Doc.: IEEE 802.15-04/140r12 Submission March 2005 Kohno NICT, Welborn Freescale, Mc Laughlin decaWave Slide 1 Project: IEEE P802.15 Working Group for Wireless

March 2005

Kohno NICT, Welborn Freescale, Mc Laughlin decaWaveSlide 1

doc.: IEEE 802.15-04/140r12

Submission

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)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 ]Connector’s 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)[email protected], [email protected], [email protected] ]Source: [Michael Mc Laughlin] Company [decaWave, Ltd.]Voice:[+353-1-295-4937], FAX: [-], E-Mail:[[email protected]]Source: [Matt Welborn] Company [Freescale Semiconductor, Inc]Address [8133 Leesburg Pike Vienna, VA USA]Voice:[703-269-3000], E-Mail:[matt.welborn @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.

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Overview

• The DS-UWB proposal– Proposal overview– Comments of voters– Scaling for the future – new UWB rules

• Your support for the TG3a standard

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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 (>1.5 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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

DS-UWB Operating Bands

• 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

3 4 5 6 7 8 9 10 11

Low Band

3 4 5 6 7 8 9 10 11

High Band

GHz GHz

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Data Rates Supported by DS-UWB

55 MHz24½28 Mbps

110 MHz12½55 Mbps

220 MHz6½110 Mbps

440 MHz3½220 Mbps

660 MHz2½330 Mbps

660 MHz2¾500 Mbps

660 MHz21 660 Mbps

1320 MHz1¾1000 Mbps

Symbol RateCode LengthFEC RateData Rate

(Similar Modes defined for high band – up to 2 Gbps)

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Range for 110 and 220 Mbps

Channel Model

90% outage range

110Mbps

90% outage range

220Mbps

AWGN 23.4m 16.5m

CM1 14.0m 9.7m

CM2 11.9m 8.1m

CM3 12.4m 7.9m

CM4 11.8m 7.4m

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Range for 500 and 660 Mbps

Channel Model

500Mbps 90% outage

range

660Mbps 90% outage

range*

AWGN 8.5m 9.1m

CM1 4.3m 4.2m

CM2 3.7m 3.2m

•This result if for code length = 1, rate ½ k=6 FEC•Additional simulation details and results in 15-04-483-r5

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

Environment Range Criteria

AWGN 5.3 m Mean

Low band CM1 1.7 m 85% Outage

Low band CM1 2.7 m 90% Mean

Low band CM 6*

(3 ns RMS delay spread)

2.2 m

3.3 m

90% Outage 90% Mean

High band CM1 2 m 90% Outage

High band CM2 1 m 90% Outage*CM 6 is a modification of CM1 with 3 ns RMS delay spread – details in doc 05/051r1

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Concerns with the DS-UWB Proposal

• Only four “No” voters submitted comments– Concerns of others have apparently been resolved or they

simply don’t 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 doesn’t 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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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?”

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Continuous power now get stacked into a more powerful burst

Shared Duty Cycle Operation for Single Applications

1 ms

TVApplication 1

Old Regulation – RMS of Any Burst Below LimitScaling to long range requires lower rate – and uses more of the channel

1 ms Integration Time

TVApplication

1

+6 dB

FCC Hard Limit is

Peak in 50 MHz RBW

-41.25 dBm/MHz RMS over 1ms Power limit

-41.25 dBm/MHz RMS over 1ms Power limit

New Regulation – Burst Can Go Above Limit According To Duty Cycle(RMS over 1ms must be below limit) Longer range is now possible

Same Application: scale to longer range by trading lower data rate for range

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Shared Duty Cycle Operation for Multiple Applications

1 ms

-41.25 dBm/MHz Power limit

TVApplication 1

MP-3Application 2

Hard DriveApplication 3

ProjectorApplication 4

Old Regulation – RMS of Each Burst Below Limit

1 ms

-41.25 dBm/MHz Power limit

TVApplication

1

MP-3Application 2

Hard DriveApplication 3

ProjectorApplication 4

+6 dB

New Regulation – Bursts to each receiver must meet RMS over 1ms limit

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Shared Duty Cycle Operation for UWB Applications

1 ms Integration Time

+6 dB

-41.25 dBm/MHz RMS over 1ms Power limit+10 dB

TVApplication

1

TVApp1

TVApplication

1

• 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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

Typical Output Waveforms (at pin) for DS-UWB Transmit Pulse Generator

L=24

L=6

L=2

L=1

Code Length

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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 L=6 to L=2 to L=1 (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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

March 2005


doc.: IEEE 802.15-04/140r12

Submission

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

Documents

Doc.: IEEE 802.15-04/140r12 Submission March 2005 Kohno NICT, Welborn Freescale, Mc Laughlin decaWave Slide 1 Project: IEEE P802.15 Working Group for Wireless