of X(z). Inverse Z-Transform Let, X(z) be Z-transform of x(n). Now the signal x(n) can be uniquely determined from X(z) and its region of convergence (ROC). The inverse Z-transform of X(z) is defined as, 1 x(n) = $ x(z) z"- dz .....(3.3) 27j n-1 --- The inverse Z-transform of X(z) is symbolically denoted as, Z-{X(z)} ; where, Z-1 is the operator that represents the inverse Z-transform 1 :. x(n) = Z-'{X(z)} z- 2aj do We also refer x(n) and X(z) as a Z-transform pair and this relation is expressed as, = $X(z) zndz 2 Z x(n) + X(2) n) z Z