Multi-IF-Over-Fiber System With Adaptive Frequency Transmit Diversity for High Capacity Mobile Fronthaul

Bekkali, Abdelmoula; Ishimura, Shota; Tanaka, Kazuki; Nishimura, Kosuke; Suzuki, Masatoshi

doi:10.1109/jlt.2019.2926411

Cited by 13 publications

(4 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SFP+, QSFP28,...) optical modular transceivers that are widely used for both telecom and data communications applications. Moreover, all-optical FSO system will be compatible with the high capacity analog radio-over fiber system which is considered as a potential candidate for B5G/6G networks [28]- [30]. However, they require advanced laser beam pointing and tracking control mechanism.…”

Section: B All-optical Fso Transceiversmentioning

confidence: 99%

New Generation Free-Space Optical Communication Systems With Advanced Optical Beam Stabilizer

Bekkali¹,

Fujita²,

Hattori³

2022

J. Lightwave Technol.

Self Cite

View full text Add to dashboard Cite

In this paper, we introduce a novel concept and design of a full-duplex and all-optical FSO transceiver and evaluate its transmission performance in 200 m outdoor environment. Our transceiver enables a reliable fiber-to-fiber FSO link with intelligent lens-based optical-beam-stabilization (OBS) by utilizing miniaturized and cost-effective 3-axis voice-coil motors (VCMs) actuators. The VCM-based moving lens that is widely used in smartphone cameras for auto-focus and opticalimage-stabilization is customized and optimized for our designed transceiver to expand the transmitter and receiver field-of-view, control both the transmitted and incident laser beam alignment, suppress the effects of random beam angle-of-arrival fluctuations induced by the atmospheric turbulence and pointing errors and maintain efficient direct coupling to the fiber core at the receiver. Unlike the 2-axis fast-steering-mirrors, the use of 3-axis VCM lenses can not only maintain the beam alignment, but also control the beam collimation and adjust the difference between the lens focal plane and projection plane for a higher fiber coupling efficiency. Using our developed FSO transceivers, we demonstrate an error-free transmission of the standard signals 10GbE LAN and common public radio interface (LTE-CPRI) over 200 m links. We also performed a continuous 24-hour transmission evaluation in a clear weather day, with only occasional burst errors were recorded and a total 24-hour BER of 3×10 −10 . The obtained results demonstrate the potential of our proposed FSO transceiver to ensure high-capacity communication links and facilitate the adoption of the FSO system as a viable candidate to address the main requirements of B5G/6G networks.

show abstract

Section: B All-optical Fso Transceiversmentioning

confidence: 99%

New Generation Free-Space Optical Communication Systems With Advanced Optical Beam Stabilizer

Bekkali¹,

Fujita²,

Hattori³

2022

J. Lightwave Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although the capacity and reach can be further improved using complexvalued modulation, the hardware complexity of transmitter was almost doubled owing to the IQ modulator and another DAC, which is not suitable for such a cost-sensitive scenario. Meanwhile, the transmitter structures proposed in References [26,27] are also complicated, and the subcarrier allocation algorithm was designed only for multi-carrier modulation, such as the orthogonal frequency division multiplexing (OFDM) signal, which is not compatible with PAM. The main contribution of our work is to offer a cost-effective solution employing imbalanced MZM with single DAC.…”

Section: Comparison Of Preivous Workmentioning

confidence: 99%

“…Moreover, dispersion pre-compensation [24,25] can be performed by the inverse dispersion transfer function, if complex-valued modulation is allowed. In addition, frequency nulls can be moved or avoided with more complicated transmitter structures, such as parallel IM/phase modulation (PM) [26], dual-parallel MZM (DP-MZM) [27], and polarization modulation (PolM) [28]. Going back to the hardware complexity constraint of conventional IM-DD links, 10 km SSMF transmission of 100 G PAM-6/8 signals are achieved with the help of pre-chirping by operating DDMZM at single-arm driven mode [29].…”

Section: Introductionmentioning

confidence: 99%

Imbalanced Mach-Zehnder Modulator for Fading Suppression in Dispersion-Uncompensated Direct Detection System

Zhu

Miao

et al. 2021

Electronics

View full text Add to dashboard Cite

In this work, we systematically analyze the impact of three kinds of Mach-Zehnder modulator (MZM) imbalances, including bias deviation, amplitude mismatch, and differential time skew in intensity-modulation direct-detection (IM-DD) links. It is shown that, for power fading limited transmission, the imbalances can be utilized as advantages rather than impairments. Specifically, the bias deviation with single-arm driven mode and amplitude mismatch with differential driven mode can increase the available bandwidth by shifting the frequency of fading notches. Meanwhile, time skew provides another way to avoid fading by shaping the double sideband (DSB) signal into a vestigial sideband (VSB) with an asymmetrical transfer function. In the transmission experiment, 34 Gbaud Nyquist 6/8-ary pulse amplitude modulation (PAM-6/8) signals are used for investigation in a 20 km dispersion-uncompensated standard single-mode fiber (SSMF) link. With the help of a Volterra nonlinear equalizer, all three kinds of imbalances can achieve bit-error rates (BERs) below the 7% and 20% hard-decision forward error correction (HD-FEC) thresholds for PAM-6 and PAM-8 signals, respectively. The received power sensitivity is also compared at the back-to-back (BTB) case and after fiber transmission. Both numerical simulation and experimental demonstration confirm that the dispersion-induced power fading can be effectively suppressed with bias, amplitude, or skew imbalance, providing a feasible solution for transmission distance extension of C-band DD links.

show abstract

“…There remains the A-RoF solution with the least research, especially for 5G C-RAN applications. The papers [15][16][17][18][19] show a focus on specific solutions, which consist in conducting experiments documenting that radio signals in the BB, IF, and RF bands can be transmitted in optical fiber paths. These solutions were already tested many years ago.…”

mentioning

confidence: 99%

D-RoF and A-RoF Interfaces in an All-Optical Fronthaul of 5G Mobile Systems

Zakrzewski

2020

Applied Sciences

View full text Add to dashboard Cite

This paper presents a solution for enabling the coexistence of digitized radio-over-fiber (D-RoF) and analog radio-over-fiber (A-RoF) interfaces operating in the optical fronthaul of 5G mobile systems. In the first section, we formulate the need to introduce new technologies to the cloud/centralized radio access network (C-RAN) (Next Generation RAN (NG-RAN) in 5G systems). A proposition of construction of the optical remote radio head (O-RRH)/gNodeB-distributed unit (gNB-DU), which will enable the operation of digital Splits/Options and new proposed analog Splits/Options, is presented. The methods performing calculations of bit rate and optical bandwidth demand in the fronthaul/midhaul, with reference to the parameters of the new-radio-release-15 (NR-Rel-15) wireless interface and subsequent releases, towards the next generations, are presented. The bandwidth demands were calculated for selected Splits/Options, and the results are shown in diagrams. A special section is devoted to description of the results achieved and presenting potential applications of the proposed construction of a radio-photonic device as well as new Splits/Options of the next generation fronthaul/midhaul. The basic concept in the NG-RAN domain, which is promoted by 5GPPP, is the multi-layered architecture of XHaul [1,2]. This solution is based on an optical network that is designed to support traffic from various Split/Option interfaces. This architecture also includes D-RAN solutions, which means joint support for management of traffic from the fronthaul and backhaul. Based on this solution, the authors of publications [3][4][5] proposed network architectures based on optical and microwave (radio-line) transport. The presented solutions introduce traffic optimization, which, however, does not take into account the possibility of transmitting signals occurring in the A-RoF format in the network. The architecture of an Optical Transport Network (OTN) system is prepared for an efficient transport of digital traffic, which is provided at client access points. The situation is similar in the case of Time Shared Optical Network (TSON), which is a very good solution supporting the transport of information from radio-over-Ethernet (RoE) (enhanced common public radio interface (eCPRI) as well as next generation fronthaul interface (NGFI)) interfaces. A lot of research and development have been devoted to various optimization solutions for transportation systems of streams from D-RoF interfaces. The author reviewed the available studies [6][7][8][9][10][11][12][13], which contained the results of studies showing the undoubted legitimacy of using the D-RoF technique. In these studies, particular emphasis was put on showing that a particular type of Split/Option or method of digitizing a radio signal to a bit form gives the opportunity to increase a link efficiency. There is no difference in the selection of the Split/Option method in the context of the load on the fronthaul network or the RRH unit. In special solutions, attempts were made to use com...

show abstract

Multi-IF-Over-Fiber System With Adaptive Frequency Transmit Diversity for High Capacity Mobile Fronthaul

Cited by 13 publications

References 27 publications

New Generation Free-Space Optical Communication Systems With Advanced Optical Beam Stabilizer

New Generation Free-Space Optical Communication Systems With Advanced Optical Beam Stabilizer

Imbalanced Mach-Zehnder Modulator for Fading Suppression in Dispersion-Uncompensated Direct Detection System

D-RoF and A-RoF Interfaces in an All-Optical Fronthaul of 5G Mobile Systems

Contact Info

Product

Resources

About