Challenges in Gbps Wireless Optical Transmission

In this paper, the link budget of Gbps wireless infrared indoor communication is analysed. We particularly focus on the receiver sensitivity and identify the most suitable wavelengths range. We show that an optical receiver operating at 1 Gbps will hardly achieve the shot noise limit, which is determined by the received amount of background light. Regarding the link budget, we present two case studies. One deals with (very) short range communication, the other one with a wireless personal area network. We reveal that a network demands for avalanche photodiodes as well as beam steering. This clearly causes major challenges regarding compact and inexpensive components

Lightweight, mobile free-space optical communications in disaster scenarios for transmission of Earth observation data: feasibility study

Free-space optical (FSO) links are an effective alternative to radio frequency (RF) to handle high-rate data transmission in case of a general communication service failure in disaster scenarios. Establishing high data rate links under the impacts of extreme environmental conditions, like the unregulated RF spectrum, is a very challenging issue. This paper focuses on multicopter (e.g., quadrocopter or hexacopter) based earth observation systems. Its main objective is to show that FSO communication can provide a high-rate link for transmitting earth observation data from a multicopter to a ground station, even under environmental disaster conditions. Before analyzing the feasibility of such an optical multicopter system, the main system structure will be discussed in detail. Several system designs will be compared and evaluated based on link budget calculations. In this process, a novel Grating Light Valve (GLV) retroreflector modulator technology will be introduced in this work. The study will emphasize that a reliable 100 Mbit/s FSO data transmission will be feasible to provide a downlink capacity for multicopter based earth observation systems

A 1.25-Gb/s Indoor Cellular Optical Wireless Communications Demonstrator

This letter reports an experimental demonstration of an indoor angle-diversity optical wireless communications system. This operates at 1.25 Gb/s and provides bidirectional communications between two terminals. Each terminal uses three transmitting "cells" giving a field of view of approximately 25° × 8° over a range of approximately 3 m. Data is transmitted to a terminal that uses three receivers to obtain a similar reception field of view. Link operation at a bit-error rate <;; 10e-9 is reported, together with an overview of the system configuration

High-speed optical wireless demonstrators: Conclusions and future directions

Two high-speed angle diversity optical wireless systems have recently been implemented, as part of a European Community funded project. One operates at 1.25 Gb/s offering a limited coverage area, and the other at 280 Mb/s, with room scale coverage. In this paper, we summarize the design approach for these systems and their performance. Implications of these results for the design and implementation of future systems are also discussed

Visible-light communication system enabling 73 Mb/s data streaming

The hOME Gigabit Access (OMEGA) home-area-network project aims at bridging the gap between home and access network and providing Gb/s connectivity to users. The project considers a combination of various technologies such as radio-frequency and wireless optical links operating at infrared and visible wavelengths. When combined with power-line communications (PLC), this enables a home backbone that meets the project’s “without new wires” vision. A technology-independent MAC layer will control this network and provide services as well as connectivity to any number of devices the user wishes to connect to in any room of a house/apartment. In order to make this vision come true, substantial progress had to be achieved in the fields of optical wireless physical layer development and data-link-layer protocol design. This paper reports an experimental demonstration of an indoor visible-light wireless link including a MAC layer protocol adapted to optical wireless communications systems. The system operates at 84 Mb/s broadcast and was successfully used to transmit three high-definition video streams