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2020 - 20212
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Bölüm: Işık University, Faculty of Engineering, Department of Electrical-Electronics Engineering × Konu: Benchmarking ×

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Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Yayın
    Generic BER analysis of VLC channels impaired by 3D user-mobility and imperfect CSI
    (Institute of Electrical and Electronics Engineers Inc., 2021-07) Reddy Sekhar, K.; Miramirkhani, Farshad; Mitra, Rangeet; Turlapaty, Anish Chand
    Visible light communications (VLC) has emerged as a high-speed, low-cost, and green supplement for the existing radio frequency (RF) based infrastructures. However, the performance of VLC based systems is found to degrade significantly due to detrimental outages caused by non-negligible variations in the VLC channel-gain, that are jointly induced by radial user-mobility and random photodetector-orientation (together designated as 3D mobility in this letter). In addition to the 3D user-mobility mentioned above, the performance of VLC based systems is further limited by imperfect channel-state information (CSI). Such degradations in the VLC-link caused by the aforementioned factors necessitate the quantification of performance-metrics for further benchmarking/receiver-design. In this work, an analytical expression for bit-error rate (BER) is derived for a single LED indoor VLC system considering the radial user-mobility, random receiver orientation, and imperfect CSI altogether. Further, the derived BER expressions are validated using computer-simulations using typical VLC channel models from the literature. A close agreement between the analytical and the simulated BER is observed, which verifies the accuracy of the presented analysis.
  • Küçük Resim
    Yayın
    Improving age of information in random access channels
    (Institute of Electrical and Electronics Engineers Inc., 2020-07) Atabay, Doğa Can; Uysal, Elif; Kaya, Onur
    We study Age of Information (AoI) in a random access channel where a number of devices try to send status updates over a common medium. Assuming a time-slotted scenario where multiple transmissions result in collision, we propose a threshold-based lazy version of Slotted ALOHA and derive the time average AoI achieved by this policy. We demonstrate that the average AoI performance of the lazy policy is significantly better than Slotted ALOHA, and close to the ideal round robin benchmark.