Analyzing Interface Bonding Schemes for VLC with Mobility and Shadowing

Node mobility and shadowing are the most common reasons requiring a handover in vehicular visible light communications (VVLC). In order to provide seamless mobility during the handover, it is required to decrease the network outage duration. This paper aims to improve the outage duration in handover caused by mobility and shadow for VLC networks. We analyze interface bonding schemes using two different primary interface reselection methods. The results show that using "failure"interface selection method instead of "always"method reduces the VLC handover outage duration by 62% and 44% in bonding schemes for transmission control protocol (TCP) and user datagram protocol (UDP) network traffic, respectively

A polynomial analog baseband predistorter for compensation of wireless amplifier’s distortion

This paper presents a new analog polynomial pre-distortion circuit using 350nm CMOS technology to reduce the distortion of the power amplifier in wireless communication systems. The proposed pre-distortion circuit uses the polynomial approach. The coefficients of the polynomial are controlled by multiplying them with sufficient digit defined through the indirect learning process to provide best practice linearization. Circuit level simulation of the proposed circuit is using Cadence DFW II is used as proof of concept. The simulation set-up comprises a power amplifier, excited with a four carrier GSM signal, pre-distorted by the proposed circuit. Simulation results show that using the pre-distortion circuit the 3rd order intermodulation distortion is reduced on average by 12 and 16 dB.publishe

Lifi positioning for industry 4.0

Precise position information is considered as the main enabler for the implementation of smart manufacturing systems in Industry 4.0. In this article, a time-of-flight based indoor positioning system for LiFi is presented based on the ITU - T recommendation G.9991. Our objective is to realize positioning by reusing already existing functions of the LiFi communication protocol which has been adopted by several vendors. Our positioning algorithm is based on a coarse timing measurement using the frame synchronization preamble, similar to the ranging, and a fine timing measurement using the channel estimation preamble. This approach works in various environments and it requires neither knowledge about the beam characteristics of transmitters and receivers nor the use of fingerprinting. The new algorithm is validated through both, simulations and experiments. Results in an 1 m × 1 m × 2 m area indicate that G.9991-based positioning can reach an average distance error of a few centimeters in three dimension. Considering the common use of lighting in indoor environments and the availability of a mature optical wireless communication system using G.9991, the proposed LiFi positioning is a promising new feature that can be added to the existing protocols and enhance the capabilities of smart lighting systems further for the benefit of Industry 4.0

Distributed MIMO Experiment Using LiFi over Plastic Optical Fiber

This paper shows the feasibility of a networked LiFi system using a distributed multiple-input multiple-output (MIMO) link for optical wireless transmission and a plastic optical fiber (POF) link as a fixed front-haul between distributed optical front-ends, and a centralized signal processing unit. The concatenation of POF and optical wireless links yields an easy-to-install all-optical LiFi system which is robust against both, blockage of individual light beams and electromagnetic interference. A significant cost-down appears by the use of colored LEDs to feed the POF link with multiple optical signals, and wavelength division demultiplexing filters. The spatial crosstalk in the wireless link and the spectral crosstalk over the POF link can be jointly compensated by the same end-to-end MIMO processing. A common signal model, which includes the combined effects of both links are provided to characterize the proposed all-optical LiFi system. We report the first experimental findings when using space-division multiplexing (SDM), i.e., multiple POFs, and wavelength-division multiplexing (WDM), i.e., multiple colors in the front-haul, indicating that the performance is mostly limited by the wireless link. Moreover, we show that the positions of mobile users in the wireless link, as well as gain variations and spectral crosstalk in the front-haul link, influence the singular values and the achievable data rates of the LiFi system

ELIoT: enhancing LiFi for next-generation Internet of things

Communication for the Internet of things (IoT) currently is predominantly narrowband and cannot always guarantee low latency and high reliability. Future IoT applications such as flexible manufacturing, augmented reality and self-driving vehicles rely on sophisticated real-time processing in the cloud to which mobile IoT devices are connected. High-capacity links that meet the requirements of the upcoming 6G systems cannot easily be provided by the current radio-based communication infrastructure. Light communication, which is also denoted as LiFi, offers huge amounts of spectrum, extra security and low-latency transmission free of interference even in dense reuse settings. We present the current state-of-the-art of LiFi systems and introduce new features needed for future IoT applications. We discuss results from a distributed multiple-input multiple-output topology with a fronthaul using plastic optical fibre. We evaluate seamless mobility between the light access points and also handovers to 5G, besides low-power transmission and integrated positioning. Future LiFi development, implementation and efforts towards standardization are addressed in the EU ELIoT project which is presented here

ELIoT: New Features in LiFi for Next-Generation IoT

The Internet of Things currently is predominantly narrowband and cannot always guarantee high reliability and low latency. Future IoT applications such as flexible manufacturing, augmented reality and self-driving vehicles need sophisticated real-time processing units in the cloud to which mobile IoT devices are connected. These high-capacity links meet the requirements of the upcoming 6G systems and cannot be facilitated by the current mobile communication infrastructure. Light communication, which is also denoted as LiFi, offers huge amounts of spectrum, extra security and interference-free transmission. We present the current state-of-the-art of LiFi systems and introduce new features needed for future IoT applications. We propose a distributed Multiple-Input Multiple-Output topology with a fronthaul using plastic optical fiber. Such a system offers seamless mobility between the light access points and also to 5G, besides low latency and integrated positioning. Future LiFi development, implementation and efforts towards standardization are addressed in the EU ELIoT project which is presented here