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Proceedings Paper

Comparison between QAM-subcarrier and TDM IM/DD for HDTV distribution over optical fibers
Author(s): Ken Q. Zhang; Jonas Claesson; Lars A. Johansen
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Paper Abstract

Recent years progress in video compression has made it possible to achieve HDTV-quality in bit-rates below 30 Mbit/s. This means that a few channels may be distributed over the ether but it will also affect the way of distributing video over fibers. A question of importance is whether some kind of subcarrier multiplexed scheme or a digital version is most appropriate for the distribution. A theoretical comparison has been done between these two different methods for the fiber transmission: quadrature amplitude modulation (QAM) with subcarrier multiplexing (SCM) and binary shift keying (BSK) with time division multiplexing (TDM). QAM over subcarrier may be more flexible and more compatible with the existing CATV- systems for PAL or NTSC distribution. However, TDM makes it more easy to interact with other network levels over SDH and/or ATM. The result shows that a 20 channel HDTV distribution gains about 9 dB in power budget using TDM compared to SCM when thermal noise is the limiting factor. It means that TDM can be distributed to approximately 10 times more end users.

Paper Details

Date Published: 4 November 1993
PDF: 9 pages
Proc. SPIE 1974, Transport Technologies for Broadband Optical Access Networks, (4 November 1993); doi: 10.1117/12.161498
Show Author Affiliations
Ken Q. Zhang, Telia Research AB (Sweden)
Jonas Claesson, Telia Research AB (Sweden)
Lars A. Johansen, Telia Research AB (Sweden)


Published in SPIE Proceedings Vol. 1974:
Transport Technologies for Broadband Optical Access Networks

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