IEEE-15-05-0126-00-004a Submission March 2005 Lampe, Hach, Menzer, Nanotron; Lee, OrthotronSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal

March 2005

Lampe, Hach, Menzer, Nanotron; Lee, OrthotronSlide 1

IEEE-15-05-0126-00-004a

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: DBO-CSS PHY Presentation for 802.15.4aDate Submitted: March 07, 2005Source: [(1) John Lampe, et al, (2) Kyung-Kuk Lee, et al]Company: [(1) Nanotron Technologies, (2) Orthotron Co., Ltd.]Address: [(1) Alt-Moabit 61, 10555 Berlin, Germany, (2) 709 Kranz Techono, 5442-1 Sangdaewon-dong, Jungwon-gu, Sungnam-si, Kyungki-do, Korea 462-120]Voice: [(1) +49 30 399 954 135, (2) 82-31-777-8198 ], E-Mail: [(1) [email protected], (2) [email protected]]

Re: This is in response to the TG4a Call for Proposals, 04/0380r2

Abstract: The Nanotron - Orthotron DBO-CSS is described and the detailed response to the Selection Criteria document is provided

Purpose: Submitted as the candidate proposal for TG4a Alt-PHY

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


IEEE-15-05-0126-00-004a

Submission

Differentially Bi-OrthogonalDifferentially Bi-OrthogonalChirp-Spread-SpectrumChirp-Spread-Spectrum

PHY Proposal for 802.15.4aPHY Proposal for 802.15.4aby

John Lampe, Rainer Hach, and Lars Menzer Nanotron Technologies GmbH, Germany

[email protected]

Kyung-Kuk Lee / Jong-Wha ChongOrthotron Co., Ltd. / Hanyang Univ., Korea

[email protected]

March 2005


IEEE-15-05-0126-00-004a

Submission

Contents

■ DBO-CSS System Overview

■ Selection Criteria Document Topics

■ PAR and 5C Requirement Checklist

■ Summary

March 2005


IEEE-15-05-0126-00-004a

Submission

DBO-CSS System Overview■ Chirp Property■ Concept of Sub-Chirps■ Block-diagram

♣ DBO-CSK: Differentially Bi-Orthogonal Chirp-Spread-Spectrum

March 2005


IEEE-15-05-0126-00-004a

Submission

0( ) Re exp[ ( ) ] [ ( ) ( )]2

BWchirp s chirp

chirp

s t j t t u t u t TT

SBW

t

t

( )chirps t

0( ) Re exp[ ( ) ] ( )2

BWchirp s RC chirp

chirp

s t j t t p t TT

Linear Chirp: Rectangular Window

Linear Chirp: Raised-Cosine Window

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

-200 -150 -100 -50 0 50 100 150 200

0

0.2

0.4

0.6

0.8

1

Correlation Property of Chirp Signal

Am

plitu

de

DBO-CSS System OverviewChirp PropertiesChirp Properties

March 2005


IEEE-15-05-0126-00-004a

Submission

-20 -10 fc 10 20 (MHz)

-50

-40

-30

-20

-10

0

Spectrum

Fbw = 7.0 MHzrolloff = 0.25;Fdiff = 6.3 MHz;Tc = 4.8usec

Same Spectrum with IEEE802.11a / 11bSame Spectrum with IEEE802.11a / 11b

I

II

III

IV

Freq. - Time

t

t

t

t

DBO-CSS System OverviewConcept of Sub-ChirpsConcept of Sub-Chirps

March 2005


IEEE-15-05-0126-00-004a

Submission

Waveform

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

0

1

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

0

1

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

0

1

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

0

1

I

II

III

IV

Freq. - Time

t

t

t

t

DBO-CSS System OverviewConcept of Sub-ChirpsConcept of Sub-Chirps

March 2005


IEEE-15-05-0126-00-004a

Submission

Digital

MOD

Digital

MOD LPLP

LPLP

I

QLO

fc

I/Q Modulator

fT = f ± 10 MHz

Low-PassFilter

Block-diagram: Block-diagram: DBO-CSSDBO-CSS TransmitterTransmitter

DBO-CSS System Overview

March 2005


IEEE-15-05-0126-00-004a

Submission

DDDLDDDL

Dig

ital D

EM

OD

Dig

ital D

EM

OD

fR = fLO

± 10 MHz

Up

Down

RSSI

I/Q Demodulator

I

QLO

LPLP

LPLP

Low-PassFilter

ADCADC

fc

1

1 DBO-CSS pulse

2

2Correlation pulse

3Trigger signal with adaptive threshold

3

ADCADC

Block-diagram: Block-diagram: DBO-CSSDBO-CSS ReceiverReceiver

DBO-CSS System Overview

March 2005


IEEE-15-05-0126-00-004a

Submission

DBO-CSS System OverviewBlock-diagram: Block-diagram: 8-ary DBO-CSS8-ary DBO-CSS ModulatorModulator

1z

CSK Gen.

1 3 4 4

P/S

8-aryDBO-CSK

SymbolMapperS/PFEC

r=1, 1/2Scram-bler

Binary Data…010011100110001101… Binary Symbol

Bi-OrthogonalSymbol

DifferentiallyBi-Orthogonal

Symbol

March 2005


IEEE-15-05-0126-00-004a

Submission

■ Band in Use■ Signal Robustness interference mitigation techniques. Interference Susceptibility Coexistence

■ Technical Feasibility Manufacturability Time to Market Regulatory Impact Backward Compatibility

■ Scalability■ Mobility ■ MAC Protocol Supplement■ PHY Layer Criteria Unit Manufacturing Cost/Complexity (UMC) Size and Form Factor Payload Bit Rate and Data Throughput

■ Simultaneously Operating Piconets■ Signal Acquisition■ Clear Channel Assessment■ System Performance Error rate Receiver sensitivity

■ Ranging■ Link Budget■ Power Management Modes■ Power Consumption■ Antenna Practicality

Selection Criteria Document Topic

March 2005


IEEE-15-05-0126-00-004a

Submission

2.4GHz ISM Band with 802.11b channel scheme 20MHz Bandwidth: Consists of 4 sub-chirp signals per Carrier

Selection Criteria Document TopicBand in Use:Band in Use:

-20 -10 fc 10 20 (MHz)

-50

-40

-30

-20

-10

0

Spectrum

Fbw = 7.0 MHzrolloff = 0.25;Fdiff = 6.3 MHz;Tc = 4.8usec

Same Spectrum with IEEE802.11bSame Spectrum with IEEE802.11b

March 2005


IEEE-15-05-0126-00-004a

Submission

■ Co-existence / Interference Mitigation Technique - Orthogonal / Quasi-Orthogonal Signal Set - High Spectral Processing Gain: Chirp - Near-Far Problem: FDM Channels (7ch @2.4GHz)

■ Interference Susceptibility - Low Cross-Correlation property with Existing Signal

■ Robustness: - Heavy Multi-path Environment - SOP

■ Low Sensitivity for Component Tolerance - Crystal : ± 40ppm

■ Mobility - Wide-band Chirp: Insensitive for Fading & Doppler Shift - Easily Maintaining Timing Sync. of Received Signal

Selection Criteria Document TopicSignal Robustness:Signal Robustness:

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicSignal Robustness: Signal Robustness: Interference Mitigation Techniques The proposed DBO-CSS PHY is designed to operate in a hostile

environment – Multipath– Narrow and broadband intentional and unintentional interferers

Since a chirp transverses a relatively wide bandwidth it has an inherent immunity to narrow band interferers

Multipath is mitigated with the natural frequency diversity of the waveform Broadband interferer effects are reduced by the receiver’s correlator Forward Error Correction (FEC) can further reduce interference and

multipath effects. Three non-overlapping frequency channels in the 2.4 GHz ISM band

– This channelization allows this proposal to coexist with other wireless systems such as 802.11 b, g and even Bluetooth (v1.2 has adaptive hopping) via DFS

DBO-CSS proposal utilizes CCA mechanisms of Energy Detection (ED) and Carrier Detection

These CCA mechanisms are similar to those used in IEEE 802.15.4-2003– In addition to the low duty cycle for the applications served by this standard

sufficient arguments were made to convince the IEEE 802 sponsor ballot community that coexistence was not an issue.

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicSignal Robustness: Signal Robustness: Interference Susceptibility

Support for Interference Ingress Example (without FEC):

– Bandwidth B of the chirp = 20 MHz

– Duration time T of the chirp = 4.8 µs

– Center frequency of the chirp (ISM band) = 2.437 GHz

– Processing gain, BT product of the chirp = 19.8 dB

– Eb/N0 at detector input (BER=10E-4) = 12.5 dB

– In-band carrier to interferer ratio (C/I @ BER=10-4)= 12.5 – 19.8 = -7.3 dB

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicSignal Robustness: Signal Robustness: Coexistence

-60-50-40-30-20-10

0

0 10 20 30 40 50

|f-fc| (MHz)

Att

enu

atio

n (

dB

)

Low interference egress IEEE 802.11b receiver

– More than 30 dB of protection in an adjacent channel

– Almost 60 dB in the alternate channel

• These numbers are similar for the 802.11g receiver

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicTechnical Feasibility: Technical Feasibility: Manufacturability

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicTechnical Feasibility: Technical Feasibility: Time to Market

No regulatory hurdles DBO-CSS based chips are available on the market No research barriers – no unknown blocks Normal design and product cycles will apply Can be manufactured in all CMOS

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicTechnical Feasibility: Technical Feasibility: Regulatory Impact

Devices manufactured in compliance with the DBO-CSS proposal can be operated under existing regulations in all significant regions of the world- Including but not limited to North and South America, Europe, Japan,

China, Korea, and most other areas- There are no known limitation to this proposal as to indoors or

outdoors The DBO-CSS proposal would adhere to the following

worldwide regulations:- United States Part 15.247 or 15.249- Canada DOC RSS-210- Europe ETS 300-328- Japan ARIB STD T-66

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicTechnical Feasibility: Technical Feasibility: Backward Compatibility

Due to the similarities with DSSS it is possible to implement this proposal in a manner that will allow backward-compatibility with the 802.15.4 2.4 GHz standard.

The transmitter changes are relatively straightforward. Changes to the receiver would include either dual

correlators or a superset of DBO-CSS and DSSS correlators.

Optional methods for backward-compatibility could be left up to the implementer - mode switching - dynamic change (on-the-fly) technique

This backward-compatibility would be a significant advantage in the marketplace by allowing these devices to communicate with existing deployed 802.15.4 infrastructure and eliminating customer confusion.

March 2005


IEEE-15-05-0126-00-004a

Submission

Mandatory rate = 1 Mb/s Optional rates = 500 Kb/s, 250 Kb/s Lower data rates achieved by using interleaved FEC Lower chirp rates would yield better performance

- longer range, less retries, etc. in an AWGN environment or a multipath limited environment

It should be noted that these data rates are only discussed here to show scalability, if these rates are to be included in the draft standard the group must revisit the PHY header such as the SFD.

Selection Criteria Document TopicScalability: Scalability: Data-rateData-rate

March 2005


IEEE-15-05-0126-00-004a

Submission

The proposer is confident that the DBO-CSS proposal would also work well in other frequency bands– Ex) Including the 5 GHz UNII / ISM bands

Selection Criteria Document TopicScalability: Scalability: Frequency BandsFrequency Bands

March 2005


IEEE-15-05-0126-00-004a

Submission

For extremely long ranges the transmit power may be raised to each country’s regulatory limit, for example:– The US would allow 30 dBm of output power with up to a 6 dB gain

antenna

– The European ETS limits would specify 20 dBm of output power with a 0 dB gain antenna

Note that even though higher transmit power requires significantly higher current it doesn’t significantly degrade battery life since the transmitter has a much lower duty cycle than the receiver, typically 10% or less of the receive duty cycle.

Selection Criteria Document TopicScalability: Scalability: Power LevelsPower Levels

March 2005


IEEE-15-05-0126-00-004a

Submission

MobilityMobility• Communication

– No system inherent restrictions are seen for this proposal• The processing gain of chirp signals is extremely robust against frequency offsets

such as those caused by the Doppler effect when there is a high relative speed vrel between two devices.

• The Doppler effect must also be considered when one device is mounted on a rotating machine, wheel, etc.

• The limits will be determined by other, general (implementation-dependent) processing modules (AGC, symbol synchronization, etc.).

• Ranging– The ranging scheme proposed in this document relies on the exchange of

two hardware acknowledged data packets• One for each direction between two nodes

– The total time for single-shot (2 data, 2 Ack) ranging procedure between the two nodes is the time tranging which, depending on the implementation, might be impacted by the uC performance. During this time the change of distance should stay below the accuracy da required by the application. The worst case is:

• For da = 1m• tranging = 2 ms this yields • vrel << 1000 m/sranging

arel t

dv

2


March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicMAC Protocol SupplementMAC Protocol Supplement

There are very minimal anticipated changes to the 15.4 MAC to support the proposed Alt-PHY. – Three channels are called for with this proposal and it is

recommended that the mechanism of channel bands from the proposed methods of TG4b be used to support the new channels.

– There will be an addition to the PHY-SAP primitive to include the choice of data rate to be used for the next packet. This is a new field.

Ranging calls for new PHY-PIB primitives are expected to be developed by the Ranging subcommittee.

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicPHY Layer Criteria: PHY Layer Criteria: Manufacturing Cost/Complexity

BaseBand Digital Estimated Complexity 500Kbps / 250Kbps [gates]

Data-Rate

250 Kbps 1MHz / 500 Kbps

Tx

Scrambler 154

1.5K / 1.6K

O O

FEC Encoder (r=1/2) 100 O X

Symbol Mapper 13 O O

Differential Encoder 56 O O

Chirp-pulse Modulator 290 O O

Framer & Others 1K O O

Rx

Differential Detector 39k

49.4K / 145K

O O

Symbol Demapper 200 O O

Max Selector 100 O O

FEC Decoder (r=1/2) 95K O X

Descrambler 154 O O

Deframer & Others 10K O O

Common 5K O O

Transceiver 152K 56K

March 2005


IEEE-15-05-0126-00-004a

Submission


• Target process:RF-CMOS, 0.18 µm feature size

Pos. Block description Estimated Area Unit

1 Receiver with high-end LNA 2.00 mm²

2 Transmitter, Pout = + 10 dBm 1.85 mm²

3 Digitally Controlled Oscillator + miscellaneous blocks 0.62 mm²

4 Digital and MAC support 0.30 mm²

5 Digital Dispersive Delay Line (DDDL) for the proposed chirp duration 0.32 mm²

6 Chirp generator for the proposed chirp duration 0.08 mm²

Occupied chip area for all major blocks required to build complete transceiver chip utilizing DBO-CSS technology 5.17 mm²

March 2005


IEEE-15-05-0126-00-004a

Submission


• Target process:RF-CMOS, 0.13 µm feature size

Pos. Block description Estimated Area Unit

1 Receiver with high-end LNA 1.90 mm²

2 Transmitter, Pout = + 10 dBm 1.71 mm²

3 Digitally Controlled Oscillator + miscellaneous blocks 0.59 mm²

4 Digital and MAC support 0.19 mm²

5 Digital Dispersive Delay Line (DDDL) for the proposed chirp duration 0.21 mm²

6 Chirp generator for the proposed chirp duration 0.06 mm²

Occupied chip area for all major blocks required to build complete transceiver chip utilizing DBO-CSS technology 4.66 mm²

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicPHY Layer Criteria: PHY Layer Criteria: Size and Form Factor

The implementation of the DBO-CSS proposal will be much less than SD Memory at the onset– Following the form factors of Bluetooth and IEEE 802.15.4 / ZigBee

The implementation of this device into a single chip is relatively straightforward– As evidenced in the “Unit Manufacturing Complexity” slides

March 2005


IEEE-15-05-0126-00-004a

Submission

SD Memory (32mm X 24 mm)

Ex)• Battery Capacity: 3V x 30mAh (324Joule)• Dimension: 10 x 2.5 (Dia. x Ht. mm)

SD Memory (32mm X 24 mm)

2.4 GHz

BasebandRFPattern Antenna

(24mm X 14mm)

Button CellButton CellBatteryBattery

5.1/5.7 GHz

Pattern Antenna(12mm X 9mm)

Baseband

RFButton CellButton Cell

BatteryBattery

Selection Criteria Document TopicPHY Layer Criteria: PHY Layer Criteria: Size and Form Factor

March 2005


IEEE-15-05-0126-00-004a

Submission

DATA Frame ACK Frame DATA Frame

TACKTLIFT

330 / 588 / 1104 μsec 114 / 156 / 240 μsec

Payload: 32byte 5byte

574 / 874 / 1474 μsec

TACK + TLIFT = 130usec

Payload Bit-rate:

■ Data-rate: 1MHz / 500Kbps / 250Kbps per piconet■ Aggregated Data-rate: Max. 4Mbps (4 X 1Mbps) per FDM Channel■ FDM Channels: 7 CH. (2.4GHz)

Data Throughput:

■ Payload bit-rate 1Mbps / 500Kbps / 250Kbps : Throughput 446 Kbps / 293 Kbps / 173.7 Kbps

Selection Criteria Document TopicPHY Layer Criteria: PHY Layer Criteria: Bit Rate and Data Throughput

March 2005


IEEE-15-05-0126-00-004a

Submission

Data Frame:Payload bit-rate : 1Mbps (r=1) / 500Kbps (r=1) / 250Kbps (r=1/2)

Preamble Delimiter Length

+Rate

5Chirp 1Chirp 6Chirp 43chirps (1Mbps) / 86chirps (500Kbps) or 172chirps (250Kbps)

MPDU

330 μsec (1Mbps) / 588 μsec (500Kbps) / 1104 μsec (250Kbps)(8 + 1)bit (32X8 +2) bit

ACK Frame:Payload bit-rate : 1Mbps(r=1) / 500Kbps (r=1) / 250Kbps (r=1/2)

Preamble Delimiter Length

+Rate

5Chirp 1Chirp 6Chirp 7chirps (1Mbps) / 14chirps (500Kbps) / 28chirps (250Kbps)

MPDU

114 μsec (1Mbps) / 156 μsec (500Kbps) / 240 μsec (250Kbps)

(8 + 1)bit (5X8 +2) bit


March 2005


IEEE-15-05-0126-00-004a

Submission


• The SFD structure has different values for, and determines, the effective data rate for PHR and PSDU

• The Preamble is 32 bits in duration (a bit time is 1 µs)• In this proposal, the PHR field is used to describe the length of the PSDU that

may be up to 256 octets in length• In addition to the structure of each frame, the following shows the structure and

values for frames including overhead not in the information carrying frame

Octets: 4 1 or 2 1 Variable (up to 256)

Preamble SFD Frame length (8 bits) PHY payload

SHR PHR PSDU

ACK Short frame ACKLong frame

SIFStacktack LIFS

Short frame

SIFSLIFS

Long frame

Acknowledged transmission

Unacknowledged transmission

Where aTurnaroundTime <- tack <- (aTurnaroundTime + aUnitBackoffPeriod)

March 2005


IEEE-15-05-0126-00-004a

Submission

Throughput with ACK and SIFS

0

100000

200000

300000

400000

500000

600000

700000

800000

900000

1000000

32 64 128 256

PSDU length (octets)

Th

rou

gh

pu

t (b

/s)

267 Kb/s plot1 Mb/s plotTack= 192 µsSIFS= 192 µs

330 Kb/s

155 Kb/s

797 Kb/s

245 Kb/s


March 2005


IEEE-15-05-0126-00-004a

Submission

Separating Piconets by frequency division– This DBO-CSS proposal includes a mechanism for FDMA by

including the three frequency bands used by 802.11 b, g and also 802.15.3• It is believed that the use of these bands will provide sufficient

orthogonality– The proposed chirp signal has a rolloff factor of 0.25 which in

conjunction with the space between the adjacent frequency bands allows filtering out of band emissions easily and inexpensively.

Selection Criteria Document TopicSimultaneously Operating PiconetsSimultaneously Operating Piconets

March 2005


IEEE-15-05-0126-00-004a

Submission

Each of CSK Signal consists of 4 sub-chirp signals.

I

II

III

IV

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

-5000 0 50000

0.2

0.4

0.6

0.8

1

Correlation Power (For Preamble Detection)

Correlation Property between the piconetDoes not need Synchronization inter-piconet

t

CSK Signal : Quasi-Orthogonal Property


March 2005


IEEE-15-05-0126-00-004a

Submission

Each of CSK Signal consists of 4 sub-chirp signals.

I

II

III

IV

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

-4000 -2000 0 2000 4000

0

0.5

1

Complex Amplitude (for Data Demod)

Correlation Property between piconetCSK Signal : Quasi-Orthogonal Property


March 2005


IEEE-15-05-0126-00-004a

Submission

I

II

III

IV

t

Duration of 2 Symbols (12 usec)

0.3usec 2.1usec d11 d12




t

t

t

4.8 usec

SOP: Assigning Different Time-Gap between the Chirp-Shift-Keying Signal Minimize ISI for CM8 NLOS: Assign the Time-Gap between symbol more then 200nsec


March 2005


IEEE-15-05-0126-00-004a

Submission

Each of CSK Signal consists of 4 sub-chirp signals. Differential Detection Property between piconet

I

II

III

IV

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

0 1 2

x 104

-1

-0.5

0

0.5

1

Interference Tested by Packet (32 bytes Random Data)


March 2005


IEEE-15-05-0126-00-004a

Submission

Available SOPs

2.4GHz: 4[piconets/FDM Ch.] x 7[FDM Ch.] = 28 SOPs 5.2GHz: 4[piconets/FDM Ch.] x 8[FDM Ch.] = 32 SOPs 5.7GHz: 4[piconets/FDM Ch.] x 6[FDM Ch.] = 24 SOPs


0 0.5 1 1.5 2 2.5 310

-4

10-3

10-2

10-1

100

Dint/Dref

PE

R

System Performance in 1 interf. piconet

AWGNCM8CM1CM5

0.5 1 1.5 2 2.5 3 3.510

-4

10-3

10-2

10-1

100

Dint/Dref

PE

R

System performance with 2 interf. piconet

AWGNCM8CM1CM5

1 1.5 2 2.5 3 3.5 410

-4

10-3

10-2

10-1

100

Dint/Dref

PE

R

System performance with 3 interf. piconet

AWGNCM8CM1CM5

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicSignal Acquisition: Signal Acquisition: Block-diagramBlock-diagram

DifferentialDetector

(T1)Symbol

De-MapperSelect

LargestData

A/D

DifferentialDetector

(T2)

March 2005


IEEE-15-05-0126-00-004a

Submission

1400 1500 1600 1700 1800 1900 2000 2100 2200

10-5

10-4

10-3

10-2

10-1

In AWGN, at FA=3.2x10-5, TxPower=10mW

Distance : meter

Pm

2 Chirp Symbols3 Chirp Symbols4 Chirp Symbols

Preamble Detection

Selection Criteria Document TopicSignal Acquisition: Signal Acquisition: Miss Detection Probability

n=2

March 2005


IEEE-15-05-0126-00-004a

Submission

Although DBO-CSS could use a shorter preamble, for consistency with IEEE 802.15.4-2003 this DBO-CSS proposal is based upon a preamble of 32 symbols which at 1MS/s is 32 µs

Existing implementations demonstrate that modules, which might be required to be adjusted for reception (gain control, frequency control, peak value estimation, etc.), can settle in this time

Selection Criteria Document TopicSignal AcquisitionSignal Acquisition

March 2005


IEEE-15-05-0126-00-004a

Submission

Selection Criteria Document TopicClear Channel AssessmentClear Channel Assessment

March 2005


IEEE-15-05-0126-00-004a

Submission

Since this proposal refers to the 2.4GHz ISM band, only channel models with complete parameter sets covering this frequency range can be considered:– These are LOS Residential (CM1) and NLOS Residential (CM2).

The SCD requirements on the payload size to be simulated seem to be somewhat inconsistent. At some point 10 packets with 32 bytes are mentioned which would be a total of 2560 bits. On the other hand a PER of 1% is required which mean simulating much more than 100 packets or 25600 bits.

Accurate results are obtained when large number of independent transmissions of symbols are simulated.

BER is , with N = number bits.– For example, with PER=1% and N=256 (32 octets) we get

BER=3.9258E-5

NBERPER )1(1

System PerformanceSystem Performance


March 2005


IEEE-15-05-0126-00-004a

Submission

Channel Model: Channel Model: LOS Residential (CM1)LOS Residential (CM1)


March 2005


IEEE-15-05-0126-00-004a

Submission

Channel Model: Channel Model: NLOS Residential (CM2)NLOS Residential (CM2)


March 2005


IEEE-15-05-0126-00-004a

Submission

• Transmit power of 10 dBm

• 1 MBit / sec• No FEC

System Performance: System Performance: PER (CM2)PER (CM2)


March 2005


IEEE-15-05-0126-00-004a

Submission

Simulation over 100 channel impulse responses (as required in the SCD) were performed for channel model 1 and channel model 2.

No bit errors could be observed on channel model 1 (simulated range was 10 to 2000m). This is not really surprising because this model has a very moderate increase of attenuation over range (n=1.79)

The results for channel model 2 are presented. The parameter n=4.48 indicates a very high attenuation for higher ranges. The results were interpreted as PER respectively and for convenience were plotted twice (linear and log y scale).

System PerformanceSystem Performance


March 2005


IEEE-15-05-0126-00-004a

Submission

This figure shows the analytical BER values for 2-ary orthogonal coherent and non coherent detection and the corresponding simulation results (1E7 symbols) for up down chirp (using the chirp signals defined above)

The performance loss due to the non-orthogonality of up and down chirps is very small.

Selection Criteria Document TopicSystem PerformanceSystem Performance

Data Rate : 1Mbps (QPSK) / 500kbps (BPSK)

10 12 14 16 18 20 2210

-4

10-3

10-2

10-1

100

Eb/No

PE

R

System Performance

AWGNCM8CM1CM5

March 2005


IEEE-15-05-0126-00-004a

Submission


1800 2000 2200 2400 2600 2800 300010

-4

10-3

10-2

10-1

100

AWGN(Data Rate : 1Mbps (QPSK) / 500kbps (BPSK)n=2

Distance (meter)

March 2005


IEEE-15-05-0126-00-004a

Submission

CM2(Data Rate : 1Mbps (QPSK) / 500kbps (BPSK)

500 550 600 650 700 750 800 850 900 950 100010

-2

10-1

100

n=2


March 2005


IEEE-15-05-0126-00-004a

Submission

TOA EstimationTOA Estimation Coarse: Differential demodulation peak Fine: Correlation peak Precise: Receive signal post-processing

(Spectrum estimation or curve fitting) Simulation Results

TOA ProcessingTOA Processing

SDS TWR Technique Error Sensitivity Analysis Simulation Results

Selection Criteria Document TopicRangingRanging

March 2005


IEEE-15-05-0126-00-004a

Submission

Noise and Jitter of Band-Limited Pulse

Given a band-limited pulse with noise σu we want to estimate how the jitter (timing error) σt, is affected by the bandwidth B. Jitter can be represented as a variation in the rising edge of a pulse through a given threshold,

Since the power σ2 of band-filtered AWGN is proportional to the bandwidth we know that:

t

urv

BB

B

vr

ut

1~

σu threshold

σt t

u Signal with rising speed vr

noise bar

Approximate the impact of σu by:

Bt

uv

rise

peakr ~

Assume the rising speed of the signal is proportional to the signal bandwidth:

Which leads to:

BNBu ~

Selection Criteria Document TopicRanging: Ranging: TOA Estimation for RangingTOA Estimation for Ranging

March 2005


IEEE-15-05-0126-00-004a

Submission

The SN at the matched filter output is 2Es/N0

If we assume a pulse with a rise time trise which is the inverse of the pulse bandwidth B (trise = 1/B) we can derive:

Bandwidth and signal to noise ratio can be traded against each other.

BE

N

st

1

20

Selection Criteria Document TopicRanging: Ranging: TOA Estimation for RangingTOA Estimation for Ranging

March 2005


IEEE-15-05-0126-00-004a

Submission

■ Coarse Timing Detection - Peak of Differential Detection (Averaging over 4 or more Symbols)

■ Fine Timing Detection - Cross-Correlation of Sampled Input Signal - Fine Timing by Interpolation (Fraction of Sampling-Clock Resolution < 1nsec) - Averaging over 4 or more Symbols - Less than 1m Ranging Resolution @ Eb/No >= 24dB

Arbitrary Sampling Instant

Detected TimingDetected TimingPeak

Edge

Selection Criteria Document TopicRanging: Ranging: TOA Estimation Using Chirp SignalsTOA Estimation Using Chirp Signals

March 2005


IEEE-15-05-0126-00-004a

Submission

One special property of chirp signals is that

Time shifts can be transformed into

frequency shifts

thus

TOA estimation can be transformed to spectral estimation

which has the advantage that

Wide bandwidth and high sampling frequency are not required


March 2005


IEEE-15-05-0126-00-004a

Submission

f

t

t

A

f

t

t

A

Assume a linear chirp signal

and a time-shifted copy of this signal

By multiplying the two, a constant frequency signal is generated!


March 2005


IEEE-15-05-0126-00-004a

Submission

f

t

t

A

t

h

f

t

t

A

Given a channel impulse response (CIR),

transmitting a chirp signal over it,

and multiplying with a chirp signal of equal characteristic…

frequency

will result in a signal with frequency componentscorresponding to the pulses of the CIR.

power


March 2005


IEEE-15-05-0126-00-004a

Submission

From the estimated frequency components, the time positions of the multipath components can be calculated

and thus the time of the first arrival can be found!


March 2005


IEEE-15-05-0126-00-004a

Submission


March 2005


IEEE-15-05-0126-00-004a

Submission

12 14 16 18 20 22 24 26 2810

0

101

102

Eb/No (dB)

tim

e e

rror

devia

tion (

nsec)

Timing-error Variance (Chirp BW: 20MHz)

■ Estimation Precision: < 1m @ Eb/No greater than 24dB


AWGN

March 2005


IEEE-15-05-0126-00-004a

Submission

Tround ... round trip time

Treply ... reply time

Tprop ... propagation of pulse

Double-Sided: Each node executes a round trip measurement.

Symmetrical: Reply Times of both nodes are identical (TreplyA =TreplyB).

Results of both round trip measurements are used to calculate the distance.

TroundA

Tprop

TreplyA

t

Tprop Tprop

t

TroundBTreplyB

Node A

Node B

Tprop

Selection Criteria Document TopicRanging: Ranging: Symmetrical Double-Sided Two-Way Ranging (SDS TWR)

March 2005


IEEE-15-05-0126-00-004a

Submission

Ranging: Ranging: Effect of Time Base Offset Errors

12,21 replyBreplyAroundBroundA TTTT

4

)1()1()1()1( 2211 replyAAroundBBreplyBBroundAAprop

TeTeTeTeT

Assuming offset errors eA, eB of the timebases of node A and B we get:

On the condition that the two nodes have almost equal behavior,we can assume:

This has the effect that timebase offsets are canceled out:

)2

1(2

)(

4

)1()1()1()1(

BAreplyAroundAreplyAAroundABreplyABroundAAprop

eeTTTeTeTeTeT

total error due to clock

Calculations show that for 40 ppm crystals and 20 µs max differencebetween TroundA and TroundB and between TreplyA and TreplyB

an accuracy below 1 ns can easily be reached!


March 2005


IEEE-15-05-0126-00-004a

Submission

Example system EtA = ±40 ppm, EtB = ± 40 ppm (worst case combination):

d ∆d

(ΔTreply

= 20 ns)

∆d

(ΔTreply

= 200 ns)

∆d

(ΔTreply

= 2 µs)

∆d

(ΔTreply

= 20 µs)

10 cm ± 0.012 cm ± 0.12 cm ± 1.2 cm ± 12 cm

1 m ± 0.012 cm ± 0.12 cm ± 1.2 cm ± 12 cm

10 m ± 0.05 cm ± 0.12 cm ± 1.2 cm ± 12 cm

100 m ± 0.4 cm ± 0.4 cm ± 1.2 cm ± 12 cm

1 km ± 4 cm ± 4 cm ± 4 cm ± 12 cm

10 km ± 40 cm ± 40 cm ± 40 cm ± 40 cm

A ΔTreply of between 2 µs and 20 µs is typical for a low-cost implementation.

– Implementations with symmetry error below 2 µs are feasible.

Conclusion: Even a 20 µs symmetry error allows excellent single-pulse accuracy of distance.

Ranging: Ranging: Influence of Symmetry Error


March 2005


IEEE-15-05-0126-00-004a

Submission

Example system:Simulates SDS TWR +

Dithering & Averaging

Crystal Errors ±40 ppm

Single shot measurements

@ 1 MBit/s data rate (DATA-ACK)

Transmit Jitter = ± 4 ns (systematic/pseudo RN-Sequence)

Pulse detection resolution = 4 ns

Pulses averaged per packet = 32

Symmetry error = 4 µs (average)

Distance = 100 m

Results of Distance Error ∆d:

|∆dWC| < 50 cm

|∆dRMS| < 20 cm

Ranging: Ranging: Simulation of a SDS TWR System


March 2005


IEEE-15-05-0126-00-004a

Submission

Parameter mandatory option 1 option 2 option 3 　

peak payload bit rate(Rb) 1000 500 250 250 kbps

Average Tx Power(Pt) 10 10 10 1000 mW

Average Tx Power(Pt) 10 10 10 30 dBm

Tx antenna gain(Gt) 0 0 0 0 dBi

fc' = sqrt(fminfmax) -10dB 2.44 2.44 2.44 2.44 GHz

Path loss at 1meter(L1=20log10(4pifc'/c)) 40.2 40.2 40.2 40.2 dB

distance 30 30 100 1000 m

path loss at d m(L2=20log10(d)) 29.5 29.5 40 60 dB 　

Rx antenna gain(Gr) 0 0 0 0 dBi

Rx power(Pr = Pt+Gt+Gr-L1-L2(dB)) -59.7 -59.7 -70.2 -70.2 dBm

Average noise power per bit -114.0 -117.0 -120.0 -120.0 dBm

Rx Noise Figure(Nf) 7 7 7 7 dB

Average noise power per bit(Pn=N+Nf) -107.0 -110.0 -113.0 -113.0 dBm

Minimum Eb/No(S) 12.5 12.5 12.5 12.5 dB

Implementation Loss(I) 3 3 3 3 dB

Link Margin (M=Pr-Pn-S-I) @ distance d 31.8 34.8 27.3 27.3 dB

Proposed Min. Rx Sensitivity Level -91.5 -94.5 -97.5 -97.5 dBm

Selection Criteria Document TopicLink BudgetLink Budget

March 2005


IEEE-15-05-0126-00-004a

Submission

Power management aspects of this proposal are consistent with the modes identified in the IEEE 802.15.4: 2003 standard

There are no modes lacking nor added Once again, attention is called to the

1 Mbit/s basic rate of this proposal and resulting shorter “on” times for operation

Selection Criteria Document TopicPower Management ModesPower Management Modes

March 2005


IEEE-15-05-0126-00-004a

Submission

The typical DSSS receivers, used by 802.15.4, are very similar to the envisioned DBO-CSS receiver

The two major differences are the modulator and demodulator– The power consumption for a 10 dBm transmitter should be 198 mW or less

The receiver for the DBO-CSS is remarkably similar to that of the DSSS with the major difference being the correlator

– The difference in power consumptions between these correlators is negligible so the power consumption for a 6 dB NF receiver should be 40 mW or less

Power save mode is used most of the time for this device and has the lowest power consumption

– Typical power consumptions for 802.15.4 devices are 3 µW or less Energy per bit is the power consumption divided by the bit rate

– The energy per bit for the 10 dBm transmitter is less than 0.2 µJ– The energy per bit for the receiver is 60 nJ

As an example, the energy consumed during an exchange of a 32 octet PDU between two devices would be 70.6 µJ for the sender and 33.2 µJ for the receiver

Selection Criteria Document TopicPower ConsumptionPower Consumption

March 2005


IEEE-15-05-0126-00-004a

Submission

1Mbps / 500Kbps (No FEC) 250Kbps (FEC: r=1/2)

Logic Die Area Power Logic Die Area Power

RF@ Tx Power:

10mW

Tx + D/A - 1.7 mm2 130 mW - 1.7 mm2 130 mW

Rx + A/D - 1.6 mm2 25 mW - 1.6 mm2 25 mW

Common - 0.3 mm2 10 mW - 0.3 mm2 10 mW

Baseband@ Sampling-rate:

40MHz

Tx 1.5K 0.04 mm2 0.48 mW 1.6K 0.06 mm2 0.52 mW

Rx 49.4K 0.63 mm2 0.71 mW 145K 1.5 mm2 2.08 mW

Common 5K 0.08 mm2 0.42 mW 5K 0.08 mm2 0.42 mW

TotalTx

56K 4.35 mm2141 mW

152K 5.24 mm2141 mW

Rx 36.1 mW 37.5 mW

Deep Sleep 5 uW 5 uWTarget Library : 0.18 um Technology

■ Power Consumption for Average Throughput 1 Kbps (w/o FEC) - PTX : 141[mW] / 293 = 481 [uW] - PRX : 36.1[mW] /293 = 123 [uW]

■ Battery: 324[Joule] for Button Cell (10mm D. X 2.5mm H) / 12,000[Joules] for AA Alkaline Cell - (PTX + 50 X PRX)/51 = 130[uW] ----- (Assume TTX : TRX = 1:50 duty-cycle for sensor node) - Battery Life TB = 324/130e-6/3600/24 = 28.8 days Continuously (Button Cell) - Battery Life TB = 12000/130e-6/3600/24/365 = 2.93 years Continuously (AA Alkaline Cell)

Selection Criteria Document TopicPower ConsumptionPower Consumption

March 2005


IEEE-15-05-0126-00-004a

Submission

The antenna for this DBO-CSS proposal is a standard 2.4 GHz antenna such as widely used for 802.11b,g devices and Bluetooth devices.

These antennas are very well characterized, widely available, and extremely low cost.

Additionally there are a multitude of antennas appropriate for widely different applications.

The size for these antennae is consistent with the SCD requirement.

Selection Criteria Document TopicAntenna PracticalityAntenna Practicality

March 2005


IEEE-15-05-0126-00-004a

Submission

■ Antenna Size - less than SD-Memory size: 24mm X 14mm @2.4GHz 12mm X 9mm @5.2/5.7GHz

■ Frequency / Impulse Response - Almost Flat Freq. Response: Narrow-band

■ Radiation Characteristics - Isotropic: 0dBi

Selection Criteria Document TopicAntenna PracticalityAntenna Practicality

March 2005


IEEE-15-05-0126-00-004a

Submission

PAR and 5C RequirementChecklist

March 2005


IEEE-15-05-0126-00-004a

Submission

Requirements ChecklistDBO-CSS Proposal Meets the PAR and 5C: Precision ranging capability accurate to one meter or better Extended range over 802.15.4-2003 Enhanced robustness over 802.15.4-2003 Enhanced mobility over 802.15.4-2003 International standard Ultra low complexity (comparable to the goals for 802.15.4-2003) Ultra low cost (comparable to the goals for 802.15.4-2003) Ultra low power consumption (comparable to the goals for 802.15.4-2003) Support coexisting networks of sensors, controllers, logistic and peripheral devices in multiple compliant co-located systems.

March 2005


IEEE-15-05-0126-00-004a

Submission

Summary

March 2005


IEEE-15-05-0126-00-004a

Submission

SummaryDBO-CSS is simple, elegant, efficient: Combines DSSS and UWB strengths Precise location-awareness Robustness – multipath, interferers, correlation, FEC, 3 channels, CCA Mobility enhanced Optional backward compatibility with 802.15.4-2003 Excellent throughput SOPs – FD channels Signal Acquisition – excellent Link Budget and Sensitivity – excellent Very minimal MAC changes, CCA supported Power Management and Consumption - meets or exceeds requirements Antenna – many good choices Can be implemented with today’s technologies

• Low-complexity, low-cost• Size and Form Factor – meets or exceeds requirements• Low power consumption

Globally certifiable Scalability with many options for the future Meets all PAR and 5C requirements

Documents

IEEE-15-05-0126-00-004a Submission March 2005 Lampe, Hach, Menzer, Nanotron; Lee, OrthotronSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal