The Research And The Implementation Of Shortwave IF Digital Platform Based On Software Radio

This thesis is a research project on hardware platform design which is developed according to the practical problems encountered in the process of production of the company.By virtue of the programming flexibility and wide applications of FPGA,a platform based on the DSP+FPGA architecture,is used to realize intermediate frequency digitalized paltform with software radio.A hardware processing platform which digitialize in the intermediate frequency band and the baseband is designed and implemented.The platform not only improves the performance of the radio transceiver,but also made the radio part has the function of software radio,which can realize a variety of business communications by loading different software modules.Thus,flexbility and adaptability of the platform is greatly increased.Performance test and experimental verification of the platform are accomplished and the platform is put into production so far.The master design of a shortwave IF digitalized hardware platform is accomplished on the basis of analysis and investigation on the two kinds of the existing shortwave IF platform,including platform principle scheme design,components selection,interface definition,schematic design,PCB drawing,bottom level driving program design and testing program design.Digital Up Convertion(DUC)and Digital Down Conversion(DDC)realized with FPGA and system debug are accomplished in cooperation.The organization of the thesis is according to the order of the works incorporated in the platform design.The background and the purpose of the thesis and the overall organization of the thesis are first introduced.Second,the principle of the platform is introduced,including the introduction of the used circuit chipset of the hardware platform and the purpose and the property of the main circuit in the platform.For ease of understanding,the brief design block diagram of the interface circuit in schematic design is given.Third,the principle of the IF digitalization is presented,where a brief analysis of the filters used in digital up conversion and digital down conversion is given.Realization of the bottom level driving program in the platform hardware design,the implementation scheme of the some software,and the detailed design of the various filters of DUC and DDC using FPGA,are given.Finally,debug of the hardware platform is given.Testing instruments prepared for debugging and testing environment building are introduced according to the author's experience on debugging.Additionally,the procedures of debug are depicted,the need in debug to pay attention to is summarized,and the occurring problems in the process of debug and the corresponding analytical thinking and solutions are summarized.Attentions on the schematic diagram design and PCB drawing is briefly drawn,and the future development directions on the platform is prospected.