The book contains: Concept of Time-domain representations for LTI systems - 1: Convolution, impulse response representation, Convolution Sum and Convolution Integral. Time-domain representations for LTI systems - 2: Properties of impulse response representation, Differential and difference equation Representations, Block diagram representations. Applications of Fourier representations: Introduction, Frequency response of LTI systems, Fourier transform representation of periodic signals, Fourier transform representation of discrete time signals. Sampling theorm and Nyquist rate. Z-transforms - 2: Transform analysis of LTI Systems, unilateral Transform and its application to solve difference equations. Z-Transforms - 1: Introduction, Z - transform, properties of ROC, properties of Z - transforms, inversion of Z - transforms.