040626r3

1
Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
DS-UWB Proposal Update Date Submitted
Januuary 2005 Source Ryuji Kohno(1), Hiroyo
Ogawa(1), Honggang Zhang(2), Kenichi Takizawa(1)
Company (1)National Institute of Information
and Communications Technology (NICT) NICT-UWB
Consortium (2) Create-Net Connectors  Address
(1)2415E. Maddox Rd., Buford, GA 30519,USA,
(2)3-4, Hikarino-oka, Yokosuka, 239-0847, Japan
(3) Via Soleteri, 38, Trento, Italy
Voice(1)81-468-47-5101, FAX
(1)81-468-47-5431, E-Mail(1)kohno_at_nict.go.jp,
honggang_at_create-net.it, takizawa_at_nict.go.jp
Source Michael Mc Laughlin Company
decaWave, Ltd. Voice353-1-295-4937, FAX
-, E-Mailmichael_at_decawave.com Source Matt
Welborn Company Freescale Semiconductor,
Inc Address 8133 Leesburg Pike Vienna, VA
USA Voice703-269-3000, E-Mailmatt.welborn
_at_freescale.com Re Abstract Comment
resolution and technical update on DS-UWB (Merger
2) Proposal Purpose Provide technical
information to the TG3a voters regarding DS-UWB
(Merger 2) Proposal Notice This document has
been prepared to assist the IEEE P802.15. It is
offered as a basis for discussion and is not
binding on the contributing individual(s) or
organization(s). The material in this document is
subject to change in form and content after
further study. The contributor(s) reserve(s) the
right to add, amend or withdraw material
contained herein. Release The contributor
acknowledges and accepts that this contribution
becomes the property of IEEE and may be made
publicly available by P802.15.
2
Overview

• The DS-UWB proposal
• Proposal overview
• Comments of voters
• Scaling for the future new UWB rules
• Your support for the TG3a standard

3
Key Features of DS-UWB

• Based on true Ultra-wideband principles
• Large fractional bandwidth signals in two
  different bands
• Benefits from low fading due to wide bandwidth
  (gt1.5 GHz)
• Best relative performance at high data rates
• An excellent combination of high performance and
  low complexity for WPAN applications
• Support scalability to ultra-low power operation
  for short range very high rates using
  low-complexity implementations
• Performance exceeds the Selection Criteria in all
  aspect
• Better performance and lower power than any other
  proposal considered by TG3a
• Excellent basis for operation under gated UWB
  rules

4
DS-UWB Operating Bands
Low Band
High Band
3
4
5
6
7
8
9
10
11
3
4
5
6
7
8
9
10
11
GHz
GHz

• Each piconet operates in one of two bands
• Low band (below U-NII, 3.1 to 4.9 GHz) Required
  to implement
• High band (optional, above U-NII, 6.2 to 9.7 GHz)
  Optional
• Different personalities propagation
  bandwidth
• Both have 50 fractional bandwidth
• Each band supports up to 6 different piconets

5
Data Rates Supported by DS-UWB
(Similar Modes defined for high band up to 2
Gbps)
6
Range for 110 and 220 Mbps
7
Range for 500 and 660 Mbps

• This result if for code length 1, rate ½ k6
  FEC
• Additional simulation details and results in
  15-04-483-r5

8
Performance at High Rates (1 Gbps)

• DS-UWB has multiple modes (with FEC) supporting
  1 Gbps (2 bands)
• Simulations in different AWGN and multipath
  channel conditions
• This is the only proposal considered by TG3a that
  has demonstrated the capability to satisfy this 1
  Gbps requirement from the SG3a CFAs TG3a
  Requirements Document
• No MIMO or higher order modulation (e.g. 16-QAM)
  is required

CM 6 is a modification of CM1 with 3 ns RMS
delay spread details in doc 05/051r1
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DS-UWB The Best Solution

• We have presented a proposal superior to any
  others considered by TG3a
• Lower complexity
• Higher performance
• Satisfies all 15.3a applications requirements to
  1 Gbps
• Scalable to other application spaces and
  regulatory requirements
• Multi-Gbps for uncompressed video/transfer
  applications
• Low rate/low complexity applications many
  DS-type approaches are under consideration by
  TG4a
• Compliant with all established regulations
  proposed regulations
• Lowest interference effects for other systems
• OOB emissions well below any proposed limits
• Capability to support other regulatory
  restrictions

10
Concerns with the DS-UWB Proposal

• Only four No voters submitted comments
• Concerns of others have apparently been resolved
  or they simply dont care to participate in the
  process
• Most comments submitted had previously been
  addressed
• Compliance with unknown regulations, lack of
  industry support, etc.
• Some were demands over and above TG3a
  requirements
• Your Gbps mode doesnt work well enough for me
• I require proof from real demonstrations, etc.
• We have demonstrated that DS-UWB meets or exceeds
  all TG3a requirements and outperforms all other
  proposals previously considered

11
Recent Regulatory Activity

• Summary of FCC waiver grant
• Implications of these changes for DS-UWB
• Performance benefits for DS-UWB and 15.3a
• Characteristics of DS-UWB that support operation
  under gated UWB provisions
• Significant performance benefits for DS-UWB

12
FCC Waiver Grant for Frequency Hopping and
Gating UWB

• FCC waiver-grant removes transmit power penalty
• Old rule forced UWB devices to transmit
  continuously during compliance test
• But NO UWB device actually transmits continuously
• MB-OFDM hops
• DS-UWB and others are gated on and off
• Forcing continuous transmissions artificially
  penalized all UWB devices
• They appeared to be emitting much more power
  during the test than they actually do in practice
• FCC waiver grant for hopped gated UWB changes
  compliance test now to be done in normal mode
• This captures the true power emissions with no
  penalty
• Allows higher transmitter power
• The waiver-grant is technology neutral
• The change applies to ALL UWB devices
• Applies to both frequency hopping (MB-OFDM) and
  gated (DS-UWB) systems

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The Long-Term Impact for UWB Technology TG3a

• Scaling technology and application requirements
• Higher rates for new applications
• Bigger files, higher image resolution, more data
  in less time
• PHY needs to go faster
• More devices and applications in the same space
• Increased network capacity
• Smaller/lower power/lower cost
• How will Gated UWB technology enable this
  scaling to meet future application requirements?
• What fundamental approaches to UWB system design
  will be most effective for gated UWB benefits?
• Depends on waveform and network characteristics

14
Understanding the Impact of Gated UWB

• Misconceptions
• This gating is no different than the normal
  rate-versus-range scaling we already use
• Any waveform can benefit equally from gated
  operation
• You just have to turn it on and off fast, right?

15
Shared Duty Cycle Operation for Single
Applications
-41.25 dBm/MHz RMS over 1ms Power limit
Same Application scale to longer range by
trading lower data rate for range
TV Application 1
1 ms
Old Regulation RMS of Any Burst Below
Limit Scaling to long range requires lower rate
and uses more of the channel
New Regulation Burst Can Go Above Limit
According To Duty Cycle (RMS over 1ms must be
below limit) ? Longer range is now possible
FCC Hard Limit is Peak in 50 MHz RBW
6 dB
-41.25 dBm/MHz RMS over 1ms Power limit
TV Application 1
Continuous power now get stacked into a more
powerful burst
1 ms Integration Time
16
Shared Duty Cycle Operation for Multiple
Applications
-41.25 dBm/MHz Power limit
TV Application 1
MP-3 Application 2
Hard Drive Application 3
Projector Application 4
1 ms
Old Regulation RMS of Each Burst Below Limit
New Regulation Bursts to each receiver must
meet RMS over 1ms limit
-41.25 dBm/MHz Power limit
6 dB
TV Application 1
MP-3 Application 2
Hard Drive Application 3
Projector Application 4
1 ms
17
Shared Duty Cycle Operation for UWB Applications
-41.25 dBm/MHz RMS over 1ms Power limit
10 dB
6 dB
TV App1
TV Application 1
TV Application 1
1 ms Integration Time

• New regulations for gating provide system
  flexibility
• Multiple ways to send same data over same range
• Each has same total energy emitted into the air,
  but
• Higher data rates allow more total network
  capacity
• Also enables lower power solution for handheld
  applications
• Gated operation can deliver lower overall power
  consumption

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Summary of Gated UWB Operation

• Provides system with significant flexibility to
  trade-off transmit duty cycle and power
• Enables better range and robustness for existing
  applications
• Enables significant increases in network capacity
• Results in same UWB energy emissions for a given
  data transmission

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This Ruling to Allow Gated UWB will Change UWB
Forever

• Represents a change in fundamental UWB system
  design trade-offs
• Significant incentive for designers to use lower
  duty cycle to increase transmit power
• Increases network capacity for free
• Requires scaling to higher data rates to enable
  low duty cycle
• All waveforms do not benefit equally from the
  gated UWB provisions
• Requires scaling to higher data rates without
  loss of efficiency or performance
• There are key system-level issues that need to be
  examined to understand gated UWB
• DS-UWB is ideally suited to support gated UWB
  operation and benefit from the many system-level
  advantages it can provide

20
Technology Issues for Gated UWB

• PHY layer issues
• Scalability to higher peak-to-average power
  levels
• Both regulatory and implementation aspects
• MAC layer issues
• Requires efficient coordination of
  shared-duty-cycle devices
• System level issues
• Scalability to much higher data rates the
  Sweet Spot for gated UWB network performance

21
PHY Layer Issues for Gated UWB

• Regulatory requirements to limit peak UWB power
• UWB signals are still limited to the same peak
  power limits under FCC rules
• Waveforms that have high peak power (e.g. low PRF
  pulsed signals) will be peak-limited and cannot
  use gating
• Exact degree of benefit depends on specific
  waveform
• Peak-limited waveforms are prevented from
  gating
• Example waveform with only 2 dB of margin to
  peak limit
• Can only increase peak power by 2 dB before
  reaching limit
• Only minimal benefit could be obtained from
  gating provisions
• TG must carefully analyze the peak levels needed
  for any particular waveform

22
PHY Layer Issues for Gated UWB

• Scalability to higher peak-to-average power
  levels is critical for efficient implementation
• Peak power levels required to generate transmit
  waveform are different for different waveforms
• Low-PRF pulsed signals (for example) have
  relatively high peak levels
• Any waveform that already has high peak
  requirements could preclude efficient operation
  as a gated UWB system
• DS-UWB is designed to be a low peak-to-average
  waveform

23
Typical Output Waveforms (at pin) for DS-UWB
Transmit Pulse Generator
Code Length
L24
L6
L2
L1
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DS-UWB Designed for Low Peak Power

• DS-UWB is designed to be a low peak-to-average
  waveform
• Peak-to-average is close to that of a sine wave
  at lowest rates (3 dB)
• Peak-to-average power ratio actually scales lower
  as code lengths get shorter from L6 to L2 to
  L1 (as data rates get higher)
• Becomes essentially a constant envelope signal
• Would still be low if scaled to 2 Gbps PHY burst
  rate (e.g. QPSK)
• DS-UWB is ideal for use in a gated UWB system
• Minimizes the need to generate high-peak transmit
  signals simplifies implementation
• Could support very low duty cycle ( higher Tx
  power) before reaching FCC peak power limits
• Maximized potential benefit from gated UWB
  operation
• Other waveforms that use lower pulse rates or
  high order modulation will have much higher
  peak-to-average power ratios

25
MAC Layer Issues for Gated UWB

• Benefits of gated UWB provisions requires
  efficient coordination of shared-duty-cycle
  devices
• The 802.15.3a MAC is already designed to provide
  efficient coordination of devices using TDMA
• Centralized MAC architectures can provide easy
  solutions for low duty-cycle transmission
  scheduling
• Overhead of MAC (beacons, acknowledgements, etc)
  can also benefit from shorter transmission times
• Operation at higher data rates requires careful
  control of overhead to ensure efficient network
  performance

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Key System Level Issue Scalability

• Scalability to much higher data rates is
  essential to realize the benefits of low duty
  cycle operation
• This is the Sweet Spot for gated UWB
  performance
• Allows increased network capacity
• Like creating free additional spectrum
• Support more applications with little impact to
  network
• Without sacrificing power efficiency
• Higher Eb/No requirements preclude benefits of
  gating
• Ultimate scalability depends on instantaneous
  signal bandwidth

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The Advantages of Higher Data Rates

• The new provisions for gated UWB systems create
  an even greater advantage for high rate systems
• Before, only applications that needed highest
  rates at short range were affected by
  effectiveness of high rate modes
• High speed file transfer, uncompressed video,
  etc.
• Now, every application can be improved through
  the use of efficient high rate modes
• Those requiring longer ranges operate at lower
  duty cycle and send the same data in less time
• As UWB technology matures, systems will be
  designed to transfer data at highest supported
  data rates
• Maximizes network capacity for supporting more
  applications
• No transmit power penalty range trade-off is
  completely changed
• Technologies that do not scale will be left
  behind or will be limited in their ability to
  provide the performance

28
Requirements for Benefits of Gated UWB

• There are fundamental differences between PHY
  waveforms due to bandwidth and modulation choices
  
• Some will be more effective for gated operation,
  others will not
• PHY must provide baseline low peak power
  operation
• PHY must scale to higher transmit peak power
  operation
• Without complex implementation or precluding CMOS
  
• Without performance degradation due to clipping
  or non-linearities
• PHY must scale effectively to high data rates (1
  Gbps)
• Without increasing peak power levels (QAM or more
  carriers)
• Without sacrificing modulation power efficiency
  (e.g. 16-QAM/PSK)
• Without sacrificing frequency diversity and
  resulting in degraded performance due to
  multipath fading

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Numerous Future Benefits to DS-UWB from Gated UWB
Operation Stay Tuned

• Higher network capacity as technology scales
• Support more applications and longer ranges
• Better ranging performance
• Using higher SNR improves DLOS path detection
• Higher SNR during preamble
• Simplifies acquisition rake/equalizer training
• All the same benefits to DS-UWB for controlling
  transmit spectrum using pulse shaping
• No TX-RX coordination is required to change band
  or tone mapping
• Improved performance against narrowband
  interference
• Simple mechanism to increase signal to
  interference power
• Equivalent to using lower data rate with more
  processing gain
• Scaling to even higher data rates
• 2 Gbps or more in low band, even higher in 6-10
  GHz band
• Limitation is signal bandwidth since transmit
  power can increase

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DS-UWB is ready to Benefit from Gated UWB Ruling

• Inherently provides low peak power operation
• Scalable to higher peak power without sacrificing
  efficiency or excessive complexity
• Scalable to higher data rates to support
  applications with low duty cycle
• 15.3 MAC that supports requirements for efficient
  gated UWB operation

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Conclusions Your Support

• DS-UWB technology provides the best design for
  TG3a to be a successful standard
• The recent ruling to allow gating has
  fundamentally changed the UWB landscape
• DS-UWB is uniquely situated to benefit
• We invite your support for DS-UWB during the
  confirmation vote on Wednesday