Remote Beamforming Scheme with Fixed Wavelength Allocation for Radio-Over-Fiber Systems Employing Single-Mode Fiber

2021 ◽  
pp. 1-1
Author(s):  
Kota Ito ◽  
Mizuki Suga ◽  
Yushi Shirato ◽  
Naoki Kita ◽  
Takeshi Onizawa
Keyword(s):  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Wavelength Allocation

scholarly journals Neural Network DPD for Aggrandizing SM-VCSEL-SSMF-Based Radio over Fiber Link Performance

Photonics ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 19
Author(s):  
Muhammad Hadi ◽  
Muhammad Awais ◽  
Mohsin Raza ◽  
Kiran Khurshid ◽  
Hyun Jung
Keyword(s):  
Neural Network ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Error Vector Magnitude ◽  
Computational Overhead ◽  
Link Performance ◽  
Modulation Signal ◽  
Experimental Findings ◽  
Memory Polynomial

This paper demonstrates an unprecedented novel neural network (NN)-based digital predistortion (DPD) solution to overcome the signal impairments and nonlinearities in Analog Optical fronthauls using radio over fiber (RoF) systems. DPD is realized with Volterra-based procedures that utilize indirect learning architecture (ILA) and direct learning architecture (DLA) that becomes quite complex. The proposed method using NNs evades issues associated with ILA and utilizes an NN to first model the RoF link and then trains an NN-based predistorter by backpropagating through the RoF NN model. Furthermore, the experimental evaluation is carried out for Long Term Evolution 20 MHz 256 quadraturre amplitude modulation (QAM) modulation signal using an 850 nm Single Mode VCSEL and Standard Single Mode Fiber to establish a comparison between the NN-based RoF link and Volterra-based Memory Polynomial and Generalized Memory Polynomial using ILA. The efficacy of the DPD is examined by reporting the Adjacent Channel Power Ratio and Error Vector Magnitude. The experimental findings imply that NN-DPD convincingly learns the RoF nonlinearities which may not suit a Volterra-based model, and hence may offer a favorable trade-off in terms of computational overhead and DPD performance.

scholarly journals RL-SARSA Machine Learning Based Analog Radio over Fiber System

2019 ◽  
Author(s):  
Muhammad Usman Hadi
Keyword(s):  
Machine Learning ◽  
Bit Error Rate ◽  
Fiber Length ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Fiber System ◽  
Decision Method ◽  
Effective Decision ◽  
Radio Over Fiber System

We propose a 10-Gb/s 64-quadrature amplitude modulation (QAM) signal-based Radio over Fiber (RoF) system for 50 km of standard single mode fiber length which utilizes Reinforcement Learning (RL) SARSA based decision method to indicate an effective decision which mitigates nonlinearity. By utilizing RL-SARSA algorithm, the results demonstrate that significant reduction can be obtained in terms of bit error rate.

scholarly journals Nonlinearities Diminution in 40 Gb/s 256 QAM Radio over Fiber Link via Machine Learning Method

2019 ◽  
Author(s):  
Muhammad Usman Hadi
Keyword(s):  
Machine Learning ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Support Vector ◽  
Potential Candidate ◽  
Input Signal Power ◽  
Quadrature Phase ◽  
Fiber Link ◽  
Mach Zehnder Modulator

Machine learning (ML) methodologies have been looked upon recently as a potential candidate for mitigating nonlinearity issues in optical communications. In this paper, we experimentally demonstrate a 40-Gb/s 256-quadrature amplitude modulation (QAM) signal-based Radio over Fiber (RoF) system for 50 km of standard single mode fiber length which utilizes support vector machine (SVM) decision method to indicate an effective nonlinearity mitigation. The influence of different impairments in the system is evaluated that includes the influences of Mach-Zehnder Modulator nonlinearities, in-phase and quadrature phase skew of the modulator. By utilizing SVM, the results demonstrated in terms of bit error rate and eye linearity suggest that impairments are significantly reduced and licit input signal power span of 5dBs is enlarged to 15 dBs.

Radio-Over-Fiber Dual-Parallel Mach-Zehnder Modulator System for Photonic Generation of Millimeter-Wave Signals Through Two Stages

2021 ◽  
Author(s):  
Fabio Barros de Sousa ◽  
Fiterlinge M. de Sousa ◽  
Igor R. S. Miranda ◽  
Waldomiro Paschoal ◽  
Marcos B. C. Costa
Keyword(s):  
Millimeter Wave ◽  
Transmission Rate ◽  
Access Network ◽  
Single Mode ◽  
Fiber Amplifier ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Base Stations ◽  
Erbium Doped Fiber Amplifier ◽  
Mach Zehnder Modulator

Abstract In this work, we presented a radio-over-fiber (ROF) access network through two modulation stages for the generation of multiple millimeter wave (mm-wave) signals with frequencies of 20GHz, 40GHz, 60GHz and 80 GHz for the transmission rate of 10 Gbps as a function of the variation of link distance and signal power. The specific purpose of the paper was to design and to investigate a RoF system based on the variation of mm-wave frequencies in order to implement a simple and effective system. In stage 1, there are two modulators in parallel (MZMa and MZMb) called dual-parallel Mach-Zehnder modulator (DP-MZM) and in stage 2 there is only one modulator (MZMc), connected to three pulse generators: Non-Return-to-Zero (NRZ), Return-to-Zero (RZ). A single-mode fiber (SMF) and Gaussian and an erbium-doped fiber amplifier (EDFA) were also used to send signals to base stations (BSs). The numerical analyzes of the results of the eye diagrams showed excellent bit error rate (BER) and quality factor (Q-factor) values, which proved the good performance of the proposed ROF DP-MZM system, for the three encoding formats used, which was able to generate 3-tupling mm-wave for multiple wireless accesses.

Performance Appraisal of Sigma Delta Modulated Radio over Fiber System

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Usman Hadi ◽  
Nelofar Aslam ◽  
Hyun Jung
Keyword(s):  
Performance Appraisal ◽  
High Speed ◽  
Access Network ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Error Vector Magnitude ◽  
Sigma Delta Modulation ◽  
Fiber System ◽  
Sigma Delta

AbstractRadio over fiber (RoF) is a promising solution for the next-generation wireless networks including fifth-generation Cloud/Centralized Radio Access Network (C-RAN). There exists a possibility to use Sigma Delta Modulated RoF (S-DRoF) that combines the advantages of analog RoF and digital RoF by means of sigma delta modulation (SDM) at the transmitter side subsequently replacing the employment of expensive and high-speed digital-to-analog converters. In this paper, we demonstrate the usage of second-order SDM for LTE 20 MHz signal having 64 QAM modulation on a central carrier frequency of 1.14 GHz for the implementation of S-DRoF for 20 km of standard single mode fiber with baud rate from 25 to 100 Mbaud. Furthermore, a comprehensive analysis of the design of SDM is explained followed by the experimental setup. The performance is reported in terms of error vector magnitude, constellations and adjacent channel power ratio. The results show that the proposed architecture performance is in with accordance to the limitations set by the 3GPP (Third Generation Partnership Project) standards and is a reasonable choice either for upgrading installed systems as well as for the new deployments.

scholarly journals Experimental Demonstration of MASH Based Sigma Delta Radio over Fiber System for 5G C-RAN Downlink

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Usman Hadi ◽  
Muhammad Umair Hadi ◽  
Nelofar Aslam ◽  
Rafaqat Ali ◽  
Kiran Khurshid ◽  
...  
Keyword(s):  
Access Network ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Noise Shaping ◽  
Error Vector Magnitude ◽  
Fiber System ◽  
Sigma Delta ◽  
Digital Radio ◽  
Multi Stage

AbstractSigma Delta Radio over Fiber (S-DRoF) systems are looked upon as an enabling technology due to their advantages that comes due to combination of analog and digital radio over fiber (RoF) systems. In this paper, we have proposed and experimentally demonstrated a Multi-stAge-noise-SHaping (MASH) based Sigma Delta Modulated RoF system targeting 5G C-RAN (cloud/centralized radio access network) fronthaul applications. The evaluation has been done for LTE 20 MHz signal having 256 quadrature amplitude modulation with a carrier frequency of 3.5 GHz up to 5 Km of Standard Single Mode Fiber (SSMF). Furthermore, a comprehensive analysis of the design is explained followed by the experimental setup. The performance is reported in terms of error vector magnitude (EVM) and adjacent channel leakage ratio. It is concluded that S-DRoF substantiates the desired range of the 5G C-RAN fronthaul networks.

scholarly journals Polarization Division Multiplexing of OFDM Radio-over-Fiber Signals in Passive Optical Networks

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Maria Morant ◽  
Joaquin Pérez ◽  
Roberto Llorente
Keyword(s):  
Optical Networks ◽  
Spectral Efficiency ◽  
Optical Network ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Passive Optical Network ◽  
Passive Optical Networks ◽  
The Impact ◽  
Polarization Division Multiplexing

This paper describes the state-of-the-art of polarization multiplexing for optical networks transmission. The use of polarization division multiplexing (PDM) permits to multiply the user capacity and increase the spectral efficiency. Combining PDM and orthogonal frequency division multiplexed (OFDM) modulation allows maximizing the optical transmission capacity. The experimental demonstration of transmitting OFDM signals following ECMA-368 ultrawide band (UWB) standard in radio-over-fiber using PDM in passive optical networks is herein reported. The impact of cross-polarization and cochannel crosstalk is evaluated experimentally in a three-user OFDM-UWB subcarrier multiplexed (SCM) configuration per polarization. Each SCM uses up to three OFDM-UWB channels of 200 Mbit/s each, achieving an aggregated bitrate of 1.2 Gbit/s with 0.76 bit/s/Hz spectral efficiency when using PDM transmission. The experimental results for the polarization-multiplexed SCM indicate that a 4 dB additional polarization crosstalk interference can be expected compared to a nonpolarization-multiplexed transmission system which translates to 2.4 dB EVM penalty in the UWB signals. The successful PDM transmission of SCM multiuser OFDM-UWB over a passive optical network of 25 km standard-single mode fiber (SSMF) reach is demonstrated.

scholarly journals Optical Multilevel Pulse Width Modulation for Analog Mobile Fronthaul

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 49
Author(s):  
Lorenzo Combi ◽  
Alberto Gatto ◽  
Pierpaolo Boffi ◽  
Umberto Spagnolini ◽  
Paola Parolari
Keyword(s):  
Wavelength Division Multiplexing ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Optical Network ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Radio Over Fiber ◽  
Passive Optical Network ◽  
Modulation Formats ◽  
Digital Radio

The evolution of radio access networks is towards a centralized architecture (C-RAN), with massive antenna deployments and large radio-frequency bandwidths. In the next future, traditional optical transport technologies based on digital radio over fiber will no longer be able to support the mobile fronthaul traffic connecting antennas hosted at remote radio units and centralized baseband units. Analog radio over fiber can be selected to support the mobile fronthaul (MFH) network and, in particular, pulse width modulation (PWM) is a viable alternative for analog signal transport. In order to increase the MFH spectral efficiency, we propose to exploit multilevel PWM (M-PWM) in a wavelength division multiplexing-passive optical network (WDM-PON) network, comparing its performance with a conventional 2-level PWM solution. Experimental results show successful transmission over 7.5-km standard single mode fiber (SSMF) of up to 16 aggregated LTE-like 20-MHz signals with 64-QAM on each subcarrier, while up to eight aggregated LTE-like 20-MHz signals with 256-QAM could be supported. M-PWM thus allows either using higher order modulation formats or aggregating a higher number of LTE channels.

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