Abstract

Directly modulated lasers (DMLs) and electro-absorption modulated lasers (EMLs) are key transmitter options in future short-haul networks. However, both of them suffer from frequency chirp, which incurs nonlinear distortions, especially to high order modulation signals. In this paper, we investigate their application in PAM4-based digital mobile fronthaul and propose a scheme to remarkably improve the fidelity of radio signal. We first give a detailed study of the BER distribution of DML/EML based PAM4 signals and find that the BER of the second bit is much higher than that of the first bit in both systems. Accordingly, we propose to adopt sample bit interleaving to reduce the radio signal distortions caused by sample bit errors. Experimental results of 56Gbps I/Q data transmission reveal that, in a DML-based transmission system, the proposed scheme respectively leads to up to 8dB and 13dB EVM reduction to accommodate 33 × 100MHz 1024QAM OFDM signals and 64QAM OFDM signals in 10km and 20km cases. As well as in an EML-based transmission system, 14dB EVM reduction is achieved in 10km to finally accommodate 33 × 100MHz 256QAM OFDM signal.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

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References

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    [Crossref]
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    [Crossref] [PubMed]
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    [Crossref]
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    [Crossref]
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    [Crossref]
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    [Crossref]
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    [Crossref]
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    [Crossref]
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    [Crossref] [PubMed]
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    [Crossref]
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    [Crossref] [PubMed]
  19. B. Guo, W. Cao, A. Tao, and D. Samardzija, “CPRI compression transport for LTE and LTE-A signal in C-RAN,” in Proceedings of Int. Conf. on Comm. and Networking in China. (IEEE, 2012) pp. 843–849.
  20. CPRI specification V6.1 (2014–7-1). (2014). [Online]. Available: http://www.cpri.info/spec.html
  21. 3GPP TS 36.104 version 14.3.0, “Base station (BS) radio transmission and reception,” 2017.
  22. N. Kikuchi, R. Hirai, and T. Fukui, “Non-linearity compensation of high speed PAM4 signals from directly modulated laser at high extinction ratio,” in Proceedings of European Conference on Optical Communication (ECOC) (2016), paper M2B.4.
  23. J. M. Castro, R. J. Pimpinella, B. Kose, Y. Huang, A. Novick, and B. Lane, “Eye skew modeling measurements and mitigation methods for VCSEL PAM-4 channels at data rates over 66 Gb/s,” in Optical Fiber Communications Conference (OFC) (2017), paper W3G.3.
    [Crossref]
  24. P. T. Ferrera, S. Straullu, S. Abrate, and R. Gaudino, “Upstream and downstream analysis of an optical fronthaul system based on DSP-assisted channel aggregation,” J. Opt. Commun. Netw. 9(12), 1191–1201 (2017).
    [Crossref]
  25. B. Wedding, B. Franz, and B. Junginger, “10-Gb/s optical transmission up to 253 km via standard single-mode fiber using the method of dispersion supported transmission,” J. Lightwave Technol. 12(10), 1720–1727 (1994).
    [Crossref]

2018 (1)

2017 (10)

H. Li, R. Hu, Q. Yang, M. Luo, Z. He, P. Jiang, Y. Liu, X. Li, and S. Yu, “Improving performance of mobile fronthaul architecture employing high order delta-sigma modulator with PAM-4 format,” Opt. Express 25(1), 1–9 (2017).
[Crossref] [PubMed]

M. Xu, F. Lu, J. Wang, L. Cheng, D. Guidotti, and G. K. Chang, “Key technologies for next-generation digital RoF mobile fronthaul with statistical data compression and multiband modulation,” J. Lightwave Technol. 35(17), 3671–3679 (2017).
[Crossref]

J. Wang, Z. Yu, K. Ying, J. Zhang, F. Lu, M. Xu, L. Cheng, X. Ma, and G. K. Chang, “Digital mobile fronthaul based on delta-sigma modulation for 32 LTE carrier aggregation and FBMC signals,” J. Opt. Commun. Netw. 9(2), A233–A244 (2017).
[Crossref]

K. Zhang, Q. Zhuge, H. Xin, M. Osman, E. E. Fiky, L. Yi, W. Hu, and D. V. Plant, “Intensity directed equalizer for the mitigation of DML chirp induced distortion in dispersion-unmanaged C-band PAM transmission,” Opt. Express 25(23), 28123–28135 (2017).
[Crossref]

C. Sun, S. H. Bae, and H. Kim, “Transmission of 28-Gb/s Duobinary and PAM-4 signals using DML for optical access network,” IEEE Photonics Technol. Lett. 29(1), 130–133 (2017).
[Crossref]

H. Ji, L. Yi, L. Xue, and W. Hu, “Upstream dispersion management of 25 Gb/s duobinary and PAM-4 signals to support 0–40 km differential reach,” Chin. Opt. Lett. 15(2), 022502 (2017).
[Crossref]

K. Zhang, Q. Zhuge, H. Xin, H. He, W. Hu, and D. V. Plant, “Low-Cost WDM fronthaul enabled by partitioned asymmetric AWGR with simultaneous flexible transceiver assignment and chirp management,” J. Opt. Commun. Netw. 9(10), 876–888 (2017).
[Crossref]

H. Xin, K. Zhang, H. He, W. Hu, and M. Zhang, “Fidelity enhancement in high-data-rate digital mobile fronthaul with sample bits interleaving and unequally-spaced PAM4,” Opt. Express 25(5), 5559–5570 (2017).
[Crossref] [PubMed]

H. Y. Chen, N. Kaneda, J. Lee, J. Chen, and Y. K. Chen, “Optical filter requirements in an EML-based single-sideband PAM4 intensity-modulation and direct-detection transmission system,” Opt. Express 25(6), 5852–5860 (2017).
[Crossref] [PubMed]

P. T. Ferrera, S. Straullu, S. Abrate, and R. Gaudino, “Upstream and downstream analysis of an optical fronthaul system based on DSP-assisted channel aggregation,” J. Opt. Commun. Netw. 9(12), 1191–1201 (2017).
[Crossref]

2016 (2)

2015 (2)

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

K. Zhong, X. Zhou, T. Gui, L. Tao, Y. Gao, W. Chen, J. Man, L. Zeng, A. P. T. Lau, and C. Lu, “Experimental study of PAM-4, CAP-16, and DMT for 100 Gb/s short reach optical transmission systems,” Opt. Express 23(2), 1176–1189 (2015).
[Crossref] [PubMed]

2014 (1)

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

1998 (1)

1994 (1)

B. Wedding, B. Franz, and B. Junginger, “10-Gb/s optical transmission up to 253 km via standard single-mode fiber using the method of dispersion supported transmission,” J. Lightwave Technol. 12(10), 1720–1727 (1994).
[Crossref]

Abrate, S.

Agata, A.

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Bae, S. H.

B. G. Kim, S. H. Bae, H. Kim, and Y. C. Chung, “RoF-based mobile fronthaul networks implemented by using DML and EML for 5G wireless communication systems,” J. Lightwave Technol. 36(14), 2874–2881 (2018).
[Crossref]

C. Sun, S. H. Bae, and H. Kim, “Transmission of 28-Gb/s Duobinary and PAM-4 signals using DML for optical access network,” IEEE Photonics Technol. Lett. 29(1), 130–133 (2017).
[Crossref]

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Cartledge, J. C.

Chang, G. K.

Che, D.

Chen, H. Y.

Chen, J.

Chen, W.

Chen, Y. K.

Cheng, L.

Christensen, B.

Chung, Y. C.

B. G. Kim, S. H. Bae, H. Kim, and Y. C. Chung, “RoF-based mobile fronthaul networks implemented by using DML and EML for 5G wireless communication systems,” J. Lightwave Technol. 36(14), 2874–2881 (2018).
[Crossref]

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Effenberger, F.

Ferrera, P. T.

Fiky, E. E.

Franz, B.

B. Wedding, B. Franz, and B. Junginger, “10-Gb/s optical transmission up to 253 km via standard single-mode fiber using the method of dispersion supported transmission,” J. Lightwave Technol. 12(10), 1720–1727 (1994).
[Crossref]

Gao, Y.

Gaudino, R.

Gui, T.

Guidotti, D.

Han, S.

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

He, H.

He, Z.

Hong, U. H.

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Hu, R.

Hu, W.

Ji, H.

Jiang, P.

Junginger, B.

B. Wedding, B. Franz, and B. Junginger, “10-Gb/s optical transmission up to 253 km via standard single-mode fiber using the method of dispersion supported transmission,” J. Lightwave Technol. 12(10), 1720–1727 (1994).
[Crossref]

Kaneda, N.

Kim, B. G.

Kim, H.

B. G. Kim, S. H. Bae, H. Kim, and Y. C. Chung, “RoF-based mobile fronthaul networks implemented by using DML and EML for 5G wireless communication systems,” J. Lightwave Technol. 36(14), 2874–2881 (2018).
[Crossref]

C. Sun, S. H. Bae, and H. Kim, “Transmission of 28-Gb/s Duobinary and PAM-4 signals using DML for optical access network,” IEEE Photonics Technol. Lett. 29(1), 130–133 (2017).
[Crossref]

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Lau, A. P. T.

Lee, J.

Li, G.

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

Li, H.

Li, X.

Lin, I. C.

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

Liu, X.

Liu, Y.

Lu, C.

Lu, F.

Luo, M.

Ma, X.

Man, J.

Osman, M.

Pan, Z.

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

Plant, D. V.

Rowell, C.

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

Shieh, W.

Shim, H. K.

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Straullu, S.

Sun, C.

C. Sun, S. H. Bae, and H. Kim, “Transmission of 28-Gb/s Duobinary and PAM-4 signals using DML for optical access network,” IEEE Photonics Technol. Lett. 29(1), 130–133 (2017).
[Crossref]

Suzuki, M.

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Tanaka, K.

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

Tao, L.

Wang, J.

Wedding, B.

B. Wedding, B. Franz, and B. Junginger, “10-Gb/s optical transmission up to 253 km via standard single-mode fiber using the method of dispersion supported transmission,” J. Lightwave Technol. 12(10), 1720–1727 (1994).
[Crossref]

Xin, H.

Xu, M.

Xu, Z.

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

Xue, L.

Yang, Q.

Yi, L.

Ying, K.

Yu, S.

Yu, Z.

Yuan, F.

Zeng, L.

Zhang, J.

Zhang, K.

Zhang, M.

Zhong, K.

Zhou, X.

Zhuge, Q.

Chin. Opt. Lett. (1)

IEEE Commun. Mag. (1)

I. C. Lin, C. Rowell, S. Han, Z. Xu, G. Li, and Z. Pan, “Toward green and soft: A 5G perspective,” IEEE Commun. Mag. 52(2), 66–73 (2014).
[Crossref]

IEEE Photonics Technol. Lett. (2)

S. H. Bae, H. K. Shim, U. H. Hong, H. Kim, A. Agata, K. Tanaka, M. Suzuki, and Y. C. Chung, “25-Gb/s TDM optical link using EMLs for mobile fronthaul network of LTE-A system,” IEEE Photonics Technol. Lett. 27(17), 1825–1828 (2015).
[Crossref]

C. Sun, S. H. Bae, and H. Kim, “Transmission of 28-Gb/s Duobinary and PAM-4 signals using DML for optical access network,” IEEE Photonics Technol. Lett. 29(1), 130–133 (2017).
[Crossref]

J. Lightwave Technol. (4)

J. Opt. Commun. Netw. (4)

Opt. Express (6)

Other (7)

“5G network architectures: a high level perspective”, (Huawei Technologies, 2016). https://www.huawei.com/minisite/5g/img/5G_Network_Architecture_A_High-Level_Perspective_en.pdf

H. Xin, K. Zhang, H. He, M. Zhang, and W. Hu, “High tolerance against chirp induced PAM4 eye skewing in DML-based digital mobile fronthaul with 11dB EVM Reduction,” in Proceedings of European Conference on Optical Communication (ECOC) (2017), paper M1B.3.
[Crossref]

B. Guo, W. Cao, A. Tao, and D. Samardzija, “CPRI compression transport for LTE and LTE-A signal in C-RAN,” in Proceedings of Int. Conf. on Comm. and Networking in China. (IEEE, 2012) pp. 843–849.

CPRI specification V6.1 (2014–7-1). (2014). [Online]. Available: http://www.cpri.info/spec.html

3GPP TS 36.104 version 14.3.0, “Base station (BS) radio transmission and reception,” 2017.

N. Kikuchi, R. Hirai, and T. Fukui, “Non-linearity compensation of high speed PAM4 signals from directly modulated laser at high extinction ratio,” in Proceedings of European Conference on Optical Communication (ECOC) (2016), paper M2B.4.

J. M. Castro, R. J. Pimpinella, B. Kose, Y. Huang, A. Novick, and B. Lane, “Eye skew modeling measurements and mitigation methods for VCSEL PAM-4 channels at data rates over 66 Gb/s,” in Optical Fiber Communications Conference (OFC) (2017), paper W3G.3.
[Crossref]

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Figures (10)

Fig. 1
Fig. 1 Illustration of the interaction between adiabatic chirp and chromatic dispersion.
Fig. 2
Fig. 2 Analysis of received PAM4 signal in DML-based transmission. Eye diagrams of 28G Baud PAM4: (a) 0km and (b) 20km. (c) Amplitude distribution of received symbols after 20km transmission. (d) Different types of symbol error ratio (SER) versus decision point. (e) Total BER as well as 1stb and 2ndb versus decision point.
Fig. 3
Fig. 3 (a) Channel response of 40km fiber under different bias voltages, (b) Frequencies of first dip at 40km, the calculated chirp factors and transfer function.
Fig. 4
Fig. 4 Analysis of received PAM4 signal in EML-based transmission. Eye diagrams of 28G Baud PAM4: (a) 0km and (b) 10km. (c) Amplitude distribution of received symbols after 10km transmission.
Fig. 5
Fig. 5 Principle of sample bits interleaving and corresponding line coding. Gray mapping rule is adopted for PAM4 modulation and demodulation.
Fig. 6
Fig. 6 Experimental setup of DML/EML-based digital mobile fronthaul system. AWG (arbitrary waveform generator), DML (directly modulated laser), EML (Electro-absorption Modulated Lasers), VOA (variable optical attenuator), TIA (trans-impedance amplifier), DSO (digital storage oscilloscope), FFE (feed forward equalizer).
Fig. 7
Fig. 7 BER measurement results of DML-based transmission: (a) BtB, (b) 10km, (c) 20km.
Fig. 8
Fig. 8 EVM performance of recovered wireless signal after DML transmission: (a) BtB, (b) 10km, (c) 20km.
Fig. 9
Fig. 9 BER measurement results of EML-based transmission: (a) BtB, (b) 10km.
Fig. 10
Fig. 10 EVM performance of recovered wireless signal after EML transmission: (a) BtB, (b) 10km.

Equations (2)

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Δ f = C P ( t )
P r ( 1 + α 2 ) cos 2 ( 2 π 2 β 2 L f 2 tan 1 α )

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