Editing Group delay and phase delay (section)

{{Short description|Delays experienced through a linear time-invariant system}}

In [[signal processing]], '''group delay''' and '''phase delay''' are functions that describe in different ways the delay times experienced by a signal’s various sinusoidal frequency components as they pass through a [[linear time-invariant system|linear time-invariant (LTI) system]] (such as a [[microphone]], [[coaxial cable]], [[amplifier]], [[loudspeaker]], [[communications system]], [[ethernet cable]], [[digital filter]], or [[analog filter]]).

Unfortunately, these delays are sometimes [[frequency]] dependent,<ref name="RabinerGold1975" /> which means that different sinusoid frequency components experience different time delays. As a result, the signal's [[waveform]] experiences [[distortion]] as it passes through the system. This distortion can cause problems such as poor [[High fidelity|fidelity]] in [[analog video]] and [[analog audio]], or a high [[bit-error rate]] in a digital bit stream.