Ph. D. Thesis Proposal Presentation

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Universitat Politècnica de Catalunya (UPC)Dept. of Signal Theory and Communications (TSC)

Optical Communications Group (GCO)www.tsc.upc.edu/gco

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HomodyneHomodyne OLTOLT--ONUONU designdesign for for

accessaccess opticaloptical networksnetworks

AdvisorAdvisorAdvisorAdvisor: Josep Prat : Josep Prat : Josep Prat : Josep Prat StudentStudentStudentStudent: Josep M: Josep M: Josep M: Josep Mªªªª FFFFààààbregabregabregabrega


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ThesisThesisThesisThesis proposalproposalproposalproposal

� Introduction

∙ Homodyne systems in access networks

� State of the art

∙ What we have done

� Thesis index

� Work plan

� Publications and dissemination


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IntroductionIntroductionIntroductionIntroduction

� Migration from TDM/WDM to pure WDM [1]

� Ultra-dense WDM PONs

∙ Multiple low capacity channels

� E.g. 1 Gbps

λ

More than 1500 ch. at C band

...........................

3 GHzOL


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IntroductionIntroductionIntroductionIntroduction

∙ IM-DD systems limited

� Sensitivity

�Optical filters selectivity

∙ Coherent systems

�Heterodyne

– Image frequency problems

�Homodyne

– Phase locking problems [2] LocalLaser

+

-

+

-OpticalInput Ip(t)


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Network Schemes

D-WDM MUX

(RN 1)

CO

powersplitter(RN 2)

λ1 .. λN D-WDM bands

Nx PONs

λ1D-WDM band

λN D-W

DM band

K UD-WDM channels

D-WDM band

CPE

CPE

CPE

CPE

CPE

CPE

K CPEs

D-WDM MUX

(RN 1)

CO

D-WDM MUX

(RN 1)

CO

powersplitter(RN 2)

λ1 .. λN D-WDM bands

Nx PONs

λ1D-WDM band

λN D-W

DM band

K UD-WDM channels

D-WDM band

CPE

CPE

CPE

CPE

CPE

CPE

K CPEsOLT

CO

CPE

CPE

CPE

CPE

CPE

CPE

CPE

CPE

CPE

CPE

CPE

CPE

CPE

CPE

2) with MUX & splitters[D8]:1) with splitters

CO

RN16 RN1

RN i

ON ONU

1:32

ON ONU

Pump Pump

down-signals

WDM WDM 100 km Ring

1:32

ON ONU

ON ONU

Add/Drop

rEDFs rEDFs

λ i2 λ i1

Pump

up-signals

3) SARDANA [3]:

K UD-WDM channelsK UD-WDM channels

RN x up

� 1 wavelength � 1 user� Long reach (>100 km)� Large number of users

(>1500 @ 1 Gbps)� No TDM bandwidth

sharing


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OLT and ONU OLT and ONU OLT and ONU OLT and ONU philosophyphilosophyphilosophyphilosophy

� OLT Tx/Rx and ONU are intended to have the same architectures

� PSK main modulation format for bothupstream and downstream

� Other modulation formats can be envisaged (PSK/IM, QAM/QAM)

� Main impairments

∙ Laser phase noise

∙ Polarization fluctuations


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� Introduction


� StateStateStateState of of of of thethethethe artartartart

∙ WhatWhatWhatWhat wewewewe havehavehavehave donedonedonedone

� Thesis index

� Work plan



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ONU ONU ONU ONU SchemesSchemesSchemesSchemes

� Optical Phase-Locked Loop

� Phase/Polarization diversity

� Phase/Polarization scrambling


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ONU Schemes: oPLL ONU

� Several oPLL architectures to study∙ Costas Loop [4]∙ Decision Driven [5]∙ Balanced [6]∙ Lock-In amplifier (heterodyne) [7]∙ SubCarrier Modulated [8]

� BER-floor∙ 10º � 10-9 BER � SCM ∙ 28º � 10-3 BER � Lock-In

� Hold-In margin∙ SCM: 7.68 GHz ∙ Lock-In: 896 MHz

0

3

6

9

12

15

18

21

24

27

30

0 1 2 3 4 5 6 7

Total laser linewidth (MHz)

Ph

ase

erro

r d

evia

tio

n (

deg

rees

)

SubCarrier Modulated

CostasBalanced

Heterodyne

Linewidth tolerance for several loops

Local

Laser

+

-

+

-

PM or IM Modulator

Phasecontrol and

recovery

Optical In/Out Data out

0

1

2

3

4

5

6

7

8

9

Heterodyne Balanced Costas SC-PLL

Ho

ld-I

n m

arg

in (

GH

z)

Hold-In Margin for several loops


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ONU Schemes: 90º Hybrid ONU

� Low cost if implemented with polymeric waveguides� Polarization insensitive when combined with PBS� Possible use of advanced and non-linear signal

processing techniques to improve data detection [9]� Total laser linewidth per symbol rate ratio tolerance

up to 3.2% using linear phase estimation [10]

Locallaser

PM or AM Modulator

Data

Data Out

90º Hybrid

ADCI and Q

Post-processing

Optical In /Out

Wavelength control

I

Q


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ONU schemes: Phase Scrambling ONU

� Very simple optics� Total laser linewidth per symbol rate ratio

tolerance up to 18%� <3GHz ch. spacing at 1 Gbps (<1.5 dB penalty)� -38.7 dBm sensitivity @ 10-9 BER� ~3 dB penalty due to phase scrambling� Idea and first experiments [D2, D4, D9, D12]� Digital Signal Processing version based in

Fuzzy logic data estimation [D3]� Version with both, polarization and phase

scrambling

Local

Laser

+

-

+

- I and QPost-processingPM or IM

ModulatorPhase

Scrambler

CLKRecovery

Data outOptical In/Out

I Q

t0 t0+T/2 t0+Tt

I Q

t0+3T/2 t0+2T

-10

-9

-8

-7

-6

-5

-4

-3

-2

-48 -46 -44 -42 -40 -38 -36

Input power (dBm)

log

(BE

R)

Downstream

Upstream

0

0,5

1

1,5

2

2,5

3

3,5

0 1 2 3 4 5 6 7

Channel spacing (GHz)

Sen

siti

vity

pen

alty

(d

B)

Sensitivity penalty vs channel spacing

Sensitivity measurements


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ONU schemes: Phase Scrambling ONU

� Low cost homodyne receiver� Very simple optics� Total laser linewidth per symbol rate ratio

tolerance up to 3.2%� ~3 dB penalty due to phase scrambling� Sensitivity expected -36 dBm @ 10-9 BER� Idea and first results [D4]

Optical In /Out

-5

-4

-3

-2

-1

1 2 3 4 5 6 7 8 9 10

Linewidth/bitrate (%)

log

(BE

R)

γ =1

γ =

Square wave

Local

Laser

+

-

+

- I and QPost-processingPM or IM

Modulator

CLKRecovery

Data out

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

-43 -42 -41 -40 -39 -38 -37 -36 -35

Received Power (dBm)

log

(BE

R)

γ =1

γ =

Square wave

Sensitivity results

BER-floor vs laser linewidth

127º


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OLT Scheme

� Transceivers scheme same as ONU

� Polarization scrambling can be done at OLT

K Tx/Rx

Tx/Rx

BidirectionalPolarizationScrambler

t t+T t+2T

Q Q Q QI I I I

H H H HV V V V

� At the OLT

∙ Phase scrambling is done at Tx/Rx

∙ Polarization scrambling is done after coupling transceiver outputs

� At the ONU

∙ Only phase scrambling


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� Introduction




� ThesisThesisThesisThesis indexindexindexindex

� Work plan



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ThesisThesisThesisThesis indexindexindexindex

� Executive summary � Introduction

∙ Background ∙ Scope of work ∙ Document organization

� Network topologies ∙ Tree topologies ∙ Ring topologies

� OLT and ONU architectures ∙ Lock-In amplifier oPLL architecture∙ Phase / polarization diversity architectures

� i. Full phase / polarization diversity– 1. K-L phase estimation– 2. Fuzzy data estimation

� ii. Time switched phase / polarization diversity– 1. Differential detection– 2. K-L phase estimation– 3. Fuzzy data estimation

� c. Performance summary

� Cost analysis and comparison � Conclusions and future lines � Publications � References � Appendixes


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� Introduction




� Thesis index

� WorkWorkWorkWork planplanplanplan



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WorkWorkWorkWork PlanPlanPlanPlan

� Research period∙ Reach a complete knoweldege on:

� Signal processing

� Network topologies

� Tx/Rx architectures

∙ Propose improvements/original techniques

� Evaluation of the architectures∙ Simulations

∙ Proof-of-concept experiments.

� Prototype implementation∙ Prototype assembled in some PON testbeds

∙ Arrange stays outside UPC (perform late experiments)

� Redaction of the thesis


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WorkWorkWorkWork PlanPlanPlanPlan

Redaction of the thesis (6 months)

Prototype implementation (6 months)

Evaluation of the architectures (12 months)

Research period (19 months)

2009

2008

2007

2006

decnovoctsepaugjuljunmayaprmarfebjan


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� Introduction




� Thesis index

� Work plan

� PublicationsPublicationsPublicationsPublications and and and and disseminationdisseminationdisseminationdissemination


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PublicationsPublicationsPublicationsPublications and and and and disseminationdisseminationdisseminationdissemination

PATENTSPATENTSPATENTSPATENTS[D1] Josep Prat, Josep M. Fàbrega “Receptor homodino para comunicaciones ópticas con procesado a posteriori,” P-200700041, priority date:

29/12/2006[D2] Josep Prat, Josep M. Fàbrega, Joan M. Gené “Receptor coherente homodino para comunicaciones ópticas con demodulación diferencial,” P-

200500998, priority date: 21/04/2005

JOURNAL ARTICLESJOURNAL ARTICLESJOURNAL ARTICLESJOURNAL ARTICLES[D3] J. M. Fàbrega, J. Prat, “Experimental Investigation of Channel Crosstalk in a Time-Switched Phase Diversity Optical Homodyne Receiver,” OSA

Optics Letters, vol. 34, No. 4, February 2009[D4] J. M. Fàbrega, J. Prat, “Homodyne receiver prototype with time-switching phase diversity and feedforward analog processing,” OSA Optics

Letters, vol. 32, No. 5, March 2007[D5] J. M. Fàbrega, J. Prat, “Fuzzy Logic Data Estimation Based PSK Receiver with Time-switched Phase Diversity”, IEE Electronics Letters, vol. 42,

no. 16, August 2006

CONFERENCESCONFERENCESCONFERENCESCONFERENCES[D6] J. M. Fabrega, E. T. López, J. A. Lázaro, M. Zuhdi, J. Prat, “Demonstration of a full duplex PON featuring 2.5 Gbps sub carrier multiplexing

downstream and 1.25 Gbps upstream with colourless ONU and simple optics” European Conference on Optical Communications ECOC'08, Brussels, Belgium, September 2008.

[D7] J. M. Fabrega, L. Vilabru, J. Prat, “Experimental Demonstration of Heterodyne Phase-locked loop for Optical Homodyne PSK Receivers in PONs” International Conference on Transparent Optical Networks ICTON’08, Athens, Greece, June 2008.

[D8] J. M. Fabrega, J. Prat, “Simple Low-Cost Homodyne Receiver,” European Conference on Optical Communications ECOC'07, Berlin, Germany, September 2007.

[D9] J. Prat, J. A. Lázaro, J. M. Fabrega, V. Polo, C. Bock, C. Arellano, M. Omella, “Next Generation Architectures for Optical Access and EnablingTechnologies,” 5ª Reunión española de Optoelectrónica OPTOEL’07, Bilbao, Juliol de 2007

[D10] J. M. Fabrega, J. Prat, ““““Channel Crosstalk in ultra-dense WDM PON using Time-Switched Phase Diversity Optical Homodyne Reception,”International Conference on Transparent Optical Networks ICTON’07, Rome, Italy, July 2007.

[D11] J. M. Fabrega, J. Prat, “Homodyne PSK Receiver with Electronic-Driven Phase Diversity and Fuzzy Logic Data Estimation”, EuropeanConference on Optical Communications ECOC'06, Cannes, France, September 2006.

[D12] C. Bock, J. M. Fabrega, J. Prat, “Ultra-Dense WDM PON based on Homodyne Detection and Local Oscillator Reuse for UpstreamTransmission”, European Conference on Optical Communications ECOC'06, Cannes, France, September 2006.

[D13] J. M. Fabrega, J. Prat, “Homodyne Receiver Implementation with Diversity Switching and Analogue Processing”, European Conference on Optical Communications ECOC'06, Cannes, France, September 2006.

[D14] J. M. Fabrega, J. Prat, “Optimization of Heterodyne Optical Phase-Locked Loops: Loop Delay Impact and Transient Response Performances”, International Conference on Telecommunications ICT’06, Funchal (Madeira), Portugal, May 2006.

[D15] J. M. Fabrega, J. Prat, “New Intradyne Receiver with Electronic-Driven Phase and Polarization Diversity”, Optical Fiber CommunicationOFC/NFOEC’06, paper JThB45, Anaheim (CA), USA, March 2006.

[D16] J. Prat, J.M. Fabrega, “New Homodyne Receiver with Electronic I&Q Differential Demodulation”, European Conference on OpticalCommunications ECOC'05, paper We4.P.104, Glasgow, UK, September 2005.

� 2 patents

� 3 journal articles

� 11 conference contributions (6 ECOC, 1 OFC, and others)


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ReferencesReferencesReferencesReferences

[1] C.-H. Lee, W. V. Sorin and B. Y. Kim, “Fiber to the Home Using a PON Infrastructure”, Journal of Lightwave Technology, vol. LT-24, no. 12, Dec. 2006, pp. 4568-4583

[2] L. Kazovsky, G. Kalogerakis and W.-T. Shaw, “Homodyne Phase-Shift-Keying Systems: Past Chalenges and Future Opportunities,” Journal of Lightwave Technology, vol. LT-24, no. 12, Dec. 2006, pp. 4876-4884

[3] J. A. Lázaro et al. “Scalable Extended Reach PON,” in Proc. OFC/NFOEC 2008, OThL2.

[4] H.K.Philipp, A.L.Scholtz, E.Bonek, W.R.Leeb, “Costas Loop Experiments for a 10.6µm Communications Receiver”, IEEE Transactions on Communications, vol. COM-31, no. 8, Aug. 1983.

[5] L.G. Kazovsky, “Decision-Driven Phase-Locked Loop for optical homodyne receivers: performance analysis and laser linewidth requirements” Journal of LightwaveTechnology, vol LT-3, no. 6, Dec. 1985

[6] L.G. Kazovsky, “Balanced PLL for optical homodyne receivers: performance analysis, design considerations, and laser linewidth requirements,” Journal of LightwaveTechnology, vol LT-4, no. 2, Feb. 1986

[7] K.H. Kudielka and W. Klaus, “Optical homodyne PSK receiver: Phase synchronization by maximizing baseband signal power,” in Proc. LEOS 1999, TuU2.

[8] S. Camatel et al., “Optical phase-locked loop for coherent detection optical receiver,”Electronics Letters, vol. 40, no. 6, Mar. 2004

[9] R. Noé, “Phase noise-tolerant synchronous QPSK/BPSK baseband-type intradynereceiver concept with feedforward carrier recovery,” Lightwave Technology, Journal of, 2005, 23, 802-808 (2005)

[10] M. G. Taylor, “Accurate digital phase estimation process for coherent detection using a parallel digital processor” 31st European Conference on Optical Communication, 2005. ECOC 2005. Volume 2, 25-29 Sept. 2005 Page(s):263 - 264 vol.2


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Universitat Politècnica de Catalunya (UPC)Dept. of Signal Theory and Communications (TSC)

Optical Communications Group (GCO)www.tsc.upc.edu/gco

Univ

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Politè

cnic

ade C

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lunya

ThanksThanks!!!!

Josep MJosep MJosep MJosep Mªªªª FFFFàààà[email protected]

Ph. D. Thesis Proposal Presentation

Technology

Transcript of Ph. D. Thesis Proposal Presentation