method of SDR are discussed by data transmission of voice including DUG modulation in transmit module and DDC demodulation in receive module. Moreover, satisfied results are obtained by validation on the SB3410 platform in BlueWave system.In addition, the results with MATLAB and system design are given. Analysis shows that the results of this thesis are valuable to future research.