OPTOELECTRONICS LETTERS Vol.15 No.1, 1 January 2019
A dispersion flattened fiber front-haul transmission
system with high bitrate signal at low input optical
power
*
WANG Xiao (王潇)
1†
, ZHU Long-yang (朱龙洋)
1†
, ZHENG Hong-jun (郑宏军)
1
**, LI Xin (黎昕)
1
, BAI
Cheng-lin (白成林)
1
, HU Wei-sheng (胡卫生)
2
, and XU Heng-ying (许恒迎)
1
1. Shandong Provincial Key Laboratory of Optical Communication Science and Technology, School of Physics Sci-
ence and Information Technology, Liaocheng University, Liaocheng 252059, China
2. State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronic Information
and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
1
(Received 13 June 2018; Revised 11 August 2018)
©Tianjin University of Technology and Springer-Verlag GmbH Germany, part of Springer Nature 2019
We propose a dispersion flattened fiber (DFF) front-haul transmission system with high bitrate, polarization multi-
plexing (PM) and quadrature amplitude modulation (QAM) signal at low input optical power. The modulation format
of the system is PM-16QAM, and the bitrate is 256 Gbit/s. The transmission characteristics over DFF link system are
experimentally studied, which are compared with those over non-zero dispersion shifted fiber (NZDSF) link and stan-
dard single mode fiber (SSMF) link. The experimental results show that the error vector magnitude (EVM) of
256 Gbit/s and PM-16QAM signal over 25 km DFF link is 0.75% better than that over 25 km NZDSF link at least, and
the bit error rate (BER) and Q-factor are much better than those of NZDSF. Their EVM and BER are both decreased
with the increase of input optical power, and the Q-factor is increased. Those characteristics over 25 km SSMF are the
worst at the same case. The larger the dispersion is, the more the constellation points are deviated from their respective
centers and the worse the constellation characteristics are. The greater the attenuation of the DFF is, the smaller the
input power of the DFF is, the more the constellation points are deviated from their centers and the worse the constel-
lation characteristics are. This study provides a new idea and experimental support for long span front-haul propaga-
tion in mobile communication.
Document code: A Article ID: 1673-1905(2019)01-0031-4
DOI https://doi.org/10.1007/s11801-019-8096-3
* This work has been supported by the National Natural Science Foundation of China (Nos.61671227, 61431009 and 61501213), the Shandong
Provincial Natural Science Foundation (No.ZR2011FM015) and Taishan Scholar Research Fund of Shandong Province.
†
The authors contributed equally to this work.
** E-mail: hjzheng@yahoo.com
In recent years, the mobile communication service de-
mand and service traffic are exponentially increased. The
common public radio interface (CPRI) or open base sta-
tion architecture initiative (OBSAI), which is the
front-haul transmission interface of mobile network, has
great limitations in data rate, bandwidth and time delay
aspects. Therefore, China Mobile Communications Re-
search Institute and other companies proposed the next
generation front-haul interface (NGFI)
[1]
to satisfy the
development demands of fifth generation mobile commu-
nications (5G). NGFI refers to the front-haul interface
between radio cloud center (RCC) for baseband process-
ing and the radio remote system (RRS) in the next genera-
tion wireless network. It provides five flexible interface
schemes, which can employ analog transmission or digital
transmission technology to reduce the system parameters
requirements. And it provides an important reference for
further research on the mobile front-haul transmission
network
[1]
. The single span transmission distance between
the RCC and the RRS is generally limited to 20 km in
NGFI. It is urgent to realize long single-span front-haul
transmission using a link with good characteristics.
The dispersion flattened fiber (DFF)
[2]
can eliminate
performance degradation caused by dispersion. In addi-
tion, DFF can make the supercontinuum wider and more
flattened
[3]
. Ref.[4] theoretically shows that the transmis-
sion performance of RZ-DPSK system using DFF is su-
perior to that using non-zero dispersion flattened fiber
(NZDFF). Good propagation characteristics at normal
dispersion region in DFF are experimentally studied
[5]
.
Ref.[6] experimentally demonstrates the good transmis-
sion characteristics of 10 Gbit/s optical millimeter wave
in long DFF-like span using equalization amplification.
Ref.[7] numerically studies nonlinear chirped-pulse
propagation and supercontinuum generation in disper-
sion-flattened dispersion-decreasing fibers. In summary,