Single-lane > 100 Gb/s CAP-based data transmission over VCSEL-MMF links using low-complexity equalization

In this paper, we review recent work on the development of a novel low-complexity equalizer that can enable single-lane <100 Gb/s short-reach optical links based on carrierless amplitude and phase modulation. This equalizer, named the CAP equalizer, can mitigate the transmission impairments in the link due to a non-ideal channel frequency response, providing significant performance advantage over conventional FFE and DFE equalizers and enabling higher data rates and longer reach. Its use is demonstrated in a VCSEL-based MMF link achieving data transmission of 112 and 124 Gb/s over 100 m OM4 MMF

OFDM-PWM scheme for visible light communications

In this paper, we propose an improved hybrid optical orthogonal frequency division multiplexing (O-OFDM) and pulse-width modulation (PWM) scheme for visible light communications. In this scheme, a bipolar O-OFDM signal is converted into a PWM format where the leading and trailing edges convey the frame synchronization and modulated information, respectively. The proposed scheme is insensitive to the non-linearity of the light emitting diode (LED) as LEDs are switched ‘on’ and ‘off’ between two points. Therefore, the tight requirement on the high peak-to-average-power-ratio (PAPR) in O-OFDM is no longer a major issue. The simulation and experimental results demonstrate that the proposed scheme offers an improved bit error rate performance compared to the traditional asymmetrically clipped O-OFDM (ACO-OFDM)

Multi-band Carrier-less Amplitude and Phase Modulation for VLC: An Overview

The rapid development of solid-state lighting technologies has been the stimulus for visible light communications (VLC) to be the focus of enormous interest over the last decade. The key feature of simultaneous data transmission and illumination using white light-emitting diodes (LEDs) makes VLC a potential candidate for future power efficient communication networks that aim to meet the ever-increasing demands for high-speed internet services. Researchers, motivated by the success of VLC technology, have developed a number of techniques and methods to support communication systems with both high transmission speeds and spectral efficiency. Here, we provide an overview of the multi-band carrier-less amplitude and phase (m-CAP) modulation technique enabling highly spectrally efficient VLC links in bandlimited environments

Development of a MATLAB application to generate NOMA-CAP 5G signals

Incoming 5G Era requires new modulation formats to increase spectral efficiency while enabling high flexibility. This project is focused on adapting and testing new 5G modulation formats for optical communications using cost-effective devices.The demand over high speed fixed and wireless networks increases every day. NOMACAP is being studied as a way to improve the spectral efficiency of 5G signals. That is why the objective of this thesis is to develop an application that allows us to freely generate simulated 5G NOMA-CAP signals with the settings we desire making it easier its study. We will also use said application to do three tests with different configurations that make use of all the new possibilities that the application brings.Actualmente la demanda por una comunicación inalámbrica rápida aumenta cada día. NOMA-CAP se está estudiando como una manera de mejorar la eficiencia espectral de 5G. El objetivo de esta tesis es desarrollar una aplicación que nos permita generar señales 5g NOMA-CAP con las características que deseemos, haciendo así más fácil el estudio de NOMA-CAP. Luego usaremos la aplicación para estudiar tres casos distintos que usaran los distintos modos que ofrece la aplicación.Actualment la demanda per 5G augmenta constantment. S?està estudiant NOMA-CAP com un mètode per incrementar la eficiència espectral de 5G. L?objectiu d?aquesta tesis és desenvolupar una aplicació que ens permeti generar senyals 5G NOMA-CAP amb les característiques que volem, fent així més fàcil el futur estudi de NOMA-CAP. Després utilitzarem aquesta aplicació per provar tres situacions diferents que utilitzin les diferents opcions que ofereix l?aplicació

Multi-band carrier-less amplitude and phase modulation with decision feedback equalization for bandlimited VLC systems

This paper presents simulation results that show the principle of implementing multi-band carrierless amplitude and phase (m-CAP) modulation enhanced by the decision feedback equalizer (DFE) for a bandlimited visible light communications (VLC) system. When deploying different number of sub-carriers m = {1, 2, 5, 10}, we show the bit error rate (BER) performance of m-CAP over a fixed system bandwidth of 1 Hz with and without a DFE. We show that we can achieve a BER of 10-4 for the m-CAP system for m = {1, 2}, which is well below the 7% and 20% forward error correction (FEC) BER limits of 3.8×10-3 and 2×10-2, respectively

Visible Light Communications for Indoor Applications

The field of visible light communications (VLC) has undergone a rapid development in recent years. The increased utilization of light emitting diodes (LEDs) has opened new possibilities for especially indoor services such as broadband internet connection and po- sitioning. Thus, a research within VLC is the main focus of the thesis and is divided into two main parts. At rst, the multiband carrier-less amplitude and phase (m-CAP) mod- ulation, introducing a newly adopted format for spectrally e cient VLC links, is under investigation using both theoretical and experimental approaches. The recommendations for m-CAP transmitter site design are proposed. Next, the channel modeling of indoor VLC is investigated with emphasis on the dynamically changing environments caused by moving people and non-line of sight (NLOS) propagation and new statistical models are derived.Katedra elektromagnetického pol