Instructor: Eng. Nada Khatib

Website: http://www.philadelphia.edu.jo/academics/nkhatib/

Digital Signal Processing (0650322) Introduction to DSP

Philadelphia University/Faculty of Engineering

Communication and Electronics Engineering

Eng. Nada Khatib Ch 1- Introduction 1

Outline

• What is Digital Signal Processing?

• Advantages of DSP over ASP

• Disadvantages of DSP

• Basic elements of DSP system

• DSP application

Eng. Nada Khatib Ch 1- Introduction 2

What is Digital Signal Processing

– DSP is a technique of performing operations (filtering, compression, spectrum anlaysis,…) on signals (speech signal, ECG signal,….) represented digitally using coding on special digital purpose hardware, a microprocessor or digital signal processor chip

Eng. Nada Khatib 3 Ch 1- Introduction

Eng. Nada Khatib 4

Microphone

Thermocouple

temperature sensor

Electrocardiogram electrodes

Ch 1- Introduction

one dimensional

single channel signal

one dimensional

multichannel signal

Eng. Nada Khatib 5

Black and White Picture

Ch 1- Introduction

Two dimensional signal

y

x

I(x1,y1( x1

y1

Color TV Picture

Three dimensional signal

and three channel signal

Types of signal processing

• The signal processing can be broadly divided into two categories:

– ASP

– DSP

Eng. Nada Khatib Ch 1- Introduction 6

Analog and digital ssytems

Eng. Nada Khatib Ch 1- Introduction 7

Digital Low Pass Filter Analog Low Pass Filter

b0=b1=wc /(wc +1) and

a1=-(wc-1)/(wc+1) Ωc= 1/RC

Difference equation:

y(n)=-a1y(n-1)+b0x(n)+b1x(n-1)

Differential equation:

oo

in vdt

dvRCv

Basic elements of DSP system – Most of signals encountered in science and

engineering are analog in nature.

– To perform the processing digitally, there is a need for an interface between the analog signal and the digital processor.

Eng. Nada Khatib 8 Ch 1- Introduction

Advantages of DSP over ASP

• Greater flexibility

• More accurate

• Easily stored

• Implementation of Sophistication processing

• cheaper

Eng. Nada Khatib Ch 1- Introduction 9

Disadvantages of DSP

– DSP is not without disadvantages. However the significant of these disadvantages is being continually diminished by new technology.

• speed

• Finite wordlength problems.

Eng. Nada Khatib 10 Ch 1- Introduction

DSP application • Speech processing

– Speech recognition

– Speech to text

– Speak and spell

• Biomedical

– Patient monitoring

– ECG analysis

– Medical imaging

• Telecommunication

– Adaptive equalizer

– Channel coding Eng. Nada Khatib 11 Ch 1- Introduction

DSP application

• Military

– Secure communication

– Radar processing

• Consumers applications

– Digital cameras

– Mobile phone

– MP3 player

• Image processing

– Satellite weather map

– Image enhancement Eng. Nada Khatib 12 Ch 1- Introduction

DSP application

Eng. Nada Khatib 13 Ch 1- Introduction

DSP application

Eng. Nada Khatib Ch 1- Introduction 14

ECG recorder with

the removed 60 Hz

interference

ECG

preamplifier

60-Hz

interference

Digital notch fi l ter for

eliminating 60-Hz

intererenceECG signal

with 60-Hz

inteference