High-current adaptive impedance matching in narrowband power-line communication systems

This paper proposes a high current impedance matching method for narrowband power-line communication (NPLC) systems. The impedance of the power-line channel is time and location variant; therefore, coupling circuitry and the channel are not usually matched. This not only results in poor signal integrity at the receiving end, but also leads to a higher transmission power requirement to secure the communication process. To offset this negative effect, a high-current adaptive impedance circuit to enable impedance matching in power-line networks is reported. The approach taken is to match the channel impedance of N-PLC systems is based on the General Impedance Converter (GIC). In order to achieve high current a special coupler in which the inductive impedance can be altered by adjusting a microcontroller controlled digital resistor is demonstrated. It is shown that the coupler works well with heavy load current in power line networks. It works in both low and high transmitting current modes, a current as high as 760 mA has been obtained. Besides, compared with other adaptive impedance couplers, the advantages include higher matching resolution and a simple control interface. Experimental results are presented to demonstrate the operation of the coupler. © 2011 IEEE.

40 Gbit/s optical communication system

The University of Bristol is studying the feasibility of deploying 40 Gbit/s optical time division multiplexed (OTDM) transmission networks to support new telecommunication services such the Internet and video-on-demand systems. Among the functional blocks being considered in the project are the optical pulse sources, signal multiplexers and demultiplexers, clock recovery subsystems, signal detection and dispersion accommodation methods.

Feasibility of AlGaInAs lasers for high speed uncooled communication systems

The feasibility of using AlGaInAs lasers for high-speed modulation at high temperatures was evaluated and compared with performance of GaInAsP devices. Both drift-diffusion and rate equation simulation were involved so that the temperature dependence of material parameters was found in terms of overall dynamic performance. Differential gain was estimated by means of drift-diffusion simulations.

National Agricultural Research Organization. National Fisheries Resources Research Institute (NaFIRRI) Annual Report 2010/2011

The Mandate of the National Fisheries Resources Research institute (NaFIRRI) is to manage, promote and undertake applied and basic research of strategic and national importance in aquaculture, capture fisheries, water environment, socio-economics and marketing, information communication management and any emerging issues in the fisheries

Optical communication system performance using fibre Bragg grating dispersion compensators

Operating limits of a chirped fibre grating dispersion compensator are determined using a complete optical system model. A 10cm compensator extends the transmission range of an optimised 10Gbit/s MQW electroabsorption modulator from 80km to 425km.

Resonant-cavity LED transceiver arrays for optical wireless communication

155Mb/s operation of an optical wireless link is achieved by using the spectral characteristics and angular emission spectra of a 7-element tracking array of 980nm RC-LEDs. Preliminary results show extension to 200 Mb/s/channel. © 2006 Optical Society of America.

Roadmapping in industrial companies: Experiences

From its origins in the US electronics sector in the 1970s, technology roadmapping has been adapted (and adopted) widely, for many different innovation, strategy and policy applications. Communication is commonly cited as one of the key benefi ts of roadmapping, particularly in terms of the process that brings different organizational perspectives together, with the roadmap providing a common visual 'language'. There is signifi cant demand for methods that are agile, in the sense of being rapid, flexible and effective to apply, focused on strategic decisions and actions. 'Fast-start' roadmapping workshop techniques enable key stakeholders to address strategic issues efficiently using the visual structure of roadmaps to capture, discuss, prioritize, explore and communicate. This paper presents the learning from a set of five diverse applications of the fast-start approach in the Basque Country, which demonstrate the agility of the technique.