2.1 Discrete-Time Signals: Time-Domain Representation Signals represented as sequences of numbers, called samples Sample value of a typical signal or sequence denoted as x[n] with n being an integer in the range-oo≤n≤∞ x[n] defined only for integer values of n and undefined for noninteger values of n Discrete-time signal represented by {x[n]}
1. Any arbitrary input sequence x[n] can be expressed as a linear combination of delaved and advanced unit sample sequences [n]=x[k][n-k] k=-0 2. .Linear Time-Invariant()System A system satisfying both the linearity and the time-invariance property. .If yiln] is the output due to an input xiln] and y2ln] is the output due to an input x2n] then for an input xn]=axiln]+bx2n] the output is given by ]=]+by2[n]
