Design of Digital Down Conversion based on FPGA

Digital Down Conversion(DDC) is one of the key technologies for software radio,which converts high frequency data streams into low frequency data streams for easy subsequent real-time processing by DSP devices.In this paper,an FPGA based DDC framework is proposed,and the design methods for DDC modules,including Numerical Controlled Oscillator(NCO),frequency mixing module,CIC filter,HB filters,FIR filter,are discussed in detail.The simulation results of each module show that the design is correct,and the simulation results of final system indicate that the proposed Digital Down Conversion(DDC) system is feasible and parcticable.