The Research Of The Software Defined Radio Channelized Receivers

Software Defined Radio (SDR), first proposed in 90's in last century, is a kind of technology which has great future in communication application. The basis idea of software radio is to place the A/D and D/A close up the antenna as possible as and use software to realize all the function of any radio based on an opening and blocking currency hardware platform.In this paper the technique of channelization based on SDR receivers is discussed: sampling rate conversion; decimate and filters; polyphase filters; and digital down conversion. The project utilizing cascaded integrator comb filter, half band filter and finity impulse filter to design the down digital converter is put forward and system simulation is accomplished and simulated. Then the model of the real signal receiver is established after investigating the application of polyphase filter in channelized receiver. Signals are received by doubling filter's passband bandwidth without hardware structure change and bandpass sampling the signals after filtering. With fixed output data rate, high processing efficiency, the hardware implementation is much easier using low speed device.This paper studies the design of digital down converter based on coordinate rotation digital computer (CORDIC) algorithm , the method can improve the efficiency of signal processing, reduce the design cost of hardware. Then manifests its high efficiency by the use of simulation.