Doc.: IEEE 802.15-05-0006-00-004a Submission Rick Roberts (Harris Corporation) Project: IEEE P802.15 Working Group for Wireless Personal Area Networks

Rick Roberts (Harris Corporation)

doc.: IEEE 802.15-05-0006-00-004a

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: [Harris TG4a CFP Proposal Response]Date Submitted: [“January 2005”]Source: [Rick Roberts] Company [Harris Corporation]Address [MS 1/9842, Box 37, Melbourne, Fl. 32902-0037]Voice:[321-729-3018], FAX: [], E-Mail:[[email protected]]

Re: [Harris TG4a response to call for proposals.]

Abstract: [Harris TG4a response to call for proposals]

Purpose: [For presentation and consideration by the IEEE802.15.4a committee]

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.


doc.: IEEE 802.15-05-0006-00-004a

Submission

Hybrid UWB/UNB Communications with Ranging

Four Classes of Devices

Class 1 – Low Complexity UWB for Communications with Ranging

Class 2 – Backwards Compatible UWB with RFI Protection

Class 3 – UWB/UNB with propagated node into GPS denied areas

Class 4 – High Precision UWB for Ranging with Communications


doc.: IEEE 802.15-05-0006-00-004a

Submission

Class 1 UWB Communications with Ranging

AC AC

wireless thermostat

apartment 1 apartment 2

Range Assisted Addressing


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Submission

Class 2 RFI Protected UWB Communications with Ranging

GPS Equipped Truck

Synthetic TriangulationAllows Precise Localization

Mobile Meter Reader Example


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Submission

Public Safety Application propagated node into GPS denied area

30 m

20 m

20 m

50 m

command post

UWB

802.11

802.11

802.11

Back ChannelOut-of-scope(non-ranging)

NFER

Class 3 UWB/UNB with propagated node into GPS denied areas


doc.: IEEE 802.15-05-0006-00-004a

Submission

Mandatory UWB PHY


doc.: IEEE 802.15-05-0006-00-004a

Submission

• Direct Sequence Spread Spectrum• -3 dB Bandwidth (each band): 666.7 MHz• Center Frequencies: Every 250 MHz (3.6 GHz to 10.1 GHz)

3.1 GHz 10.6 GHz

26 possible overlapping bands

• Pulse Response: Root Raised Cosine, 25% Excess Bandwidth

Fc +250

+333.3

+416.6

Fc(-3 dB)=333.3 MHz

3.6 GHz10.1 GHz

Noise Bandwidth (NBW) = 666.6 MHz

Frequency Plan


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Submission

Advantages of Multiple frequency bands• Allows coarse spectral shaping for ingress/egress RFI avoidance• Allows multi-user separation by frequency channels• Allows implementation of lower frequency bands in today’s CMOS

3.1 GHz

3.6 GHz

interference

Interference avoided by skipping a frequency band


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Submission

Narrower Bandwidth, Spectrally Shaped UWB, Offers Advantages

• Spectral Shaping Results in more NBW which means more TX power• 25% Excess BW, Raised Cosine Pulse

• -10 dB bandwidth: 708 MHz• NBW: 667 MHz

• Gaussian Pulse• -10 dB bandwidth: 708 MHz• NBW: ~388 MHz

• Raised Cosine Pulse Power Advantage: ~2.35 dB • More power, better controlled spectrum

• Wider Wavelets offer implementation advantage• Less complexity if a RAKE is deployed• 666.6 MHz of bandwidth still offers good multipath resolution


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Submission

Spectral Shaping within a frequency channel

• “delay and add” notch formation

• delay may be either a delay line or second impulse generator

t0 t1

f

f


doc.: IEEE 802.15-05-0006-00-004a

Submission

CDMA spread spectrum within each frequency channel

• Chipping rate 666.6 Mcps, 25% root raised cosine, Nyquist filtering

• Bit Rate (Rb) options (1 bit per symbol)• Coherent: 1 Mbps, 500 Kbps, 250 Kbps, 125 Kbps• Non-Coherent: 62.5 Kbps• Symbol Duration >> Delay Spread (shouldn’t need DFE)

• Number of chips per bit• 1 Mbps: 666• 500 kbps: 1332• 250 kbps: 2664• 125 kbps: 5328 • 62.5 Kbps: 10656

• Actual codewords are TBD (ternary symbols: +1, -1, 0)

• Processing gain (PG): 28.2 dB to 40.3 dB• PG = 10*log10(NBW/Rb) = 10*log10(666.6e6/Rb)


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Submission

Advantages of high chipping rate

• Minimizes the time waveform peak to average ratio

• Each individual chip has low amplitude (integrated in the receiver)

• Ternary codes: number of active chips per symbol is TBD

• Enables high degree of integration on low voltage CMOS

• Large code space allows selection of a number of good codes

• Ternary codes are best for low cross-correlation• Time hopping codes are a possibility

• Having a large number of codes allows code hopping multiple access


doc.: IEEE 802.15-05-0006-00-004a

Submission

Peak-to-Average: high chip rate vs. low chip rate

• For Equal TX Output, low chipping rate has a higher peak power and the high chipping rate has a lower peak power

• Lower peak power is easier to integrate into low voltage semiconductor process

Low Chip Rate Peak

High Chip Rate Peak


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Submission

SOP (Simultaneous Operating Piconets)

Two Methods to Accommodate SOP:

1. Multiple Frequency Channels (FDMA)

2. Within a frequency channel, use code division multiple access (CDMA)• Each of possible 4 CDMA piconets uses a chipping rate offset• Chipping rate offset prevents static cross correlation degradation


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Submission

Acquisition Preamble

• Acquisition is strictly a function of SNR, not bit rate or symbol rate

• For a given signal strength, the longer the preamble (observation time) the more robust the acquisition (more integration results in higher SNR)

• Three preamble lengths:• Mandatory medium length preamble for normal use• Optional short preamble for higher mobility, high SNR scenarios• Optional long preamble for long range, low SNR scenarios

• Acquisition can be either a code search (traditional spread spectrum) - or – • If SNR is high enough and channel is benign enough, use of a squaring loop enables cyclo-stationary assisted acquisition (recover carrier/clock frequency from collapsed spectrum – very useful for 62.5 Kbps non-coherent OOK)


doc.: IEEE 802.15-05-0006-00-004a

Submission

Two Modulation, Demodulation Modes

1. Coherent demodulation at Rb = 125 Kbps and higher

2. OOK (on-off keying) Non-Coherent demodulation at Rb = 62.5 Kbps

Coded Wavelets

Data Source

Coded Wavelets

Analog SP Digital SP

Coded Wavelets

Data Source Analog SP Digital SP( )2


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Submission

Coherent Demodulation Receiver Architecture(applying processing gain early reduces dynamic range requirements)

BPF I&D ADC BasebandDigital

LocalCode

Generator

LocalWavelet

Generator

1 MHz


doc.: IEEE 802.15-05-0006-00-004a

Submission

OOK Non-Coherent Demodulator Receiver Architecture• useful for short range, low complexity solutions• sub-optimal solution (degrades with interference or multipath)

BPF ( )2 LPF ADC

>= 62.5 KHz Sample Rate

Fc=31.25 KHz

OOKDecoder

OffsetFrequencyCorrection

(could be done digitally)


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Submission

Optional Reed-Solomon FEC

RS(38,32), GF(8), corrects 3 symbol errors … good burst error properties

RS(38,32) AWGN Coding Gain

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

4 4.5 5 5.5 6 6.5 7 7.5

Eb/No

Pe

Theory

RS(38,32)


doc.: IEEE 802.15-05-0006-00-004a

Submission

Acquisition Characteristics

Coherent Preamble• TBD• Very Robust, Long Range Acquisition• Good in Multipath and SOP Performance• More Overhead

Non-Coherent Preamble• TBD• Less Robust, Short Range Acquisition• Poorer in Multipath and SOP Performance• Less Overhead


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Submission

Link Margin Tables (Coherent Demodulation)

Bit Rate 1.00E+06TX NBW MHz 6.67E+02TX Power -13.06095602Fc 3.50E+09Path Loss 1m 43.32313307Distance meters 30Path Loss Distance 29.54242509RX Ant Gain 0RX Power dBm -85.92651419Noise Figure 7No -167Require EbNo 7Implementation Loss 0Link Margin 14.07348581Zero Margin Range meters 151.6336347



doc.: IEEE 802.15-05-0006-00-004a

Submission

Link Margin Table (Non-Coherent Demodulation)



doc.: IEEE 802.15-05-0006-00-004a

Submission

Ranging is based upon Two Way Ranging, Time of Arrival (TWR-TOA)

Figure 2: Two Way Ranging (TWR) transaction enabling to estimate the round-trip Time-OF-Flight between two asynchronous terminals (feeding TOA-based positioning algorithms)

Received packets

A

B

TOF

TOF

ChannelAcquisition

Synchro H

Communication Payload

Preamble Acquisition Header

Tround

Response Delay

Elapsed times measured by the system


doc.: IEEE 802.15-05-0006-00-004a

Submission

Mobile (xm,ym)

Anchor 2 (xA2,yA2)

Anchor 3 (xA3,yA3)

Anchor 1 (xA1,yA1)

Positioning from TOA

3 anchors with known positions (at least) are required to retrieve a 2D-position from 3

TOAs

22

3

222

221

33

22

11

MAMA

MAMA

MAMA

yyxxd

yyxxd

yyxxd

321

~,

~,

~ddd

Measurements Estimated Position

MM yx ~,~

Specific Positioning Algorithms

Positioning from TOA


doc.: IEEE 802.15-05-0006-00-004a

Submission

MSC for TWR TOA/TDOA token exchange

The time of flight between the two devices is then calculated as

Tflight = {T1(3) - T1(0) - τ}/2

where the time epochs are defined in the figure.


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Submission

Ranging Token: TBD


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Submission

High Rate Clock

Counter start

stop

count

PHY SAP - START CLOCK COMMAND

PHY Correlator

Vthresh

Local PHY Trigger Mechanism (TBD)

High Rate PHY Clock


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Submission

Channel Model Performance

TBD


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Submission

MAC Modifications


doc.: IEEE 802.15-05-0006-00-004a

Submission

PHY PIB ranging attributes

AttributeIdentifier Type Range Description

phyRangeClockFreq 0x04 Integer 0-10000 High Rate Ranging Clock Frequency (MHz)

phyRangeCount 0x05 Integer 0-99999 Ranging Counter Count Value

phyNferFreq 0x08 Integer 0-999999 NFER Operating Frequency (KHz)

phyNferAngle 0x09 Integer 0-99999 E-H field angle, tenths of degrees

For suggested MLME primitive and parameter modifications, see document 15-04-0581-06-004a.


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Submission

Name Type Valid Range Description

SrcID Integer Any valid DEVID as defined in TBD

The device ID of the source

DestID Integer Any valid DEVID as defined in TBD

The device ID of the desti nation

Timeout Integer As defined in TBD The time limit for completion of the ranging

packet exchange.

Reason Code Integer 2 octets:first two bits indicate

if requrested RangeType is

supported(10.1.4.2)

next 11 bits indicate supported RangeTypes

(0=not supported, 1=supported)

b0,1=enumerated(as per 10.1.4.2)b2= TWR TOA

b3= TWR TOA DOUBLEb4= OWR TOA-Ab5= OWR TOA-Pb6= TWR TDOA

b7= TWR TDOA DOUBLEb8= OWR TDOA-Ab9= OWR TDOA-P

b10= SSRb11= AOAb12= NFER

b13=reservedb14=reservedb15=reserved

RangeType Integer 0 to 10(4 bits from octet)

0=TWR TOA1=TWR TOA DOUBLE

2=OWR TOA-A3=OWR TOA-P4=TWR TDOA

5=TWR TDOA DOUBLE6=OWR TDOA-A7=OWR TDOA-P

8=SSR9=AOA

10=NFER11 to 255=reserved

Name Request Indication Response Confirm

MLME-RANGE 10.1.1 10.1.2 10.1.3 10.1.4

MLME-RANGE primitive and parameters


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Submission

Optional NFER PHY


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Submission

TBD


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Submission

Optional High Precision UWB PHY


doc.: IEEE 802.15-05-0006-00-004a

Submission

High Precision UWB TOA Implies Wide Bandwidth

(Approximate) Range Resolution vs. Bandwidth (AWGN Channel)(Based on Square Root Raised Cosine Filtering)

0.01

0.1

1

10

0 500 1000 1500 2000 2500 3000

Bandwidth MHz

Re

solu

tion

Me

ters


doc.: IEEE 802.15-05-0006-00-004a

Submission

TBD

Documents

Doc.: IEEE 802.15-05-0006-00-004a Submission Rick Roberts (Harris Corporation) Project: IEEE P802.15 Working Group for Wireless Personal Area Networks