Svetla Jivkova

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—In this paper, we examine an infrared link composed of a multibeam transmitter and a direction-diversity receiver, employing code combining. The latter represents an added dimension to the conventional diversity concepts, which are limited to combining the individual received symbols. Rate-compatible punctured convolutional codes are used to encode(More)
Optical (infrared) wireless communications links offer an attractive solution for indoor applications. To enable terminal mobility and reduce temporal dispersion, we use a configuration known as Multi-Spot-Diffusing (MSD), which is a Multi-Input, Multi-Output (MIMO) architecture. In this configuration, a transmitter generates multiple narrow beams that get(More)
—In multispot-diffuse multiple-input–multiple-output (MSD-MIMO) system configuration, a communications channel can be considered virtually ideal at data rates of hundreds of megabits per second. Thus, the main concern is power efficiency. We propose a transceiver optical design that creates a recon-figurable transmitter output and independent communications(More)
We evaluate transmission link performance for a Multi-Spot Diffusing Configuration (MSDC) for indoor wireless optical LANs. MSDC utilizes a multibeam transmitter and a composite receiver consisting of 7 narrow field-of-view (FOV) branches. Numerical evaluation is performed for two values of the receiver FOV corresponding to the cases when at least one or(More)
A number of attempts have been made in an effort to combine the advantages of line-of-sight and diffuse configurations for indoor optical wireless communications via sophisticated combinations of elements that are characteristic for these architectures. A different approach has been followed in the present investigation, namely, developing a transceiver(More)
—While use of power-efficient signaling schemes appears to be effective at compensating for the inherent high path-loss associated with pure diffuse infrared links, it begins to lose its effectiveness as the data rate is increased. At very high data rates, intersymbol interference (ISI) can result in a very high and sometimes irreducible power penalty,(More)
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