Design Techniques for High Performance Optical Wireless Front-Ends

The demand for wireless broadband communication is growing steadily with the volatile increase of internet and mobile applications. Optical wireless and radio communications are both the viable solutions, but the promise of high un-regulated bandwidth at a low cost makes optical wireless an attractive technical alternative. The data rate in Gbps achieved in laboratory is yet not been available in indoor systems. Current research in wireless optical concentrates on increasing communication capacity and improving the performance. In this paper, the major design, performance, safety issues, and recent trends are discussed to close the gap between theory and practice.

1999

This is the second of two papers discussing practical issues and results on the implementation of low-cost transceivers for several wireless optical LANs, covering most physical layer elements. Target optical LANs under consideration have bit-rates varying between 4Mbps and 25Mbps, and input photodiode capacitance may vary between 10pF and 50pF. PPM modulation, either in a 4-PPM or 16-PPM format, is typically used in the physical layer. Several differential front-end topologies are presented both in discrete and integrated (CMOS) implementations, targeting different LANs. Strategies for bandwidth improvement, interference reduction and dynamic range improvement have been used in some of these topologies. These strategies lead to a switched-gain transceiver with a transimpedance gain*bandwidth of 25THzΩ , achieved with a 10pF capacitance photodiode.

IEEE Photonics Journal, 2011

Enabling technologies for optical wireless broadband access networks have been explored and developed with respect to optical components, modules, transmission systems, and networks. In this paper, we review the most significant accomplishments reported during 2010 with emphasis on radio-over-fiber (RoF) technology that is critical for the deployment of optical wireless broadband access networks in the near future.

The demand of bandwidth in mobile communication is growing exponentially day-by-day, as the numbers of users have been increased drastically over the span of last five years. The next generation wireless communication systems therefore need to be of higher standards, so as to support various Broadband wireless servicessuch as, Video conferencing, mobile videophones, high-speed Internet access etc. The existing wireless systems can hardly provide transmission capacity of the order of few Mbps. However, millimeter (mm) waves and optical fiber technology has the potential of providing data capacity of the order of Mbps and Tbps respectively. Therefore the requirements of broadband wireless system can be met through the integration of optical fiber and millimeter wave wireless systems. In this paper we suggest a modified millimeter wave wireless system using orthogonal frequency division multiplexing (OFDM) technique, integrated with optical fiber as a feeder network. Here we have inves...

IntechOpen eBooks, 2019

The emerging fifth-generation mobile communications are envisaged to support massive number of deployment scenarios based on the respective use case requirements. The requirements can be efficiently attended with ultradense small-cell cloud radio access network (C-RAN) approach. However, the C-RAN architecture imposes stringent requirements on the transport networks. This book chapter presents high-capacity and low-latency optical wired and wireless networking solutions that are capable of attending to the network demands. Meanwhile, with optical communication evolutions, there has been advent of enhanced photonic integrated circuits (PICs). The PICs are capable of offering advantages such as lowpower consumption, high-mechanical stability, low footprint, small dimension, enhanced functionalities, and ease of complex system architectures. Consequently, we exploit the PICs capabilities in designing and developing the physical layer architecture of the second standard of the next-generation passive optical network (NG-PON2) system. Apart from being capable of alleviating the associated losses of the transceiver, the proposed architectures aid in increasing the system power budget. Moreover, its implementation can significantly help in reducing the opticalelectrical-optical conversions issue and the required number of optical connections, which are part of the main problems being faced in the miniaturization of network elements. Additionally, we present simulation results for the model validation.

2014

Resumo – Este é o primeiro de dois artigos que discutem a implementação de emissores/receptores para redes locais não cabladas utilizando a tecnologia de infravermelhos, de baixo custo. O trabalho aqui apresentado cobre maioritariamente os elementos da camada física. As redes locais não cabladas consideradas têm taxas de transmissão entre 4Mbps e 25Mbps, e a capacidade do fotodíodo receptor entre 10pF e 50pF. Os tipos de modulação considerados são tipicamente 4-PPM ou 16-PPM. Neste artigo são apresentadas diferentes topologias de front-end, quer em implementações discretas, quer em integradas (CMOS), tendo como objectivo diferentes redes alvo. Estratégias para melhoramento de largura de banda, redução de interferência, e melhoramento de gama dinâmica foram usadas em algumas destas topologias. Estas estratégias

EURASIP Journal on Wireless Communications and Networking, 2012

This article presents an overview of optical wireless (OW) communication systems that operate both in the short-(personal and indoor systems) and the long-range (outdoor and hybrid) regimes. Each of these areas is discussed in terms of (a) key requirements, (b) their application framework, (c) major impairments and applicable mitigation techniques, and (d) current and/or future trends. Personal communication systems are discussed within the context of point-to-point ultra-high speed data transfer. The most relevant application framework and related standards are presented, including the next generation Giga-IR standard that extends personal communication speeds to over 1 Gb/s. As far as indoor systems are concerned, emphasis is given on modeling the dispersive nature of indoor OW channels, on the limitations that dispersion imposes on user mobility and dispersion mitigation techniques. Visible light communication systems, which provide both illumination and communication over visible or hybrid visible/ infrared LEDs, are presented as the most important representative of future indoor OW systems. The discussion on outdoor systems focuses on the impact of atmospheric effects on the optical channel and associated mitigation techniques that extend the realizable link lengths and transfer rates. Currently, outdoor OW is commercially available at 10 Gb/s Ethernet speeds for Metro networks and Local-Area-Network interconnections and speeds are expected to increase as faster and more reliable optical components become available. This article concludes with hybrid optical wireless/radio-frequency (OW/RF) systems that employ an additional RF link to improve the overall system reliability. Emphasis is given on cooperation techniques between the reliable RF subsystem and the broadband OW system.

The demand of bandwidth in mobile communication is growing exponentially day-by-day, as the numbers of users have been increased drastically over the span of last five years. The next generation wireless communication systems therefore need to be of higher standards, so as to support various Broadband wireless services-such as, Video conferencing, mobile videophones, high-speed Internet access etc. The existing wireless systems can hardly provide transmission capacity of the order of few Mbps. However, millimeter (mm) waves and optical fiber technology has the potential of providing data capacity of the order of Mbps and Tbps respectively. Therefore the requirements of broadband wireless system can be met through the integration of optical fiber and millimeter wave wireless systems.

Transactions on Emerging Telecommunications Technologies, 2019

; oulun yliopisto Tieto-ja sähkötekniikan tiedekunta, Centre for wireless communications ahmed, iqrar; Oulun Yliopisto Tieto-ja sähkötekniikan tiedekunta, Centre for wireless communications Kumpuniemi, Timo; oulun yliopisto Tieto-ja sähkötekniikan tiedekunta, Centre for wireless communications Katz, Marcos; oulun yliopisto Tieto-ja sähkötekniikan tiedekunta, Centre

Salvatore Sciarrino (b. 1947), a largely self-taught composer, creates beautiful music using specific techniques to create extraordinarily quiet sounds, stillness, and transparency. This composer’s unique and intriguing music largely resides in the vague borders between sound and silence. His music is paradoxical, often using sound to portray how silence may sound, and invites listeners to find beauty within quiet sonorous atmospheres. The material in this lecture examines Sciarrino’s compositional style, focusing on his characteristic markings and creative sonorities. It also introduces flutists to Sciarrino’s music and helps “decode” his symbols to make his complex music more approachable. As part of the lecture, a guide to Sciarrino’s notational symbols will be distributed to assist performers in the execution of various techniques found throughout the pieces encountered in the collection. It is the presenter’s intention that flutists become more acquainted with L’opera per flauto and Sciarrino’s style so that they may elect to explore and program these unique and fascinating works more frequently.