Hardware Platform Design Of Software Deifned Radio Based On FPGA

With the popularity of internet, people’s demands for information are higherthan ever before, especially for radio media, such as wireless internet browsing,wireless internet cinema, wireless video conferencing wireless remote medicaldiagnostics, wireless payments and so on. A super-high-speed4G mobilecommunication system is proposed for facing rapid growth of various multimediadata services. If technical measures could not be taken, there will beincompatible between4G system and the past. In order to satisfy users’requirements for system performance and solve the conflict brought byincompatibility, software designed radio technology will be the trend of wirelesscommunications. Software designed radio is a communication system thatrealizes various functions through designing software without changing originalhardware platform. It has many advantages such as low cost, high speed, andhigh stability. Therefore software defined radio will become the future ofwireless communications.In this paper, a wide range of broadband band-pass sampling softwaredesigned radio architecture is applied, the system completes the receiving ofintermediate frenquency signal, and intermediate frenquency analog signal issampled by the A/D converter. Digital down conversion is completed so that thesignal is demodulated by FPGA. The software defined radio hardware platform isproposed based on Altera Corporation EP2C8Q208FPGA. Because of itsreconfiguration and highly integrated features, not only the complexity ofreceiver will be cut down, but also the cost of system will be reduced. Byanalyzing the structure of the different RF front-end and the sampling rate ofintermediate frequency, A/D converter and the main chip are determinedultimately. The software designed radio receiver of hardware platform isconstructed to fulfill usual functions on the basis of FPGA. Meanwhile, on this hardware platform, a very important function, named digital down conversion, isdevised as a part of software designed radio. In the theory, architecture of digitaldown conversion and its parts are deeply analyzed, devised and simulated indetail as well as processing the baseband signal. Finally, the simulation withQPSK demodulation demonstrate flexibility and reliability of this hardwareplatform by Quartus II.