scholarly journals A Spatial Time-Frequency Hopping Index Modulated Scheme in Turbulence-free Optical Wireless Communication Channels

2020 ◽  
Vol 68 (7) ◽  
pp. 4437-4450 ◽  
Author(s):  
Francisco J. Escribano ◽  
Alexandre Wagemakers ◽  
Georges Kaddoum ◽  
Joao V. C. Evangelista
Author(s):  
Mahmoud M. A. Eid ◽  
Ashraf S. Seliem ◽  
Ahmed Nabih Zaki Rashed ◽  
Abd El-Naser A. Mohammed ◽  
Mohamed Yassin Ali ◽  
...  

<p><span id="docs-internal-guid-52da184f-7fff-738a-f0e7-e8dd779e097b"><span>This paper has presented high modulated soliton power transmission interaction with optical fiber and optical wireless communication channels at flow rate of 40 Gbps and 20 km link range. The proposed modulation schemes are continuous phase frequency shift keying (CPFSK), Quadrature amplitude modulation (QAM), differential phase shift keying (DPSK), frequency shift keying (FSK), pulse amplitude modulation (PAM), minimum shift keying (MSK), and optical quadrature phase shift keying (OQPSK). CPFSK has presented better performance than other proposed modulation schemes for both optical fiber and optical wireless communication channels. The enhancement of optical signal/noise ratio at fiber/wireless channel, received electrical power and signal/noise ratio at optical receiver with increase of bits per symbol for different proposed modulation schemes except for CPFSK scheme. Therefore it is evident that CPFSK modulation scheme is more efficient and better performance than other modulation schemes for different communication channels. The obtained results are simulated with optisystem program version 13. </span></span></p>


Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5067
Author(s):  
Dima Bykhovsky

The coherence time is the time over which the channel-gain-values correlation coefficient drops below a predefined threshold. The coherence time is typically used to quantify the pace of appreciable channel changes and is important, for example, for determining handoff and resource allocation time constraints. The goal of this work is to experimentally measure the coherence time of indoor optical wireless communication (OWC) channels under various mobile scenarios. The amount of movement was quantified by mobile sensor measurements. The experiments show that it is reasonable to assume that the channel varies slowly for a time period of ~100 milliseconds for most mobile scenarios.


Author(s):  
Rajbir Singh

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.


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