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Unipolar forms of orthogonal frequency division multiplexing (OFDM) such as DC biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM) are widely used in intensity-modulated and direct detection (IM/DD) systems. At low data rate, ACO-OFDM is more efficient in terms of optical power but it suffers from spectral inefficiency. For large constellations, DCO-OFDM with large DC...
The number of wireless communication applications has drastically increased during the 2000s and the radio frequencies spectrum, as well as resources, has started to get scarcer. As the time to market is much faster, it's now not possible to produce a new chip every six months for a new specific application. That's why the concept of Software Defined Radio (SDR), introduced by John Mitola in 1992,...
The present paper describes the physical layer of an ultra-wideband impulse radio (UWB-IR) communication system, together with its implementation in a fully integrated transceiver. The objective of this work was to design and test a low-power radio communication system for medium data-rate, short-range communication. The system is based on frequency hopping on-off keying modulation (FH-OOK) for transmission,...
Broadband radio-over-fiber networks are raising great interest for intrabuilding distribution and signal processing of ultrawide-band (UWB) signals. In this paper, a unique optical system based on an external modulator biased either in linear or nonlinear regime has been used to realize both distribution of multiband orthogonal frequency-division multiplexing (MB-OFDM) UWB signal and all-optical frequency...
The dasiaprofessionalpsila bachelorpsilas degree programmes ldquonetworks and telecommunicationsrdquo specialising in ldquowireless networks and securityrdquo has existed since 2005 in Grenoble. This programme is actually the 5th and 6th semesters of a three-year degree. In order to encourage international exchanges within this programme, in September 2007 we launched as part of it an ldquointernationalrdquo...
In this paper we present a system simulation tool (SST) to analyze the performances of orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) receiver. The non-linear receiver RF front-end operates in presence of adjacent channel interferers. The RF front-end signal to noise ratio (SNR) and the third order inter-modulation products (IIP3) are considered and their effects on the bit...
This paper presents a pulsed ultra-wideband communication (UWB) system suitable for sensor network applications. The low complexity, low power architecture allows data communications as well as geolocation of the transmitting node. The system is based on a frequency hopping OOK modulation at the transmitting side combined with a non-coherent detector at the receiver. To validate the concept two RF...
A new easily reusable electrode which eliminates the need for a gel at the electrode-skin interface is proposed. It is based on a ceramic material whose Na+ ion conductivity is high at room temperature. The electrical properties of this ceramic based electrode are reported.
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