TY - JOUR
T1 - Cascaded If-over-fiber links with hybrid signal processing for analog mobile fronthaul
AU - Tanaka, Kazuki
AU - Kao, Hsuan Yun
AU - Ishimura, Shota
AU - Nishimura, Kosuke
AU - Kawanishi, Tetsuya
AU - Suzuki, Masatoshi
N1 - Funding Information:
Manuscript received March 16, 2020; revised May 13, 2020; accepted June 7, 2020. Date of publication June 12, 2020; date of current version October 15, 2020. This work was supported by the R&D contract “Wired-and-Wireless Converged Radio Access Network for Massive IoT Traffic (JPJ000254)” with the Ministry of Internal Affairs and Communications, Japan, for radio resource enhancement. (Corresponding author: Kazuki Tanaka.) Kazuki Tanaka is with KDDI Research, Fujimino 356-8502, Japan, and also with the School of Fundamental Science and Engineering, Waseda University, Shinjuku 169-8555, Japan (e-mail: au-tanaka@kddi-research.jp).
Publisher Copyright:
© 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See https://www.ieee.org/publications/rights/index.html for more information.
PY - 2020/10/15
Y1 - 2020/10/15
N2 - We present an intermediate frequency-over-fiber (IFoF) transmission system that uses cascaded connections between a broadband link and multiple narrowband links for future mobile fronthaul (MFH). The downlink MFH system employs analog and digital signal processing after broadband and narrowband IFoF transmissions, respectively, for extractions and frequency conversions of IF signals. The bandwidth of the optical components for the downlink MFH system is investigated and compared with that for the subcarrier multiplexed passive optical network (SCM-PON). The results support the satisfactory performance of the MFH system for bandwidth reduction. Two types of our developed digital signal processors for the MFH system are also described in detail: One is for an output of a single radio frequency (RF) stream, whereas the other is for simultaneous outputs of multiple RF streams. In addition, using either of the digital signal processors, we experimentally demonstrate the downlink MFH system's transmission of 64-QAM filtered OFDM (f-OFDM) signals with 360-MHz signal bandwidth and 3.6-MHz guard bands between adjacent IF signals and 64-QAM OFDM signals with 380.16-MHz signal bandwidth and 19.84-MHz guard bands between IF signals. In both experiments, eighteen IF signals are successfully transmitted over 20-km and 1-km fibers, which includes analog and real-time digital signal processing for IF channel extractions and frequency conversions. The results obtained in this study demonstrate the potential of cascaded IFoF links using hybrid signal processing for 5G and future MFH systems.
AB - We present an intermediate frequency-over-fiber (IFoF) transmission system that uses cascaded connections between a broadband link and multiple narrowband links for future mobile fronthaul (MFH). The downlink MFH system employs analog and digital signal processing after broadband and narrowband IFoF transmissions, respectively, for extractions and frequency conversions of IF signals. The bandwidth of the optical components for the downlink MFH system is investigated and compared with that for the subcarrier multiplexed passive optical network (SCM-PON). The results support the satisfactory performance of the MFH system for bandwidth reduction. Two types of our developed digital signal processors for the MFH system are also described in detail: One is for an output of a single radio frequency (RF) stream, whereas the other is for simultaneous outputs of multiple RF streams. In addition, using either of the digital signal processors, we experimentally demonstrate the downlink MFH system's transmission of 64-QAM filtered OFDM (f-OFDM) signals with 360-MHz signal bandwidth and 3.6-MHz guard bands between adjacent IF signals and 64-QAM OFDM signals with 380.16-MHz signal bandwidth and 19.84-MHz guard bands between IF signals. In both experiments, eighteen IF signals are successfully transmitted over 20-km and 1-km fibers, which includes analog and real-time digital signal processing for IF channel extractions and frequency conversions. The results obtained in this study demonstrate the potential of cascaded IFoF links using hybrid signal processing for 5G and future MFH systems.
KW - Centralized radio access network (C-RAN)
KW - Digital signal processing
KW - Fifth generation (5G)
KW - Mobile fronthaul
KW - Radio-over-fiber (RoF)
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U2 - 10.1109/JLT.2020.3001930
DO - 10.1109/JLT.2020.3001930
M3 - Article
AN - SCOPUS:85100310866
SN - 0733-8724
VL - 38
SP - 5656
EP - 5667
JO - Journal of Lightwave Technology
JF - Journal of Lightwave Technology
IS - 20
M1 - 9115812
ER -