Algorithm of software digital down converter
Fu Ce · 2004
The paper put forward a design NCO (numerical controlled oscillator) with phase accumulation algorithm and fraction ratio decimation filter with mixing linear interpolation algorithm and CIC(cascaded integrator comb) filter, so that the DDC (digital down converter) process could be implemented in software on general purpose DSP(digital signal processing) chip and afford greater flexibility. Matlab simulation for a decimation filter whose decimation ratio is 29/31 was made. The results indicate that the algorithm improves the speed of DDC and implements programmable NCO and decimation filter by design software DDC with high performance DSP. 6 figs, 7 refs.