z-Transform The dtft provides a frequency-domain representation of discrete-time signals and lti discrete-time systems Because of the convergence condition, in many cases, the dtft of a sequence may not exist As a result, it is not possible to make use of such frequency-domain characterization in these cases Copyright C 2001, S K MitraCopyright © 2001, S. K. Mitra 1 z-Transform • The DTFT provides a frequency-domain representation of discrete-time signals and LTI discrete-time systems • Because of the convergence condition, in many cases, the DTFT of a sequence may not exist • As a result, it is not possible to make use of such frequency-domain characterization in these cases