# Introduction to signals and systems

Download 155.77 Kb.
 Date 08.03.2021 Size 155.77 Kb. #56016
INTRODUCTION TO SIGNALS AND SYSTEMS
 INTRODUCTION TO SIGNALS AND SYSTEMS: A signal is a function of time, e.g., f is the force on some mass vout is the output voltage of some circuit p is the acoustic pressure at some point notation: f, vout, p or f(.), vout(.), p(.) refer to the whole signal or function f(t), vout(1.2), p(t + 2) refer to the value of the signals at times t, 1.2, and t + 2, respectively for times we usually use symbols like t, t , t1, . . AM radio signal FM radio signal cable TV signal audio signal NTSC video signal 10BT Ethernet signal telephone signal Signal: something conveys information, represented mathematically as functions of one or more independent variables. Classified as: Continuous-time (analog) signals, discrete-time signals, digital signals Signal-processing systems are classified along the same lines as signals: Continuous-time (analog) systems, discrete-time systems, digital systems Discrete-Time signals are represented as In sampling of an analog signal xa(t): 1/T (reciprocal of T) : sampling frequency Fig:1 Graphical representation of a discrete time signal; the abscissa is continuous while the x[n] is defined only at discrete instances System a system transforms input signals into output signals a system is a function mapping input signals into output signals we concentrate on systems with one input and one output signal, i.e., single-input, single-output (SISO) systems notation: y = S(u) means the system S acts on input signal u to produce output signal y Block System systems often denoted by block diagram boxes denote systems; arrows show inputs & outputs lines with arrows denote signals (not wires) special symbols for some systems SIGNALS AND SYSTEMS Modeling the physical world Physical system (e.g., LRC circuit) – using mathematical equation Input/output signal – using mathematical function Example :LRC LRC represented by a mathematical Equation ordinary diff. eqn. No sampling (continuous time system) V(i) is a mathematical function Different systems can be MODELED using the same mathematical function Human speech production system — anatomy and block diagram Signals and System Categorizations Continuous time (analog) Discrete time (digital) Continuous System Example A digital player/recorder Analog Input Sampling Signal Reconstructed Digital Output Digital Signal References: Authors are unknown.Download 155.77 Kb.Share with your friends:

The database is protected by copyright ©ininet.org 2023
send message

Main page