Low Pass Filter Using FIR compiler

[Christian Chetcuti]

I am multiplying a 2kHz sinewave with another 100khz sinewave to obtain
a dsb-sc signal. These sinewaves were designed using DDS cores.

I am also using a 50mHz clock. I would like to demodulate this dsb-sc
signal. I am doing this by multiplying the dsb-sc signal with the
carrier (100khz signal). Now i have to pass this signal through a low
pass filter.

I have generated a coefficient file (.coe) from matlab and am using the
FIR compiler to actually generate the low pass filter.

I have put 50mhz as the input clock frequency but the problem is that i
am not exactly sure what to put in as the sampling frequency. Could
anyone provide some help regarding this.

 

[FvM]

Sampling frequency should be as low as possible to allow handy filter order, but must at least fulfill the Nyquist criterion for the input signal. You can play around with the matlab filter tool to get a feeling of meaningful filter parameters.

I find IIR filters more effective for my range of applications.