scholarly journals Distortion losses of high-speed single-photon avalanche diode optical receivers approaching quantum sensitivity

2020 ◽  
Vol 378 (2169) ◽  
pp. 20190194 ◽  
Author(s):  
John Kosman ◽  
Kevin Moore ◽  
Harald Haas ◽  
Robert K. Henderson
Keyword(s):  
High Speed ◽  
Limit Of Detection ◽  
Single Photon ◽  
Visible Light Communication ◽  
Optical Signal ◽  
Quantum Limit ◽  
Modulation Scheme ◽  
Communication Link ◽  
Nonlinear Behaviour ◽  
Error Performance

The high internal gain of single-photon avalanche diodes (SPADs) operating in Geiger mode allows the quantum limit of detection to be approached. This offers a significantly improved sensitivity for optical communication over existing photodiodes. A fully integrated CMOS SPAD array receiver (RX) is presented which achieves 500 Mb s −1 four-level pulse amplitude modulation in a visible light communication link within 15.2 dB of the quantum limit. However, SPAD dead time induces around 5.7 dB of transient distortion which restricts error performance and data rate. We propose a model describing a discrete photon counting system which exhibits this nonlinear behaviour and compare it to practical measurements with the RX. A unipolar intensity modulated optical signal is considered, as opposed to bipolar electric fields in conventional radio frequency wireless systems. Intermodulation between the DC and harmonic components of the data-carrying waveform is investigated, and the resulting degradation of signal-to-noise-and-distortion ratio and bit error rate is evaluated. The model is developed as a tool for understanding distortion to ultimately allow rectification through RX architecture, modulation scheme, coding and equalization techniques. This article is part of the theme issue ‘Optical wireless communication’.

Modulation and Demodulation Techniques in Indoor Visible Light Communication System

2014 ◽  
Vol 685 ◽  
pp. 306-309
Author(s):  
Hao Wang ◽  
Ze Yu Han
Keyword(s):  
Visible Light ◽  
Communication Technology ◽  
Communication System ◽  
High Speed ◽  
Data Transfer ◽  
Visible Light Communication ◽  
Communication Link ◽  
High Data ◽  
Modulation And Demodulation ◽  
The Impact

Visible light communication technology is a emerging wireless and optical communication technology developed after invention and application of white LED.In this paper, we have a research based on indoor visible light communication system of lighting white LED,discuss of the visible light communication channel characteristics,detailedly analysis of the indoor visible light communication link. This paper focuses on the modulation and demodulation method applied to visible light communication. In the past visible light communication is mainly used off keying modulation,however, the data transfer speed is limited due to the influence of ISI .This paper presents a solution based on OFDM modulation and demodulation, to reduce the impact brought from inter-symbol string under high data transfer speed.Based on data analysis and computer simulation,the program presented in this paper can be used as indoor lighting and high-speed data transmission.Finally, give scheme to achieve visible light communication modulation and demodulation,provide a theoretical basis for further experiments.

scholarly journals Machine Learning-Assisted Adaptive Modulation for Optimized Drone-User Communication in B5G

Drones ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 128
Author(s):  
Sudheesh Puthenveettil Gopi ◽  
Maurizio Magarini ◽  
Saeed Hamood Alsamhi ◽  
Alexey V. Shvetsov
Keyword(s):  
Machine Learning ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Adaptive Modulation ◽  
Data Rate ◽  
Practical Implementation ◽  
Modulation Scheme ◽  
Error Performance ◽  
Wireless Broadcast ◽  
Atmospheric Disturbances

The fundamental issue for Beyond fifth Generation (B5G) is providing a pervasive connection to heterogeneous and various devices in smart environments. Therefore, Drones play a vital role in the B5G, allowing for wireless broadcast and high-speed communications. In addition, the drone offers several advantages compared to fixed terrestrial communications, including flexible deployment, robust Line of Sight (LoS) connections, and more design degrees of freedom due to controlled mobility. Drones can provide reliable and high data rate connectivity to users irrespective of their location. However, atmospheric disturbances impact the signal quality between drones and users and degrade the system performance. Considering practical implementation, the location of drones makes the drone–user communication susceptible to several environmental disturbances. In this paper, we evaluate the performance of drone-user connectivity during atmospheric disturbances. Further, a Machine Learning (ML)-assisted algorithm is proposed to adapt to a modulation technique that offers optimal performance during atmospheric disturbances. The results show that, with the algorithm, the system switches to a lower order modulation scheme during higher rain rate and provides reliable communication with optimized data rate and error performance.

scholarly journals Modeling and Analysis of DIPPM: A New Modulation Scheme for Visible Light Communications

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Sana Ullah Jan ◽  
Young-Doo Lee ◽  
Insoo Koo
Keyword(s):  
Visible Light ◽  
Direct Detection ◽  
Visible Light Communication ◽  
Modulation Scheme ◽  
Light Sources ◽  
Visible Light Communications ◽  
Error Performance ◽  
Communication Performance ◽  
Modeling And Analysis ◽  
Dimming Control

Visible Light Communication (VLC) uses an Intensity-Modulation and Direct-Detection (IM/DD) scheme to transmit data. However, the light source used in VLC systems is continuously switched on and off quickly, resulting in flickering. In addition, recent illumination systems include dimming support to allow users to dim the light sources to the desired level. Therefore, the modulation scheme for data transmission in VLC system must include flicker mitigation and dimming control capabilities. In this paper, the authors propose a Double Inverse Pulse Position Modulation (DIPPM) scheme that minimizes flickering and supports a high level of dimming for the illumination sources in VLC systems. To form DIPPM, some changes are made in the symbol structure of the IPPM scheme, and a detailed explanation and mathematical model of DIPPM are given in this paper. Furthermore, both analytical and simulation results for the error performance of 2-DIPPM are compared with the performance of VPPM. Also, the communication performance of DIPPM is analyzed in terms of the normalized required power.

High-speed fiber system capacity with bidirectional Er-Yb CDFs based on differential phase shift keying (DPSK) modulation technique

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud M. A. Eid ◽  
Huda Said Abd El-Hamid ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
High Speed ◽  
Optical Power ◽  
Optical Signal ◽  
Pump Wavelength ◽  
System Capacity ◽  
Modulation Scheme ◽  
Fiber System ◽  
Absorption Bands ◽  
Differential Phase Shift ◽  
Signal Gain

Abstract This paper simulates the bidirectional Er-Yb codoped fiber amplifiers (CDFs)-based DPSK modulation scheme for high speed fiber system capacity. The combination of Erbium-Ytterbium codoped fibers into a single fiber has been developed for the extension of the absorption bands for doped fibers. The signal gain variations versus pump wavelength variations have been demonstrated for various doped amplifiers with the proposed Er-Yb CDFs at amplifier length of 5 m. Also the signal gain variations versus pump wavelength variations have been illustrated for the proposed Er-Yb CDFs at 5 m amplifier length in different pumping configurations. The total optical power, max. Q factor, total electrical power, output optical signal/noise ratio, and signal gain variations versus fiber length variations have between simulated and clarified in the presence of bidirectional various lengths of Er-Yb CDFs.

scholarly journals Power Distribution and BER in Indoor VLC with PPM Based Modulation Schemes: A Comparative Study

2018 ◽  
Author(s):  
Suzan M. El-Garhy ◽  
Heba Fayed ◽  
Moustafa Aly
Keyword(s):  
Light Source ◽  
Power Distribution ◽  
Direct Detection ◽  
Optical Power ◽  
Visible Light Communication ◽  
Modulation Scheme ◽  
Pulse Position Modulation ◽  
Bit Rate ◽  
Error Performance ◽  
Power Requirement

Visible Light Communication (VLC) uses an intensity-modulation and direct-detection (IM/DD) scheme to transmit data. The light source utilized in VLC structures is constantly switched on and off rapidly, resulting in flickering. Furthermore, most of illumination systems exclude dimming support to permit customers to dim the light source to the desired stage. Therefore, the modulation scheme for information transmission in VLC should consist of flicker mitigation and dimming manage abilities. Double inverse pulse position modulation (DIPPM), sub-carrier pulse position modulation (SC-L-PPM), and M-ary variable pulse position modulation (M-VPPM) are recommended for minimizing the flicker issues and supporting an excessive degree of dimming for VLC systems. In this paper, a comparison is introduced between DIPPM, SC-L-PPM, and M-VPPM according to error performance and bit rate. In addition, a simulation is carried out to measure the optical power distribution for a LED lamp in an indoor room topology for each modulation technique. The obtained results indicated that SC-L-PPM is the best choice regarding the bit error rate (BER) and optical power distribution compared to the other two schemes. A 10-6 BER is achieved with a very low power requirement at L=8, while a remarkable power distribution of 1.5 to 6.5 dBm is observed from 3×5×5 m3 room corners to the center, respectively. According to the bit rate, it is noticed that, M-VPPM is the most efficient one compared to the two other schemes. It achieves 2.3×107 bps at signal to noise ratio (SNR) of 22 dB and M=8.

Measurement of High Speed Polarization Change of Optical Signal through an OPGW Caused by Serge Current

2016 ◽  
Vol 136 (7) ◽  
pp. 887-892
Author(s):  
Ikuo Yamashita ◽  
Shun Morimura ◽  
Hitoshi Murai ◽  
Osamu Ogawa ◽  
Masahiro Kurono
Keyword(s):  
High Speed ◽  
Optical Signal ◽  
Polarization Change

Analysis of Inter-Satellite Optical Wireless Communication System

2017 ◽  
Vol 7 (10) ◽  
pp. 10
Author(s):  
Rajbir Singh
Keyword(s):  
Wireless Communication ◽  
Optical Networks ◽  
Data Transmission ◽  
High Speed ◽  
Open Space ◽  
Communication Link ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
High Speed Data ◽  
Speed Data Transmission

Optical networks are bandwidth efficient networks are used for long haul communication providing seamless data transfer. For high speed data transmission in open space between different satellites, Inter-satellite Optical wireless communication (IsOWC) is widely used .In this paper we have evaluated the performance of IsOWC communication link for high speed data transmission .The performance of the system is evaluated on the basis of qualitative parameters such as Q-factor and BER using optisystem simulator.

An all optical photonic crystal half adder suitable for optical processing applications

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamed Azhdari ◽  
Sahel Javahernia
Keyword(s):  
Photonic Crystal ◽  
Optical Waveguides ◽  
High Speed ◽  
Building Blocks ◽  
Optical Signal ◽  
Ring Resonators ◽  
Optical Processing ◽  
Nonlinear Photonic Crystal ◽  
Half Adder ◽  
All Optical

Abstract Increasing the speed of operation in all optical signal processing is very important. For reaching this goal one needs high speed optical devices. Optical half adders are one of the important building blocks required in optical processing. In this paper an optical half adder was proposed by combining nonlinear photonic crystal ring resonators with optical waveguides. Finite difference time domain method wase used for simulating the final structure. The simulation results confirmed that the rise time for the proposed structure is about 1 ps.

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