Research Of Multi-channel Software Radio Transmitter

Software radio technology achieves all kinds of communication functions by installing different software on a universal and on-limits smart wireless platform. Software radio system fits several frequency bands, can change working mode flexible and can be compatible with all kinds of equipment under different systems and standards. The key technologies of software radio include smart antenna,broad band radio frequency signal processing,broad band A/D transform and high speed DSP etc. Software radio, is the third revolution after the first from fixed to mobile and the second from analog to digital in wireless domain, is the direction of the technology's develop in radio domain now and even future, has unexampled advantage on improving system's agility, is the main technology of the future radio communication system. FPGA has become the first choice for designing the software radio system because of its unique advantages in distributed computing, parallel processing and pipelining. This paper mainly researches the relative theories and realize schemes of software radio transmitter, and realize it based on FPGA.The paper first deeply discusses the basic theories of software radio transmitter: technology of sampling,multiple rate signal processing,modulation and demodulation. Based on these discusses, the technique of poly-phase filter's application in channelized transmitter is deeply researched. Then mathematic model of a real signal channelized transmitter is deduced and established, the method of channels' division and the calculation formulae of the center frequency of a real channel is given, research in the realization based on FPGA of the important modules of this transmitter is done, scheme of realization is given. Finally the sixteen channels channelized transmitter system debugging based on these modules is achieved.The paper mainly researches how to realize arithmetic on hardware on stage of lab. The production can be used for following research and is worthy for all kinds of communication systems applied in software radio concept.