project: ieee p802.15 working group for wireless personal area networks (wpans)

July 2005

Francois Chin (I2R)Slide 1

doc.: IEEE 802.15-05-0231-07-004a

Submission

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)(WPANs)Submission Title: [Impulse Radio Signaling for Communication and Ranging]

Date Submitted: [18 July 2005]

Source: [Francois Chin, Yuen-Sam Kwok, Sai-Ho Wong, Zander Lei, Xiaoming Peng]

Company: [Institute for Infocomm Research, Singapore]

Address: [21 Heng Mui Keng Terrace, Singapore 119613]

Voice: [65-68745687] FAX: [65-67744990] E-Mail: [[email protected]]

Re: []

Abstract: [Presents signaling options to achieve precision ranging with both coherent and non-coherent receivers]Purpose: [To discuss which signal waveform would be the most feasible in terms of performance and implementation trade-offs]

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.

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Objectives

• PRF values for Mandatory and optional wider band systems

• Impulse Radio Signaling Proposal

• Common Signaling for different receivers, for Synchronisation, Ranging and Data Communications– Deterministic Pulse structures

– Optimal Receiver Code Sequences

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Minimum PRF Requirements (BW~500MHz)BW ~ 500 MHz

Technology CMOS 90nm 1.0 Vpp CMOS 90nm 1.0 Vpp

TChip (nsec) 2 2

Sequence Bipolar Ternary (equal ±1 & 0)

VPeak (v) 0.5 0.5

PAve (dBm) -14.3 -14.3

PPeak (dBm) 3.8 3.8

Chip Rate (MHz) @ VPeak ~7.75 ~15.5

PRF (MHz) @ VPeak ~7.75 ~7.75• Key Requirement is to meet CMOS Tx Vpp constraint

• For Ternary signaling– 1.0Vpp @ 15.5MHz CRF without backoff & perfect antenna – 1.2Vpp @ 15.5MHz CRF without backoff & 30% (or 1.5dB) feed loss– 1.0Vpp @ 15.5MHz CRF without 1.5dB backoff & 30% (or 1.5dB) feed loss

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Minimum PRF Requirements (BW~1.5GHz)BW ~ 1500 MHz

Technology CMOS 90nm 1.0 Vpp CMOS 90nm 1.0 Vpp

TChip (nsec) 0.66 0.66

BW (MHz) Bipolar Ternary (equal ±1 & 0)

VPeak (v) 0.5 0.5

PAve (dBm) -9.6 -9.6

PPeak (dBm) 4.4 4.4

Chip Rate (MHz) @ VPeak ~62 ~124

PRF (MHz) @ VPeak ~62 ~62• Key Requirement is to meet CMOS Tx Vpp constraint

• For Ternary signaling– 1.0Vpp @ 124MHz CRF without backoff & perfect antenna – 1.2Vpp @ 124MHz CRF without backoff & 30% (or 1.5dB) feed loss– 1.0Vpp @ 124MHz CRF without 1.5dB backoff & 30% (or 1.5dB) feed loss

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

124 MHz CRF Mode is logical…• ~1.5GHz system, 3x larger bandwidth means

– 3x shorter pulse duration– 3x higher average transmit power

• The keep the same peak transmit power, ~1.5GHz system should have ~9x higher CRF (or PRF), compared to ~500MHz system• 124MHz CRF = 8 x 15.5 MHz CRF• Or in terms of PRF, 62 MHz = 8 x 7.75 MHz

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Minimum numbers of Chip Rates

• After considering antenna feed loss and PSD backoff, we have min 2 CRFs– ~15.5MHz for ~500MHz systems– ~124MHz for ~1500MHz systems

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Main Features of proposed Impulse Radio Signaling

Proposal main features:• Impulse-radio based (pulse-shape independent)

• Ternary Codes for Common Preamble & Data signaling for different classes of nodes / type of receivers (coherent / differential / noncoherent)

• Perfect balance ternary sequences for synchronisation & ranging preambles – Perfect Autocorrelation for coherent and energy detectors

• M-ary signaling for data transmission to achieve higher spreading gain - Robustness against SOP interference

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Key Features of proposed System• Impulse-radio based (pulse-shape independent)• Chip Repetition Frequency = ~15.5MHz (corresponding to

PRF of ~7.75MHz)• 1 Mbps mandatory and 10Mbps optional modes


• 31-Chip Perfect Balance Ternary Sequences (PBTS) for synchronisation & ranging preambles – Perfect Autocorrelation for coherent and energy detectors

• 16-ary Ternary Orthogonal Keying (derived from 31-chip sequence PBTS) for data transmission to achieve higher spreading gain - Robustness against SOP interference

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Criteria of Code Sequence Design

1. The code sequence should have perfect auto-correlation

properties for synchronisation and ranging (leading edge

detection) for all the below receivers

a. Coherent receiver

b. Energy detection receiver

c. Differential chip receiver

2. The sequence Set should have orthogonal (or near orthogonal)

cross correlation properties to minimise symbol decision error

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Base Sequence Set (31-chip Ternary)

These are Wideband Access-I2R proposed

Perfect Balance Ternary Sequences

for Preambles for Ranging

Seq 1 +0++000-+-++00++0+00-0000-0+0--

Seq 2 +-0+0+00+000+0++---0-+00-++0000

Seq 3 0+-+000+0-0++0-0000+-00-00-++++

Seq 4 0+0000-00-0+-00+++-+000-+0+++0-

Seq 5 -++0-+---00+00++0000+0+-0+0+000

Seq 6 0++-++0+000+00-0-0++0000--+00-+

• 31-chip Ternary Sequence Set• Only one base sequence and one fixed band (no hopping) will be

used by all devices in a piconet• Logical channels for support of multiple piconets

•6 sequences = 6 logical channels (e.g. overlapping piconets) for each FDM 500MHz Band

• The same base sequence will be used for •acquisition / ranging; and•Data transmission via symbol-to-chip mapping

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Base Sequence Properties (Auto-Corr.)

0 5 10 15 20 25 30 350

2

4

6

8

10

12

14

16Coherent Receiver: Periodic Autocorrelation Function

0 5 10 15 20 25 30 350

2

4

6

8

10

12

14

16Non-Coherent Receiver: Periodic Autocorrelation Function

•Perfect balance ternary sequences for synchronisation & ranging preambles – Perfect Autocorrelation for coherent and energy detectors

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Base Sequence Properties (Cross-Corr.)

0 5 10 15 20 25 30 35-4

-3

-2

-1

0

1

2

3

4Coherent Receiver: Periodic Cross-correlation Function

0 5 10 15 20 25 30 35-4

-3

-2

-1

0

1

2

3

4Non-Coherent Receiver: Periodic Cross-correlation Function

First 3 sequences have lowest possible cross-correlation values…

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Spectral PAR (PSD Backoff)PSD Backoff ~ 1.0dB @ 15.5 MHz

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Synchronisation Preamble

• The Ternary Base Sequence has excellent autocorrelation properties

• Synchronisation / Ranging Preamble is constructed by repeating the preamble

• Noted that with this new improved ternary sequences, there is no need for Receiver-specific signaling

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

…………………………

1 2 3 314 5 6 7 8 30

Non-inverted pulses are blue,Inverted pulses are green.

CHIP Repetition Interval ~ 65ns

……………

Ternary Signaling for Preambles

Symbol Interval ~2us Symbol Interval ~2us

Synchronisation / Ranging preamble = Binary Base Sequence repeated For K times…

.................……………

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Modulation & Coding

Bit to symbol mapping: group every 4 bits into a symbol

Symbol-to-chip mapping:Each 2-bit symbol is mapped to one of 16 31-chip sequence, according to 16-ary Ternary Orthogonal Keying

Zero Padding:suggested 1 PRI for reducing inter-symbol interference

Symbol Repetition:for data rate and range scalability

Scrambling:with bipolar sequence @ 15.5MHz, to suppress cross correlation sidelobes due to excessive delay spread

Pulse Genarator: Transmit Ternary pulses @ 15.5MHz

Bit-to-Symbol

Symbol Repetition

CodedBits Scrambling

{0,1,-1} Ternary Sequence

Symbol-to-Chip

Pulse Generator

ZeroPadding

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Symbol Cyclic shift to right by n chips, n=

32-Chip value

0000 0 + 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - 0

0001 2 - - + 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 0

0011 4 + 0 - - + 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 – 0 0

0010 6 – 0 + 0 - - + 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 0

0110 8 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0

0111 10 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0 – 0

0101 12 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0

0100 14 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + - + + 0 0 + + 0 0

1100 16 + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + - + + 0 0 + 0

1101 18 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + - + + 0 0

1111 20 + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + - + 0

1110 22 - + + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 - + 0

1010 24 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0 0 0

1011 26 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + + 0 0

1001 28 + 0 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0 + 0

1000 30 0 + + 0 0 0 - + - + + 0 0 + + 0 + 0 0 - 0 0 0 0 - 0 + 0 - - + 0

Symbol-to-Chip Mapping:Gray coded 16-ary Ternary Orthogonal Keying

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Code Sequences for different Receivers

Receiver Type

Preamble / Data Sequence

Receive Sequence

Coherent Ternary Ternary

Differential Chip

Ternary Differential(Ternary)

Energy Detector

Ternary Bipolar

•For both Preamble and Data•Ternary to Bipolar conversion ± → +

0 → -

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Cross Sequence Correlation Properties for Coherent Receiver

RX Mapping Matrix * TX Mapping Matrix' =

For Coherent Detector, RX Mapping Matrix = TX Mapping Matrix

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Symbol Cyclic shift to right by n chips, n=

32-Chip value

0000 0 + - + + - - - + + + + + - - + + - + - - + - - - - + - + - + + -

0001 2 + + + - + + - - - + + + + + - - + + - + - - + - - - - + - + - -

0011 4 + - + + + - + + - - - + + + + + - - + + - + - - + - - - - – - -

0010 6 – - + - + + + - + + - - - + + + + + - - + + - + - - + - - - - -

0110 8 - - + - + - + + + - + + - - - + + + + + - - + + - + - - + - - -

0111 10 - - - - + - + - + + + - + + - - - + + + + + - - + + - + - - + -

0101 12 - + - - - - + - + - + + + - + + - - - + + + + + - - + + - + - -

0100 14 + - - + - - - - + - + - + + + - + + - - - + + + + + - - + + - -

1100 16 + - + - - + - - - - + - + - + + + - + + - - - + + + + + - - + -

1101 18 - + + - + - - + - - - - + - + - + + + - + + - - - + + + + + - -

1111 20 + - - + + - + - - + - - - - + - + - + + + - + + - - - + + + + -

1110 22 + + + - - + + - + - - + - - - - + - + - + + + - + + - - - + + -

1010 24 + + + + + - - + + - + - - + - - - - + - + - + + + - + + - - - -

1011 26 - - + + + + + - - + + - + - - + - - - - + - + - + + + - + + - -

1001 28 + - - - + + + + + - - + + - + - - + - - - - + - + - + + + - + -

1000 30 - + + - - - + + + + + - - + + - + - - + - - - - + - + - + + + -

Rx Sequence for Energy Detector

Ternary to Bipolar conversion of Base Sequence #1

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Sync & Ranging - Energy Detector operation (example)

BPF ( )2 LPF / integrator

ADC

Sample Rate 1/Tc

SlidingCorrelator

Noncoherent detection of OOK

{1,-1} Binary Sequence

Soft output

Unipolar M-Seq [+ + + 0 0 0 + + 0 + + + 0 + 0 + 0 0 0 0 + 0 0 + 0 + + 0 0 + + ]

Bipolar M-Seq [+ + + - - - + + - + + + - + - + - - - - + - - + - + + - - + + ]

Ternary Seq [+ - - 0 0 0 + - 0 + + + 0 + 0 - 0 0 0 0 + 0 0 - 0 - + 0 0 - - ]

After Square Law & Integration in PRI

0 20 40 60 80 100 120 140 160-4

-2

0

2

4

6

8

10

12

14

16Energy Detector Correlator output (Ternary signaling, Bipolar Despreading Seq)

In AWGN

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Cross Sequence Correlation Properties for Energy Detector

RX Mapping Matrix * abs(TX Mapping Matrix)' =

For Energy Detector, RX Mapping Matrix = Ternary2Bipolar(TX Mapping Matrix)

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Why M-ary Orthogonal Keying ?

• Good coding gain as M-ary Orthogonal Keying is power-limited coding

•More coding gain is achieved with higher M values•Marginal gain for M > 16

• Robust against SOP interference & inter-pulse interference due to high despreading gain per M-ary symbol

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Simulation Results

AWGN Performance & Multipath Performance

I. For Coherent Symbol Detector

II. For Energy Detector

III. For differential Chip Detector (to be provided later)

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Bandwidth ~500MHz

Ternary Pulse Rep. Freq. 15.5 MHz

# Chip / symbol (Preambles) 31

# Chip / symbol (Comms.) 31 + 1 Zero padding = 32

Channel coding e.g. Conv code K = 3, r=1/2 (Hard decoding)

Symbol Rate (Comms.) 15.5/32 MHz = 0.484375 MSps

coded bit / sym 4 coded bit / symbol

Mandatory bit rate 1/2 x 4 bit/sym x 0.484375 MSps = 0.96875 Mbps

Higher bit rate 10.33 Mbps (Details in following pages)

#Code Sequences for Ternary Orthogonal Keying

16 (4 bit/symbol)

Lower bit rate scalability Symbol Repetition

Modulation {+1,-1, 0} ternary pulses

Total # simultaneous piconets supported

6 per FDM band

Multple access for piconets CDM (fixed code) + FDM (fixed band)

Proposed Mandatory System Parameters

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Multipath Performance (1 Mbps, 500MHz BW)

0 5 10 15 20 25 3010

-4

10-3

10-2

10-1

100

Eb/N0

PE

R

32-Chip , 1/2 rate CC (K=5)

AWGN CohAWGN EDCM1 Coh 1-RAKECM1 ED 1-RAKECM1 Coh 4-RAKECM1 ED 4-RAKECM8 Coh 1-RAKECM8 ED 1-RAKECM8 Coh 4-RAKECM8 ED 4-RAKE

• Random transmit scrambling seq.

• Coherent and energy detectors

• AWGN, CM1 & CM8• 1-Rake & 4-Rake • Ideal Channel

acquisition + timing estimation

• Benefit of ½ rate CC not obvious in isolated piconet operation; advantage may be in SOP operation

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

SOP + Multipath (1 Mbps, 500MHz BW)

To be provided later

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Bandwidth ~500MHz

Pulse Rep. Freq. 15.5 MHz

# Chip / symbol (Preamble) 31

# Chip / symbol (Comms.) 1

Channel coding e.g. Conv code K = 3, r=2/3

Symbol Rate 15.5 MSps


Max bit rate 2/3 x 1 bit/sym x 15.5 MSps = 10.33 Mbps

#Code Sequences for Orthogonal Keying

Nil

Modulation {+1,-1} bipolar pulses


-

Multple access for piconets CDM (fixed code per piconet)

Proposed Mandatory System Parameters (Max Bit Rate Mode)

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission


0 2 4 6 8 10 12 14 16 18 2010

-4

10-3

10-2

10-1

100

PE

R

Eb/N

0

Coherent Detector performance, Ternary Signaling @ 15.5MHz with BW = 496MHz

AWGN CC onlyCM1 CC only 1-RAKECM1 CC only 4-RAKE

• No Ternary Ortho.Keying

• Coherent detector only• AWGN, CM1• 1-Rake & 4-Rake • Ideal Channel


July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Proposed Optional Wider Band ~ 1.5GHz systems

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Key Features of proposed wider band system• Impulse-radio based (pulse-shape independent)• Chip Repetition Frequency = ~124MHz (corresponding to PRF of

~62MHz)• 1 Mbps mandatory and 10Mbps optional modes


• 127-Chip Perfect balance ternary sequences for synchronisation & ranging preambles – Perfect Autocorrelation for coherent and energy detectors

• 16-ary Ternary Orthogonal Keying (with 256-chip sequence) for data transmission to achieve higher spreading gain - Robustness against SOP interference, especially in 1.5GHz system (without FDMA for SOP)

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Base Sequence Set (127-chip Ternary)

These are Wideband Access-I2R proposed

Perfect Balance Ternary Sequences

for Preambles for Ranging

Seq 1 0000+++-++-0+0+0-00++00-++0+--0-00+0++000+-0+++-0-+0-0--0--00+00

+000+-+0000+0-++--00+0+0+--00--0+000-00+-+-000-0-0000++00000+00

Seq 2 -00+++0+-0+++0+00+00+0-+000--+00+0000-0-++00000++0-000000-00---+

++-000-0-0+0-+++00+-00-0+000+000+-0000--+-0--+-+0+0-+0+0+00-+0-

Seq 3 +-00-000+-000-0--+0000+0000+-0+00000+++--0++000000+0+0++0+++----00-+0+-0+0-0+000-00+00-+00++-+000+++0+--0-0-+-+0-00-0+-00+0-00+

Seq 4 000-0-0-0-++-+0+00+0+000-+0+++000----+++0000+++0--++00+0-+00+00+

000000-000-00--000-0+-+0-0+-0-+00000+-00++0-0+00--+00++-+0+-0+0

Seq 5 0+-0++0+000+--+-0000++-000+0+00++000000++0-0--+0-00+0-0+0++0+--0

0+0000+000+00-00+-++0-0+00000-0-+-+00---0----+++0+-00+0-+000-+0

• 127-chip Ternary Sequence Set• Only one base sequence and one fixed band (no hopping) will be

used by all devices in a piconet• Logical channels for support of multiple piconets

•5 sequences = 5 logical channels (e.g. overlapping piconets) for 1500MHz Band

• The same base sequence will be used for •acquisition / ranging; and•Data transmission via symbol-to-chip mapping

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

…………………………

1 2 3 1274 5 6 7 8 126

Non-inverted pulses are blue,Inverted pulses are green.

CHIP Repetition Interval ~ 8.1ns

……………

Ternary Signaling for Preambles

Symbol Interval ~1.03us Symbol Interval ~1.03us

Synchronisation / Ranging preamble = Binary Base Sequence repeated For K times…

.................……………

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Bandwidth 1488MHz

Ternary Pulse Rep. Freq. 124 MHz


# Chip / symbol (Comms.) 256 (Details later)


Symbol Rate 124/256 MHz = 0.484375 MSps


Mandatory bit rate 1/2 x 4 bit/sym x 0.484375 MSps = 0.96875 Mbps

Max bit rate 10.33 Mbps (see next page)


16 (4 bit/symbol)

(16*k-chip cyclic right shift, across the 16 sequences)

Lower bit rate scalability Symbol Repetition



>6


Proposed Optional Wider Band System

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission


• Random Transmit scrambling seq.





July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

SOP + Multipath (1 Mbps, 1500MHz BW)

To be provided later

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

Bandwidth 1488 MHz

Pulse Rep. Freq. 124 MHz


# Chip / symbol (Comms.) 32 (identical to that for ~500MHz system)


Symbol Rate 124/32 MHz = 3.875 MSps


Max bit rate 2/3 x 4 bit/sym x 3.875 MSps = 10.33 Mbps


16 (4 bit/symbol)

(identical to that for ~500MHz system)



>6


Proposed Optional Wider Band System (Max Bit Rate)

July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

0 2 4 6 8 10 12 14 16 18 2010

-4

10-3

10-2

10-1

100

Coherent Detector performance,Ternary Signaling @ 124MHz with BW = 1488MHz

PE

R

Eb/N

0

AWGN BOK onlyCM1 BOK only 1-RAKE

CM1 BOK only 4-RAKE

AWGN CC+BOK

CM1 CC+BOK 1-RAKECM1 CC+BOK 4-RAKE


• Random Transmit scrambling seq.





July 2005


doc.: IEEE 802.15-05-0231-07-004a

Submission

SummaryThe proposed Impulse-radio based system:• has ternary signaling only that

– Can be received simultaneously by different types of receivers, namely coherent, differential, and energy detectors

– Can be used for both Preamble and Comm. simultaneously• Synchronisation & Ranging – Repeated Ternary Base Sequence for

preambles– Simple sliding correlator can be used for Ranging & Sync

• Data Communications – 4bit/symbol Ternary Orthogonal Keying Symbol (with cyclic shift version of base sequence + zero padding)– Good coding gain due to M-ary orthogonal keying– Is robust against SOP interference due to high spreading gain per

symbol

project: ieee p802.15 working group for wireless personal area networks (wpans)

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