Linear Discrete-Time Systems Accumulator-y1{n=∑x[(l,y2[m=∑x2[C For an input x[n]=ax[n]+Bx2n the output is y{n]=∑ax[(]+Bx2[ =a∑x(]+β∑x2[(]=ayfn]+By2n C=-0 Hence the above system is linear Copyright C 2001, S K. MitraCopyright © 2001, S. K. Mitra 11 Linear Discrete-Time Systems • Accumulator - • For an input the output is • Hence, the above system is linear =  =  =− =− n n y n x y n x   [ ] [], [ ] [] 1 1 2 2 [ ] [ ] [ ] x n = x1 n +  x2 n = ( + ) =− n y n x x  [ ] [] []  1  2 [ ] [ ] [ ] [ ] x1 x2 y1 n y2 n n n =  +   = +  =− =−  