The book contains: Concept of Discrete-Time Signals and Systems: Discrete-Time Signals: Some Elementary Discrete-Time signals, Classification of Discrete-Time Signals, Simple Manipulation; Discrete-Time Systems: Input-Output Description, Block Diagram Representation, Classification, Interconnection; Analysis of Discrete-Time LTI Systems: Techniques, Response of LTI Systems, Properties of Convolution, Causal LTI Systems, Stability of LTI Systems; Discrete-Time Systems described by Difference Equations; Implementation of Discrete-Time Systems; Correlation of Discrete-Time Signals: Cross-correlation and Auto-correlation Sequences, Properties. Properties of Continuous-Time Systems: Block Diagram and System Terminology, System Properties: Homogeneity, Time Invariance, Additivity, Linearity and Superposition, Stability, Causality.