Discrete-Time LTI Systems:The Convolution Sum An arbitrary discrete-time signal can be thought of as a weighted superposition of shifted (discrete-time)impulses. x[n]=…+x[-1][n+1]+x[0][n]+x[l][n-1]+… =>xk][n-k] xn:the entire signal []a specific value of the signal x[n]at time k.Discrete-Time LTI Systems: The Convolution Sum • An arbitrary discrete-time signal can be thought of as a weighted superposition of shifted (discrete-time) impulses. [ ] [ 1] [ 1] [0] [ ] [1] [ 1] [ ] [ ] [ ]: the entire signal [ ]: a specific value of the signal [ ] at time . k x n x n x n x n x k n k x n x k x n k                   