Introduction to Ultra WideBand Systems

1
Introduction to Ultra WideBand Systems

• Chia-Hsin Cheng

2
Outlines

• Introduction
• The history of UWB
• UWB Regulations (FCC Rules)
• UWB signals
• UWB in IEEE 802 Standards
• The Application of UWB

3
Introduction

• The world of ultra wideband (UWB) has changed
  dramatically in very recent history. In the past
  20 years, UWB was used for radar, sensing,
  military communications and niche applications.
• A substantial change occurred in February 2002,
  when the FCC (2002a,b) issued a ruling that UWB
  could be used for data communications as well as
  for radar and safety applications.
• Recently, UWB technology has been focused on
  consumer electronics and communications.
• Ideal targets for UWB systems are low power, low
  cost, high data rates, precise positioning
  capability and extremely low interference.

4
UWB Transmitter Defined

• UWB transmitter signal BW
• Or, BW ³ 500 MHz regardless of fractional BW

fu-fl
2
³ 0.20
fufl
Where fu upper 10 dB down point fl lower
10 dB down point
Source US 47 CFR Part15 Ultra-Wideband
Operations FCC Report and Order, 22 April
2002 http//www.fcc.gov/Bureaus/Engineering_Techn
ology/Orders/2002/fcc02048.pdf
5
UWB Large Fractional Bandwidth
CDMA 1.288Mcps/1.8 GHz 0.07 bandwidth
one chip
Power Spectral Density (dB)
6
Large Relative (and Absolute) Bandwidth
Narrowband (30kHz)
Part 15 Limit ( -41.3dBm/Hz )
Wideband CDMA (5 MHz)
UWB (Several GHz)
Frequency

• UWB is a form of extremely wide spread spectrum
  where RF energy is spread over gigahertz of
  spectrum
• Wider than any narrowband system by orders of
  magnitude
• Power seen by a narrowband system is a fraction
  of the total
• UWB signals can be designed to look like
  imperceptible random noise to conventional radios

7
Why is Ultra Wideband So Effective?

• Shannon showed that the system capacity, C, of a
  channel perturbed by AWGN ---

Where C Max Channel Capacity (bits/sec)
B Channel Bandwidth (Hz) S Signal Power
(watts) N Noise Power (watts) Capacity per
channel (bps) µ B Capacity per channel (bps) µ
log(1S/N)

• Increase B
• Increase S/N, use higher order modulation
• Increase number of channels using spatial
  separation
• (e.g., MIMO)

8
Throughput

• Low Power UWB Comparable to High Power Wireless
  Systems

UWB throughput between 802.11a and b
9
UWB Properties

• Extremely difficult to detect by unintended users
• Highly Secured
• Non-interfering to other communication systems
• It appears like noise for other systems
• Both Line of Sight and non-Line of Sight
  operation
• Can pass through walls and doors
• High multipath immunity
• Common architecture for communications, radar
  positioning (software re-definable)
• Low cost, low power, nearly all-digital and
  single chip architecture

10
Outlines

• Introduction
• The history of UWB
• UWB Regulations (FCC Rules)
• UWB signals
• UWB in IEEE 802 Standards
• The Application of UWB

11
The history of UWB Technology

• Before 1900 Wireless Began as UWB
• Large RF bandwidths, but did not take advantage
  of large spreading gain
• 1900-40s Wireless goes tuned
• Analog processing filters, resonators
• Separation of services by wavelength
• Era of wireless telephony begins AM / SSB / FM
• Commercial broadcasting matures, radar and signal
  processing
• 1970-90s Digital techniques applied to UWB
• Wide band impulse radar
• Allows for realization of the HUGE available
  spreading gain
• Now UWB approved by FCC for commercialization

For further details, refer to ref.1
12
What UWB is Today

• 7,500 MHz available spectrum for unlicensed use
• US operating frequency 3,100 10,600 MHz
• Emission limit -41.3dBm/MHz EIRP
• Indoor and handheld systems
• Other restrictions and measurement procedures in
  Report and Order
• UWB transmitter defined as having the lesser of
• Fractional bandwidth greater than 20
• Occupies more than 500 MHz
• UWB is NOT defined in terms of
• Modulation
• or Carrierless
• or Impulse radio

13
Outlines

• Introduction
• The history of UWB
• UWB Regulations (FCC Rules)
• UWB signals
• UWB in IEEE 802 Standards
• The Application of UWB

14
Summary of the FCC Rules

• Significant protection provided for sensitive
  systems
• GPS, Federal aviation systems, etc.
• Lowest emission limits ever by FCC
• Incorporates NTIA (National Telecomm. and Info.
  Administration) recommendations
• Allows UWB technology to coexist with existing
  radio services without causing interference
• FCC opened up new spectrum for UWB transmissions
• One of the bands is from 3.1GHz to 10.6GHz
• Maximum power emission limit is - 41.3dBm/MHz

15
FCC UWB Device Classifications

• Report and Order authorizes 5 classes of devices
  with different limits for each
• Imaging Systems
• Ground penetrating radars, wall imaging, medical
  imaging
• Thru-wall Imaging Surveillance Systems
• Communication and Measurement Systems
• Indoor Systems
• Hand-held Systems
• Vehicular Radar Systems
• collision avoidance, improved airbag activation,
  suspension systems, etc.

16
FCC First Report and Order Authorizes Five Types
of Devices
Class / Application Frequency Band for Operation at Part 15 Limits User Limitations
Communications and Measurement Systems 3.1 to 10.6 GHz (different out-of-band emission limits for indoor and hand-held devices) No
Imaging Ground Penetrating Radar, Wall, Medical Imaging lt960 MHz or 3.1 to 10.6 GHz Yes
Imaging Through-wall lt960 MHz or 1.99 to 10.6 GHz Yes
Imaging Surveillance 1.99 to 10.6 GHz Yes
Vehicular 22 to 29 GHz No
17
UWB Emission Limits for GPRs, Wall Imaging,
Medical Imaging Systems
Operation is limited to law enforcement, fire and
rescue organizations, scientific research
institutions, commercial mining companies, and
construction companies.
Source www.fcc.gov
18
UWB Emission Limits for Thru-wall Imaging
Surveillance Systems
Operation is limited to law enforcement, fire and
rescue organizations. Surveillance systems may
also be operated by public utilities and
industrial entities.
Source www.fcc.gov
19
UWB Emission Limit for Indoor Systems
Source www.fcc.gov
20
Proposed UWB Emission Limit for Outdoor Systems
Proposed in preliminary Report and Order, Feb.
14, 2002.
Source www.fcc.gov
21
Actual UWB Emission Limit for Hand-held Systems
UWB Band-width must be contained here
First Report and Order, April 22, 2002.
22
Outlines

• Introduction
• The history of UWB
• UWB Regulations (FCC Rules)
• UWB signals
• UWB in IEEE 802 Standards
• The Application of UWB

23
UWB Signals

• Monocycle Shapes for UWB
• Data Modulation
• Modulation Schemes

24
Monocycle Shapes for UWB

• Monocycle shapes will affect the performance
• Listed monocycles duration is 0.5ns
• Gaussian pulse
• Gaussian Monocycle
• Scholtzs Monocycle
• Manchester Monocycle
• RZ- Manchester Monocycle
• Sine Monocycle
• Rectangle Monocycle

25
Monocycle Shapes for UWB (cont.)

• Gaussian Pulse

26
Monocycle Shapes for UWB (cont.)

• Gaussian monocycle
• Similar to the first derivative of Gaussian pulse

27
Monocycle Shapes for UWB (cont.)

• Scholtzs monocycle
• Similar to the second derivative of Gaussian pulse

28
Monocycle Shapes for UWB (cont.)

• Manchester Monocycle
• It has amplitude A during half of the monocycle
  width and has amplitude A during the other half.

29
Monocycle Shapes for UWB (cont.)

• RZ- Manchester Monocycle
• It has amplitude A and A only a portion of each
  half monocycle width.

30
Monocycle Shapes for UWB (cont.)

• Sine Monocycle
• Just a period of sine wave

31
Monocycle Shapes for UWB (cont.)

• Rectangle Monocycle
• It has uniform amplitude A during the whole pulse
  width.

32
Data Modulation

• A number of modulation schemes may be used with
  UWB systems. The potential modulation schemes
  include both orthogonal and antipodal schemes.

• Pulse Position Modulation (PPM)
• Pulse Amplitude Modulation (PAM)
• On-Off Keying (OOK)
• Bi-Phase Modulation (BPSK)

33
Modulation Schemes

• Many different pulse generation techniques may be
  used to satisfy the requirements of an UWB
  signal.
• The FCC requires that the fractional bandwidth is
  greater than 20 , or that the bandwidth of the
  transmitted signal is more than 500MHz, whichever
  is less.
• The most common UWB concepts
• Time-hopping (TH) technique
• Direct-Sequence (DS) technique
• Multi-band (MB) technique

34
TH-UWB

• TH-PPM
• 1. transmitting 0

pulse wtr(t)
Str(t)
Tc
t
Tf
Ts data symbol time
35
TH-UWB

• TH-PPM
• 2 . transmitting 1

d
d
d
d
Str(t)
Tc
t
Tf
Ts
36
DS-UWB

• DS-UWB

37
Multiband UWB

• Refer to OFDM course

38
Outlines

• Introduction
• The history of UWB
• UWB Regulations (FCC Rules)
• UWB signals
• UWB in IEEE 802 Standards
• The Application of UWB

39
UWB in IEEE 802 Standards

• IEEE 802 Organization
• IEEE 802.15.3a
• IEEE 802.15.4a

40
IEEE 802 Organization
LAN/MAN Standards Committee (Wireless Areas)
MBWA IEEE 802.20
WLAN IEEE 802.11
WPAN IEEE 802.15
WMAN IEEE 802.16
Coexistence TAG IEEE 802.19
Regulatory TAG IEEE 802.18
802.15.1 Bluetooth
802.15.3 High Data Rate MAC 2.4 GHz PHY
Task Group 3a Alt PHY (UWB)
802.15.2 Coexistence
802.15.4 Zigbee 2.4 GHz
Study Group 4a (UWB?)
Mini-Glossary WLAN-wireless Local Area Network
MAN-Metropolitan Area Network TAG-Technical
Advisory Group-MBWA-Mobile Broadband Wireless
Access
Based on Overview of 802.15.3 and 3a, R. F.
Heile, Workshop on Current Developments in UWB,
Institute for Infocomm Research, Singapore
41
IEEE Project 802 Local and Metropolitan Area
Network Standards Committee

• Accredited by ANSI, Sponsored by IEEE Computer
  Society
• Ethernet, Token Ring, Wireless, Cable Modem
  Standards
• Bridging, VLAN, Security Standards
• Meets three times per year (400-600 individuals,
  15 non-US)
• Develops equivalent IEC/ISO JTC 1 standards
• JTC 1 series of equivalent standards are ISO
  8802-nnn
• IEEE URLs
• 802 http//grouper.ieee.org/groups/802/
• 802.15 http//grouper.ieee.org/groups/802/15/

42
Standards Range and Data Rate
43
Candidate UWB Systems
44
802.15.3a high data rate WPAN standard

• Direct sequence (DS-UWB)
• Championed by Motorola/XtremeSpectrum
• Classic UWB, simple pulses,
• 2 frequency bands 3.1-4.85GHz, 6.2-9.7GHz
• CDMA has been proposed at the encoding layer
• Spectrum dependent on the shaping filter
  possible differing devices worldwide
• Multiband Orthogonal Frequency Division
  Multiplexing (MB-OFDM)
• Intel/TI/many others
• Similar in nature to 802.11a/g
• 14 528MHz bands (simplest devices need to
  support 3 lowest bands, 3.1GHz 4.7 GHz)
• Spectrum shaping flexibility for international use

45
Detail of DS-CDMA Candidate for 802.15.3a

• Multi-band DS-CDMA Physical Layer Proposal
• Summary from IEEE document 15-03-0334-02-003a-Merg
  er-2-CFP-Presentation.ppt

46
Two Band DS-CDMA
Low Band
High Band
3
4
5
6
7
8
9
10
11
3
4
5
6
7
8
9
10
11

• Low Band (3.1 to 5.15 GHz)
• 25 Mbps to 450 Mbps

• High Band (5.825 to 10.6 GHz)
• 25 Mbps to 900 Mbps

Multi-Band
3 Spectral Modes of Operation
With an appropriate diplexer, the multi-band mode
will support full-duplex operation (RX in one
band while TX in the other)
3
4
5
6
7
8
9
10
11

• Multi-Band (3.1 to 5.15 GHz plus 5.825 GHz to
  10.6 GHz)
• Up to 1.35 Gbps

47
Joint Time Frequency Wavelet Family
48
Spectral Flexibility and Scalability

• PHY Proposal accommodates alternate spectral
  allocations
• Center frequency and bandwidth are adjustable
• Supports future spectral allocations
• Maintains UWB advantages (i.e. wide
  bandwidth for multipath resolution)
• No changes to silicon

Example 2 Support for hypothetical above 6 GHz
UWB definition
Example 1 Modified Low Band to include
protection for 4.9-5.0 GHz WLAN Band
3
4
5
6
7
8
9
10
11
Note 1 Reference doc IEEE802.15-03/211
3
4
5
6
3
4
5
6
49
Detail of OFDM Candidate for 802.15.3a

• Multi-band OFDM Physical Layer Proposal
• Summary from IEEE document 03267r1P802-15_TG3a-Mul
  ti-band-OFDM-CFP-Presentation.ppt

50
Overview of Multi-band OFDM

• Basic idea divide spectrum into several 528 MHz
  bands.
• Information is transmitted using OFDM modulation
  on each band.
• OFDM carriers are efficiently generated using an
  128-point IFFT/FFT.
• Internal precision is reduced by limiting the
  constellation size to QPSK.
• Information bits are interleaved across all bands
  to exploit frequency diversity and provide
  robustness against multi-path and interference.
• 60.6 ns cyclic prefix provides robustness against
  multi-path even in the worst channel
  environments.
• 9.5 ns guard interval provides sufficient time
  for switching between bands.

51
Multi-band OFDM TX Architecture

• Block diagram of an example TX architecture
• Architecture is similar to that of a conventional
  and proven OFDM system. Can leverage existing
  OFDM solutions for the development of the
  Multi-band OFDM physical layer.
• For a given superframe, the time-frequency code
  is specified in the beacon by the PNC (PicoNet
  Controller). The time-frequency code is changed
  from one superframe to another in order to
  randomize multi-piconet interference.

52
Band Plan

• Group the 528 MHz bands into 4 distinct groups
• Group A Intended for 1st generation devices (3.1
  4.9 GHz)
• Group B Reserved for future use (4.9 6.0 GHz)
• Group C Intended for devices with improved SOP
  performance (6.0 8.1 GHz)
• Group D Reserved for future use (8.1 10.6 GHz)

53
802.15.4a alternate PHY for 802.15.4

• Addresses the following
• Globally deployable
• Compatible / interoperable with 802.15.4
• Longer range
• Higher reliability
• Ranging/localization support
• Lower latency support for mobility
• Low cost
• Current UWB systems not quite suitable
• 90 nm CMOS is expensive, 200 mW is a lot of power
  
• Still in early stages
• Proposals due Jan. 2005!
• DS-UWB a major contender (Motorola)
• Chirp Spread Spectrum another cool tech
  (Nanotron)
• Many axes for diversity Basic tech (2.4 v. UWB),
  ranging (UWB v. CSS v. Phase-based ranging),
  pulse shapes, channel arbitration (CSMA v. CDMA)

54
Outlines

• Introduction
• The history of UWB
• UWB Regulations (FCC Rules)
• UWB signals
• Standards of IEEE 802
• The Application of UWB

55
The Application of UWB

• Ultra-wideband is the contortionist of the
  wireless world it is flexible enough to work in
  many different ways while still maintaining its
  character.
• These applications are distributed amongst three
  categories
• Communications and sensors
• Position location and tracking
• Radar

56
The Application of UWB
Single and multi-family dwelling residents who
have at least one of the following configurations
in their dwellings

• Remote control for
• Multimedia PC with interactive gaming options
• Consumer devices like,TV (w internet
  access),Home Theatre, video gaming console, DVD
  player,STB, DVCR, Home Stereo, TiVo
• Interconnectivity between devices (Tomoguchis,
  Gameboys, etc.)
• Home security, home automation or HVAC systems
  (sensors, control units)
• Illumination control (light switches, spot light
  control)
• Small Office/Home Office (SOHO) control of
• multimedia presentations
• conference rooms
• training rooms
• automation or control functions
• Industry applications for control and
  surveillance
• Healthcare industry for monitoring and wearable
  sensors, patient monitoring

Source doc. IEEE 802.15-01/036r0
57
Source Walter Hirt, Dennis L. Moeller, "The
Global View of a Wireless System Integrator,"
International Symposium on Advanced Radio
Technologies (ISART), Boulder, CO, USA, 4-6 March
2002
58
3G and beyond
4G
POTENTIAL FOR UWB
59
Potential Application Scenarios
Intelligent Wireless Area Network (IWAN) ?
Wireless Body Area Network (WBAN) ?
? Hot-spot Wireless Personal Area Network (WPAN)
Sensor, Positioning, and Identification Network
(SPIN) ?
Outdoor Peer-to-Peer Networking (OPPN) ?
60
UWB Consumer Applications
Freescale Semi.
Home Entertainment
Mobile Devices
Computing
Automotive
61
Entertainment Applications

• Connect between sources and displays
• Drivers are wire elimination for installand
  freedom of component placement
• Requirements
• Bandwidth
• Each MPEG2 HD Stream 20-29 Mbps
• Two full rate streams required for PIP
• Handheld can be used for PIP viewingor channel
  surfing (SD stream)
• Range
• Media center to display or handheld
• Anywhere in the room (lt10m)
• QoS with low latency
• Channel change, typing, gamers
• Available Now both SD and HD

62
Content Transfer Mobile Devices

• Applications
• Smartphone/PDA, MP3, DSC
• Media Player, Storage, display
• Requirements
• Mobile device storage sizes
• Flash 5, 32, 512, 2048 MB
• HD 4, , 60 GB
• Range is near device (lt 2m)
• User requires xfer time lt 10s

Low Power Use Cases
Images from camera to storage/network
MP3 titles to music player
Low Power High Data Rate Use
Exchange your music data
MPEG4 movie(512 MB) to player
Print from handheld
Mount portable HD
63
Content Streaming
Use Cases

• Applications
• Digital video camcorder (DVC)
• Smartphone/PDS, Media player
• Requirements
• Range is in view of display (lt 5m)
• DV Format 30 Mbps with QoS
• MPEG 2 at 12-20Mbps
• Power budget lt 500 mW

Stream DV or MPEGDS-UWB is just a shift register
Stream presentationfrom Smartphone/PDA to
projector
Channel surf and PIP to handheld
64
References

• 1 K. Siwiak and D. McKeown, Ultra-Wideband
  Radio Technology, Wiley UK, 2004.
• 2 Mohammad Ghavami, Lachlan Michael, Ryuji
  Kohno. Ultra-Wideband Signals and Systems in
  Communication Engineering, John Wiley Sons,
  Ltd, 2004.
• 3M.-G. Di Benedetto and G. Giancola,
  UnderstandingUltra Wide Band radio Fundamentals,
  Prentice Hall, 2004.
• Ian Oppermann. UWB Theory and Applications. John
  Wiley Sons, Ltd., 2005.
• 4 Xiaomin Chen and Sayfe Kiaei, "Monocycle
  Shapes for Ultra Wideband System, IEEE
  International Symposium on Circuits and Systems,
  vol. 1, pp. 597-600,May 2002.