Role of laser linewidth in high speed DWDM system by incorporating duobinary modulation scheme

This work is focused on realization of DWDM system of 1.6 Tb/s ultra high capacity using duobinary return to zero modulation scheme with EDFA and dispersion compensation scheme.Duo binary format is used as it is suitable for high spectral efficiency at large transmission distance.40 channels having capacity of 40 Gbps data rate each are multiplexed with channel spacing of 100 GHz to realize 1.6 Tbps as total transmission over optical span of 60 Km by using pre and post compensation technique.The comparison of parameters is observed in terms of Q value and eye opening keeping BER in acceptable range Moreover, the role of laser line-width is also investigated to minimize the non linearity and four wave mixing effect

Role of turbulences in WDM-polarization interleaving scheme based inter-satellite communication system

Inter-Satellite communication is the revolutionary technology used to transmit the signals between the satellites.This work is focused to carry out the investigation of turbulences in Inter-Satellite communication system by incorporating WDMPI interleaving scheme. A 6 x 20 Gbps channels are transported over Inter-Satellite link having span of 1000 km to realize the total transmission of 120 Gbps.The role of transmitter pointing errors and receiving pointing errors in the OWC link is investigated and results are reported in terms of SNR, total received power and eye diagrams

Mode Division Multiplexing of LG and HG modes in Ro-FSO

Radio-over-free-space-optics (Ro-FSO) is a strongcontender for providing a ubiquitous platform for seamlessintegration of high capacity radio and optical networks withoutexpensive optical fiber cabling. This work presents mode divisionmultiplexing of LG and HG modes in a 40 GHz Ro-FSOtransmission system to realize 4 x 20Gbps over a free space opticallink under clear weather conditions. The signal-to-noise-ratio,received power and constellations will be analyzed

2x20 Gbps - 40 GHz OFDM Ro-FSO transmission with mode division multiplexing

Radio-over-Free-Space-Optics (Ro-FSO) is a promising technology for future wireless networks.In this work, we have designed a hybrid orthogonal frequency division multiplexing (OFDM) Ro-FSO system for transmission of two independent channels by mode division multiplexing.Two independent 40 GHz radio signals are optically modulated at 20Gbps by mode division multiplexing of two laser modes LG00 and LG10 and transmitted over a free-space link of 20 km to 100 km. The performance of proposed Ro-FSO system is also evaluated under the effect of strong atmospheric turbulences

Realization of free space optics with OFDM under atmospheric turbulence

Free space optics (FSO) technology provides a promising solution for future broadband networks, offering high data transmission compared to RF technology. This work is focused on investigating the performance of an FSO system with OFDM and QAM. A 10 Gbps data stream is transmitted using a 4-level QAM sequence through the FSO system under different atmospheric conditions. Results indicate that the integration of SOA prolongs the maximum achievable distance with acceptable SNR to 185 km under clear weather conditions whereas under atmospheric fog, the maximum distance is extended to 2.5 k

5Gbps HG 0,1 and HG 0,3 optical mode division multiplexing for RoFSO

Radio-over-free-space optics (Ro-FSO) technology harnesses the large capacity of optical fiber and the mobility native to wireless networks.To increase the capacity of Ro-FSO networks, this work introduces a new optical mode division multiplexing (MDM) scheme for Ro-FSO by incorporating optical Hermite-Gaussian modes HG 0, 1 and HG 0, 3 for transmitting two distinct 2.5 Gbps data modulated on 10 GHz radio subcarriers.Signal-to-noise ratios and biterror-rates show successful 2 × 2.5Gbps data transmission of 10GHz radio-modulated subcarriers over the two HG optical carriers through a 800m free-space channel

A data driven approach in less expensive robust transmitting coverage and power optimization

This paper aims the development of a new reduced-cost algorithm for a multi-objective robust transmitter placement under uncertainty. Toward this end, we propose a new hybrid Kriging/Grey Wolf Optimizer (GWO) approach combined with robust design optimization to estimate the set of Pareto frontier by searching robustness as well as accuracy (lower objective function) in a design space. We consider minimization of the energy power consumption for transmitting as well as maximization of signal coverage in a multi-objective robust optimization model. The reliability of the model to control signal overlap for multiple transmitting antennas is also provided. To smooth computational cost, the proposed method instead of evaluating all receiver test points in each optimization iteration approximates signal coverages using Kriging interpolation to obtain optimal transmitter positions. The results demonstrate the utility and the efficiency of the proposed method in rendering the robust optimal design and analyzing the sensitivity of the transmitter placement problem under practically less-expensive computational efforts (350% and 320% less than computational time elapsed using standalone GWO and NSGAII respectively)

High Resolution-Based Coherent Photonic Radar Sensor for Multiple Target Detections

The last decade witnessed remarkable growth in the number of global road accidents. To minimize road accidents, transportation systems need to become more intelligent. Multiple detection of target vehicles under adverse weather conditions is one of the primary challenges of autonomous vehicles. Photonic radar sensors may become the promising technology to detect multiple targets to realize autonomous vehicles. In this work, high-speed photonic radar is designed to detect multiple targets by incorporating a cost-effective wavelength division multiplexing (WDM) scheme. Numerical simulations of the proposed WDM-based photonic radar is demonstrated in terms of received power and signal to noise (SNR) ratio. The performance of the proposed photonic radar is also investigated under diverse weather conditions, particularly low, medium, and thick fog. The proposed photonic radar demonstrated a significant range resolution of 7 cm when the target was placed at 80 m distance from the photonic radar sensor-equipped vehicle. In addition to this, traditional microwave radar is demonstrated to prove the effectiveness of the proposed photonic radar

Optimization of AMI-MDM-RoFSO under atmospheric turbulence

Radio over Free Space (Ro-FSO) is promising candidate for providing ubiquitous digital services especially in rural areas. This work investigates the performance of MDM of two 5Gbps-10GHz data channels over FSO link using LP 01 and LP 02 modes under the effect of atmospheric turbulences. The signal to noise ratio (SNR), total received power, modal decomposition at receiver at the receiver is also reported. The reported result shows the successful transmission of two channels with acceptable SNR over FSO link under atmospheric turbulences

Free-space optical mode division multiplexing for switching between millimeter-wave picocells

For connectivity between millimeter-wave radio femtocells or picocells, a free-space optical link may be used in a ubiquitous radio-over-free-space-optics (Ro-FSO) platform.This work introduces a new optical Hermite-Gaussian mode division multiplexing scheme for multiplexing radio signals between different picocells in a Ro-FSO network using a spatial correlator.Distinct 2.5GHz 10GHz radio-modulated subcarrier data streams from two picocells over two 850nm optical Hermite-Gaussian mode carriers were successfully multiplexed to two picocells separated by 500 meters. At the receiver, the signals were retrieved on the two modes using nonintermetric decomposition and spatial correlation optical Hermite-Gaussian modes into linearly polarized modes.Optical signal-to-noise ratios, bit-error-rates and modal decomposition results demonstrate effective data transmission between the picocells