I have a circuit that is outputting a good solid analog signal which is being read by an AD converter. While the signal is good and noise free, the ADC is not and is adding a lot of gibberish to my signal which is being sent to a PC. As of now I have tried using a simple discrete kalman filter to numerically reduce the noise and it works fairly well but I think I need something better. Given the structure of the signal a low pass filter isn't going work and neither will any type of bandpass. Is there a numerical filter out there that is better than a kalman filter for removing gaussian noise from data?