scholarly journals The channel capacity of a fiber optics communication system: perturbation theory

2002 ◽  
Vol 20 (3) ◽  
pp. 530-537 ◽  
Author(s):  
E.E. Narimanov ◽  
P. Mitra
Keyword(s):  
Perturbation Theory ◽  
Fiber Optics ◽  
Channel Capacity ◽  
Communication System

scholarly journals BPL-PLC Voice Communication System for the Oil and Mining Industry

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4763
Author(s):  
Grzegorz Debita ◽  
Przemysław Falkowski-Gilski ◽  
Marcin Habrych ◽  
Grzegorz Wiśniewski ◽  
Bogdan Miedziński ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Communication System ◽  
Communication Systems ◽  
High Efficiency ◽  
Coal Dust ◽  
Mining Industry ◽  
Power Line ◽  
Communication Link ◽  
Voice Communication ◽  
Medium Voltage

Application of a high-efficiency voice communication systems based on broadband over power line-power line communication (BPL-PLC) technology in medium voltage networks, including hazardous areas (like the oil and mining industry), as a redundant mean of wired communication (apart from traditional fiber optics and electrical wires) can be beneficial. Due to the possibility of utilizing existing electrical infrastructure, it can significantly reduce deployment costs. Additionally, it can be applied under difficult conditions, thanks to battery-powered devices. During an emergency situation (e.g., after coal dust explosion), the medium voltage cables are resistant to mechanical damage, providing a potentially life-saving communication link between the supervisor, rescue team, paramedics, and the trapped personnel. The assessment of such a system requires a comprehensive and accurate examination, including a number of factors. Therefore, various models were tested, considering: different transmission paths and types of coupling (inductive and capacitive), as well as various lengths of transmitted data packets. Next, a subjective quality evaluation study was carried out, considering speech signals from a number of languages (English, German, and Polish). Based on the obtained results, including both simulations and measurements, appropriate practical conclusions were formulated. Results confirmed the applicability of BPL-PLC technology as an efficient voice communication system for the oil and mining industry.

scholarly journals Performance Improvement for Mixed RF–FSO Communication System by Adopting Hybrid Subcarrier Intensity Modulation

2019 ◽  
Vol 9 (18) ◽  
pp. 3724 ◽  
Author(s):  
Jiang ◽  
Zhao ◽  
Liu ◽  
Deng ◽  
Luo ◽  
...  
Keyword(s):  
Atmospheric Turbulence ◽  
Channel Capacity ◽  
Communication System ◽  
Rayleigh Distribution ◽  
Intensity Modulation ◽  
Phase Shift Keying ◽  
Free Space Optical ◽  
Pointing Error ◽  
Shift Keying ◽  
Binary Phase Shift Keying

The improvement for hybrid radio frequency–free space optical (RF–FSO) communication system in wireless optical communications has acquired growing interests in recent years, but rarely improvement is based on hybrid modulation. Therefore, we conduct a research on end-to-end mixed RF–FSO system with the hybrid pulse position modulation–binary phase shift keying–subcarrier intensity modulation (PPM–BPSK–SIM) scheme. The RF link obeys Rayleigh distribution and the FSO link experiences Gamma–Gamma distribution. The average bit error rate (BER) for various PPM–BPSK–SIM schemes has been derived with consideration of atmospheric turbulence influence and pointing error condition. The outage probability and the average channel capacity of the system are discussed as well. Simulation results indicate that the pointing error aggravates the influence of atmospheric turbulence on the channel capacity, and the RF–FSO systematic performance is improved obviously while adopting PPM–BPSK–SIM under strong turbulence and severe pointing error conditions, especially, when the system average symbol length is greater than eight.

Performance Analysis of a STBC FDM FSO Communication System with Direct Detection Receiver under Turbulent Condition

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Bobby Barua ◽  
S. P. Majumder
Keyword(s):  
Atmospheric Turbulence ◽  
Channel Capacity ◽  
Communication System ◽  
Direct Detection ◽  
Weather Conditions ◽  
Optical Receiver ◽  
Communication Link ◽  
Link Distance ◽  
Receive Diversity ◽  
Turbulent Condition

AbstractWeather conditions are severely degraded the performance of FSO communication link. Atmospheric turbulence is one of the important weather conditions that degrade the performance even under clear sky condition. In this paper, we provide a noble analytical approach to evaluate the performance of STBC coded FDM FSO communication system with direct detection optical receiver under turbulent condition. Analysis is carried out to find the channel capacity of RF subcarrier modulation taking into consideration the effect of strong atmospheric turbulence which is modeled as gamma-gamma distribution and the probability density function of the conditional CNR, conditioned on a given turbulence-induced fading is derived considering equal gain receive diversity combining technique with direct detection optical receiver followed by RF synchronous demodulation. Results are evaluated numerically in terms of average CNR, BER and channel capacity for several system parameters like turbulence variance, link distance, data rate, etc.

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