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IEEE 802.15 <subject>

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Submission Title: [Time Domain s Proposal for UWB Multi-band Alternate Physical Layer for 802.15.3a] Date Submitted: [8 March, 2003] Source: [Joy Kelly] Company ... – PowerPoint PPT presentation

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Title: IEEE 802.15 <subject>


1
Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
Time Domains Proposal for UWB Multi-band
Alternate Physical Layer for 802.15.3a Date
Submitted 8 March, 2003 Source Joy Kelly
Company Time Domain Corporation Address 7057
Old Madison Pike, Huntsville, AL 35802
US Voice256-428-6576, FAX 256-428-6785,
E-Mailjoy.kelly_at_timedomain.com Re 802.15.3a
Call for Proposals Abstract This presentation
summarizes Time Domains UWB Multi-band proposal
for the 802.15.3a Alternate PHY
standard. Purpose The presentation responds to
the Call for Proposals issued by TG 802.15.3a, in
consideration for the 802.15.3 Alternate PHY
standard. 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
Time Domain Corporation Proposal for UWB
Multi-band Alternate Physical Layer for TG
802.15.3a
3
Key Features of TDCs Multi-band Solution
  • Efficient spectrum use
  • Enables a world-wide WPAN standard
  • Enables dynamic response to
  • Narrowband interference
  • Harsh multipath environments
  • Simple Signaling scheme
  • Low complexity
  • Low power
  • Provides 6 independent channels
  • Straightforward strategies to maintain link in
    harsh multipath environments
  • Graceful scalability with backward compatibility
  • Path to 1 Gb/s
  • Devices with different capability can communicate

4
Overview of Time Domains Multi-band Solution
5
TDCs Multi-band Architecture
6
Overview of UWB Solution Space
7
Flexible Spectrum Use
3.1
10.6
Sacrifice 1 band for coexistence (dependent upon
geographical location)
  • 520 MHz wide bands to best utilize spectrum
  • 437 MHz band separation
  • Adjacent band isolation 12 dB
  • Alternate band isolation is 21 dB
  • Center frequencies chosen for ease of
    implementation

8
Signal Design
  • 3.89 ns chip time
  • Rectified cosine envelope

x
9
Length 7 Time-Frequency Code
  • Time-Frequency Multiple Access (TFMA) radio
  • One frequency on the air at a time
  • Enables simplicity in receiver architecture
  • Provides low power solution

10
Time-Frequency Code Design
  • Length 7 time-frequency codes
  • At most one collision between any two length 7
    codes
  • 6 codes in family 6 piconets
  • Linear congruential design
  • Multipath tolerance (approx 27 ns)
  • Code property holds for sparsely populated
    sequences

11
Data Modulation
  • Use low order modulation for simplicity and
    reasonable dynamic range requirements
  • BPSK
  • QPSK
  • Apply modulation to carrier on a per-chip basis
  • Length 7 code (using all frequencies) yields raw
    data rates
  • 257 Mb/s for BPSK
  • 514 Mb/s for QPSK

12
Forward Error Correction (FEC)
  • Convolutional encoder
  • ½ rate optionally punctured to ¾ rate
  • Constraint length 7
  • Industry standard generating polynomials
  • Effect is to spread each bit across spectrum
  • Multi-band method with per-band modulation
    enables weighting of each frequency band in soft
    decision

13
Modulation Schemes
  • 8 modulation combinations defined
  • Fits within existing 3-bit PHY Header field

Mode 0 is base rate used for all header
/beacon / CAP signaling
14
Flexibility of Multi-band Dynamic Band
Management
  • Monitor and report per-band performance
  • Detect spectral problems, if any
  • Four categories
  • Narrowband interferer
  • Channel fading in a band
  • Nearby interfering piconet (near/far)
  • Multiple piconets in extreme multipath

15
Solution for Narrowband Interference Channel
Fading
  • Coordinate between devices (DEVs) within piconet
    to drop affected bands

Source DEV
Destination DEV
16
Solution for Nearby Interfering Piconet
Multiple Piconets in Extreme Multipath
  • TF codes provide good channel isolation
  • In extreme situations, additional isolation
    required

Near-Far Conditions
  • Activate FDMA (frequency division multiple
    access) strategy
  • Continue using same TF codes
  • Return to TFMA when conditions permit

Example CM4 CIR Plot
17
Scalability of TDC Multi-bandArchitecture
  • Very high data rates
  • Scalability and flexibility within a piconet
  • Uncoordinated piconet operation

18
Scalability Very High Data Rates
Example code
  • Codes are re-used in upper frequency group
  • Enables 14-band DEVs allowing gt 1 Gb/s raw data
    rate
  • Requires transmission and reception of two bands
    simultaneously

19
Scalability Flexibility Within a Piconet
0
1
2
3
4
5
6
0
1
2
3
4
5
6
DEV 1
0
1
2
3
4
5
6
DEV 2
Digital Camera
0
1
2
3
4
5
6
DEV 3
Hard Drive
  • Signaling design enables DEVs of different
    capability within a piconet to communicate
  • Band assessment, negotiation easily enabled via
    minimal MAC supplements
  • Enables products of varying capabilities to be
    tailored for different applications

20
Scalability Uncoordinated Piconets
  • Code collision property holds for 14 bands
  • 1 collision in 7 2 in 14
  • Each piconet is independently configured

21
Example Implementation
22
Supporting Text Key Points NotCovered in
Presentation
Key Points Page numbers
Acquisition performance and timeline (8.6 ms acquisition time) 22-23 104 - 107
MAC enhancements 49 - 56
Power consumption 125 - 133
Packet definition 20 - 26
Extensive analysis simulation results 57 - 121
23
TDCs Multi-band Performance Results
24
Summary Performance Results from Selection
Criteria
  • Link budget
  • System Performance
  • Simultaneous Operating Piconets
  • Interference Susceptibility
  • Coexistence
  • Regulatory Benefit
  • Power Consumption

25
Link Budget
  • Determined free space AWGN link budget margin for
    Multi-band radio
  • Noise figure estimated at 7 dB
  • Implementation loss estimated at 5 dB
  • Performed per-band analysis to account for
    antenna capture effects

26
Link Budget Margin7-Band Radio
Includes 7 dB NF and 5 dB For implementation
losses
MODE 5
MODE 7
MODE 0
MODE 3
27
System Performance Simulator Description
  • High-fidelity system simulation
  • Operates primarily in the time domain
  • Packet-oriented, i.e. for each packet
  • Adjusts gain
  • Thresholds preamble to acquire
  • Characterizes received signal to demodulate
  • Demodulates and check-sums Header and Payload
  • Describes an implementation model
  • 7 dB Noise Figure
  • 5-bit ADC Quantization
  • Real-time AGC algorithm
  • Realistic receive templates
  • Non-ideal channel estimation
  • Phase errors

28
System PerformanceSingle-Link Performance in
Multipath
  • Results simulated for all 400 CIRs in CMs 1-4
  • 10 distances simulated per CIR (from 24 m to 1 m)
  • 200 packets/run
  • 1024 octet payload
  • Results presented for
  • 128 Mb/s and 257 Mb/s operation
  • No rake (one-finger) and two-finger rake

29
System Performance 128 Mb/s, BPSK, ½-rate FEC
  • 7 bands (skips UNII band)
  • 100 CIRs from each of CM1 CM4
  • 200 packets
  • 7dB Noise Figure
  • Path-loss exponent of 2.0 in all cases

Average Distance at which PER 8, Best 90
Channels
20
17.7
18
16.0
15.3
16
13.6
13.3
14
Distance (m)
LOS 0 to 4
12
10.7
NLOS 0 to 4
10
NLOS 4 to 10
7.7
8
Rms 25
5.3
6
4
2
0
One RAKE Finger
Two RAKE Fingers
30
System Performance 257 Mb/s, QPSK, ½-rate FEC
  • 7 bands (skips UNII band)
  • 100 CIRs from each of CM1 CM4
  • 200 packets
  • 7dB Noise Figure
  • Path-loss exponent of 2.0 in all cases

31
Simultaneously Operating Piconets
  • Objective evaluate uncoordinated piconet
    channelization in multipath
  • N 1 interferer case examined
  • Variation in both quality of reference link and
    interfering channels impacts SOP performance
  • Important to capture both effects in analysis

32
Simultaneously Operating Piconets
Test Procedure
  • Five reference links chosen from each channel
    model, based on the quintiles of system
    performance results
  • Reference link distance (dref) was half the 8
    PER distance (notionally giving 6 dB margin)
  • Each reference link was tested against 60
    interfering links (15 from each CM)
  • Interfering link distance (dint) was varied from
    2 dref to dref /8
  • PER was recorded as a function of the ratio of
    dint to dref

33
Simultaneously Operating Piconets Reference link
freespace
PER
IntDist/RefDist
For 8 PER, dint / dref .37
34
Simultaneously Operating Piconets Reference link
freespace, 15 m
For 8 PER , average dint / dref for CM 1 - 3
.49

35
Simultaneously Operating Piconets
Reference link
POOR
GOOD
FAIR
PER
IntDist/RefDist
For 8 PER , average dint / dref for CM 1 - 4
0.38
36
Simultaneously Operating Piconets
Reference link
GOOD
POOR
FAIR
PER
IntDist/RefDist
For 8 PER, average dint / dref for CM 1 - 4
0.75
37
Simultaneously Operating Piconets
Reference link
GOOD
FAIR
POOR
PER
IntDist/RefDist
at 8 PER, average dint / dref for CM 1 - 2 1.75
38
Interpretation of Simultaneously Operating
Piconet Analysis
  • Quality of reference link has more impact on SOP
    performance than nature of interfering channel

Average 8 PER Distance Ratios from Simultaneously Operating Piconet Test Average 8 PER Distance Ratios from Simultaneously Operating Piconet Test Average 8 PER Distance Ratios from Simultaneously Operating Piconet Test Average 8 PER Distance Ratios from Simultaneously Operating Piconet Test
Reference Link, System Performance Rank Interfering link from Interfering link from Interfering link from
Reference Link, System Performance Rank CM1 CM2 CM3
100th percentile 0.38 0.64 0.60
60th percentile 1.4 1.15 1.63
20th percentile 1.65 1.55 ---------
39
Strategies for Harsh Environments
  • For significant fading on bands, drop the faded
    bands
  • For very severe multipath and/or near-far
    scenarios, use FDMA
  • ?Both strategies yield dramatic improvement in
    SOP performance

40
Simultaneously Operating Piconets
Performance in harsh environments before dropping
weak bands
PER
IntDist/RefDist
For 8 PER, average dint / dref for CM 1 - 4 1.6
41
Simultaneously Operating Piconets
Performance in harsh environments after dropping
weak bands
Num. Bands Modulation Data Rate Reference
Link Interfering Links N 1 interferer
4 (0, 2, 6, 7) BPSK, ½-rate FEC 73 Mb/s CM1, CIR
40 CMs 1-4, CIRs 81-95 (interferer still
transmitting on all bands)
PER
IntDist/RefDist
For 8 PER, average dint / dref for CM 1 - 4
0.85
42
Simultaneously Operating Piconets
Performance in harsh environments after FDMA
Num. Bands Modulation Data Rate Reference
Link Interfering Links N 1 interferer
4 (0, 2, 6, 7) QPSK, ½-rate FEC 147 Mb/s CM1, CIR
40 CMs 1-4, CIRs 81-95 (interferer transmitting
on bands 1, 3, 5)
PER
IntDist/RefDist
For 8 PER, average dint / dref for CM 1 - 4
0.38
43
Simultaneous Operating Piconets Simulation
Results Summary
  • Time-frequency codes provide 8-10 dB piconets
    isolation in freespace
  • Multipath decreases piconet isolation
  • Piconet isolation enhanced by dropping severely
    faded bands
  • FDMA techniques are employed in near/far and
    severe multipath scenarios

44
Interference Susceptibility Analysis
  • Assessed interference susceptibility to following
    devices
  • Specific devices
  • IEEE 802.11 a, IEEE 802.11 b, IEEE 802.15.4,
    Bluetooth, Microwave oven
  • Generic devices
  • In-band tone and modulated interferers
  • Models of each interferer included in simulation
  • Interference rejection factors determined for
    specific interferers
  • For generic in-band interferers, performance
    measured after interfered band dropped
  • Some interference impact due to receive
    templates side-lobes from other bands

45
Interference Rejection Factors for Specific
Devices
46
Coexistence
  • UWB impact on 802.11a, 802.11b, 802.15.1,
    802.15.3, and 802.15.4 assessed
  • AWGN analysis
  • Analyzed UWB impact to victim receivers noise
    floor
  • Determined 802.15.3a Coexistence Mask
  • Assessed filtering required for waveforms to meet
    coexistence mask

Multi-band approach naturally reduces emissions
in the selected band and reduces additional
filtering needs
47
Coexistence Mask
FCC Handheld Emissions Mask
ISM minimum criteria coexistence met
EIRP (dBm/MHz)
UNII notch for minimum criteria coexistence
UNII notch for desired criteria coexistence
ISM notch for desired criteria coexistence
Frequency (GHz)
48
Tx Filtering to Meet Coexistence Criteria
  • Coexistence criteria in ISM band met with no
    additional attenuation
  • All UNII coexistence criteria met with less than
    3dB additional attenuation
  • Negligible effect on link budget performance

49
Regulatory Benefit
  • Multi-band approach accommodates regulatory
    requirements of virtually any worldwide region
  • Proposed PHY conforms to all regions adopting US
    FCC UWB regulations
  • Waveform and band definitions meet both indoor
    and handheld masks
  • Proposed PHY meets projected regulatory
    requirements of Europe and Japan

50
Power consumption
Power Mode Activity Power Consumption
Idle On state awaiting Tx and Rx commands 100 mW
Tx/Rx Prep Preparing for Tx or Rx, programming registers 80 mW
Active Rx Receiving _at_ 128 Mbit/sec 275 mW
Active RX Receiving _at_ 257 Mbit/sec 325 mW
Active Tx Transmitting ( any data rate ) 190mW
CCA Clear channel assessment 225 mW
Power save Power save mode 30 mW
51
Conclusions
  • Time Domains Proposal
  • Achieves data rate and range requirements
  • Enables low complexity, low power solution
  • Exceeds channelization (6 channels)
  • Supplies robustness mechanisms for harsh
    environments
  • Provides flexibility in spectrum use
  • Defines growth path via number of bands
  • Requires minimal MAC supplements

Our proposed architecture enables full potential
of UWB for worldwide marketplace with
simplicity, flexibility, and great performance
52
802.15.3a Early Merge Work
Time Domain will be cooperating with
Intel Discrete Time General Atomics
Wisair Philips FOCUS Enhancements
  • Objectives
  • Best technical solution
  • ONE solution
  • Excellent business terms
  • Fast time to market

We encourage participation by any party who can
help us reach these goals.
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