Pioneer Succeeds in DevelopingHigh Performance 8-VSB Demodulation Algorithm for DTVImproves the performance of indoor reception | News Releases | News and Events | About Us

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Pioneer

July 5, 2000
Pioneer Corporation

Pioneer Succeeds in Developing
High Performance 8-VSB Demodulation Algorithm for DTV
Improves the performance of indoor reception

Tokyo, Japan, July 5th, 2000 --- Pioneer Corporation ( Head Office: Tokyo Japan / President: Kaneo Ito ) announced that it has succeeded in developing a high performance 8-VSB ^*1 demodulation algorithm for use in DTV (Terrestrial Digital Television of North America) receivers. This technology has a special adaptive equalization algorithm feature^*2 and has the advantage of robustness against multi-path^*3.
The performance of indoor reception will be improved a great deal with this new technology.

* Pioneer will read a paper on this innovative technology at the "IEEE Broadcast Technology Society, 50th Annual Broadcast Symposium" (From September 27, Virginia, USA).

Background of the Development

In November 1998, terrestrial digital television broadcasting began in the United States. During the development of related DTV receivers, Pioneer has been developing 8-VSB demodulation technology.
It has been reported that 8-VSB systems have difficulty with indoor reception because of the poor performance of indoor antennas affected by the problem of multi-path. This has become one of the major problems with digital TV reception in the U.S., where manyhouseholds use indoor antennas.
Pioneer has paid particular attention to the problem of indoor reception from the beginning and has extensively researched the related reception technology. As a result, the company has at last succeeded in developing a high performance demodulation algorithm that is highly resistant to multi-path.

< Features >

The developed 8-VSB demodulation technology has a special feature in the form of an adaptive equalizer. The brand-new architecture derived from the equalization algorithm demonstrated high performance in eliminating the inter-symbol interference caused by short delay multi-path (*4) and dynamic multi-path (*5). ( See Technical Note )
Pioneer has also developed a trial LSI and evaluated its performance in practical field tests.

*1 8-VSB ( Eight Level Vestigial Sideband Modulation)
The digital modulation scheme specified in the ATSC (Advanced Television Systems Committee) standard, where three bits of binary data are mapped into eight discrete amplitude levels that will modulate the amplitude of a carrier wave suppressed with a prescribed vestigial sideband shape.

*2 Adaptive equalization algorithm
The signal processing method to eliminate the inter-symbol interference of received symbol.

*3 Multi-path
A propagation phenomenon which results in more than one signal reaching the receiver, one by a direct path, the other by a reflected or distorted path.

*4 Short delay multi-path
One signal by a direct path, the other by a short delay reflected or distorted path.

*5 Dynamic multi-path
One signal by a direct path, the other by a dynamic varying reflected or distorted path.

< Technical Note >

The following graph shows the expected performance of Pioneer's new equalizer. Here its performance is evaluated in comparison with a conventional Decision Feedback Equalizer (DFE) that is widely employed in current DTV receivers.
The performance of both equalizers were evaluated in seventeen multi-path-conditions that were sampled in actual field conditions^*1. On the graph, the required C/N^*2 at TOV^*3 is plotted for each multi-path-condition. For example, in multi-path-condition `A`, where the conventional DFE requires 28dB C/N for acceptable reception, our equalizer can work properly even at 20dB C/N. Here, we can easily imagine that a current DTV receiver with a conventional DFE cannot demodulate the signal even though the reception point is near the transmitter.
For all multi-path-conditions, our equalizer shows better performance than the conventional DFE. It should also be mentioned that the advantage of our equalizer is more than 5dB in five multi-path-conditions. As a result, we believe that our new technology can largely extend the service availability of DTV.