MULTIMEDIA SYSTEMS IREK DEFEE SIGNAL MODULATION for MULTIMEDIA DATA TRANSMISSION with special emphasis on wireless.

MULTIMEDIA SYSTEMSIREK DEFEE

SIGNAL MODULATIONfor

MULTIMEDIA DATA TRANSMISSION

with special emphasis on wireless


• Content:

- SIGNAL MODULATION TECHNIQUES

- RADIO WAVE PROPAGATION

- WIRELESS SYSTEMS

- WIRELESS DATA TRANSPORT

- SOURCE AND CHANNEL CODING

(WHICH WE ARE NOT COVERING)


SIGNAL MODULATION TECHNIQUES:

HOW TO OVERLAY BITS OR STREAMS OF

BITS ON A SIGNAL TO CARRY THEM?

FOR MULTIMEDIA TRANSMISSION WE

NEED TO TRANSFER A LOT OF DATA

THUS, WE NEED TO PACK THE DATA

EFFICIENTLY ON TRANSMISSION

CARRIER ( WHICH CAN BE RADIO WAVES,

ELECTRIC CURRENT, PHOTONS)


Let’s start from the beginning:Sinusoidal Waveform

• The signal at frequency around fc:

s(t) = Acos(2fct + )• To encode digital symbol of {0, 1},

– One can encode using the amplitude A– One can encode using the phase – One can encode using the frequency fc

– Use some combination of amplitude, phase, or frequency.


Let’s start from the beginning:Sinusoidal Waveform

• The signal at frequency around fc:

s(t) = Acos(2fct + )• To encode digital symbol of {0, 1},

– One can encode using the amplitude A– One can encode using the phase – One can encode using the frequency fc

– Use some combination of amplitude, phase, or frequency.


Amplitude-Shift Keying (ASK)Change amplitude A

CARRIER


ASK (cont.)

• The signal is

0

0)2cos(2

2

1

ts

TttfT

Ets bc

b

b


Phase-shift Keying (PSK)Change phase


PSK (cont.)

• Signal is

bcb

b

bcb

b

TttfT

Ets

TttfT

Ets

0)2cos(2

0)2cos(2

2

1


Frequency-shift keying (FSK)


FSK (cont.)

• Signal is

bb

b

bb

b

TttfT

Ets

TttfT

Ets

0)2cos(2

0)2cos(2

22

11


FIGURE 1/V.29

Signal space diagram at 9600 bit/s

HOW TO PUT MORE BITS ON THE CARRIER?1. BY USING MORE PHASE SHIFTS E.G. 8-PSK

HERE WE USE8 PHASEVALUESEACH VALUEENCODES3 BITS


90°

180° 0°

270°

A

B

D

C

(Re)

(Im)

–4 –2 2 4

2

4

–2

–411100 11011

01110 00001 01100

10110100011011110000

00111 01001 00110 01011 00100

11101110101111011001

00000 01111 00010 01101 00011

10100100111010110010

01000 00101 01010

1100011111

T1702150-93/d03

FIGURE 3/V.32

32-point signal structure with trellis coding for 9600 bit/sand states A B C and D used at 4800 bit/s and for training

NOTE – The binary numbers denote Y0 Y1 Y2 Q3 Q4 .n n n n n

2. BY USING MORE AMPLITUDE LEVELSAND PHASE SHIFTS – EXAMPLE 16-QAM

HERE EACHPHASE/AMPLITUDEVALUE ENCODES 5 BITS


0 0 0 0 1 1 1

0 0 1 1 1 1 1

0 0 0 0 1 1 0

0 0 1 1 1 1 0

0 0 0 1 1 1 0

0 0 1 0 1 1 0

0 0 0 1 1 1 1

8

6

4

2

-2

-4

-6

-8

0 1 0 1 0 0 0 0 1 0 0 0 0 02 7 0 °

1 1 0 0 0 0 1 1 1 1 1 0 0 0 1 1 0 1 0 0 1 1 1 1 0 0 0 0

0 0 0 0 1 0 1 0 1 1 0 0 0 1 0 1 1 1 0 0 1 0 0 0 0 0 1 1

1 0 1 0 1 0 1 1 0 0 1 0 1 1 1 0 1 0 1 1 1 1 0 0 1 1 1 1 1 0 0 1 1 0 1

0 1 0 1 1 0 1 0 0 1 1 0 1 1 0 1 0 1 1 0 0 0 1 0 0 1 0 0 0 0 1 1 1 0 1 0 1 0 0 1 0 1

1 1 1 0 1 0 11 1 0 1 0 1 11 1 1 0 1 0 01 1 0 1 0 1 01 1 1 1 1 0 01 1 0 0 0 1 01 1 1 1 1 0 11 1 0 0 0 1 1

0 0 0 0 0 0 0 0 1 1 0 0 1 1 0 0 0 0 1 0 0 0 1 1 0 0 1 0 0 1 1 1 0 1 0 0 0 0 0 0 1 0 0 1 1 1 0 1 1 0 0 0 0 0 0 1

1 0 0 1 0 0 01 0 1 0 0 0 11 0 0 1 1 0 01 0 1 0 0 1 01 0 0 1 1 1 01 0 1 0 1 1 01 0 0 1 0 1 01 0 1 0 1 0 01 0 0 1 0 0 11 0 1 0 0 0 0

0 0 1 1 0 0 1 0 0 1 1 0 1 0 0 1 0 1 1 1 0 0 1 0 0 1 1 0 0 0 1 1 1 0 0 0 1 0 0 1 1 1 0 0 1 1 0 0 0

1 1 1 0 1 1 11 1 1 0 1 1 01 1 0 1 1 1 01 1 1 1 1 1 01 1 0 0 1 1 01 1 1 1 1 1 11 1 0 0 1 1 11 8 0 °

-6-8 -4 -2 2 4 6 8

0 °

1 0 0 0 0 0 01 0 1 1 0 0 1

0 1 1 1 1 1 10 0 0 1 0 1 00 1 1 1 1 1 00 1 1 0 1 1 00 0 0 1 1 0 00 1 1 0 1 1 10 0 0 1 0 0 0

1 0 1 1 0 0 0 1 0 0 0 0 0 1 1 0 1 1 1 0 0 1 0 0 0 0 1 0 1 0 1 1 1 1 0 1 0 0 0 1 1 0 1 0 1 1 0 1 0 1 0 0 0 1 0 0

0 0 1 0 0 0 00 1 0 0 0 1 10 0 1 0 1 0 00 1 0 1 0 1 00 1 0 1 0 1 10 0 1 0 0 0 1 0 0 1 0 0 1 0

1 1 0 0 1 0 1 1 1 1 1 0 1 1 1 1 1 1 0 1 0 1 1 0 1 1 0 0

0 1 0 0 0 1 0

1 1 1 0 0 1 0 1 1 0 1 1 0 1

0 1 1 1 1 0 10 0 0 1 0 1 10 1 1 1 1 0 00 1 1 0 1 0 00 0 0 1 1 0 1

1 0 1 1 1 0 1 1 0 0 0 0 1 1 1 0 1 1 1 1 1 1 0 0 0 1 1 1 1 0 1 1 0 1 1 1 0 0 0 1 0 1

0 0 1 0 1 0 10 1 0 0 0 0 10 0 1 0 1 1 10 1 0 1 0 0 10 0 1 0 0 1 1

1 1 0 0 0 0 0 1 1 1 1 0 0 1 1 1 0 1 0 0 0 1 1 1 0 0 0 1

0 1 1 1 0 0 00 1 1 0 0 0 09 0 °

C

D

A

B

1 1 1 0 0 1 11 1 0 0 1 0 0

0 1 0 1 1 1 1

1 1 0 1 1 1 1

0 0 0 1 0 0 1

0 1 1 0 1 0 1

1 0 1 0 0 1 1

(Im )

(Re)

T1701310-90

n n n n n n n

F IG U R E 2 -1 /V .32 b is

N o te – B ina ry nu m bers refer to Y 0 , Y 1 , Y 2 , Q 3 , Q 4 , Q 5 , Q 6 .A , B , C , D refe r to syn ch ro n iz ing signal e lem en ts .

S ig n a l sp a ce d iagram an d m a p p in g for m od u la t io n a t 14 4 00 b it/s p er secon d

128-QAM EXAMPLE -COMBINATION OF AMPLITUDEAND PHASE ENCODES SPECIFIC BIT PATTERN


392 330 274 222 177 135 102 77 55 41 35 31 37 48 65 91 118 155 198 248 303 361

380 316 255 203 158 119 84 60 39 24 17 15 20 30 49 72 101 138 182 230 283 348 415

384 324 277 229 189 156 96 87 83 92 172 208 254 299 354

355 294 243 201 160 98 79 64 58 62 71 90 180 221 271 323 387

406 350 306 266 234 253 288 327 379

360 310 263 165 242 289 338 391

412 371 340 353 390

401 357 318 298 337 378

398

408 396 394 400 414

375 349 339 329 326 335 347 359 386

314 290 279 269 265 273 281 302 322

282 257 236 224 216 212 218 228 247 270

206 185 173 164 162 170 181 197 220

146 133 123 121 125 137 154 179 207193226

131 110 100 117 140

126 112 14154

367 304 244 194 148 108 75 50 28 13 6 4 8 21 38 63 93 127 171 219 275 336 402

362 296 238 186 142 103 69 43 22 1 0 5 16 32 56 85 122 163 213 267 328 3959

365 300 240 190 144 106 73 45 25 3 2 7 18 36 59 88 124 166 217 272 331 39711

372 307 251 199 152 113 80 52 33 19 12 10 14 26 42 66 134 174 225 280 341 40997

388 320 261 210 167 128 67 47 34 27 23 29 40 57 81 111 147 187 237 291 35194

410 343 284 232 183 149 89 68 53 46 44 51 61 78 99 132 168 209 258 315 376115

369 311 259 214 175 95 82 74 76 86 157 195 235 285 342 399139 116 104 12970

403 345 292 249 205 191 227 268 319 373176 150 136 161130 114 107 105 109 120

382 332 287 250 231 264 308 358 413215 184 178 202169 153 145 143 151 159

377 333 293 278 312 352 404260 233 223 245211 200 192 188 196 204

383 346 325 363 407313 286 276 295262 252 241 239 246 256

405 385370 344 334 356321 309 301 297 305 317

411 393389 374 366 364 368 381

–11

–15

–19

–23

–27

–31

–35

–39

–43

9

5

1

–3

–7

45

41

37

13

17

21

25

29

33

–43 –39 –35 –31 –27 –23 –19 –15 –11 –7 –3 1 5 9 45413713 17 21 25 29 33

T1403000-97/d05

Figure 5/V.34 – One-quarter of the points in the superconstellation

EXAMPLE OF NUMBERS ENCODING BYSPECIFIC BIT PATTERNS

Thesevalues of signal are encoded by specificmodulation patternson the previouspage


• The more bits we put the better signal to

noise must be (small phase and amplitude

values are lost in noise)

How to put even more bits on a signal?

By using multicarrier modulation –

bits are overlayed on many carriers at the

same time.


• ONE USES MANY CHANNELS. EACH CHANNEL IS MODULATED E.G. WITH 8 KBITS/S. WITH MANY CHANNELS

OVERALL DATA RATE GROWS

• EACH CHANNEL CAN BE INDIVIDUALLY TUNED TO THE

TRANSMISSION BANDWIDTH, E.G.

SOME CHANNELS CAN BE SKIPPED

COMPLETELY.

Now we have many carriers


s1 (t) = Acos(2f1ct + )

s3 (t) = Acos(2f3ct + )s2 (t) = Acos(2f2ct + )

sn (t) = Acos(2fnct + )………………………

The carriers are assumed to be close to each otherf1c fnc……………..

f

A

How the overall modulated signal will look ?

In time domain In frequency domain

signals overlap they also overlap

Example of four subcarriers Spectra of individual subcarriers

We have to add additional condition for signals in order to be able to separate them

• This condition is orthogonality


* 1 ,

0 , i j

i jx t x t dt

i j

* 1 ,

0 , i j

i jX f X f df

i j

In time domain In frequency domain

The carriers must satisfy these special conditionsThen by summing and adding upp it will be possibleto separate themThis principle is called OFDM, ORTHOGONALFREQUENCY DIVISION MULTIPLEX


• WHERE ARE THESE SIGNAL

MODULATION TECHNIQUES APPLIED?1. PSK, QPSK – GOOD FOR WEAK SIGNALS,

APPLIED IN THE GSM MOBILE SYSTEM, ALSO IN DIGITAL TELEVISION FROM SATELLITES

2. QAM – REQUIRES STRONGER SIGNALS, APPLIED IN DIGITAL CABLE TELEVISION

AND IN THE EXTENSION OF GSM CALLED EDGE

3. MULTICARRIER OFDM – APPLIED IN TERRESTRIAL DIGITAL TELEVISION, IN WIRELESS LAN, AND IN NEW 4G MOBILE NETWORK VERY EFFICIENT USE OF BANDWIDTH, CAN BE ADJUSTED FOR BAD SIGNAL PROPAGATION


The OFDM modulation

• It uses radio bands very effectively• Applications in wireless networks

Digital Terrestrial Television: e.g. 8 000, 32 000

Digital Mobile Television 4 000and 8 000 carriers

Wireless LAN (802.11a/g): 52 carriers

Ultra Wide Band: many carriers in many bands

NEW 4th generation mobile system called LTE (Long Term Evolution)- thousands of carriers


The OFDM modulation cntd.• Applications in wired networks

ADSL – broadband networking over telephone lines

It seems OFDM is the winning signal modulation

technology for multimedia data transmission:- it allows high data bandwidth and is robust against

signal loss

- it is complicated but this is not a problem with current hardware and computer technology

c@Irek Defée MULTIMEDIA SYSTEMS

EXAMPLE OF APPLICATION OF OFDM :

ADSL SYSTEM

BROADBAND NETWORKING

For the home


• NETWORKING FOR HOME HAS TO BE CHEAP AND DISTRIBUTED ON LARGE SCALE• HOW TO MAKE IT? - LAYING NEW CABLES – NOT

ECONOMICAL (MAYBE IN NEW BUILDINGS)

- WIRELESS – BROADBAND NOT POSSIBLE (MAYBE IN THE FUTURE??)


• THE ONLY REALISTIC POSSIBILITY

IS TO USE EXISTING CABLING

THERE ARE TWO TYPES OF EXTERNAL

CABLES FOR CARRYING INFORMATION

AVAILABLE IN HOMES:

TELEPHONE (ALMOST EVERYWHERE)

CABLE TV (IN MANY PLACES)


• TELEPHONE NETWORK IS DESIGNED AS NARROWBAND, CABLES ARE FOR

SPEECH, 4kHz BAND

BUT EVERYBODY HAS SEPARATE LINE

• CABLE TV IS DESIGNED AS BROADBAND BUT ALL USERS SHARE

THE SAME CABLE (FOR TV SIGNAL)

IT LOOKS IMPOSSIBLE TO USE THEM


• WITH THE OFDM TECHNOLOGY THIS

CAN CHANGE. TELEPHONE CABLE

IS NARROWBAND BUT ITS BANDWIDTH IS NOT 4 kHz.

Bandwidth of typical telephone cable:

4kHz 1MHzABOVE THE 4kHz CABLE BANDWIDTH IS VERY VARIABLE. IT IS DIFFERENT FOR EACH CABLE AND DEPENDS ON DISTANCE


• UNTIL RECENTLY UNEQUALIZED BANDWIDTH WAS NOT USEFUL,

TOO MUCH SIGNAL DEGRADATION

• NEW SIGNAL PROCESSING TECHNIQUES ENABLE ITS USE


ADSL

ASYMMETRIC DIGITAL SUBSCRIBER LOOP

THE TECHNIQUE FOR USING ”BAD” CABLE

BANDWIDTH BASED ON

OFDM MULTICARRIER SIGNAL MODULATION


TELEPHONE NETWORK

TELEPHONEEXCHANGE

BROADBAND LINK

LINKS TO CUSTOMERSARE FEW KMLONG, CABLING IS NARROWBAND

DSLAM

MODEM

MODEM

MODEM

ADSL IN

ADSL MODEMS ENABLE TO USE MORE BANDWIDTH


MULTICARRIER MODULATION IN ADSL

f

4 kHz CARRIER CHANNELS

EACH CHANNEL IS SEPARATELY MODULATED WITH A SIGNAL.

SIGNAL LEVEL OF EACH CHANNEL CAN BEMATCHED TO THE GAIN AT ITS FREQUENCY

VOICE BANDHIGH BAND


• IN PRACTICAL SYSTEM ONE USES

256 CHANNELS. EACH CHANNEL IS

MODULATED WITH E.G. 32 KBITS/S

IN TOTAL THIS GIVES 8 Mbits/sec !!!• EACH CHANNEL CAN BE INDIVIDUALLY

TUNED TO THE TRANSMISSION SIGNAL

LEVEL, E.G. SOME CHANNELS CAN BE SKIPPED COMPLETELY.


• COMPLETE SYSTEM

f4 25 160 240 .....................1200 kHz

TEL. UPSTREAM DOWNSTREAM DATA DATA FROM USER TO USER

THE SYSTEM IS ASYMMETRIC, IT SENDS MORE DATA DOWN THE LINE THAN UP (E.G. 256 kbits/s up)BUT FOR HOME USERS THIS IS OK


• THERE ARE VERY MANY DETAILS IN ADSL STANDARD:- HOW THE CARRIERS ARE MODULATED?

(QAM MODULATION)- HOW THE MODULATION IS REALIZED?

(512-POINT FFT)- HOW THE ERROR CORRECTION IS PERFORMED? (FEC)- HOW THE SIGNALS ARE

SYNCHRONIZED? (PILOT TONE)


• THESE DETAILS CAN BE FOUND IN THE ADSL STANDARD AND OVERVIEWS ON THE WEB.

• ADSL IS NOW OFFERED COMMERCIALLY ON LARGE SCALE

PRICES (ARE IN THE RANGE OF

FEW TENS OF €/m FOR 1-8 Mb/s BANDWIDTH. THE SYSTEM WORKS VERY RELIABLY.


• BUT FROM PRACTICE IT IS KNOWN

THAT ADSL HAS A PROBLEM TOO:

- BANDWIDTH OFFERED DEPENDS ON

DISTANCE, CABLE QUALITY AND

MAY VARY WIDELY


New ADSL standards

• These are ADSL2 and ADSL2+. They

provide improvements by: - using higher signal power- bonding several phone lines- using greater bandwidth comparing to ADSL

(up to 2.2 MHz)- real time channel estimation and adaptation

of bitrate to channel conditions


ANOTHER EXAMPLE:Proposed Ultra Wide Band Network

• Ultra Wide Band is wireless network

of very short range but with very

high data transfer rate (600 Mb/s to

1000 Mb/s and more)

This network can eliminate e.g. MONITOR

cable. Then mobile device can drive

the monitor directly.


UWB -Ultra Wideband Communication

• UWB system is proposed for high speed communication between devices, to eliminate cables:


Where is UWB?Look around the show for various applications…

Disk Backup

Print Files

Camera Downloads

MP3 File Transfers

Movie Transfers

Video Streaming

…and more!


What Problem Does UWB Solve?

The Customer’s Frustration with Cables:

• Tangle of cables in our Homes and Offices

• Ever increasing file sizes of content to be downloaded and enjoyed by Consumers

• Consumers don’t want to wait long for a file to transfer

• User Models limited by the use of Cables• Customers to-day prefer Wireless

UWB is more than a Cable replacement technology

Create new User Models and product opportunities not possible today with cables

BUT…..MUST Match the Security of cables

MUST be easy to use

UWB is more than a Cable replacement technology

Create new User Models and product opportunities not possible today with cables

BUT…..MUST Match the Security of cables

MUST be easy to use


The Vision: Creating new User Models and Product opportunities

PersonalWireless Storage/Wallet

Photo & Video ClipDisplay

Photo Printer

SHARE and EXCHANGECreate New User Models not

possible in the Cabled World

Connecting PC, CE and Mobile Segments

Multi Channel Speakers

In Car Media center& video

Share video clipsMusic & Photos

Media Center


The Model that Consumers Expect

• Compatible and InteroperableCompatible and Interoperable out of the box

• ManyMany suppliers supporting a Common Standard at all levels of the ecosystem

Buy it Plug it in Use it…Easily!


UWB opportunity

• If Ultra Wide Band networking becomes

popular and monitors/TV’s will

get it, then there will be no need to

connect TV and monitor by cable

to their signal sources. Mobile devices

will display on them directly


Imagine this

Mobile device has wireless

links to keyboard and display

Bluetooth

UWB

Ultra Wide Band

Mobile devices are more and

more capable (processors,

memory, hard discs), resembling

PC from few years ago


Principle of UWB

• Ultra wideband system uses very broad

frequency band:

There are UWB standards proposed which are based on several principles: One of them is MULTIBAND OFDMwith many thousands of carriers.


UWB is Multi-band OFDM

• Central Idea #1: – Divide the spectrum into bands that are 528 MHz wide.

• Advantages:– Transmitter and receiver process smaller bandwidth signals.– Instantaneous processing BW = 528 MHz.

f3432MHz

3960MHz

4488MHz

5016MHz

5544MHz

6072MHz

6600MHz

7128MHz

7656MHz

8184MHz

8712MHz

9240MHz

9768MHz

Band #1

Band #2

Band #3

Band #4

Band #5

Band #6

Band #7

Band #8

Band#9

Band #10

Band #11

Band #12

Band #13

10296MHz

Band #14

Band Group #1 Band Group #2 Band Group #3 Band Group #4 Band Group #5


Exploiting the Band Plan

• Exploit range of band group’s to separate applications:

Longer Range Apps Use BG #1 and #2

f3432MHz

3960MHz

4488MHz

5016MHz

5544MHz

6072MHz

Band #1

Band #2

Band #3

Band #4

Band #5

Band #6

Band Group #1 Band Group #2


Exploiting the Band Plan

• Exploit range of band group’s to separate applications:

` Shorter Range Apps Use BG #3 and #4

f3432MHz

3960MHz

4488MHz

5016MHz

5544MHz

6072MHz

6600MHz

7128MHz

7656MHz

8184MHz

8712MHz

9240MHz

9768MHz

Band #7

Band #8

Band#9

Band #10

Band #11

Band #12

10296MHz

Band Group #3 Band Group #4


Overview of Multi-band OFDM

• Central Idea #2: – Interleave OFDM symbols across all bands.

• Advantages:– Exploits frequency diversity.– Provide robustness against multi-path / interference.– Same transmit power as if the entire band is used.

TimeFreq (MHz)

3168

3696

4752

4224

Band # 1

Band # 2

Band # 3


• EDGE – ENHANCED DATA RATE FOR

GSM EXPANSION

TECHNIQUE FOR INCREASING THE BIT

RATE OF GSM SYSTEM BY USING

8-PSK.

IT IS ADOPTED FOR DATA TRANSFER

BUT REQUIRES MAJOR HARDWARE

UPGRADES IN THE SYSTEM

IMPORTANT EXAMPLE


• Ultra Wide Band connections were demonstrated for television sets

• Television sets are

• becoming so thin that that there is no place

• for connectors

• Signal can be

transmitted by wireless UWB link.

CURRENT STATUS OF UWB


ANOTHER EXAMPLE Home Communication over Powerlines

• Powerlines are everywhere, in every room

at home. There is a question if they could be used

for data transmission. After very long development

it looks that powerline communication will become

available e.g. one can see products from:

www.devolo.com


• The system is very simple to install:


• How this system operates?

It is based on a standard called Homeplug. For signal

transmission the band which is used is 2-28 MHz

with OFDM modulation. It has 917 carriers and

carriers can be independently modulated by

different modulations from PSK up to 1024 QAM

The maximum data rate can be up to 150 Mb/s,

practical rates are 40-85 Mb/s.

The standard has a lot of other details:

www.homeplug.org

FURTHER EXAMPLES OF OFDMWIRELESS SYSTEMS


1. LTE – next generation mobile system2. WiMax – next generation network3. WLAN – local area network


LTE – Next mobile system after 3G

• LTE = Long Term Evolution

• Extension of 3G network

• Higher databandwith, uses OFDM modulation

• LTE is fully oriented to multimedia and advanced applications -> analyze next slide



LTE OFDM• Orthogonal Frequency-Division Multiplexing

• FDM where carriers are appropriately spaced to insure orthogonality. Notice the overlap!!

• Spectrally efficient!!


OFDM signal in time and frequencyOFDM signal in time and frequency

Fig. Frequency –time representation

Fig. MIMO

Please note that signals on different subcarriers (frequency axis)carry modulation symbols (time axis). Modulation symbols (QPSK or QAM) are separated by short breaks (guard intervals)


LTE Parameters System to the User– How much data can be sent to the user

– The system is very flaxible, has many parameters

Transmission BW1.25 MHz 2.5 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Sub-frame duration 0.5 ms

Sub-carrier spacing 15 kHz

Sampling frequency 1.92 MHz(1/2 3.84 MHz)

3.84 MHz 7.68 MHz(2 3.84 MHz)

15.36 MHz(4 3.84 MHz)

23.04 MHz(6 3.84 MHz)

30.72 MHz(8 3.84 MHz)

FFT size 128 256 512 1024 1536 2048

Number of occupied sub-carriers†, ††

76 151 301 601 901 1201

Number of OFDM symbols

per sub frame(Short/Long CP)

7/6

CP length (μs/samples)

Short (4.69/9) 6,(5.21/10) 1*

(4.69/18) 6,(5.21/20) 1

(4.69/36) 6,(5.21/40) 1

(4.69/72) 6,(5.21/80) 1

(4.69/108) 6,

(5.21/120) 1

(4.69/144) 6,(5.21/160) 1

Long (16.67/32) (16.67/64) (16.67/128) (16.67/256) (16.67/384) (16.67/512)


How much data teh user can sentTransmission BW 1.25

MHz2.5 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Timeslot duration 0.675 ms

Sub-carrier spacing 15 kHz

Sampling frequency 1.92 MHz

(1/2 3.84 MHz)

3.84 MHz 7.68 MHz(2 3.84 MHz)

15.36 MHz

(4 3.84 MHz)

23.04 MHz

(6 3.84 MHz)

30.72 MHz

(8 3.84 MHz)

FFT size 128 256 512 1024 1536 2048

Number of occupied sub-carriers†, ††

76 151 301 601 901 1201

Number of OFDM symbols

per Timeslot(Short/Long CP)

9/8

CP length (μs/samples) Short 7.29/14 7.29/28 7.29/56 7.29/112 7.29/168 7.29/224

Long 16.67/32 16.67/64 16.67/128 16.67/256 16.67/384 16.67/512

Timeslot Interval (samples) Short 18 36 72 144 216 288

Long 16 32 64 128 192 256

LTE parameters User to the System


LTE modulation structure

In the LTE the channel width and number of carriers is flexible 12 carriers form one resource block, 1 slot in time is 0.5 msand it carries 7 OFDM symbols, 1 subframe is 2 slots

LTE DATA TRANSFER CAPACITY

• There are so many parameters in the system

that data transfer can be very flexibly adjusted. One can say that practically several tens of megabits per second is possible. Thus, LTE will be the first wide area wireless network with full multimedia data transfer capabilities



WiMax Network

• New type of networks to be deployed in the near future

• Two types specified:

• One type of them is a substitute for ADSL,

with wireless modems – fixed network

• Antoher type is full mobile network


WiMAX• World Interoperability for Microwave Access

• There are two main applications of WiMAX:

1) Fixed WiMAX (IEEE 802.16-2004) - Fixed WiMAX applications are point-to-multipoint enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL for homes and businesses.

2) Mobile WiMAX (IEEE 802.16e-2005) - Mobile WiMAX offers the full mobility of cellular networks at true broadband speeds.


WiMAXFixed WiMAX Architecture


WiMAXMobile WiMAX Architecture


WiMax Basics

• WiMax allows data transport over multiple broad frequency ranges

• WiMax’s transmission range and data rate vary significantly depending on the frequency bands an implementation uses

• Orthogonal frequency division multiplexing (OFDM)

• 10 to 66 GHz range

• 75 Mbits


WiMax frequency bands• IEEE 802.16a

Spectrum: 2 to 11GHzMore flexible while maintaining the technology’s data rate and transmission range

• IEEE 802.16b5 and 6 GHz frequencyprovides quality of servicepriority transmission for real-time voice and video and to offer differentiated service levels for different traffic types


WiMax Technical Specifications

• OFDM modulation with 256 cariers, 192 useful• Mobile WiMax 256 to 1024 carriers• Modulation PSK, QPSK, 16 QAM, 64 QAM


WiMax Data Rates

• Note: there are several channel bandwidths,

many modulation types and OFDM carriers


WiMax Technical Specifications

• Up to 280 Mbps per base stations• Base station transmission range up to 50 km• True broadband for portable users - providing

broadband connectivity for laptops and PDAs with integrated WiMax technology


WiMax radio frequency bands

• 2.3 GHz, 2.5 GHz, 3.4 GHz, 3.6 GHz,

• 5.4 GHz, 5.8 GHz and possibly others

• such as 700 MHz and 900 MHz or even up to 66 GHz


WLANWIRELESS LOCALAREA NETWORK


What is Wireless LAN?


Wireless LAN Solution

• Extends the local area network • Freedom to access the corporate network

- high-speed rates- features comparable to those of wired networks

• Reliable communications in network access areas

- meeting rooms- other corporate offices- airports - hotels - remote and home offices

• Secure access to important information - e-mail- corporate data- the Internet


Wireless LAN PC CardWireless LAN PC Card • Each wireless station and access point has a wireless LAN card• Provides an interface between an end-user device and radio waves

Wireless LAN Access PointWireless LAN Access Point• Connected to the wired network

• Acts as bridge between wireless and wired network• Enables high-performance network access

Internet

E-mail E-mail

serverserver

WWWWWWserverserver

Radio signalRadio signal

Security solutionSecurity solution

+

FirewallFirewall

How Does Wireless LAN Solution Work?


THE WIRELESS LAN SOLUTION

COMMON AREASMEETING ROOMS

TRAINING CENTERSTEMPORARY

OFFICES

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• THERE ARE FOUR FAMILIES OF

WLAN STANDARDS:

WLAN Standard Over-the-Air (OTA) Estimates (Bitrate of signals transmitted)

Actual rate for data transmission(Data transfer)

802.11b OLD 11 Mbps 5 Mbps

802.11g 54 Mbps 25 Mbps (when .11b is not present)

802.11a 54 Mbps 25 Mbps

802.11n 200+ Mbps 100 Mbps Note: 802.11n is new and not commonly available yet


• WLAN RADIO BANDS

IEEE 802.11g 2.4 GHz

IEEE 802.11a 5 GHz (200MHz)

IEEE 802.11n 2.4 and 5 GHz

• MODULATION:

- OFDM - (MULTICARRIER

MODULATION) IEEE 802.11a and g


What is IEEE802.11b WLAN?It is substitute for the Ethernet. All userssend and receive packets in the same band.radio resources are allocated for them onrandomized basis. The more users are on-line, the less bandwidthis available. IEEE 802.11b bandwidth is:11 Mb/s theoretically 5 Mb/s practically – shared by all usersRange: 15-100m (bulidings, open spaces)


• CHANNEL BANDWIDTH

20 MHz – 52 CARRIER FREQUENCIES 48 USED FOR DATA

QPSK AND QAM MODULATION IS USED FOR CARRIERS GROSS BIT RATES ARE FROM 6-54 Mb/sec USEFUL BIT RATES ABOUT HALF OF

THAT


• THE SYSTEM DATA TRANSFER IS

ORGANISED AS TIME DIVISION

MULTIPLEX IN FRAMES

EACH FRAME HAS LENGTH OF 2 ms

AND WITHIN IT PACKETS OF DATA

SEND (48 BYTES)


• PERFORMANCE CAN REACH PRACTICALLY 20 Mb/sec

• THE NUMBER OF USERS:

TRANSMISSION RANGE IS 30-150 M (TRANSMITTER POWER 0.2-1W) THERE ARE MAX. 19 CHANNELS• DEPENDING ON THE BANDWIDTH THERE COULD BE ABOUT 50-70(?) USERS FOR 1 ACCESS POINT


The 802.11n standard

• This is new standard improving on the older ones

• The major improvements are:

- Better OFDM modulation up to 65 Mb/s

- It can use several transmission and receiving systems and the same time


Multiple stream transmission in 802.11n

Here there is a scheme with 2 streams, in the 802.11n standard there can be 2,3, or 4 streams, the bit rate will be 2x,3x,4x higher.In the end we can have up to 100 Mb/s data transfer with 4 streams.The standard has also optional modes of operation (with wider channels)The data rate then could be up to 300 Mb/s.

Digital Terrestrial and Mobile Television

• There are 3 standards: DVB-T, DVB-T2 and DVB-H

• OFDM modulation is used with 2000, 4000, 8000…. up to 32 000 carriers

• Each carrier can be modulated with PSK, 16-QAM, 64-QAM up to 256-QAM

• Data rates are between 20-40 Mbits/sec in single TV

channel with 8 MHz width

Digital Television is widely used in Europe

MULTIMEDIA SYSTEMS

IREK DEFEE

MULTIMEDIA SYSTEMS IREK DEFEE SIGNAL MODULATION for MULTIMEDIA DATA TRANSMISSION with special emphasis on wireless.

Documents

multimedia transmission

patternsthesevalues

better signal

sinusoidal waveformthe

amplitudeand phase

small phase

combination of amplitude

signal space diagram