scholarly journals Tunable Optoelectronic Chromatic Dispersion Compensation Based on Machine Learning for Short-Reach Transmission

2019 ◽  
Vol 9 (20) ◽  
pp. 4332 ◽  
Author(s):  
Stenio M. Ranzini ◽  
Francesco Da Ros ◽  
Henning Bülow ◽  
Darko Zibar
Keyword(s):  
Machine Learning ◽  
Digital Signal Processor ◽  
Forward Error Correction ◽  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
Digital Signal ◽  
Single Mode ◽  
Hybrid Structure ◽  
Optical Module ◽  
Hybrid Module

In this paper, a machine learning-based tunable optical-digital signal processor is demonstrated for a short-reach optical communication system. The effect of fiber chromatic dispersion after square-law detection is mitigated using a hybrid structure, which shares the complexity between the optical and the digital domain. The optical part mitigates the chromatic dispersion by slicing the signal into small sub-bands and delaying them accordingly, before regrouping the signal again. The optimal delay is calculated in each scenario to minimize the bit error rate. The digital part is a nonlinear equalizer based on a neural network. The results are analyzed in terms of signal-to-noise penalty at the KP4 forward error correction threshold. The penalty is calculated with respect to a back-to-back transmission without equalization. Considering 32 GBd transmission and 0 dB penalty, the proposed hybrid solution shows chromatic dispersion mitigation up to 200 ps/nm (12 km of equivalent standard single-mode fiber length) for stage 1 of the hybrid module and roughly double for the second stage. A simplified version of the optical module is demonstrated with an approximated 1.5 dB penalty compared to the complete two-stage hybrid module. Chromatic dispersion tolerance for a fixed optical structure and a simpler configuration of the nonlinear equalizer is also investigated.

Optical OFDM for Downstream Transmission in Long-Reach PON

2014 ◽  
Vol 631-632 ◽  
pp. 860-863 ◽  
Author(s):  
Xiao Xue Gong ◽  
Hui Li ◽  
Peng Chao Han ◽  
Yu Fang Zhou
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Direct Detection ◽  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
Optical Network ◽  
Digital Signal ◽  
Least Square ◽  
Passive Optical Network ◽  
Spectrum Efficiency ◽  
Flexible Resource

Orthogonal Frequency Division Multiplexing (OFDM) has gained great attention in the next generation Long-Reach Passive Optical Network (LR-PON) due to its high spectrum efficiency, flexible resource allocation and natural compatibility with Digital Signal Processing (DSP)-based implementation. In this paper, we propose and demonstrate a 40Gbit/s direct-detection long reach OFDM-PON system for downstream transmission over 100km standard signal mode fiber (SSMF). By using a simple Least Square (LS) method for the channel estimation, our proposed system achieves high bit rate without the need for chromatic dispersion compensation.

scholarly journals Multi-Twin-SSB Modulation with Direct Detection Based on Kramers–Kronig Scheme for Long-Reach PON Downstream

2019 ◽  
Vol 9 (4) ◽  
pp. 748 ◽  
Author(s):  
Xiang Gao ◽  
Yuancheng Cai ◽  
Bo Xu ◽  
Xiaoling Zhang ◽  
Kun Qiu
Keyword(s):  
Optical Networks ◽  
Forward Error Correction ◽  
Direct Detection ◽  
Chromatic Dispersion ◽  
Optical Network ◽  
Single Mode ◽  
System Optimization ◽  
Single Mode Fiber ◽  
High Data ◽  
Multi Band

As the demand for high data volumes keeps increasing in optical access networks, transmission capacities and distance are becoming bottlenecks for passive optical networks (PONs). To solve this problem, a novel scheme based on multi-twin single sideband (SSB) modulation with direct detection is proposed and investigated in this paper. At the central office, two SSB signals are generated simultaneously with the same digital-to-analog converters (DACs). The twin-SSB signal is not only robust against frequency selected power fading introduced by chromatic dispersion (CD), but also improves the spectral efficiency (SE). By combining a twin-SSB technique with multi-band carrier-less amplitude/phase modulation (multi-CAP), different optical network units (ONUs) can be supported by flexible multi-band allocation based on software-reconfigurable optical transceivers. The Kramers–Kronig (KK) scheme is adopted on the ONU side to effectively mitigate the signal–signal beat interference (SSBI) induced by the square-law detection. The proposed system is extensively studied and validated with four sub-bands using 50 Gbps 16 quadrature amplitude modulation (QAM) modulation for each sub-band using numerical simulations. Digital pre-equalization is introduced at the transmitter-side to balance the performance of different ONUs. After system optimization, a bit error rate (BER) threshold for hard decision forward error correction (HD-FEC) code with 7% redundancy ratio (BER = 3.8 × 10−3) can be reached for all ONUs over 50-km standard single-mode fiber.

scholarly journals Unrepeatered 240-km 64-QAM Transmission Using Distributed Raman Amplification over SMF Fiber

2020 ◽  
Vol 10 (4) ◽  
pp. 1433
Author(s):  
P. Rosa ◽  
G. Rizzelli ◽  
X. Pang ◽  
O. Ozolins ◽  
A. Udalcovs ◽  
...  
Keyword(s):  
Digital Signal Processor ◽  
Back Propagation ◽  
Digital Signal ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Raman Amplification ◽  
Raman Fiber Laser ◽  
Modulation Format ◽  
Transmission Distance ◽  
Nonlinear Compensation

We present a theoretical and experimental investigation of unrepeatered transmission over standard single-mode fiber (SMF-28) using several schemes of distributed Raman amplification, including first, second, and dual order. In order to further extend the transmission distance, we utilize advanced bidirectional higher-order ultra-long Raman fiber laser-based amplification, where we use fiber Bragg gratings (FBGs) to reflect Stokes-shifted light from the secondary pumps. Our work demonstrates the possibility of transmission up to 240-km span length with a total span loss of 52.7 dB. Here, we use a 28-Gbaud signal using a 64-quadrature amplitude modulation (QAM) modulation format. Our results highlight the contribution of nonlinear compensation using digital back propagation in a digital signal processor (DSP) code at the receiver.

Performance Enhancement of Ultra High Capacity 2.5 Tbps DWDM System Using DCF and Optimized Modulation Format

2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Sooraj Parkash
Keyword(s):  
Performance Enhancement ◽  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
High Capacity ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Modulation Formats ◽  
Modulation Format ◽  
Point To Point ◽  
Dwdm System

AbstractThis paper successfully demonstrate point-to-point (P2P) 2.5 TB/s DWDM system in downstream for 100 wavelengths having 0.4 nm (50 GHz) channel spacing by using post-dispersion compensation scheme. Each channel is transmitting 25 GB/s data rate in down link. A 20 km dispersion compensating fiber (DCF) followed by 80 km standard single mode fiber (SSMF) which passes 20 times through fiber span for compensating the chromatic dispersion. The maximum reach of designed system is (100×20) 2,000 km. In this paper we also performed the comparison of different modulation formats such as NRZ, RZ and CRZ. It has been observed that CRZ modulation format can achieve BER as better as e

Proposed Square Lattice Photonic Crystal Fiber for Extremely High Nonlinearity, Birefringence and Ultra-High Negative Dispersion Compensation

2019 ◽  
Vol 40 (4) ◽  
pp. 401-410 ◽  
Author(s):  
Md. Ibadul Islam ◽  
Kawsar Ahmed ◽  
Shuvo Sen ◽  
Bikash Kumar Paul ◽  
Md. Shadidul Islam ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
Single Mode ◽  
Square Lattice ◽  
Geometrical Properties ◽  
High Birefringence ◽  
Crystal Fiber ◽  
Negative Dispersion

Abstract A photonic crystal fiber in square lattice architecture is numerically investigated and proposed for broadband dispersion compensation in optical transmission system. Simulation results reveal that it is possible to obtain an ultra-high negative dispersion of about −571.7 to −1889.7 (ps/nm.km) in the wavelength range of 1340 nm to 1640 nm. Experimentally it is demonstrated that the design fiber covers a high birefringence of order 4.74×10‒3 at the wavelength of 1550 nm. Here, numerical investigation of guiding properties and geometrical properties of the proposed PCF are conducted using the finite element method (FEM) with perfectly match layers. Moreover, it is established more firmly that the proposed fiber successfully compensates the chromatic dispersion of standard single mode in entire band of interest. Our result is attractive due to successfully achieve ultra-high negative dispersion that is more promisor than the prior best results.

scholarly journals Design and Analysis of CMOS Full Adder

2021 ◽  
pp. 99-103
Author(s):  
Saurabh J Shewale ◽  
Sonal A Shirsath
Keyword(s):  
Low Power ◽  
Digital Signal Processor ◽  
High Performance ◽  
Critical Path ◽  
Digital Signal ◽  
Full Adder ◽  
Hybrid Structure ◽  
Computing Systems ◽  
Area Efficiency ◽  
Performance Computing

This paper presents a comparative study of Complementary MOSFET (CMOS) full adder circuits. Our approach is based on hybrid design full adder circuits combined in a single unit. Full adder circuit is an essential component for designing of various digital systems. It is used for different applications such as Digital signal processor, microcontroller, microprocessor and data processing units (DSP). In most of these systems the adder lies in the critical path that determines the overall speed of the system. Full adder is mainly used in VLSI devices like microprocessor for computational purposes. The proposed full adder cell has low power consumption, better area efficiency. Recently, there have been massive research interests in this area due to the growing need for low-power and high-performance computing systems. Our aim is to design and compare the full adder circuit in various technologies and compare their power capacity. By using the hybrid structure of NMOS and PMOS, we have implemented the circuit of full adder.

DSP Implementation of an Active Bearing Mount for Rotors Using Hybrid Control

2000 ◽  
Vol 122 (4) ◽  
pp. 420-428 ◽  
Author(s):  
Mingsian R. Bai ◽  
Weibin Luo
Keyword(s):  
Digital Signal Processor ◽  
Hybrid Control ◽  
Digital Signal ◽  
Hybrid Structure ◽  
Experimental Investigations ◽  
Least Mean Square ◽  
Linear Quadratic ◽  
Electromagnetic Actuators ◽  
Multiple Channel ◽  
Periodic Disturbances

An on-line active technique for suppressing rotor vibration is proposed. Electromagnetic actuators are mounted on the housing of a ball bearing for generating counter forces to cancel the transverse vibrations due to imbalance, misalignment, and so forth. Controllers based on feedback structure, feedforward structure and hybrid structure are investigated. The multiple channel active control systems are implemented on the platform of a digital signal processor. Numerical simulation and experimental investigations indicate that the proposed methods are effective in suppressing the periodic disturbances. In particular, the hybrid control by using feedback linear quadratic gaussian control and feedforward least mean square algorithm with synthetic reference achieves the best performance in terms of vibration attenuation and convergence speed. [S0739-3717(00)00904-1]

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