Direct and External Hybrid Modulation Approaches for Access Networks

The demand for low-cost high-speed transmission is a major challenge for 5G future networks. To meet this optical communication demand, holistic and painstaking approaches are required in designing a simplified system model. Since the demands for high bandwidth are growing at unprecedented speed as we approach the Zettabyte era, it is crucial to minimize chromatic dispersion (CD) associated to high bit-rate signals. Mitigating CD electronically comes at high cost which may not be compatible with 5G. Photonic Integrated Circuit (PIC) as an enabler for fast speed optical transmission is still undergoing its growth stage and its major speed and efficiency have not yet been attained. However, proper and right combination of components and approaches can potentiate this technology in a more cost-efficient way. Hybrid modulation (HM)-PIC presents a simplified approach in terms of cost and efficiency for 5G networks. Hybridization of existing modulation components and approaches in PIC can enhance the generation of high bit-rate signals without the need for electrical CD compensation. A detailed study of hybrid multilevel signal modulation concept as a valuable solution for Data Centers (DC) high data-rate signals and next-generation Passive Optical Networks (PONs) is proposed.

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Systematic Performance Comparison of (Duobinary)-PAM-2,4 Signaling under Light and Strong Opto-Electronic Bandwidth Conditions

Photonics ◽

10.3390/photonics8030081 ◽

2021 ◽

Vol 8 (3) ◽

pp. 81

Author(s):

Ramón Gutiérrez-Castrejón ◽

Md Ghulam Saber ◽

Md Samiul Alam ◽

Zhenping Xing ◽

Eslam El-Fiky ◽

...

Keyword(s):

Optical Networks ◽

High Speed ◽

Performance Comparison ◽

Sampling Point ◽

Bit Rate ◽

Performance Limits ◽

Specific System ◽

Rate System ◽

Modulation Formats ◽

Modulation Format

We present a systematic comparison of PAM-2 (NRZ), Duobinary-PAM-2, PAM-4, and Duobinary-PAM-4 (duo-quaternary) signaling in the context of short-reach photonic communications systems using a Mach–Zehnder modulator as transmitter. The effect on system performance with a relaxed and constrained system’s opto-electronic bandwidth is analyzed for bit rates ranging from 20 to 116 Gb/s. In contrast to previous analyses, our approach employs the same experimental and simulation conditions for all modulation formats. Consequently, we were able to confidently determine the performance limits of each format for particular values of bit rate, system bandwidth, transmitter chirp, and fiber dispersion. We demonstrate that Duobinary-PAM-4 is a good signaling choice only for bandwidth-limited systems operating at relatively high speed. Otherwise, PAM-4 represents a more sensible choice. Moreover, our analysis put forward the existence of transition points: specific bit rate values where the BER versus bit rate curves for two different formats cross each other. They indicate the bit rate values where, for specific system conditions, switching from one modulation to another guarantees optimum performance. Their existence naturally led to the proposal of a format-selective transceiver, a component that, according to network conditions, operates with the most adequate modulation format. Since all analyzed modulations share similar implementation details, signaling switching is achieved by simply changing the sampling point and threshold count at the receiver, bringing flexibility to IM/DD-based optical networks.

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A 5G C-RAN Optical Fronthaul Architecture for Hotspot Areas Using OFDM-Based Analog IFoF Waveforms

Applied Sciences ◽

10.3390/app9194059 ◽

2019 ◽

Vol 9 (19) ◽

pp. 4059 ◽

Cited By ~ 6

Author(s):

Charoula Mitsolidou ◽

Christos Vagionas ◽

Agapi Mesodiakaki ◽

Pavlos Maniotis ◽

George Kalfas ◽

...

Keyword(s):

Wavelength Division Multiplexing ◽

Integrated Circuit ◽

Orthogonal Frequency Division Multiplexing ◽

Access Network ◽

Intermediate Frequency ◽

Error Vector Magnitude ◽

Photonic Integrated Circuit ◽

Wavelength Division ◽

High Data ◽

Radio Access

Analog fronthauling is currently promoted as a bandwidth and energy-efficient solution that can meet the requirements of the Fifth Generation (5G) vision for low latency, high data rates and energy efficiency. In this paper, we propose an analog optical fronthaul 5G architecture, fully aligned with the emerging Centralized-Radio Access Network (C-RAN) concept. The proposed architecture exploits the wavelength division multiplexing (WDM) technique and multicarrier intermediate-frequency-over-fiber (IFoF) signal generation per wavelength in order to satisfy the demanding needs of hotspot areas. Particularly, the fronthaul link employs photonic integrated circuit (PIC)-based WDM optical transmitters (Txs) at the baseband unit (BBU), while novel reconfigurable optical add-drop multiplexers (ROADMs) cascaded in an optical bus are used at the remote radio head (RRH) site, to facilitate reconfigurable wavelength switching functionalities up to 4 wavelengths. An aggregate capacity of 96 Gb/s has been reported by exploiting two WDM links carrying multi-IF band orthogonal frequency division multiplexing (OFDM) signals at a baud rate of 0.5 Gbd with sub-carrier (SC) modulation of 64-QAM. All signals exhibited error vector magnitude (EVM) values within the acceptable 3rd Generation Partnership Project (3GPP) limits of 8%. The longest reach to place the BBU away from the hotspot was also investigated, revealing acceptable EVM performance for fiber lengths up to 4.8 km.

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High-speed energy-efficient InP photonic integrated circuit transceivers

Optical Interconnects XIX ◽

10.1117/12.2515218 ◽

2019 ◽

Author(s):

Kevin A. Williams ◽

Marija Trajkovic ◽

Valeria Rustichelli ◽

Florian Lemaître ◽

Huub P. Ambrosius ◽

...

Keyword(s):

Integrated Circuit ◽

Energy Efficient ◽

High Speed ◽

Photonic Integrated Circuit

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A Comparison between off and On-Chip Injection Locking in a Photonic Integrated Circuit

Photonics ◽

10.3390/photonics6040103 ◽

2019 ◽

Vol 6 (4) ◽

pp. 103 ◽

Cited By ~ 2

Author(s):

Alison Perrott ◽

Ludovic Caro ◽

Mohamad Dernaika ◽

Frank Peters

Keyword(s):

Integrated Circuit ◽

High Speed ◽

Power Spectra ◽

Dynamical Behaviour ◽

Injection Locking ◽

Semiconductor Diode ◽

Photonic Integrated Circuit ◽

Semiconductor Diode Laser ◽

Spectrum Analyser ◽

On Chip

The mutual and injection locking characteristics of two integrated lasers are compared, both on and off-chip. In this study, two integrated single facet slotted Fabry–Pérot lasers are utilised to develop the measurement technique used to examine the different operational regimes arising from optically locking a semiconductor diode laser. The technique employed used an optical spectrum analyser (OSA), an electrical spectrum analyser (ESA) and a high speed oscilloscope (HSO). The wavelengths of the lasers are measured on the OSA and the selected optical mode for locking is identified. The region of injection locking and various other regions of dynamical behaviour between the lasers are observed on the ESA. The time trace information of the system is obtained from the HSO and performing the FFT (Fast Fourier Transform) of the time traces returns the power spectra. Using these tools, the similarities and differences between off-chip injection locking with an isolator, and on-chip mutual locking are examined.

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High bit rate burst mode optical OFDM for next generation passive optical networks

36th European Conference and Exhibition on Optical Communication ◽

10.1109/ecoc.2010.5621162 ◽

2010 ◽

Cited By ~ 4

Author(s):

Luiz Anet Neto ◽

Ahmed Gharba ◽

Philippe Chanclou ◽

Naveena Genay ◽

Benoit Charbonnier ◽

...

Keyword(s):

Optical Networks ◽

Passive Optical Networks ◽

Next Generation ◽

Bit Rate ◽

Burst Mode ◽

Optical Ofdm ◽

High Bit Rate

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High speed (≥6 GHz) InGaAs/InP avalanche photodiodes grown by gas source molecular beam epitaxy with a thin quaternary grading layer for high bit rate (≥5 Gbit/s) systems

Journal de Physique III ◽

10.1051/jp3:1993102 ◽

1993 ◽

Vol 3 (9) ◽

pp. 1761-1767

Author(s):

G. Ripoche ◽

J.-L. Peyre ◽

M. Lambert ◽

S. Mottet

Keyword(s):

Molecular Beam Epitaxy ◽

High Speed ◽

Molecular Beam ◽

Avalanche Photodiodes ◽

Bit Rate ◽

Gas Source ◽

High Bit Rate

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High Speed Passive Optical Network Based Elastic Optical Communication System

Journal of Optical Communications ◽

10.1515/joc-2019-0121 ◽

2019 ◽

Vol 0 (0) ◽

Author(s):

Nikhlesh Kumar Mishra ◽

Kamal Kishore Upadhyay ◽

N. K. Shukla

Keyword(s):

Optical Networks ◽

Communication System ◽

High Speed ◽

Optical Network ◽

Wave Length ◽

Single Mode ◽

Passive Optical Network ◽

High Data ◽

Data Rates ◽

Communication Needs

AbstractFor addressing needs of modern day communication needs, new type of networks are required to be evolved to cater the demand of high data rates. Use of survivable elastic-optical-network (EON) with existing passive-optical-networks (PON) may provide the solution for this. The present work focus on employing EON–PON based wave-length-division multiplexing enabled communication system comprises of 2×5 Gbps for downlink and 2×1 Gbps for uplink over a single-mode-fibre of length 100 km. The results are the evaluated via bit-error-rate analyser, q factor and eye diagrams.

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An ultra-dense spacing-based PON by incorporating dual drive Mach–Zehnder modulator for comb generation

Journal of Optical Communications ◽

10.1515/joc-2020-0292 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Navjot Singh ◽

Bharat Naresh Bansal

Keyword(s):

Optical Networks ◽

High Speed ◽

Low Cost ◽

Optical Network ◽

Single Mode ◽

Single Mode Fiber ◽

Passive Optical Network ◽

Passive Optical Networks ◽

Differential Phase Shift ◽

High Data

Abstract Wavelength division multiplexed passive optical is promising technique to achieve a high data rate and large number of user. The notable advantages of WDM PON is the combination of reliability, cheap in cost, accessible bandwidth, high security, large optical reach and it can support large number of ONU. There are multiple approaches to achieve high-speed WDN PON using different transmission techniques. In WDM, multiple lasers are required which increase the cost of the system. To reduce cost, an optical multicarrier generation system is proposed. An economical multiple carrier generation with the incorporation of sine generator and Mach–Zehndar modulator is demonstrated. Utmost work of sine generator and dual drive modulator was to attain low cost functioning of passive optical networks. Multicarrier generation was done and replacement of laser carriers with optical multicarrier generator. Carriers were generated with the frequency spacing of 20 GHz and these carriers were used in the passive optical networks with the tone-to-noise ratio of 40 dB, amplitude difference of 1.4 dB. For the transmission of downstream in the PON, differential phase shift keying was employed at 10 Gbps data speed. Transmission distance achieved was 30 km using single-mode fiber and this was a part of optical distribution network. Optical network unit was next part after ODN and signals were received with balanced receiver. Moreover, half signal was given to intensity modulator for the signal re-modulation. Bit error rate of 10–9 was achieved at all channels in the downstream. An upstream of 10 Gbps was accomplished in the passive optical network.

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