GOVERNMENT POLYTECHNIC, SADAR NAGPUR

(An Autonomous Institute of Government of Maharashtra)

SSEMINAREMINAR T TOPICOPIC

UWB TECHNOLOGYUWB TECHNOLOGY(ULTRA WIDE BAND TECHNOLOGY)

UNDER GUIDANCE OF

DINESH ALASPURE SIR

MADE BY

PRATIK SAWALE

ETX III YR ( 0904077 )

CERTIFICATE

THIS IS TO CERTIFY THAT, THE SEMINAR WORK ENTITLED

“UWB TECHNOLOGY”

HAS BEEN SUBMITTED BY

Mr. Pratik Sawale

3rd Year Electronics & Telecommunication

(0904077)

IN A SATISFACTORY MANNER AS A PART OF PARTIAL

FULFILLMENT OF DIPLOMA COURSE IN ELECTRONICS AND

TELECOMMUNICATION. IN GOVT. POLYTECHNIC, NAGPUR

DURING THE ACADEMIC YEAR

2011-2012

D. ALASPURE SIR Prof. S.V.TADAS

SEMINAR GUIDE HEAD OF DEPARTMENT

DEPARTMENT OF ELECTRONICS & TELECOMMUNICATION ENGG.

GOVT. POLYTECHNIC, NAGPUR.

(An autonomous institute of government of Maharashtra)

2011-2012

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ACKNOWLEDGEMENT ACKNOWLEDGEMENT

It is our more duty and responsibility to be loyal and grateful to those

who have shown us the path towards innovation and dynamism contributing

in a big way in complementing me for “UWB TECHNOLOGY” Seminar

report within the stipulated time.

It is worth mentioning here that as a guide, “Prof. MR. D.

ALASPURE SIR” has enlightened us for our seminar report. Let us be

honest to pay his utmost regards for his able guidance to which our seminar

report proved to be successful one.

We are insufficient to show our thankfulness to our Head of the

Department Prof. S. V. TADAS who at every point showed us the telescopic

way in respect of our seminar.

I also extend my thanks to all those teachers who have contributed to

make this seminar a success.

At last, I wish to avail myself of this opportunity, express a sense of

gratitude and love to my friends for their manual support, strength, help and

for everything.

Thank you!

Pratik SawaleElectronics and telecommunication

Enrol. No. 0904077

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INDEX INDEX

Contents

1. Introduction

2. What is UWB ?

3. How UWB works?

4. Narrowband communication & UWB

5. Modulation types

6. Spectrum

7. UWB Characteristics

8. Comparison with latest technologies

9. Application

10. Conclusion

11. References

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INTRODUCTIONINTRODUCTION

Just as many wireless technologies seem to be moving into high

volume production and becoming established a new technology has hit

the scene and is threatening to turn the industry upside down. Known as

Ultra Wide Band (UWB) this new technology has much to offer both in

the performance and data rates as well as the wide number of

application in which it can be used. Currently ultra wideband (UWB)

technology has been proposed for or is being used in applications from

radar and sensing applications right through to high band width

communications. Furthermore ultra wide band, UWB can be used in

both commercial and military applications.

Unlike most other wireless technologies in use today, ultra wideband

(UWB) employs a totally different method of transmission. Rather than

using a specified frequency with a carrier, the technique that is used by

traditional transmissions, UWB uses what may be termed "time

domain" electromagnetic. In other words UWB uses pulses that spread

out over a wide bandwidth, rather than transmissions that are confined

within a given channel.

It is the fact that UWB uses a different approach to wireless or radio

transmissions is part of the reason UWB development may appear to be

slow. With wireless transmissions using traditional techniques filling

the airwaves, care has to be taken when establishing UWB, that

interference does not result, and that whatever legislation is introduced,

does not have to be changed later.

UWB, or Ultra-Wide Band technology offers many advantages,

especially in terms of very high data transmission rates which are well

beyond those possible with currently deployed technologies such as

802.11a, b, g, WiMax and the like. As such UWB, ultra wideband

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technology is gaining considerable acceptance and being proposed for

use in a number of areas. Already Bluetooth, Wireless USB and others

are developing solutions, and in these areas alone its use should be

colossal.

UWB commonly refers to a signal or system that either has a large

relative bandwidth (BW) that exceeds 20% or a large absolute

bandwidth of more than 500 MHz. A 14 February 2002 report and

order by the federal communications commission (FCC) authorizes the

unlicensed use of UWB in 3.1--10.6 GHz. This is intended to provide

an efficient use of scarce radio bandwidth while enabling both high

data rate personal area network (PAN) wireless connectivity and

longer-range, low data rate applications as well as radar and imaging

systems.

WHAT IS UWB........??WHAT IS UWB........??

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Ultra-wideband is a radio technology that can be used at very low

energy levels for short-range high-bandwidth communications by

using a large portion of the radio spectrum.

Ultra-Wideband (UWB) is a technology for transmitting information

spread over a large bandwidth (>500 MHz) that should, in theory and

under the right circumstances, be able to share spectrum with other

users.

A significant difference between traditional radio transmissions and

UWB radio transmissions is that traditional systems transmit

information by varying the power level, frequency, and/or phase of a

sinusoidal wave. UWB transmissions transmit information by

generating radio energy at specific time instants and occupying large

bandwidth thus enabling a pulse-position or time-modulation. The

information can also be imparted (modulated) on UWB signals

(pulses) by encoding the polarity of the pulse, the amplitude of the

pulse, and/or by using orthogonal pulses. UWB pulses can be sent

sporadically at relatively low pulse rates to support time/position

modulation, but can also be sent at rates up to the inverse of the UWB

pulse bandwidth.

One of the valuable aspects of UWB radio technology is the ability for

a UWB radio system to determine "time of flight" of the direct path of

the radio transmission between the transmitter and receiver at various

frequencies. This helps to overcome multi path propagation, as at least

some of the frequencies pass on radio line of sight. With a cooperative

symmetric two-way metering technique distances can be measured to

high resolution as well as to high accuracy by compensating for local

clock drifts and stochastic inaccuracies.

Another valuable aspect of pulse-based UWB is that the pulses are

very short in space (less than 60 cm for a 500 MHz wide pulse, less

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than 23 cm for a 1.3 GHz bandwidth pulse), so most signal reflections

do not overlap the original pulse, and thus the traditional multipath

fading of narrow band signals does not exist. However, there still is

multipath propagation and inter-pulse interference for fast pulse

systems which have to be mitigated by coding techniques.

The fact that UWB transmissions have such a wide bandwidth means

that they will cross the boundaries of many of the currently licensed

carrier based transmissions. As such one of the fears is that UWB

transmission may cause interference. However the very high

bandwidth used also allows the power spectral density to be very low,

and the power limits on UWB are being strictly limited by the

regulatory bodies. In many instances they are lower than the spurious

emissions from electronic apparatus that has been certified. In view of

this it is anticipated that they will cause no noticeable interference to

other carrier based licensed users. Nevertheless regulatory bodies are

moving forward cautiously so that users who already have spectrum

allocations are not affected.

To date the FCC in the USA has approved UWB, ultra wideband

technology for indoor and short range outdoor communication, but

with restrictions on the frequencies over which the transmission can

spread as well as the power limits. This will enable the UWB ultra

wideband transmissions to communicate successfully, but without

affecting existing 'narrowband' transmissions.

HOW UWB WORKS........??HOW UWB WORKS........??

UWB differs substantially from conventional narrowband radio

frequency (RF) and spread spectrum technologies (SS), such as

Bluetooth Technology and 802.11a/b/g. A UWB transmitter works by

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sending billions of pulses across a very wide spectrum of frequency

several GHz in bandwidth.

The corresponding receiver then translates the pulses into data by

listening for a familiar pulse sequence sent by the transmitter. UWB’s

combination of larger spectrum, lower power and pulsed data

improves speed and reduces interference with other wireless spectra.

In the United States, the Federal Communications Commission (FCC)

has mandated that UWB radio transmissions can legally operate in the

range from 3.1 GHz up to 10.6 GHz, at a limited transmit power of –

41dBm/MHz. The result is dramatic short-range channel capacity and

limited interference.

Ultra Wideband (UWB) systems transmit signals across a much wider

frequency than conventional systems and are usually very difficult to

detect. The amount of spectrum occupied by a UWB signal, i.e. the

bandwidth of the UWB signal is at least 25% of the center frequency.

Thus, UWB's combination of broader spectrum and lower power

improves speed and reduces interference with other wireless spectra.

Specifically, UWB is defined as any radio technology having a

spectrum that occupies a bandwidth greater than 20 percent of the

center frequency, or a bandwidth of at least 500 MHz.

The most common technique for generating a UWB signal is to

transmit pulses with durations less than 1 nanosecond. It is Radio

technology that modulates impulse based waveforms instead of

continuous carrier waves.

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Table : Advantages and benefits of UWB communications over narrowband wireless technologies.

Advantage Benefit

Large channel capacityHigh bandwidth can support real-time high-definition

video streaming.

Ability to work with low SNRs Offers high performance in noisy environments.

Low transmit powerProvides high degree of security with low probability

of detection and intercept.

Resistance to jamming Reliable in hostile environments.

High performance in multipath

channelsDelivers higher signal strengths in adverse conditions.

Simple transceiver architecture

Enables ultra-low power, smaller form factor, and

better mean time between failures, all at a reduced

cost.

MODULATION TYPESMODULATION TYPES

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The most common impulse radio concepts are based on Pulse Position

Modulation. These techniques use time shift of regularly timed pulses,

as it is shown at fig.1b for two modulation states.

Bi-Phase Modulation is modulation of the pulse polarity. Fig. 1c

shows it graphically. BPM is antipodal modulation method, whereas

PPM, when separated by one pulse width delay for each pulse

position, is an orthogonal modulation method. Therefore, BPM has

theoretically the 3dB gain in power efficiency. If PPM delays by one

pulse width, then BPM can send twice number of pulses and, twice the

information.

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PAM is not the preferred modulation method for most short-range

communication. AM signal which has smaller amplitude is more

susceptible to noise than that with larger amplitude.

On Off Keying is a modulation technique where the presence or

absence of a pulse represents pair of modulation states. The major

difficulty with OOK is the presence of echoes of the original or other

pulses. It makes difficult to determine the absence of a pulse. An

example of OOK is in fig. 2c.

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FREQUENCY SPECTRUMFREQUENCY SPECTRUM

The most part of energy of the UWB signal falls into the frequency

range from 3.1 to 10.6 GHz, and the energy spectral density doesn't

exceed limit determined by Part 15 of FCC

Regulations(-41dBm/MHz). Below 3.1 GHz the signal almost

disappears, its level is lower than -60. The more ideal the form of a

pulse formed with the transmitter, the less the energy goes out of the

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main range. But however that may be, the permissible deviation of the

pulse from the ideal form must be limited, hence the second purport.

The spectral range lower than 3.1 GHz is avoided not to create

problems for GPS systems whose accuracy of operation can suffer a lot

from outside signals even if their density is lower than -41.

The signal, in this way, extends over a large bandwidth (several

gigahertzs) and can be buried in the environment noise in a way that

does not interfere with other services.

UWB CHARACTERISTICSUWB CHARACTERISTICS

Extremely low transmission energy ( less than 1mW)

Very wide fractional and absolute RF bandwidth

Very high bandwidth within short range (200Mbps within 10m)

Extremely difficult to intercept

– Short pulse excitation generates wideband spectra – low energy

densities

– Low energy density also minimizes interference to other

services

Multipath immunity

Very short pulses

Carrier less transmission

High rate communication

Penetrate through walls

Commonality of signal generation and processing architectures

Radar

– Inherent high precision – sub-centimeter ranging

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– Wideband excitation for detection of complex, low RCS targets

Geo location/Positioning

– Sub-centimeter resolution using pulse leading edge detection

– passes through building blocks, walls, etc. (LOS not required)

Low Cost

– Nearly “all-digital” architecture– ideal for microminiaturization into a chipset

Frequency diversity with minimal hardware modifications

COMPARISON WITH LATEST TECHNOLOGIESCOMPARISON WITH LATEST TECHNOLOGIES

Wi-Fi

WiFi is an infrastructure-oriented technology and therefore has

difficulty communicating peer to peer. Also it was not designed for

streaming audio and video. The IEEE standards 802.11b and 802.11g

are used, both operates in the noisy 2.4 GHz ISM band and are subject

to interference. Transfer rate is slower with a top rate of 54Mbps.

Bluetooth

It was designed as a low power technology just to cut down the power

requirements of the wired technologies. Still it consumes 50x more

power as compared to UWB. The recent version of Bluetooth supports

up to a maximum of 12Mbps that is very low as compare to UWB. It

is also having problem of interference as it uses same band as that of

WiFi system.

UWB

A UWB signal centered at 2 GHz would have a minimum bandwidth

of 500 MHz and the minimum bandwidth of a UWB signal centered at

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4 GHz would be 1 GHz. The most common technique for generating a

UWB signal is to transmit pulses with durations less than 1

nanosecond. A traditional UWB transmitter works by sending billions

of pulses across a very wide spectrum of frequency several GHz in

bandwidth. 

The corresponding receiver then translates the pulses into data by

listening for a familiar pulse sequence sent by the transmitter.

Specifically, UWB is defined as any radio technology having a

spectrum that occupies a bandwidth greater than 20 percent of the

center frequency, or a bandwidth of at least 500 MHz.

UWB APPLICATIONUWB APPLICATION

There is a wide number of applications that UWB technology can be

used for. They range from data and voice communications through to

radar and tagging. With the growing number of way in which wireless

technology can be used, the list is likely to grow.

Although much of the hype about ultra wideband UWB has been

associated with commercial applications, the technology is equally suited

to military applications. One of the advantages is that with the pulses

being spread over a wide spectrum they can be difficult to detect. This

makes them ideal for covert communications.

Commercial:

High speed LAN / WAN ( >20 Mbps)

Avoidance radar

Altimeter (aviation)

Tags for intelligent transport systems

Intrusion detection

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Geolocation

Intelligent Transportation Systems, Electronic Signs, Smart

Appliances

Wireless Interconnection

Military:

Radar

Covert communications

Intrusion detection

Precision geo-location

Data links

CONCLUSIONCONCLUSION

UWB is in early stages of developments. It is proving its worth in

various fields with advantages like high bit rate, multimedia connectivity

to wireless personal area network. World is on the verge of freedom from

wires. UWB technology offers a solution for band-width, cost, power

consumption, and size requirements of next generation consumer

electronics. 

A number of UWB components and system are in testing phase and

will be releasing in near future. UWB has been redefined as a high data

rate (480+ Mbps), short-range (up to 20 meters) technology that

specifically addresses emerging applications in the consumer electronics,

personal computing and mobile device markets. When compared to other

existing and nascent technologies capable of providing wireless

connectivity, the performance benefits of UWB are compelling. 

With the growing level of wireless communications, ultra wide band

UWB offers significant advantages in many areas. One of the main

attractions for WAN / LAN applications is the very high data rates that

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can be supported. With computer technology requiring ever increasing

amounts of data to be transported, it is likely that standards such as 802.11

and others may not be able to support the data speeds required in some

applications. It is in overcoming this problem where UWB may well

become a major technology of the future.

REFERENCEREFERENCE

INFORMATION SOURCE

http://www.radio-electronics.com/info/wireless/index.php

Ultra-Wideband (UWB) Technology, Technology & Research at Intel

www.intel.com/technology/comms/uwb/

Ultra Wideband (UWB) Frequently Asked Questions (FAQ);

http://www.multispectral.com/UWBFAQ.html

UWB OVERVIEW

Ultra-wideband - Wikipedia, the free encyclopedia

en.wikipedia.org/wiki/Ultra-wideband

UWB MODULATION

http://www.urel.feec.vutbr.cz/ra2008/archive/ra2006/abstracts/088.pdf

UWB DETAILS

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http://www.antd.nist.gov/wctg/manet/NIST_UWB_Report_April03.pdf

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