7/31/2019 An Introduction to DSP-Vignesh

1/17

An introduction toD S P

By

V.S.VIGNESH

M.Tech

7/31/2019 An Introduction to DSP-Vignesh

2/17

Contents

Signal ?Classification of signal

Signal processing

Types of SP

DSP operation

Merits of DSP over ASP

7/31/2019 An Introduction to DSP-Vignesh

3/17

Signal ?

Anything whichcarries informationis asignal.

e.g. humanvoice, smoke signals, signlanguage

Signal : f ( x1

, x2

, x3

, )

where X= time, distace,.. Etc.

7/31/2019 An Introduction to DSP-Vignesh

4/17

Types of signals

Natural / synthetic

- based on generation

1D, 2D, MD

- based on no. of independentvariables

Analog or Digital

- based on characteristics ofindependent variable

7/31/2019 An Introduction to DSP-Vignesh

5/17

Eg of Speech signal

7/31/2019 An Introduction to DSP-Vignesh

6/17

Eg of 1D signal:

- speech signal, daily max.temperature

Eg of 2D signal:

An image is a 2D signal ( vertical andhorizontal coordinates)

Multi Dimensions:Our physical world (three spatialand one temporal).

7/31/2019 An Introduction to DSP-Vignesh

7/17

-0.2

-0.1

0

0.1

0.2

0.3

0 2 4 6 8 10sampling time, tk [ms]

Voltage

[V]

ts

-0.2

-0.1

0

0.1

0.2

0.3

0 2 4 6 8 10sampling time, tk [ms]

V

oltage

[V]

ts

Analog & digital signals

Continuous functionV ofcontinuousvariable t (time,space etc) : V(t).

AnalogDiscrete functionVk of discretesampling variable tk, with k =integer: Vk = V(tk).

Digital

-0.2

-0.1

0

0.1

0.2

0.3

0 2 4 6 8 10

time [ms]

Voltage

[V]

Uniform (periodic) sampling.

Sampling frequency fS = 1/ tS

7/31/2019 An Introduction to DSP-Vignesh

8/17

signal processing

processing ?

- to obtain the signal in moredesirable form

eg : MUX, De-MUX, Noise filtering.

7/31/2019 An Introduction to DSP-Vignesh

9/17

Types

Analog signal processing

Digital signal processing

Mixed signal processing

7/31/2019 An Introduction to DSP-Vignesh

10/17

Humans are the most advanced signalprocessors

Most real-world signals are analog

Analog circuits process these signals

usingResistors, Capacitors, Inductors, AmplifiersEg: Audio processing in FM radios

Video processing in traditional TV sets

7/31/2019 An Introduction to DSP-Vignesh

11/17

ASP

7/31/2019 An Introduction to DSP-Vignesh

12/17

Limitations of ASP

Sensitivity to electrical noise

Inflexibility to changes Difficulty of implementing certain

operations

7/31/2019 An Introduction to DSP-Vignesh

13/17

DSP

the processing or manipulation ofsignals using digital techniques

A/D DSP D/Aanalogsignal analogsignal

digitalsignal

digitalsignal

7/31/2019 An Introduction to DSP-Vignesh

14/17

Pros and Cons of DSP

Pros- Flexibility can be achieved with

software implementations

- Digital storage is cheap- Digital information can be encrypted

for security

- Price/performance and reduced time-to-market

- Accuracy can be controlled

7/31/2019 An Introduction to DSP-Vignesh

15/17

cons:- Sampling causes loss of information

- A/D and D/A requires mixed-signal

hardware- Limited speed of processors

- Quantization and round-off errors

7/31/2019 An Introduction to DSP-Vignesh

16/17

Dr. Blanton - ENTC 4337 -

Introduction16

Impact of DSP on Modern Living

Cellular/mobile telephony

Speech and channel codingVoice and data processingPower managementMultipath equaliztion

Digital audio

Stereo and surround soundAudio equalization andmixingElectronic music

AutomotiveDigital AudioDigital RadioPersonal communicationsystemsActive suspension

Medical electronicsCritical/intensive care

monitorsDigital X-raysECG analyzersCardiac monitorsMedical imaging

Personal computer

Sound cardsData storage and retrievalError correction/concealmentMultimediaModems

7/31/2019 An Introduction to DSP-Vignesh

17/17

Thank you