Causality Condition of a Discrete-Time LTI System n[=∑hx1[no-k]=∑ hk ] iln-k k=-00 k=0 +∑k]x[-k k y2m]=∑kx2[no-k]=∑hkx2{no-k k=-00 k=0 +∑kx2[no-k] k=-∞0 Copyright C 2001, S.K. MitraCopyright © 2001, S. K. Mitra 7 Causality Condition of a Discrete-Time LTI System    =  =− = − = − 0 2 2 2 k o k o o y [n ] h[k]x [n k] h[k]x [n k]  − =− + − 1 2 k o h[k]x [n k]    =  =− = − = − 0 1 1 1 k o k o o y [n ] h[k]x [n k] h[k]x [n k]  − =− + − 1 1 k o h[k]x [n k]