A. M. Khalid

3.4 Gbit/s visible optical wireless transmission based on RGB LED.

In this paper, we experimentally realized a gigabit-class indoor visible light communication system using commercially available RGB White LED and exploiting an optimized DMT modulation. We achieved data rate of 1.5 Gbit/s with single channel and 3.4 Gbit/s by implementing WDM transmission at standard illumination levels. In both experiments, the resulting bit error ratios were below the FEC limit. To the best of our knowledge, these values are the highest ever achieved in VLC systems.

1-Gb/s Transmission Over a Phosphorescent White LED by Using Rate-Adaptive Discrete Multitone Modulation

Light-emitting diodes (LEDs), which will be increasingly used in lighting technology, will also allow for distribution of broadband optical wireless signals. Visible-light communication (VLC) using white LEDs offers several advantages over the RF-based wireless systems, i.e., license-free spectrum, low power consumption, and higher privacy. Mostly, optical wireless can provide much higher data rates. In this paper, we demonstrate a VLC system based on a white LED for indoor broadband wireless access. After investigating the nonlinear effects of the LED and the power amplifier, a data rate of 1 Gb/s has been achieved at the standard illuminance level, by using an optimized discrete multitone modulation technique and adaptive bit- and power-loading algorithms. The bit-error ratio of the received data was

Experimental demonstration of high speed underwater visible light communications

1.5\cdot 10^{-3}

A Visible Light localization aided Optical Wireless system

, which is within the limit of common forward error correction (FEC) coding. These results twice the highest capacity that had been previously obtained.

2.1 Gbit/s visible optical wireless transmission

We experimentally prove high-speed underwater optical wireless transmission over 2.5 m distance, using different bit rates and modulation schemes. The system uses two low-cost Light Emitting Diodes (LEDs) arrays as optical transmitter and an avalanche photodiode module as receiver. The measurements are taken using an outdoor water tank having 3.3 m diameter, where two waterproof boxes containing the transmitter and the receiver are fixed underwater at the inner borders. We test 6.25 Mbit/s with Manchester coding, 12.5 Mbit/s with NRZ 8b/10b coding and 58 Mbit/s with Discrete Multitone modulation. Bit Error Rate measurements are collected over several hours under typical summer sunlight illumination conditions. In all the experimental conditions we achieve error free transmission.

Free space optical communication in the visible bandwidth for V2V safety critical protocols

We report about a Line of Sight Optical Wireless Communication (LoS OWC) system aided by a simplified Visible Light localization algorithm for tracking purposes. We show experimentally that by combining the LoS OWC system with the localization algorithm it is possible to provide a gross data-rate exceeding 300 Mb/s over a 90° illumination angle by using a RGB visible-light LED at 90cm distance.

Diffuse IR-optical wireless system demonstration for mobile patient monitoring in hospitals

We demonstrate gigabit-class indoor visible optical wireless transmission using commercial components and DMT modulation of a common visible RGB LED. We obtained 1 Gbit/s single channel and 2.1 Gbit/s WDM transmission at usual illumination levels.

VLC-signals distribution over GI-POF for in-home wireless networks

Vehicular Communication Systems are an emerging type of networks in which vehicles and roadside units are the communicating nodes, providing each other with information, such as safety warnings and traffic information. Vehicle-to-vehicle message exchange is considered the preferred pattern for safety-critical communication (e.g. in anti-collision active systems). Recently, LED-based optical wireless communication has been also proposed for car to car message delivery. This option turns to be particularly effective in short range direct communications to exploit its line-of-sight feature and overcome the issues related to the isotropic nature of radio waves. In this paper we experimentally address this case study making use of two low cost On-Board Unit prototypes, equipped with a common Light Emitting Diode (LED) component at the transmitter and a common PIN photodiode at the receiver.

Long distance indoor high speed visible light communication system based on RGB LEDs

Patient monitoring in the hospitals is very critical and important for medical treatment during both cure and recovery. Modern hospitals usually implies the facility of mobile patient monitoring based on radio frequency technology, however the radio frequency can experience electromagnetic interference (EMI) with sophisticated medical equipment, which may cause health risk to the patient. We experimentally demonstrate a solution for mobile patient monitoring based on diffuse infra-red (IR) optical wireless technology. In order to avoid background ambient light interference generated by florescent lamps, bipolar signalling is successfully exploited. The data rate of 10 Mbit/s with NRZ-AMI (bipolar signalling) is achieved with BER <; 10-5.

Demonstrating a hybrid radio-over-fibre and visible light communication system

We present the proof of concept of a wide-band signals distribution network combining plastic optical fiber (POF) and LED-based visible light communication (VLC). The proposed architecture exploits Frequency Division Multiplexing (FDM) of multiple signals, each of which selected at a specific VLC hot-spot. The multiplexed signals are first distributed via a POF; at the hot-spot a given frequency-band is down-converted to baseband and then transmitted through the optical wireless link. We demonstrated a distribution scenario over 50 m POF/2.5 m VLC link of two hot-spots, each having 200 Mbit/s capacity. We employed optimized discrete multi-tone modulation technique with optimal bit/power loading algorithm, maintaining the bit error ratio within the FEC limit.