Low-Complexity Soft-Decision Concatenated LDGM-Staircase FEC for High-Bit-Rate Fiber-Optic Communication

2017 ◽  
Vol 35 (18) ◽  
pp. 3991-3999 ◽  
Author(s):  
Lei M. Zhang ◽  
Frank R. Kschischang
Keyword(s):  
Fiber Optic ◽  
Low Complexity ◽  
Bit Rate ◽  
Soft Decision ◽  
Fiber Optic Communication ◽  
High Bit Rate ◽  
Optic Communication

DISTRIBUTED AMPLIFIER FOR FIBER-OPTIC COMMUNICATION SYSTEMS

2003 ◽  
Vol 13 (01) ◽  
pp. 111-139 ◽  
Author(s):  
H. SHIGEMATSU ◽  
M. SATO ◽  
M. TAKECHI ◽  
T. TAKAHASHI ◽  
T. HIROSE
Keyword(s):  
Communication Systems ◽  
Fiber Optic ◽  
Data Format ◽  
Distributed Amplifiers ◽  
Distributed Amplifier ◽  
Lumped Element ◽  
Broadband Amplifier ◽  
Fiber Optic Communication ◽  
High Bit Rate ◽  
Optic Communication

We have developed distributed amplifiers for high bit-rate fiber-optic communication systems. We have designed a LiNbO 3 modulator driver using 0.15-μm double-doped AlGaAs/InGaAs/AlGaAs pseudomorphic HEMTs. We obtained a 15-dB gain and 54-GHz bandwidth with GCPW lines, and a fairly clear 6-Vp-p output at 40 Gb/s. We also developed preamplifiers for both NRZ and NRZ applications. Our preamplifier for the NRZ-data format has a 52-dBΩ gain and a 49-GHz bandwidth. It consists of a lumped element circuit and a distributed amplifier with InP-based HEMTS. We fabricated a module that consisted of the preamplifier connected to a photodiode, and confirmed a clear NRZ-output waveform at 40-Gb/s. The preamplifier with 0.15-μm double-doped AlGaAs/lnGaAs/AlGaAs pseudomorphic HEMTs for the RZ-data format has an 11-dB gain and a 57-GHz bandwidth. We also developed a PIN/preamp module that has a 44-dBΩ gain and a 45-GHz bandwidth. The module showed a superior phase characteristic and produced a clear RZ eye-pattern. Furthermore, we fabricated an ultra-broadband amplifier for over-40-Gb/s applications. We obtained a 9-dB gain and 70-GHz bandwidth. These results demonstrate that a distributed amplifier is the best candidate for over-40-Gb/s fiber optic communication systems.manuscript.

An Efficient Low Complexity Compression based Optimal Homomorphic Encryption for Secure Fiber Optic Communication

Optik ◽  
2021 ◽  
pp. 168545
Author(s):  
D. Venu ◽  
A.V.R Mayuri ◽  
S Neelakandan ◽  
G.L.N Murthy ◽  
N Arulkumar ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Homomorphic Encryption ◽  
Low Complexity ◽  
Fiber Optic Communication ◽  
Optic Communication

Optical data signals in fiber optic communication links with fading

2019 ◽  
pp. 94-104
Author(s):  
I. Juwiler ◽  
I. Bronfman ◽  
N. Blaunstein
Keyword(s):  
Spectral Efficiency ◽  
Fiber Optic ◽  
Fiber Optic Cable ◽  
Optical Signals ◽  
Dispersion Properties ◽  
Optical Cable ◽  
Time Dispersion ◽  
Communication Links ◽  
Fiber Optic Communication ◽  
Optic Communication

Introduction: This article is based on the recent research work in the field of two subjects: signal data parameters in fiber optic communication links, and dispersive properties of optical signals caused by non-homogeneous material phenomena and multimode propagation of optical signals in such kinds of wired links.Purpose: Studying multimode dispersion by analyzing the propagation of guiding optical waves along a fiber optic cable with various refractive index profiles of the inner optical cable (core) relative to the outer cladding, as well as dispersion properties of a fiber optic cable due to inhomogeneous nature of the cladding along the cable, for two types of signal code sequences transmitted via the cable: return-to-zero and non-return-to-zero ones.Methods: Dispersion properties of multimode propagation inside a fiber optic cable are analyzed with an advanced 3D model of optical wave propagation in a given guiding structure. The effects of multimodal dispersion and material dispersion causing the optical signal delay spread along the cable were investigated analytically and numerically.Results: Time dispersion properties were obtained and graphically illustrated for two kinds of fiber optic structures with different refractive index profiles. The dispersion was caused by multimode (e.g. multi-ray) propagation and by the inhomogeneous nature of the material along the cable. Their effect on the capacity and spectral efficiency of a data signal stream passing through such a guiding optical structure is illustrated for arbitrary refractive indices of the inner (core) and outer (cladding) elements of the optical cable. A new methodology is introduced for finding and evaluating the effects of time dispersion of optical signals propagating in fiber optic structures of various kinds. An algorithm is proposed for estimating the spectral efficiency loss measured in bits per second per Hertz per each kilometer along the cable, for arbitrary presentation of the code signals in the data stream, non-return-to zero or return-to-zero ones. All practical tests are illustrated by MATLAB utility.

MODELING OF FIBER-OPTIC COMMUNICATION CHANNEL FOR QUANTUM CRYPTOGRAPHIC SYSTEMS

2019 ◽  
pp. 90-95
Author(s):  
V. A. Minaev ◽  
I. D. Korolev ◽  
O. A. Kulish ◽  
A. V. Mazin
Keyword(s):  
Information Transmission ◽  
Information Transfer ◽  
Fiber Optic ◽  
Single Photon ◽  
Optical Devices ◽  
Energy Losses ◽  
Integrated Optical ◽  
Integrated Optical Devices ◽  
Fiber Optic Communication ◽  
Optic Communication

The existing methods of information delivery to the strategic and tactical management of many government agencies are expensive, not always reliable and efficient. Therefore, quantum cryptographic systems (QCS) have been actively developed in recent years. However, there are problems with the use of the QCS associated with the reliability of information transfer. First, the existing fiber-optic communication channels (FOCC) are not designed to transmit single-photon signals, which leads to the complexity of their cryptographic protection. The second is insufficiently methodically developed calculation of energy losses and errors in the evaluation of the characteristics of information transfer in FOCC QCS. In article the analysis of the energy loss factors in the classical fiber-optic channel is carried out and the additive loss formula is discussed in detail. Then we consider the fiber-optic channel of quantum information transmission with the use of integrated optical devices. The additive formula of optical losses in such a channel is discussed. The features of losses in integrated optical devices are shown. The features of quantum cryptographic system of information transmission are considered. As a result, the model of FOCC QCS taking into account energy losses is presented, which allows competently in theoretical terms and visualize the passage of information through modern quantum cryptographically secure telecommunications while providing control in government structures.

Tributary Mapping Multiplexing an Efficient Technique for High Speed Fiber Optic Communication

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Usman Illahi ◽  
Javed Iqbal ◽  
Muhammad Ismail Sulaiman ◽  
Muhammad Alam ◽  
Mazliham Mohd Su'ud
Keyword(s):  
Spectral Efficiency ◽  
High Speed ◽  
Fiber Optic ◽  
Single Channel ◽  
Efficient Technique ◽  
High Dispersion ◽  
Optical Filtering ◽  
Fiber Optic Communication ◽  
Optic Communication ◽  
Dispersion Tolerance

<p>A novel technique of multiplexing called Tributary Mapping Multiplexing (TMM) is<br />applied to a single channel wavelength division multiplexing system and performance is monitored on the basis of simulation results. To elaborate the performance of TMM in this paper, a 4-User TMM system over single wavelength channel is demonstrated. TMM showed significant tolerance against narrow optical filtering as compared to that of conventional TDM at the rate of 40 Gbit/s. The above calculations are made by optical filter bandwidth and dispersion tolerance that was allowed at minimum. The spectral efficiency achieved by this TMM was 1 b/s/Hz and it was executed by using transmitters and receivers of 10 Gbit/s without polarized multiplexing. The high spectral efficiency, high dispersion tolerance and tolerance against strong optical filtering makes TMM an efficient technique for High<br />Speed Fiber Optic Communication.</p>

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