@article{3035709,
    title = "Experimental Evaluation of Modulation Formats' Performance in Diffuse UV Channels",
    author = "Raptis, N. and Pikasis, E. and Nikas, T. and Fragkos, M.-A. and Syvridis, D.",
    journal = "IEEE Photonics Technology Letters",
    year = "2017",
    volume = "29",
    number = "11",
    pages = "897-900",
    publisher = "Institute of Electrical and Electronics Engineers, Inc. (IEEE)",
    issn = "1041-1135",
    doi = "10.1109/LPT.2017.2693561",
    keywords = "Frequency division multiplexing;  Light emitting diodes;  Modulation;  Optical communication;  Photomultipliers;  Positron emission tomography;  Pulse position modulation;  Ultraviolet spectroscopy, Atmospheric conditions;  Experimental evaluation;  Fundamental properties;  Non-line-of-sight;  Optical wireless;  Photo multiplier tube;  Point-to-point link;  Ultraviolet spectral regions, Orthogonal frequency division multiplexing",
    abstract = "The fundamental properties of free space optical channels in the ultraviolet (UV) spectral range between 200 and 280 nm are the enhanced scattering and the solar blind operation. Exploiting these properties, point-to-point links in a non-line-of-sight (NLOS) regime were experimentally tested and the performance of pulse position modulation of fourth order (4-PPM) and flip-orthogonal frequency division multiplexing (Flip-OFDM) modulation formats was evaluated. At the transmitting side, light-emitting diodes (LEDs) emitting at 265 nm were used. At the receiving side, a photo-multiplier tube was combined with an optical filter. Distances up to 20 m were covered and kilobits/s rates were applied. The performance was also evaluated after modifying artificially the atmospheric conditions by the operation of a fog machine. In short, 4-PPM outperformed Flip-OFDM, whereas a medium that offers enriched scattering due to fog may boost the performance of short-range NLOS links in the UV spectral range. © 1989-2012 IEEE."
}