technologies for future mobile transport networks

Technologies for future mobile transport networks

Pham Tien Dat1, Atsushi Kanno1, Naokatsu Yamamoto1, and Tetsuya Kawanishi1,2

1National Institute of Information and Communications Technology, Japan2Wasdea university, Tokyo, Japan

FG IMT-2020 Workshop and Demo Day: Technology Enablers for 5G

Outline

Flexible fiber-wireless mobile fronthaul

• Downlink system

• Bidirectional transmission

Seamless fiber-wireless for moving cells

Multiple radios over fiber system

Conclusion

2

Flexible fiber-wireless transport systems

BBU BBU BBU

BBU pool

Core network

MUX/DEMUX

Control office

MUX/DEMUX

RRH

RRH

RRH RAU RAU RAU

3

Fiber-wireless convergence

Seamless optical and MMW connection: Low latency, low power

RAU

DigitalE/O O/E

DSP FE

LO

MMW

Conventional optical-MMW link: Large latency, high power

RAU

DigitalE/O O/E FE

Opt. LO

MMW

4

Operating principle

λ1 λ2

f

E/O O/E Down.

Microwave

MillimeterMicrowave

λ1 λ2

O/Econverter

Optical fiberλλ1 λ2

Δf

Freq.

f = |c/λ1-c/λ2|

Up.Down.E/OO/E

Microwave

LO

MillimeterMicrowave λ

5

VSA: Vector Signal AnalyserLNA: Low Noise AmplifierATT: AttenuatorOBPF: Optical Band Pass Filter

MZM: Mach-Zehnder ModulatorEDFA: Erbium-Doped Fiber AmplifierVSG: Vector Signal GeneratorPD: photo-detector

Downlink system: experimental setup

6

P. T. Dat et al., ECOC (2016)

1 m89.2 – 92.45

GHz

CS

AWGTwo-tone

opt. gen.

MZM

20 km

PCAWG

LNALNA

RRH

88.1 GHz

LTE-A F-O

FDM

÷PDPA

RAU

ATT1,549.4 1,550 1,550.6

-90

-70

-50

-30

-10

10

Wavelength (nm)

Pow

er (

dBm

)

EDFAEDFAOBPF OBPF

Downlink system: experimental results

7

Data 1 Data 2

-2 0 2 4 6 8Tx. LTE-A Power (dBm)

8

12

16

20

24

EVM

(%)

Sig. 1, data 1

Sig. 1, data 2

Sig. 2, data 1

Sig. 2, data 2

Sig. 3, data 1

Sig. 3, data2

Sig. 4, data 1

Sig. 4, data 2

0 1 2 3 4 5 6

Rx. Opt. Power (dBm)

8

12

16

20

24

EVM

(%)

Sig. 1, data 1

Sig. 1, data 2

Sig. 2, data 1

Sig. 2, data 2

Sig. 3, data 1

Sig. 3, data 2

Sig. 4, data 1

Sig. 4, data 2

Performance versus received optical powers Performance versus LTE-A signal powers

P. T. Dat et al., ECOC (2016)

1 1.5 2 2.5 3 3.5 4 4.5-70

-60

-50

-40

-30

-20

-10

Frequency (GHz)

Pow

er (d

Bm)

Sig.1 Sig.2 Sig.3 Sig.4

Bidirectional system: experimental setup

LNA LNA

Remote Radio Head

ED

DL LTE-Ainter-band 2

VSG

UL LTE-A

LO

96 GHz

Did.


VSA_1

VSA_2

Sync.

MZM

EDFA

PD PA10 km 92.5 GHz

Com.


Central StationRemote Antenna Unit


VSG_2

ATT

RoFRx.VSA

UL LTE-ARoFRx.

LNA

ED

LNA

96 GHz

VSG_1

ATT

Sync.

EDFA

Opt. MMW Gen.

830 840 850 860 870-120

-100

-80

-60

-40

Frequency (MHz)

Pow

er (

dBm

)

2.580 2.59 2.6 2.61 2.62-120

-100

-80

-60

-40

Frequency (GHz)

Pow

er (

dBm

)

8

Bidirectional: experimental results

Successful bidirectional transmission for CA LTE-A signals Applicable for future 5G signal transmission (256-QAM with EVM < 3.5%) PONs can be applied for optical transport (ITU-T req. for PONs: 15 dB)

P. T. Dat et al., OFC (2015)DL LTE-A signal

-2 0 2 4 6


0

2

4

6

8

10

12

EV

M (%

)

64-QAM, interband 1

64-QAM, interband 2

-2 0 2 4 6


0

2

4

6

8

10

12

64-QAM, interband 1

64-QAM, interband 2

Only DL With UL

-15 -10 -5 0 5


2

4

6

8

10

12

64-QAM, no DL

64-QAM, with DL

UL LTE-A signal

>17 dB

9

Seamless fiber-wireless for moving cells

Millimeter-wave

WDM Radio over Fiber

Linearly located remote cells

Metro/Access Network Control Station

RAU #1 RAU #2 RAU #n

Multiplexer

Aisle Seat

From outside

P. T. Dat et al., IEEE Commun. Mag. (2015)

10

Network control and moving cells

Switch

Metro/Access Network

Location position

Switch control

Uplink power

λ1, λ2 λ3, λ4

Control Office

WDM RoF Tx.W

DM

D

EMU

X

λ n-1, λn

Signal Processing

Units

ModulationModulation

Modulation

11

Proof-of-concept: experimental setup

DPMZM: Dual-parallel MZMOBEF: Optical band pass elimination filterOBPF: Optical band pass filterATT: AttenuatorP-S: Power SplitterISO: IsolatorPS: Phase shifter

EDFA 1 km

MZM2 EDFALD2

20 km

CS

ATT

(1)

LD1 MZM1

DPMZMLD

OBEF EDFA OBPF

Opt. MMW Gen. 1LO_1

(3)

(2)

RAU_1PD PA

X

PD

LNA

RoFTx.

LNA

P-S

ATT. PA

ISO ISOPS

SHD

TAU

Opt. MMW Gen. 2ATT

ATT

RoFRx.

ATT

LO_2LO_3

VSA

PC VSG

(4)

(5)

(6)

1548 1552 1556-80

-60

-40

-20

0

Wavelength (nm)1547 1551 1555

-80

-60

-40

-20

0


-80

-60

-40

-20

0


-80

-60

-40

-20

0

Wavelength (nm)

Powe

r (dBm

)

1548 1549 1550 1551-80

-60

-40

-20

0


-80

-60

-40

-20


-80

-60

-40

-20

Wavelength (nm)

(1) (2) (3) (3) (4) (5) (6)

RF cable

10 MHz

RAU_2

AP 20 GHz40 GHz

41.9 GHz

23.125 GHz

IF

LO

P. T. Dat et al., OFC (2016)

12

Good performance for both backhaul and over in-train networks High-spectral efficiency, low fiber-dispersion, cost effective system

-6 -4 -2 0 2 44

6

8

10

IF Tx. Power (dBm)

EVM

(%)

-4 -2 0 2 4 64

6

8

10

IF Tx. Power (dBm)

32-QAM, CH164-QAM, CH132-QAM, CH264-QAM, CH2

32-QAM, CH164-QAM, CH132-QAM, CH264-QAM, CH2

P. T. Dat et al., OFC (2016)

Proof-of-concept: experimental results

30-MHz OFDM signal 50-MHz OFDM signal

13

Multiple radios over fiber

14

Signal-1 Subcarrier mapping IFFT-1 CP-1

Subband-1filter

Signal-K Subcarrier mapping IFFT-K CP-K Subband-K

filter

+

Multi-RATs over seamless fiber-wireless system

Data mapping using F-OFDM

4G or control signals DAC

+ E/O

Optical LO

BBU pool-1

BBU pool-N

DSP-based mapping DAC

MFHRAT-14G LTE

O/E

CPRI for fronthauling: bit rate >> 100 Gb/s/cell.

RoF: high-speed components, massive systems

Cooperation of optical and radio access networks

Multiple radios over fiber: experimental setup

20 km

MZM

EDFA

LD

CS

DPMZMLD

EDFA OBPFFrequency

Doubler

VSG VSGLTE-A

IFCom.

AWG

12 GHz

ATT

RRH

PDPDATT

25-GHz RAT

LPF

IF signal

LO signal

OBPF

OBPFVSA

21 GHz

User

RAU

PDATT

Div.LTE-A

X4

OBPF

ATT PDOBPF

2.5 m96-GHz

MFH

95 GHz

OSC

RRH

HPF

MZM: Mach-Zehnder ModulatorEDFA: Erbium-Doped Fiber AmplifierVSG: Vector Signal GeneratorCom.: RF combinerPD: photo-detector

Did. RF DividerVSA: Vector Signal AnalyserLNA: Low Noise AmplifierATT: Attenuator(O)BPF: (Optical) Band Pass Filter

PC

15

1555.6 1556Wavelength (nm)

-90

-70

-50

-30

-10

10

Pow

er (d

Bm)

Multiple radios over fiber: experimental results

-8.5 -7.5 -6.5 -5.5 -4.5


10

12

14

16

18

20

EV

M (

%)

Signal 1

Signal 2

Signal 3

Signal 4

6 8 10 12 14 16

Tx. LTE-A Power (dBm)

10

12

14

16

EV

M (%

)

Signal 1

Signal 2

Signal 3

Signal 4

0.5 1 1.5 2 2.5 3

Frequency (GHz)

-110

-90

-70

-50

-30

Po

we

r (d

Bm

)

OFDM LTE-A

Sig. 1 Sig. 2 Sig. 4Sig. 3

OFDM NOMA (16 x 16) SCMA

3.96 4 4.04Frequency (GHz)

-90

-50

-10

Pow

er (d

Bm)

OFDM

FBMC

-10 -8 -6 -4


2

4

6

8

OFDM

OFDM NOMA

OFDM SCMA

FBMC

-18 -14 -10 -6


1

2

3

4

CC1 (20 MHz)

CC2 (20 MHz)

CC3 (20 MHz)

EV

M (%

)

F-OFDM Signal

LTE-A Signal New RAT signal (OFDM/FBMC) 16

Summary

Seamless convergence of fiber-MMW would be a potential solution for future mobile fronthauling when fiber cable is not available.

Convergence of WDM IFoF and linearly located distributed antenna systems is very promising for high-speed communication to high-speed trains.

Co-design and cooperative fiber-radio access networks would be the key for future MMW and massive MIMO mobile signal, and multi-RAT transmission.

17

Thank you [email protected]

This work was conducted as a part of the “Research and development for expansion of radio wave resources,” supported by the Ministry of

Internal Affairs and Communications (MIC), Japan.

mailto:[email protected]