§4.2 The Frequency Response The quantity H(ejo) is called the frequency response of the lti discrete time system H(ejo) provides a frequency-domain description of the system H(ejo) is precisely the dtft of the impulse response hn of the system§4.2 The Frequency Response • The quantity H(ej) is called the frequency response of the LTI discrete￾time system • H(ej) provides a frequency-domain description of the system • H(ej) is precisely the DTFT of the impulse response {h[n]} of the system