Software radio digital down converter technology and FPGA implementation
Li He · Application of Electronic Technique · 2010
It need to deal with the frequency mixing、filtering、decimating and shaping of the iput signals.In the DDC system, sampled and digitized IF signals has to multiply with the orthogonal local oscillator signals generated by the Numerically Controlled Oscillator(NCO),and then be processed by the decimating filter module to output lower frequency or baseband signals with low speed.This paper resarches on the DDC technology in sofware radio systems,Comparing with the parameters of the GSM system,a FPGA-based DDC system is established.