june 2020 project: ieee p802.15 working group for wireless ... · thz transmission and the future...

doc.: IEEE 802.15-20-0148—00-0thz_Integration of high-data rate THz-wireless

11 March 2019

June 2020

Carlos Castro, Fraunhofer HHISlide 1

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Submission Title: Integration of high-data rate THz-wireless systems into fiber-optical networksDate Submitted: 8 June 2020Source: Carlos Castro Company: Fraunhofer Heinrich-Hertz-InstituteAddress: Einsteinufer 37, 10587 BerlinVoice: +49 30 31002 659 E-Mail: [email protected]

Re: n/aAbstract: THz-wireless systems, due to their ability to transmit high data rates, appear to be an ideal approach to invest fiber-based networks with an unprecedented degree of flexibility. The key for this seamless interconnection is an analog baseband interface. In this presentation, we summarize our efforts to combine fiber-optics and THz-wireless in order to achieve >100Gb/s systems; first, by introducing a real-time optical modem for a purely THz-electrical setup, and second, by introducing an optic/THz baseband interface to construct a combined transmission link: a THz-wireless fiber extender.

Purpose: Information of the Technical Advisory Group THzNotice: 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.

© Fraunhofer HHI | 16.07.2019 | 2

INTEGRATION OF HIGH-DATA RATE THZ-WIRELESS SYSTEMS INTO FIBER-OPTICAL NETWORKS

IEEE 802.15

TAG THz,

Online Meeting – 09.06.2020

[email protected]

Carlos Castro1, Robert Elschner1, Thomas Merkle2, Colja Schubert1, Ronald Freund1

1. Fraunhofer Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin, Germany

2. Fraunhofer-Institut für Angewandte Festkörperphysik, Tullastraße 72, 79108 Freiburg im Breisgau, Germany

© Fraunhofer HHI | 09.06.20 | 3

H2020 EU TERRANOVA: Terabit/s Wireless Connectivity by TeraHertz innovative technologies to deliver Optical Network Quality of Experience in Systems beyond 5G

[email protected]

Duration: 7/2017 – 12/2019

ICT-09-2017 – Networking research beyond 5G

grant agreement no. 761794


OUTLINE

Motivation

100 Gb/s real-time experiments

THz-wireless system

Optic/THz-wireless system

Conclusions and future work

[email protected]


OUTLINE

Motivation


THz-wireless system



[email protected]


MotivationTHz transmission and the future of high-speed flexible wireless networks

THz wireless data transmission at carrier frequencies in the 100 – 1000 GHz range

Large bandwidth, compatible with state-of-the-art fibre-optical transmission systems

This allows to design flexible Terabit/s Wireless Systems capable of being directly integrated into fiber-based network architectures

[email protected]

THz

300

B <= 1 GHz B <= 10 GHz B <= 100 GHz

© Fraunhofer HHI | 09.06.20 | 7 [email protected]


Possible applications can be grouped into 3 particular scenarios:

Omnidirectional

Point-to-Multipoint

Point-to-Point



Seamless interconnection between fiber networks and THz-wireless links

Joint impairment mitigation of the combined optic/THz-wireless link


OUTLINE

Motivation


THz-wireless system



[email protected]


100 Gb/s real-time experiments – THz-wireless systemExperimental real-time THz-wireless system using a digital-coherent optical modem

~34 GBd PDM-QPSK modulation

2x2 polarization MIMO

CFP2-ACO pluggable interface

QSFP28 client side interface

x36

x368.31 GHz

x36

x36Rx 2

50 cm

I /Q2 2

2x2 MIMO real-time optical modem

Q1,2 I1,2 I2,1 Q2,1

CFP2-ACO Interface

QSFP28 Interface

Rx 1Tx 1

Tx 2

I /Q1 1

InP MMIC technology

BW: 25 GHz (Tx) 50 GHz (Rx)

23 dBi antennas

~300 GHz carrier

Length: 50 cm

Height: 20 cm above the metal ground plate

Separation: 12.5 cm lateral displacement


100 Gb/s real-time experiments – THz-wireless systemDSP chain used for the 100 Gb/s THz-wireless link

Reference case: Offline DSP commonly used in fiber-optical experiments

Similar algorithms implemented in real-time modem

Map

ping

Traini

ng-se

quen

ceins

ertio

n

Pulse

shap

ing

Pre-e

mpha

sis

Chan

nel

DAC

DAC

FE co

rrecti

ons

Frame

Sync

hron

izatio

n

Carri

er-o

ffset

comp

ensa

tion

Traini

ng-A

idedT

/2-sp

aced

Equa

lizer

Carri

er-P

hase

Estim

ation

Carri

er-P

hase

Estim

ation

T-spa

cedI

/Q Eq

ualiz

er

Dema

pping

& De

cision

BER c

ount

ing

Tx DSP Rx DSP

Rand

om bi

tseq

uenc

egen

eratio

n

[email protected]


100 Gb/s real-time experiments – THz-wireless systemPhysical layer performance using a digital-coherent real-time optical modem

Long-term stable (4 days of continuous operation) pre-FEC BER below SD-FEC threshold

0 12 24 36 48 60 72 84 961E-03

1E-02

1E-01Pr

e-FE

C BE

R

Elapsed time (hours)

Pre-FEC BER SD-FEC

Tx1 Rx1

Tx2 Rx2

Comparison to offline DSP: Pre-FEC BER better due to optimized DSP

8.8·10-4

Offline 100 Gb/s QPSK

C. Castro, et al., “100 Gbit/s Terahertz-Wireless Real-Time Transmission Using a Broadband Digital-Coherent Modem”, 5G World Forum, Dresden, 2019

[email protected]


100 Gb/s real-time experiments – THz-wireless systemEthernet tests using an IXIA XGS12 100 GbE traffic platform –Frame loss rate

The traffic platform defines the number of lost frames as follows:

lost frames = Tx frames – Rx frames

‘In transit’ is therefore an actual condition

Frame loss rate: 0.03 fps (1.85 fpm)

Frame size: random (70 – 1518 Bytes)

0 60 120 180

0

100

200

300

400

500

600

Lost

fram

es

Elapsed time (minutes)

8.545 µs / (794 Bframes · 8 bB /100 Gbs ) = 135 frames

[email protected]


100 Gb/s real-time experiments – THz-wireless systemEthernet tests using an IXIA XGS12 100 GbE traffic platform –Throughput

0 128 256 384 512 640 768 896 1024

86

88

90

92

94

96

98

100

Thro

ughp

ut (G

bit/s

)

Frame size (Bytes)

Payload type: Increment Byte Payload type: Random

Payload type does not influence the overall throughput of the system

Frame size does affect the overall throughput of the system

12-Byte long ‘interframe gap’ between frames

More frames more idle time less actual transmitted data

Max. measured data rate was 98.07 Gb/s

[email protected]


OUTLINE

Motivation


THz-wireless system



[email protected]


100 Gb/s real-time experiments – Optic/THz-wireless systemLink configurations for a THz-Wireless Fiber Extender

Fiber – THz Wireless – Fiber

Tx-D

SPRx

-DSP

X

X

Y

Y

8.311 GHz

8.311 GHzSynth T z Txh

Synth T z Rxh

1 m.. .103 km

1 m.. .103 km

Real-time digital coherent optical modem Optic-THz baseband interface

DACXQ

DACYI

DACYQ

ADCXI

ADCYI

ADCXQ

ADCYQ

DACXI

DP-

MZM

DP-

CoR

x

QSF

P28

SS MF

SS MF

T z Txh

T z Rxh

DP-

CoR

xD

P-M

ZM

x36

x36

100

Gb/

s Clie

nt-S

ide I

nter

face

50 cmT z-wireless linkh

I

QI

Q

I

QI

Q

THz Rx

THz Tx

Synth THz Rx

Synth THz Tx

THz wireless link

Fiber – THz Wireless

THz Wireless – Fiber

B2B

B2B

PC: phase conjugation. Inversion of in-phase components of both polarizations at the optic-THz BB interface

THz Wireless Link300 GHz carrier50 cm distance

The goal was to construct a short-range real-time implementation of a high-speed THz-wireless fiber extender as a proof-of-concept

[email protected]


100 Gb/s real-time experiments – Optic/THz-wireless systemPhysical layer performance of an optic/THz-wireless transmission system

BER performance vs. total fiber distance for different link configurations

Neither the fiber configuration nor the optical link distance seems to affect the overall performance

High OSNR: > 35 dB

THz-wireless link is the limiting factor

[email protected]

0 20 40 60 80 100

1E-02

1E-01 Fiber - THz wireless - Fiber Fiber - THz wireless THz wireless - Fiber Fiber - THz wireless - Fiber (PC) SD-FEC

BER

Total fiber distance (km)


100 Gb/s real-time experiments – Optic/THz-wireless systemPhysical layer performance of an optic/THz-wireless transmission system

Comparison to simulation results

Performance of a combined link is determined by the link with the worse SNR condition

Assuming there’s a large SNR difference between them

Evidence shows that the THz link operates in a low SNR condition 0.01 0.1 1

0

10

20

30

40

50

SNR T

RUE (

dB)

Distance THz Link (m)

No atm. loss OSNR 32 dB OSNR 28 dB OSNR 24 dB

16-QAM

4-QAM

64-QAM

0 20 40 60 80 100

1E-02

1E-01 Fiber - THz wireless - Fiber Fiber - THz wireless THz wireless - Fiber Fiber - THz wireless - Fiber (PC) SD-FEC

BER


[email protected]


100 Gb/s real-time experiments – Optic/THz-wireless systemDSP techniques and their application to optic/THz-wireless links –Estimated total accumulated chromatic dispersion

Chromatic dispersion is estimated as a function of the fiber distance

The THz fiber extender is transparent to CD

A slope of ~17 ps/km·nm can be extracted (SSMF)

Phase conjugator by inverting in-phase components at optic-THz interface 0 20 40 60 80 100

0

500

1000

1500

2000

Chro

mat

ic d

isper

sion

(ps/n

m)


Fiber - THz wireless - Fiber Fiber - THz wireless THz wireless - Fiber Fiber - THz wireless - Fiber (PC)

[email protected]


OUTLINE

Motivation


THz-wireless system



[email protected]


Conclusions and future workTowards integrated optic/THz-wireless connectivity for Beyond 5G

[email protected]

Experimental demonstration: 100-Gb/s THz Wireless Transmission over 0.5 m

Stable BER performance over 96 hours of continuous operation

Validation of 100 Gb/s throughput (98.08 Gb/s)

Experimental demonstration: Seamless interconnection between optical ransmission links and THz-wireless technologies

Real-time 100 Gb/s transmission over fiber + THz-wireless link

Demonstrated the linearity and transparency of the THz-wireless fiber extender

Next steps: Increase range, capacity and flexibility

Extend range by using high-gain antennas (1 km-long THz-wireless transmission)

28 GBd QPSK transmission over 1 km

Improve linearity and output power of electronic front-ends (high-order modulation formats)

Adaptive PHY DSP to cope with channel dynamics (better suited DSP techniques)


Contact:

Dr.-Ing. Carlos [email protected]+49 30 31002 659

Einsteinufer 3710587 Berlin

Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, HHIWE PUT SCIENCE INTO ACTION.

This work was supported by the Fraunhofer Internal Programs under Grant No. MAVO 836 966 and by the EC Horizon 2020 Research and Innovation Program under grant agreement No. 761794.

[email protected]

june 2020 project: ieee p802.15 working group for wireless ... · thz transmission and the future...

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