What is anti-aliasing filter?

An anti-aliasing filter is a signal processing filter used to prevent aliasing, which occurs when high-frequency signals are misrepresented as lower frequencies during sampling. By attenuating frequencies above a certain cutoff point, the filter ensures that the sampled signal accurately represents the original analog signal. This is essential in digital signal processing and telecommunications to maintain signal integrity and prevent distortion. Typically, anti-aliasing filters are low-pass filters applied before the analog-to-digital conversion process.