Performance of Vehicular Visible Light Communications under the Effects of Atmospheric Turbulence with Aperture Averaging

Abstract

In this paper, we investigate the performance of a vehicular visible light communications (VVLC) link with a non-collimated and incoherent light source (a light-emitting diode) as the transmitter (Tx), and two different optical receiver (Rx) types (a camera and photodiode (PD)) under atmospheric turbulence (AT) conditions with aperture averaging (AA). First, we present simulation results indicating performance improvements in the signal-to-noise ratio (SNR) under AT with AA with increasing size of the optical concentrator. Experimental investigations demonstrate the potency of AA in mitigating the induced signal fading due to the weak to moderate AT regimes in a VVLC system. The experimental results obtained with AA show that the link’s performance was stable in terms of the average SNR and the peak SNR for the PD and camera-based Rx links, respectively with <1 dB SNR penalty for both Rxs, as the strength of AT increases compared with the link with no AT.

Increasing Vehicular Visible Light Communications Range Based on LED Current Overdriving and Variable Pulse Position Modulation: Concept and Experimental Validation

“…On the other hand, there is no need to regulate the performance of VLC receivers, as they can be adapted, developed, and improved without legal limitations. In this sense, various techniques used in the architecture of a VLC receiver to increase the range are implemented nowadays, such as: (i) avoiding the saturation of the optical element under the conditions of exposure to parasitic light (for example, direct exposure to sunlight) by limiting the VLC receiver Field of View (FoV) [ 14 , 15 ] or by using optical filters calibrated on the wavelength of the transmitter [ 16 ] and/or by implementing various construction techniques of the transimpedance amplifier [ 15 , 17 ], (ii) the use of optical collimators and of aperture averaging [ 18 , 19 , 20 ], (iii) the selection of more efficient photodetectors, (iv) the use of high-speed Complementary Metal-Oxide-Semiconductor (CMOS)-based VLC receivers [ 21 ], (v) the rejection of unwanted signals with the help of band-pass filters or advanced signal processing techniques [ 12 ], and (vi) the use of a novel concept of adaptation to the context [ 22 , 23 ].…”

“…In this context, the present article is focused on extending the range of VLC systems used in the vehicular environment. Dissimilar to most of the existing approaches on this topic, this work proposes a different paradigm, focusing on the enhancements that could be provided by an improved VLC emitter design, rather than strictly orienting on the development of the VLC receiver like most of the studies do [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Thus, in order to achieve this purpose, while also focusing on complying with the lighting norms and with the IEEE 802.15.7 specifications [ 28 ], this work investigates the possibility of increasing vehicular VLC systems communication range by overdriving the LED transmitter current and by proportionally shortening the duration of the pulses.…”

A unilateral 3D indoor positioning system employing optical camera communications

“…In addition, the quality of the received image is evaluated in terms of the peak signal-to-noise (PSNR), which is given by [30]:…”

The Effect of Air Turbulence on Vortex Beams in Nonlinear Propagation

“…These types of atmospheric applications, such as optical communication [ 25 , 26 , 27 , 28 ], remote sensing and LIDAR technology (light detection and ranging) [ 29 ], etc., require the long-distance propagation of the laser beam through the atmosphere. Turbulent air is the main obstacle during the propagation of ultrafast filamentation through the atmosphere.…”