2018/05/21 by Mohammad Soltani, Soltani, Mohammad Dehghani, Ardimas Andi Purwita +7
Engineering · #FOS: Computer and information sciences #Indoor and Outdoor Localization Technologies #Information Theory (cs.IT) #Millimeter-Wave Propagation and Modeling #Optical Wireless Communication Technologies
paper · pdf · doi:10.48550/arxiv.1805.07999
openalex publication_date 2018/05/21 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
Light-fidelity (LiFi) is a networked optical wireless communication (OWC)\nsolution for high-speed indoor connectivity for fixed and mobile optical\ncommunications. Unlike conventional radio frequency wireless systems, the OWC\nchannel is not isotropic, meaning that the device orientation affects the\nchannel gain significantly, particularly for mobile users. However, due to the\nlack of a proper model for device orientation, many studies have assumed that\nthe receiver is vertically upward and fixed. In this paper, a novel model for\ndevice orientation based on experimental measurements of forty participants has\nbeen proposed. It is shown that the probability density function (PDF) of the\npolar angle can be modeled either based on a Laplace (for static users) or a\nGaussian (for mobile users) distribution. In addition, a closed-form expression\nis obtained for the PDF of the cosine of the incidence angle based on which\nline-of-sight (LOS) channel gain is described in OWC channels. An approximation\nof this PDF based on the truncated Laplace is proposed and the accuracy of this\napproximation is confirmed by the Kolmogorov-Smirnov distance (KSD). Moreover,\nthe statistics of the LOS channel gain are calculated and the random\norientation of a user equipment (UE) is modeled as a random process. The\ninfluence of the random orientation on signal-to-noise-ratio (SNR) performance\nof OWC systems has been evaluated. Finally, an orientation-based random\nwaypoint (ORWP) mobility model is proposed by considering the random\norientation of the UE during the user's movement. The performance of ORWP is\nassessed on the handover rate and it is shown that it is important to take the\nrandom orientation into account.\n