Book contain Concept OF INTRODUCTION TO SIGNALS & SYSTEMS: Definition and classification of Signal and Systems (Continuous time and Discrete-time) Elementary signals such as Dirac delta unit step ramp sinusoidal and exponential and operations on signals. Analogy between vectors and signals Orthogonality Mean Square error FOURIER SERIES: Trigonometric & Exponential concept of discrete spectrum. FOURIER TRANSFORM: CONTINUOUS TIME FOURIER TRANSFORM: Definition Computation and properties of Fourier