Most studies on optical wireless communications (OWCs) have neglected the effect of random orientation in their performance analysis due to the lack of a proper model for the random orientation. Our recent empirical-based research illustrates that the random orientation follows a Laplace distribution for static user equipment (UE). In this paper, we analyze the device orientation and assess its importance on system performance. The probability of establishing a line-of-sight link is investigated and the probability density function (PDF) of signal-to-noise ratio (SNR) for a randomly-oriented device is derived. By means of the PDF of SNR, the bit-error ratio (BER) of DC biased optical orthogonal frequency division multiplexing (DCO-OFDM) in additive white Gaussian noise (AWGN) channels is evaluated. A closed form approximation for the BER of UE with random orientation is presented which shows a good match with Monte-Carlo simulation results.
from cs updates on arXiv.org https://ift.tt/2NJVvan
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