Digital Signal Processing Introduction

Signal

Signal is defined as any physical quantity that varies with any anther independent variable such as time,space etc. Mathematically we can represent signal as the function of independent variable.  $S_1 (t)=10t^2$

1.Speech is the signal which is the function of one independent variable

2.Image is the signal which is the function of two independent variable

3.Video is the signal which is the function of three independent variable

Mainly there are two types of signals they are

1. continuous time signal

Signal have values at any instant of time

2. discrete time signal

Signals have values only discrete instant of time

sampling theorem

If the highest frequency contain in an analog signal  $x(t)$  is  $f_(max)$  and the signal is sampled at a rate $x(t)>= 2f_(max)$  then  $x(t)$  can be exactly recovered from its sample values using interpolation function. The is the sampling frequency should be twice greater the maximum frequency of the available signal.

System

System is defined as any physical device that perform an operation on signal
Eg: filter,amplifier.

“any operation performed is known as processing , operation performed on signal is known as signal processing”

there are two types of system continuous system and discrete system. Continuous time system can be represented by using differential equations and the discrete time system can be represented by using difference equation.

Block diagram for digital signal processor

                  

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