I know that my input signal contains a main sinusoidal signal, and I know its frequency but not its amplitude.
Until now, I have been successfully using the least-squares method to generate a sinusoidal signal with the least difference from my input.
However, this method breaks down when faced with slightly more complicated input signals, where the noise is big enough to disturb the list square. As a consequence, it's not efficient anymore.
What are some other ways I can accomplish this filtering that don't have the same issue?