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R&D activities of radio-over-fiber technology
in NICTToshiaki Kuri
National Institute of Information and Communications Technology (NICT)
IMT-2020/5G Workshop and Demo Day (Geneva, Switzerland, July 11, 2017)
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Acknowledgement
I would like to thank
Dr. Atsushi Kanno (NICT),Dr. Pham Tien Dat (NICT),
Dr. Naokatsu Yamamoto (NICT),Dr. Toshimasa Umezawa (NICT), and
Prof. Tetsuya Kawanishi (Waseda Univ./NICT).
Some resultants of the “Research and Development to Expand Radio Frequency Resources” project supported by the Ministry of Internal Affairs and Communications (MIC), Japan are included in this presentation.
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Outline
1. What is Radio-over-Fiber (RoF)
2. R&D Examples of RoF technologies
3. Standardization activities of RoF
technologies at ITU-T SG15
4. Summary
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Applications of RoF technologiesWhat is radio-over-fiber (RoF) ?
[Ref.] A. Kanno, T. Kuri, and T. Kawanishi, “Radio wave transmission via an optical link,” NICT NEWS, no.432, pp.5-6, Sept. 2013.(http://nict.go.jp/en/data/nict-news/NICT_NEWS_1309_E.pdf) [Figure is modified.]
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What is radio-over-fiber (RoF) ?
• Two featuresØ Preservation of waveformØ Tolerance to electro-magnetic interference
Features of RoF technologies
RF signal source
RF signal RF signalLightwave modulated by RF signal
the same waveform
No interference from radio signal
outside of fiber
E/O conversion
Optical fiber
O/E conversion
RF: radio frequency
E/O: electrical-to-optical
O/E: optical-to-electrical
[Ref.] ITU-T G-series Recommendations – Supplement 55 (07/2015), Radio-over-fibre (RoF) technologies and their applications (http://www.itu.int/rec/T-REC-G.Sup55-201507-I).
Applicable to IMT-2020/5Gsystems
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LTE VSG
Measu
red
op
tical
po
wer
[dB
m]
LTE SARoF Tx
OLT
E/O converter O/E converter
ODN
No reach extender
(No optical amplifier)
SNI S/R R/S UNIONU
25+5+10 km
3 cascaded
SMFs
20
10
0
-10
-20
-30
-40
0 dB
10 dB
20dB
30 dB
Auto-current
controlSplitting loss
emulation
LTE band #7 EVM
measurement
0-30 dBBW: 1 nm
λc: 1549.5 nm
BW: ≤3 GHzfRF: 2.68 GHzBW: 20 MHz
RoF RxVOA EDFA OBPF
BW: ≤3 GHz
R&D examplesRoF transmission of an LTE signal over
a typical optical distribution network (ODN) used in PON systems
[Ref.] ITU-T G-series Recommendations – Supplement 55 (07/2015), Radio-over-fibre (RoF) technologies and their applications (http://www.itu.int/rec/T-REC-G.Sup55-201507-I).
Strong candidate of front-haul technologies
Radio signal generator
Remote radio head
Interconnection with RoF technology
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defined in the ITU-T G-series Recs. of PON systems
EVM
[%rm
s]
Optical path loss [dB]
Required EVM for 64QAM (8 [%rms])Required EVM for 16QAM (12.5 [%rms])
20-MHz bandwidth QPSK20-MHz bandwidth 16QAM20-MHz bandwidth 64QAM
After 40-km SMF
ODN classes
N1 classN2 class
E1 classE2 class
80
70
60
50
40
30
20
10
00 10 20 30 40 50 60
Required EVM for QPSK (17.5 [%rms])
EVM for back-to-back: < 1
[Ref.] ITU-T G-series Recommendations – Supplement 55 (07/2015), Radio-over-fibre (RoF) technologies and their applications (http://www.itu.int/rec/T-REC-G.Sup55-201507-I).
R&D examplesMeasured EVM (transmission quality)
Also useful for microwave-band IMT-2020/5G systems
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R&D examplesDSP-assisted analog RoF technologies (100-GHz-band)
≥ 40 Gbit/s
Radio receiver with digital signal processing
Optical frequency
~ 100GHz
16-QAM signal
Optical technology Digital signal
High-speed digitalsignal processing
RoF technology
Millimeter-wave-band radio signal(s)
[Ref.] A. Kanno, T. Kuri, and T. Kawanishi, “Radio wave transmission via an optical link,” NICT NEWS, no.432, pp.5-6, Sept. 2013.(http://nict.go.jp/en/data/nict-news/NICT_NEWS_1309_E.pdf) [Figure is modified.]
Optical multi-level modulator
Direct optical-to-millimeter-
wave converter
Millimeter-wave signal generator
w/ optical technol.
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R&D examples
10 Gbaud
V-pol. H-pol.
20 Gbaud
Receiver
Transceiver
Optical fiber
RF shield room
90-GHz wireless link20-Gbaud QPSK
RoF signal generator
RoF transmission experiment in shield room
Useful for future millimeter-
wave-band and high-bit-rate 5G/B5G systems
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Macro-cell Small-cell
●High data rate : > 10 Gbps ●High capacity ●Low latency ●Low cost
BBUsFibersBBU
RRH
Fiber
R&D examplesAdvanced wireless network for IMT-2020/5G systems
●High O/E efficiency ●High output power
Our developed key component for O/E conversion
Over 100GHz responsivity with no bias
[Ref.] T. Umezawa, K. Kashima, A. Kanno, A. Matsumoto, K. Akahane, N. Yamamoto, and T. Kawanishi “100-GHz Fiber-Fed Optical-to-Radio Converter for Radio- and Power-Over-Fiber Transmission,” IEEE J. Selected Topics in Quantum Elec., vol.23, no.3, May/June 2017.
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Foreign object debris (FOD) detection system by using millimeter-wave-band frequency-modulated continuous-wave (FM-CW) signal
Millimeter-wave-bandFM-CW signal
Optical distribution network
Debris (FOD) Alert
High-precision imaging technology using 90-GHz-band linear cells (Collaborative R&D project: FY2011- FY2015)
R&D examples
RoF technology
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Standardization activities at ITU-T SG15ITU-T G-series Recommendations – Supplement 55 (07/2015)
Radio-over-fibre (RoF) technologies and their applications
Table of contents1. Scope2. References3. Definitions4. Abbreviations and acronyms5. General concept6. System architectures7. Fundamental technologies8. Network models9. System design for supporting radio access system over
optical access networkBibliography
[Ref.] ITU-T G-series Recommendations – Supplement 55 (07/2015), Radio-over-fibre (RoF) technologies and their applications (http://www.itu.int/rec/T-REC-G.Sup55-201507-I).
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Standardization activities at ITU-T SG15Draft ITU-T G-series Recommendations
Radio over fiber systems（G.RoF）（from July 2015）
l Abstract（from draft version.0.6 (June 27, 2017)）This recommendation specifies radio over fiber transmission systems suitable for access network applications.
l Scope（from draft version.0.6）This recommendation develops a new type of optical access network based on radio-over-fiber (RoF) technologies. In general, RoF technologies can be classified into two groups, analog RoFand digital RoF. The digital RoF requirements may be satisfied by elements of the G.989 series with necessary enhancements. The analog RoF system is currently unspecified in any other recommendation. The recommendation will include consideration of the common applications, the requirements that stem from these, the specification of the analog optical link and/or the necessary functions to digitally carry the radio signals over various optical access systems, the associated signal processing, and the management aspects of the systems.
l Co-editors (Q2/15: SG15 Question 2 “optical systems for fibre access network”)Seung-Hyun CHO (ETRI), Toshiaki KURI (NICT), Yuanqiu LUO (Futurewei Tech. Inc.)
[Ref.] ITU-T SG15 (http://www.itu.int/ITU-T/workprog/wp_item.aspx?isn=10590)
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SummaryR&D activities of RoF technologies in NICT
• Overview of RoF technologies
• Introduction of some R&D examplesü RoF transmission of LTE signal over PON ODNü RoF transmission of W-band signalü Communication system applicationü FM-CW radar system application
• Introduction of standardization activities at ITU-T SG15ü G Suppl.55 “RoF technologies and their applications”ü G.RoF “RoF systems”
