Dynamic interferometry: measurement of space optics and structures

Author(s):  
James E. Millerd ◽  
Michael North-Morris
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Vel Murugan Gomathy ◽  
T. V. Paramasivam Sundararajan ◽  
C. Sengodan Boopathi ◽  
Pandiyan Venkatesh Kumar ◽  
Krishnamoorthy Vinoth Kumar ◽  
...  

AbstractIn the present study, the application of free space optics (FSO) transmission system to realize a long-reach high-altitude platform (HAP)-to-satellite communication link has been exploited. High-speed information transmission without interference is accomplished using orthogonal frequency division multiplexing (OFDM). Further, the information capacity of the proposed system is increased by employing mode division multiplexing (MDM). We have investigated the proposed MDM-OFDM-HAP-to-satellite FSO transmission system performance over varying FSO range, diameter of the receiver, pointing errors, and input power. Also, an improved transmission performance of the proposed system using a square root module is reported.


Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 254
Author(s):  
Juan Andrés Apolo ◽  
Beatriz Ortega ◽  
Vicenç Almenar

A hybrid fiber/wireless link based on a single visible LED and free of opto-electronic intermediate conversion stages has been demonstrated for indoor communications. This paper shows the main guidelines for proper coupling in fiber/air/detector interfaces. Experimental demonstration has validated the design results with very good agreement between geometrical optics simulation and received optical power measurements. Different signal bandwidths and modulation formats, i.e., QPSK, 16-QAM, and 64-QAM, have been transmitted over 1.5 m polymer optical fiber (POF) and 1.5 m free-space optics (FSO). Throughputs up to 294 Mb/s using a 64-QAM signal have been demonstrated using a commercial LED, which paves the way for massive deployment in industrial applications.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bentahar Attaouia ◽  
Kandouci Malika ◽  
Ghouali Samir

AbstractThis work is focused to carry out the investigation of wavelength division multiplexing (WDM) approach on free space optical (FSO) transmission systems using Erbium Ytterbium Doped Waveguide Amplifier (EYDWA) integrated as post-or pre-amplifier for extending the reach to 30 Km for the cost-effective implementation of FSO system considering weather conditions. Furthermore, the performance of proposed FSO-wavelength division multiplexing (WDM) system is also evaluated on the effect of varying the FSO range and results are reported in terms of Q factor, BER, and eye diagrams. It has been found that, under clear rain the post-amplification was performed and was able to reach transmission distance over 27 Km, whereas, the FSO distance has been limited at 19.5 Km by using pre-amplification.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kavitha Thandapani ◽  
Maheswaran Gopalswamy ◽  
Sravani Jagarlamudi ◽  
Naveen Babu Sriram

Abstract Free Space Optical (FSO) communication has evolved as a feasible technique for wireless implementations which offers higher bandwidth capacities over various wavelengths and refers to the transmission of modulated visible beams through atmosphere in order to communicate. Wavelength Division Multiplexing (WDM) is a technology that multiplexes numerous carrier signals onto single fiber using nonidentical wavelengths and enables the efficiency of bandwidth and expanded data rate. Multiple Input Multiple Output (MIMO) is implemented to improve the quality and performance of free space optical communication in various atmospheric conditions. In this paper, a WDM-based FSO communication system is being implemented that benefits from MIMO which receives multiple copies of the signal at receiver that are independent and analyzed for various streams of data in MIMO i.e. 2 × 2, 4 × 4, 8 × 8. Various factors like BER, Quality Factor are analyzed for the WDM-based FSO communication with MIMO using the OptiSystem for various data streams of MIMO under different atmospheric conditions.


Author(s):  
Thiago R. Raddo ◽  
Simon Rommel ◽  
Bruno Cimoli ◽  
Chris Vagionas ◽  
Diego Perez-Galacho ◽  
...  

AbstractThe sixth generation (6G) mobile systems will create new markets, services, and industries making possible a plethora of new opportunities and solutions. Commercially successful rollouts will involve scaling enabling technologies, such as cloud radio access networks, virtualization, and artificial intelligence. This paper addresses the principal technologies in the transition towards next generation mobile networks. The convergence of 6G key-performance indicators along with evaluation methodologies and use cases are also addressed. Free-space optics, Terahertz systems, photonic integrated circuits, softwarization, massive multiple-input multiple-output signaling, and multi-core fibers, are among the technologies identified and discussed. Finally, some of these technologies are showcased in an experimental demonstration of a mobile fronthaul system based on millimeter 5G NR OFDM signaling compliant with 3GPP Rel. 15. The signals are generated by a bespoke 5G baseband unit and transmitted through both a 10 km prototype multi-core fiber and 4 m wireless V-band link using a pair of directional 60 GHz antennas with 10° beamwidth. Results shown that the 5G and beyond fronthaul system can successfully transmit signals with both wide bandwidth (up to 800 MHz) and fully centralized signal processing. As a result, this system can support large capacity and accommodate several simultaneous users as a key candidate for next generation mobile networks. Thus, these technologies will be needed for fully integrated, heterogeneous solutions to benefit from hardware commoditization and softwarization. They will ensure the ultimate user experience, while also anticipating the quality-of-service demands that future applications and services will put on 6G networks.


IEEE Access ◽  
2020 ◽  
pp. 1-1
Author(s):  
Samir A. Al-Gailani ◽  
Mohd Fadzli Mohd Salleh ◽  
Ali A. Salem ◽  
Redhwan Q. Shaddad ◽  
Usman Ullah Sheikh ◽  
...  

2004 ◽  
Author(s):  
Arthur J. Gavrin ◽  
Kent G. Blizard ◽  
Donald J. Leo ◽  
Mathew D. Bennett
Keyword(s):  

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