I have series of amplitudes of a signal recieved at center frequency of 433.9MHz, sampling at 250000 Hz. I can see the information received is the packet I am after, just sampled too high. I believe the transmitter transmits at 3918bps. What is the best method to downsample from 250000 Hz to 3918 bps?
I have tried using a butterworth filter, which doesn't seem to work and I don't understand why. I've tried picking every 63 samples (because 250000/3918 = ~63), but didn't seem to work either. Please bare in mind I am a bit of a newbie regarding DSP.