2.1 Discrete-Time Signals: Time-Domain Representation A right-sided sequence xn]has zero- valued samples for nN 00 A right-sided sequence .If N >0,a right-sided sequence is called a causal sequence§2.1 Discrete-Time Signals: Time-Domain Representation • A right-sided sequence x[n] has zero￾valued samples for n < N1 n N1 A right-sided sequence •If N1≥ 0, a right-sided sequence is called a causal sequence