Elektrik Elektronik Mühendisliği Bölümü Yayın Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/411

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Author: search.filters.author.Gokce, Muhsin CanerPublisher: search.filters.publisher.Taylor & Francis Ltd

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Now showing 1 - 3 of 3
  • Article
    Citation - WoS: 2
    Citation - Scopus: 1
    Signal-To Ratio With Adaptive Optics Compensation in Non-Kolmogorov Weak Turbulent Atmosphere
    (Taylor & Francis Ltd, 2021) Baykal, Yahya; Gokce, Muhsin Caner; Ata, Yalcin
    This study investigates the average signal-to-noise ratio < SNR > at the shot-noise limited receiver of an optical wireless communication system (OWC) that uses collimated Gaussian beam with adaptive optics correction in non-Kolmogorov weak turbulent atmosphere. < SNR > and the variation in the percentage < SNR > are calculated and the results are presented against various adaptive optics correction modes, non-Kolmogorov power-law exponent, receiver aperture size, Gaussian beam source size, photodetector quantum efficiency, electronic bandwidth, link length, and turbulence strength. Adaptive optics correction is analyzed for tilt, defocus, astigmatism, coma and trefoil modes and their variations. The effects of adaptive optics compensation are examined that cause an increase in SNR, hence improve the performance of an OWC system using collimated Gaussian beam and operating in the non-Kolmogorov weak turbulent atmosphere.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 2
    Ber Performance Ofm-Ary Pulse Position Modulated Communication Systems in Anisotropic Non-Kolmogorov Turbulent Atmosphere
    (Taylor & Francis Ltd, 2022) Gokce, Muhsin Caner; Ata, Yalcin; Baykal, Yahya
    We investigated the effect of anisotropic non-Kolmogorov atmospheric turbulence on the performance of the optical wireless systems whenM-ary Pulse Position Modulation (PPM) is applied to a Gaussian beam. The performance of the optical wireless systems that use avalanche photodetector at the receiver is evaluated in terms of the bit error rate (BER). The effects of the parameters, such as the anisotropy factors inx-ydirections, modulation order, data bit rate, equivalent load resistor, photodetector quantum efficiency, non-Kolmogorov turbulence power law exponent, beam source size, link length, photodetector gain and structure constant on BER of theM-ary PPM Gaussian beam propagating in anisotropic non-Kolmogorov atmospheric turbulence, are examined.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 8
    Bit Error Rate Analysis of Miso Fso Systems
    (Taylor & Francis Ltd, 2016) Baykal, Yahya; Uysal, Murat; Gokce, Muhsin Caner
    Multiple-input single-output (MISO) systems are employed in free space optical (FSO) links to mitigate the degrading effects of atmospheric turbulence. In this paper, we consider a MISO FSO system with practical transmitter and receiver configuration that consists of radial laser array with Gaussian beams and a Gaussian receiver aperture function. We have employed our previously derived formulation of the power scintillation in which Huygens-Fresnel principle was employed. Therefore, we choose system parameters within the range of validity of the wave structure functions. Using the on-off keying modulation and the log-normal probability distribution function, we quantify the average bit error rate (< BER >) of laser array beams in weak turbulence. It is observed that the radial array beams at the transmitter are more advantageous than the single Gaussian beam. However, increasing the number of array beamlets to more than three seems to have negligible effects on < BER >. It is further observed that < BER > decreases when the source size, the ring radius and the receiver aperture radius increase.