ATSC/VSB Digital TV Technology Confirms Superior Performance in Argentina
Thu Oct 19 09:37:00 2000 EST
WASHINGTON, Oct. 19 /PRNewswire/ -- Four years after adoption as the U.S. standard, the digital television (DTV) transmission system called VSB continues to gain momentum, with two-thirds of U.S. households now in range of DTV signals. At the third CAPER conference in Argentina, which adopted the ATSC DTV Standard in 1998, the developer of the VSB (vestigial sideband) system, Zenith Electronics Corporation, is showcasing the superiority of the ATSC standard with ongoing indoor reception, and with a compelling comparison of VSB and COFDM receivers.
Zenith has turned the ATSC stand at CAPER into a working laboratory, complete with racks of equipment and multiple HDTV receivers and displays. There, broadcasters, government officials, and fellow equipment manufacturers are seeing first-hand the superiority of the ATSC/VSB standard over COFDM, as well as improvements in the performance of current and next-generation VSB receivers.
Underscoring VSB's superior DTV signal coverage and rejection of "impulse noise" are a series of evaluations in which multiple ghosts and other real- world impairments are introduced into VSB and COFDM modulated signals and, as a reference, into analog signals.
Using some of the same equipment and testing procedures that the U.S. FCC Advisory Committee on Advanced Television Service used to evaluate DTV systems, Zenith is showing how VSB receivers cancel multiple ghosts - and the continually advanced performance in this area with each new generation of receivers.
Richard Lewis, Zenith Senior Vice President, Research and Technology, explained that "results also show that impulse noise -- electrical interference caused by hair dryers, vacuum cleaners, automobile ignitions, electrical power lines, etc. -- severely limits COFDM's usefulness, particularly on VHF channels. User experience in Europe has exposed this problem."
"8-VSB continues to outperform COFDM," Lewis concluded, referring to VSB's superior coverage area and impulse noise performance. "Plus, new data shows that current and next-generation VSB receivers offer comparable ghost performance to COFDM in 'concrete canyon' urban environments and indoor reception, and superior VSB ghost rejection for the majority of viewers."
Finally, Lewis explained how VSB reaches significantly more viewers than COFDM. In fact, a digital television study of the New York City market by respected industry consulting engineer Jules Cohen reveals the significant loss of television viewers that would result from use of the European COFDM system. Analysis of three DTV stations in New York (WNBC-DT, WABC-DT and WPIX- DT) shows that COFDM signals would reach fewer viewers and COFDM interference would mean many more lost viewers -- together totaling almost 10 million lost viewers.
SOURCE Zenith Electronics Corporation
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