84.1 LTI Discrete-Time Systems in the Transform domain a. Applying the dtft to the diffe erence equation and making use of the linearity and the time invariance properties we arrive at the input- output relation in the transform-domain as k ≌ evoke(eo k Pk Y(e1) k=0 e where Y(eo)and x(eo) are the dfts of yin and x n, respectively§4.1 LTI Discrete-Time Systems in the Transform Domain • Applying the DTFT to the difference equation and making use of the linearity and the time￾invariance properties we arrive at the input￾output relation in the transform-domain as ( ) ( ) 0 0  =  −  = −   =  j M k j k k j N k j k k d e Y e p e X e where Y(ej) and X(ej) are the DTFTs of y[n] and x[n], respectively