Introduction In this chapter,we examine several methods for describing the relationship between the input and output signals of linear time-invariant (LTl)systems in time domain. Convolution sum/integral Linear constant-coefficient difference/differential equationIntroduction • In this chapter, we examine several methods for describing the relationship between the input and output signals of linear time-invariant (LTI) systems in time domain. – Convolution sum/integral – Linear constant-coefficient difference/differential equation