Transcript
Page 1: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

TS

KS

01 D

igital C

om

munic

ation

Lectu

re 1

Intr

od

uctio

n,

Re

pe

titio

n o

f S

&S

, C

ha

nn

el m

od

els

Mik

ae

l O

lofs

so

n

De

pa

rtm

en

t o

f E

E (

ISY

)

Div

. o

f C

om

mu

nic

atio

n S

yste

ms

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

2

TS

KS

01 D

igital C

om

munic

ation -

Form

alia

Info

rma

tio

n &

co

urs

e m

ate

ria

l:w

ww

.co

mm

sys.isy.liu

.se

/TS

KS

01

Le

ctu

rer

& e

xa

min

er:

Mik

ae

l O

lofs

so

n, m

ika

el@

isy.liu

.se

Pro

ble

m c

lasse

s a

nd

la

bs:

Mir

sa

dir

ki

, m

irsa

d@

isy.liu

.se

TV

K C

ha

ita

nya

, tv

k@

isy.liu

.se

Exa

min

atio

n:

La

bo

ratio

ns

(1h

p):

Tw

o 4

ho

ur

lab

ora

tio

ns

Sig

n-u

p o

n th

e w

eb

Wri

tte

ne

xa

m(5

hp

):

1 s

imp

le ta

sk �

De

ma

nd

: 1

/2

2 q

ue

stio

ns (

5 p

oin

ts e

ach

), m

in 3

4 p

rob

lem

s (

5 p

oin

ts e

ach

), m

in 6

Pa

ss: 1

4 p

oin

ts

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

3

Cours

e A

ims 1

(2)

Afte

r p

assin

g th

e c

ou

rse

, th

e s

tud

en

t sh

ou

ld

be

ab

le to

re

liab

ly p

erf

orm

sta

nd

ard

ca

lcu

latio

ns r

eg

ard

ing

dig

ita

l

mo

du

latio

n, b

ina

ry (

line

ar)

co

de

s fo

r e

rro

r co

ntr

ol a

nd

so

urc

e c

od

ing

.

(ba

sic

s)

be

ge

ne

rally

aq

ua

inte

d w

ith

mo

de

rn c

om

mu

nic

atio

n, e

sp

ecia

lly d

igita

l

co

mm

un

ica

tio

n, i.e

. b

e a

ble

to

brie

fly d

escrib

e s

eve

ral co

mm

un

ica

tio

n

tech

niq

ue

s.

(qu

es

tio

ns)

be

ab

le to

bri

efly a

cco

un

t fo

r so

me

co

mm

on

ch

an

ne

l m

od

els

,

esp

ecia

lly fo

r ca

ble

s, ra

dio

ch

an

ne

ls a

nd

op

tica

l ch

an

ne

ls.

(qu

es

tio

ns)

be

ab

le to

de

scrib

e p

rob

lem

s th

at a

rise

in

co

mm

un

ica

tio

n s

itu

atio

ns,

usin

g o

wn

wo

rds, a

nd

be

ab

le to

de

scri

be

, a

nd

in

a r

ele

va

nt w

ay,

co

mp

are

me

tho

ds to

co

un

tera

ct th

ose

pro

ble

ms.

(qu

es

tio

ns)

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

4

Cours

e A

ims 2

(2)

Afte

r p

assin

g th

e c

ou

rse

, th

e s

tud

en

t sh

ou

ld

be

ab

le to

acco

un

t fo

r th

e c

on

ne

ctio

n b

etw

ee

n d

iffe

ren

t co

nce

pts

in

the

co

urs

e in

a s

tru

ctu

red

wa

y u

sin

g a

de

qu

ate

te

rmin

olo

gy.

(qu

es

tio

ns)

be

ab

le to

, w

ith

so

me

pre

cis

ion

, a

na

lyze

an

d c

om

pa

re v

ari

ou

s c

ho

ice

s

of d

igita

l m

od

ula

tio

n m

eth

od

s a

nd

co

din

g m

eth

od

s in

te

rms o

f e

rro

r

pro

ba

bili

tie

s, m

inim

um

dis

tan

ce

s a

nd

re

late

d c

on

ce

pts

. (pro

ble

ms)

be

ab

le to

im

ple

me

nt su

ch

co

mm

un

ica

tio

n s

yste

ms th

at a

re tre

ate

d in

the

co

urs

e in

blo

ck fo

rm a

nd

em

pir

ica

lly e

va

lua

te th

em

. (la

bo

rati

on

s)

Page 2: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

Languages in T

uto

rial S

essio

ns

Englis

h

Sw

edis

h

5

Englis

h

Sw

edis

h

The tuto

rial series s

chedule

d f

or

Gro

up_B

is c

ancelle

d.

All

teachin

g w

ill b

e in E

nglis

h.

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

6

Overv

iew

of a C

om

munic

ation S

ituation

Ch

an

ne

lS

en

de

r

Sa

mp

lin

g

Re

co

ns

tru

cti

on

D/A

-co

nve

rsio

n

Mo

du

lati

on

Ch

an

ne

l c

od

ing

So

urc

e c

od

ing

Fil

teri

ng

LT

I -

no

n L

TI

Fa

din

g

No

ise

Inte

nti

on

al

jam

min

g

So

urc

e s

tati

sti

cs

Sto

ch

as

tic

pro

ce

ss

Ma

rko

v c

ha

ins

Au

to-c

orr

ela

tio

n

De

ma

nd

s o

n q

ua

lity

Co

st

fun

cti

on

s

Ap

pli

ca

tio

n

Pu

rpo

se

Sa

mp

lin

g

Re

co

ns

tru

kti

on

A/D

-co

nve

rsio

n

De

mo

du

lati

on

Ch

an

ne

l-d

ec

od

ing

So

urc

e d

ec

od

ing

Fil

teri

ng

Re

ce

ive

rS

ou

rce

De

sti

na

tio

n

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

7

A O

ne-w

ay T

ele

com

munic

ation S

yste

m

Ch

an

ne

l

So

urc

e

en

co

de

r

So

urc

e

de

co

de

r

So

urc

e

De

sti

na

tio

n

Ch

an

ne

l

en

co

de

rM

od

ula

tor

Ch

an

ne

l

de

co

de

r

De

-

mo

du

lato

r

Sourc

e

codin

g

Channel

codin

g

Packin

g

Unpackin

g

Err

or

contr

ol

Err

or

corr

ection

Dig

italto

analo

g

Analo

g t

o d

igital

Mediu

m

Dig

ital

modula

tion

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

8

Cours

e C

onte

nts

Tra

nsm

issio

n c

ha

nn

els

(C

ab

les, R

ad

io, O

ptica

l)

(Le

ctu

res

1 &

4)

Intr

od

uctio

n to

sto

ch

astic p

roce

sse

s.

(Le

ctu

res

2-3

)

So

ftw

are

de

fin

ed

ra

dio

(la

b p

rep

ara

tio

n).

(Le

ctu

re 5

)

Co

mp

lex b

ase

ba

nd

re

pre

se

nta

tio

n.

(Le

ctu

re 6

)

Dig

ita

l m

od

ula

tio

n.

(Le

ctu

res

7-9

)

Co

de

s fo

r e

rro

r co

ntr

ol.

(Le

ctu

res

10

-11)

So

urc

e c

od

ing

(p

ackin

g d

ata

).

(Le

ctu

res

12

)

Page 3: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

9

Repetition S

ignals

and S

yste

ms

Syste

mx(t)

y(t)

Sig

nals

:V

olt

ag

es, cu

rren

ts,

an

d o

ther

measu

rem

en

ts.

Syste

ms:

Man

ipu

late

sig

nals

.

Co

mp

lex e

xp

on

en

tial:

e

= c

os(2

f t) +

j s

in(2

f t)

Un

itste

p:

u(t)

=

Un

itim

pu

lse:

(t):

Pro

pert

y:

j 2

f t 0

0

0

0,

t<0

1,

t>0

x(t)

(t)

dt

= x

(0)

u(t

) =

()

d

t

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

10

Specia

l O

utp

uts

En

erg

y-f

ree

syste

m(t)

h(t)

Imp

uls

e r

esp

on

se

:

Ge

ne

ral ca

se

:

En

erg

y-f

ree

syste

mx(t)

y(t)

Ste

p r

esp

on

se

:

En

erg

y-f

ree

syste

mu(t)

g(t)

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

11

Lin

ear

Syste

m

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

12

Tim

e-I

nvariant and L

TI

Page 4: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

13

Convolu

tion

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

14

Outp

ut of LT

I S

yste

ms

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

15

The F

requency d

om

ain

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

16

LT

I S

yste

ms

Page 5: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

17

Cable

s

Ma

the

ma

tic

ally:

Lin

ea

rd

iffe

ren

tia

l e

qu

atio

n

LT

I syste

m, im

pu

lse

resp

on

se, fr

eq

ue

ncy

resp

on

se

Mo

de

l:

Tw

ow

ire

s:

y,

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

18

Chara

cte

ristic Im

pedance 1

(2)

Mo

de

lo

f a

n in

fin

ite

lylo

ng

ca

ble

:

Alte

rna

tive

mo

de

l:

So

lutio

n:

Re

su

lt:

Re

al p

art

ha

s to

be

po

sitiv

e:

with a

rgum

ent

in (

�/2

,/2

)

Als

oin

finitely

long

cable

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

19

Chara

cte

ristic Im

pedance 2

(2)

We

ha

d:

Serialpro

pert

ies

per

mete

r

Para

llelpro

pert

ies

per

mete

r

impedance

resis

tance

inducta

nce

adm

itta

nce

conducta

nce

capacitance

Po

ss

ible

ch

oic

e:

Re

su

lt:

Z

is r

ea

l a

nd

co

nsta

nt

Pro

pe

r te

rmin

ati

on

:

A fin

ite

ca

ble

sh

ou

ldb

e

term

ina

ted

with

th

e

imp

ed

an

ce

Z.

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

20

Fre

quency R

esponse o

f a C

able

1(2

)

Fin

ite

le

ng

thca

ble

:O

ne

lin

k:

Fre

qu

en

cy r

esp

on

se

of o

ne

lin

k:

Re

su

lt:

Page 6: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

21

Fre

quency R

esponse o

f a C

able

2(2

)

Fre

qu

en

cy

resp

on

se

of a

on

em

ete

r lo

ng

ca

ble

:

An

am

ete

r lo

ng

ca

ble

:

Re

al-

va

lue

dch

ara

cte

ristic

imp

ed

an

ce

:

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

22

Lim

it for

the F

requency R

esponse

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

23

The T

ele

phone C

hannel

Du

e to

va

rio

us filt

ers

an

d m

od

ula

tio

ns in

te

lep

ho

ne

syste

ms.

Ap

pro

xim

ate

am

plit

ud

e c

ha

racte

ristic:

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

24

Optical F

ibers

Sp

ee

d o

f lig

ht

in v

acu

um

: c

3·1

08

m/s

Sp

ee

d o

f lig

ht

in o

the

r m

ed

ia:

v<

c

Re

fra

ctio

n in

de

x:

n=

c /

v

Exa

mp

les:

Air:

n1

.00

03

(

1)

Fib

er

gla

ss:

1.5

< n

< 1

.9 (

rou

gh

ly)

Se

nd

er

sid

eR

ece

ive

r sid

e

Lig

ht

sourc

eLig

ht

dete

cto

r

LE

D

Laser

Photo

dio

de

Photo

tra

nsis

tor

Page 7: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

25

Ste

p-I

ndex F

iber

Acce

pta

nce

ha

lf-a

ng

le:

in =

arc

sin

Acce

pta

nce

fu

ll a

ng

le:

2in

Nu

me

rica

l a

pe

rtu

re:

sin

(in) =

n0

n12 �

n22

(

)

n0

n12 �

n22

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

26

Multim

ode P

ropagation

Diffe

ren

t p

ath

s -

d

iffe

ren

t d

ista

nce

s

d

iffe

ren

t d

ela

ys

p

uls

e s

pre

ad

ing

Lig

ht

pu

lse i

nL

igh

t p

uls

e o

ut

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

27

Multm

ode G

raded Index

20

12

-08

-31

TS

KS

01

Dig

ita

l C

om

mu

nic

ation

-L

ectu

re 1

28

Sin

gle

mode S

tep Index

Page 8: TSKS01 Digital Communication Lecture 1 - … · Digital to analog Analog ... Linear System 2012-08-31 TSKS01 Digital Communication - Lecture 1 11 Time-Invariant and ... Lecture 1

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w.liu

.se


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