Research Of Multichannel Software Radio Transmitter

The basis idea of software radio(SR) is to place the digitized process unit as close up the antenna as possible and use software to realize all the functions of any radio based on an opening and blocking currency hardware platform at the same time. SR is a new wireless system structure, whose foundation modern communication theory is, whose core digital signal process is, and who is supported by microelectronics technique. This paper mainly researched relevant theories and realization scheme of software radio transmitter, and carried out the corresponding system simulation.First of all, the technique of sampling, sampling rate conversion, modulation and demodulation is deeply discussed in this paper. Based on these discusses, the use of the poly-phase filter technique in a channelized transmitter is researched, then the mathematic model of a real signal channelized transmitter is deduced and established, giving the method of channels' division and the calculation formulae of the center frequency of a real channel, finally the simulation of a four channels channelized transmitter based on this model is finished, establishing a four channel channelized receiver in order to verify the feasibility and correctness of this transmitter.Both the system simulation platforms given can offer convenience for the future research. We can use them to replant any communication system and test its performance, so they are very useful.