Discrete-Time Signals: Time-Domain Representation Signals are represented as sequences of numbers, called samples Sample value of a typical signal or sequence denoted as x[n] with n being an integer in the range-∞≤n≤∞ ·x[n] defined only for integer values of and undefined for non-integer values

2.1 Discrete-time LTI Systems : The Convolution Sum （卷积和） 2.1.1 The Representation of Discrete-Time Signals in Terms of impulses

the Transform Domain An LTI discrete-time system is completely characterized in the time-domain by its impulse response {h[n]} We consider now the use of the DTFT and the z-transform in developing the transform￾domain representations of an LTI system

The dtft provides a frequency-domain representation of discrete-time signals and lti discrete-time systems Because of the convergence condition, in many cases. the dtft of a sequence may not exist as a result. it is not possible to make use of such frequency-domain characterization in these cases Copyright C 2001, S K. Mitra

BIBO Stability Condition - A discrete-time LTI system is BIBO stable if the output sequence {y[n]} remains bounded for any bounded input sequence{x[n]}

西安电子科技大学：《Digital Signal Processing》课程教学资源（课件讲稿）Chapter 2B Discrete Time Systems Part B Discrete-Time Systems

西安电子科技大学：《Digital Signal Processing》课程教学资源（课件讲稿）Chapter 5B Finite-Length Discrete Transforms Part B Discrete Fourier Transform Properties

西安电子科技大学：《Digital Signal Processing》课程教学资源（课件讲稿）Chapter 5A Finite Length Discrete Transforms Part A The Discrete Fourier Transform（DFT）

1 The Foundations: Logic and Proofs 2 Basic Structures: Sets, Functions, Sequences, Sums, and Matrices 3 Algorithms 4 Number Theory and Cryptography 5 Induction and Recursion 6 Counting 7 Discrete Probability 8 Advanced Counting Techniques 9 Relations 10 Graphs 11 Trees 12 Boolean Algebra 13 Modeling Computation

西安电子科技大学：《Digital Signal Processing》课程教学资源（课件讲稿）Chapter 2A Discrete Time Signals Part A Discrete-Time Signals