In-theatre infrared audio broadcasting.

Title: In-theatre infrared audio broadcasting.
Authors: Paiam, Mohammad Reza.
Date: 1993
Abstract: Several factors have to be analyzed before designing an appropriate communication system for in-theatre IR multi-channel audio broadcasting. The infrared channel characteristics for the in-theatre propagation environment are examined and a suitable IR transmission configuration is suggested. The free-space IR transmission has a simple channel model which simplifies the analysis. The CD digital audio technology which provides advanced digital signal processing techniques at a relatively low cost is a strong candidate for use in the system. However, the channel coding used in the CD system (known as EFM) has a high redundancy which results in a performance degradation. A more suitable channel coding scheme (which is a version of 8B10B channel modulation) is designed and simple implementations for the corresponding coder and decoder are given. The receiver design for an indoor non-directional IR communication system requires an approach different from that commonly employed in optical fibre communications. A signal-to-noise ratio analysis is carried out and a simple strategy for the receiver design is proposed. A link power budget calculation is performed to find the required transmitted optical power. Also, it is shown analog FM requires much higher transmitted optical power to provide the performance achieved by the CD-based digital audio system in the in-theatre IR audio broadcasting. Finally, a simulation is carried out to investigate the effects of the multipath dispersion on the performance of the system.
CollectionTh├Ęses, 1910 - 2010 // Theses, 1910 - 2010
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