[opendtv] Re: Toward digital TV
- From: Bob Miller <bob@xxxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Thu, 15 Dec 2005 22:03:22 -0500
The 5th generation LG prototype receiver that we tested 18 months ago is
the best by quite a margin as far as reception in a multipath
environment. It was NOT as robust by far as any 1999 COFDM receiver we
ever tried. And as far as I know 8-VSB is still limited to 19.34 Mbps.
Any COFDM receiver we ever tried was more robust at a higher data rate
than 8-VSB is capable of in 2005.
Bob Miller
Manfredi, Albert E wrote:
>Bob Miller wrote:
>
>
>
>>But COFDM DVB-T was more robust at a higher bit rate
>>than possible with 8-VSB in 2000 as demonstrated by
>>Sinclair at the Hearings. 19.76 Mbps with a mobile
>>antenna while 8-VSB was only up to 19.34 Mbps in a
>>fixed position with a directional antenna.
>>
>>
>
>First of all, more recent comparison tests do not paint
>this picture across the board, and even these more
>recent tests are a couple of years old or more. You
>keep harking back to 1999, which of course is pointless.
>
>I refer you back to the CRC comparison tests documented
>in the September 2003 issue of IEEE Transactions on
>Broadcasting, and then keep in mind what 8-VSB
>receivers have done since then when you read their
>results. This was the test where they added in the
>effect of on-channel repeaters. But they also did a
>comparison before introducing the OCRs.
>
>I also refer you to the numbers documented in FCC
>05-199 we saw yesterday, which are pretty hard for
>COFDM at 3.3 b/s/Hz (aside from echo tolerance). And
>to the numbers recommended in A/74 vs Nordig.
>
>But without getting bogged down in this incessant
>debate, the simple fact remains that the significant
>effort in 8-VSB is going to maintain a high spectral
>efficiency while increasing robustness. That's the real
>push, not E8VSB. Instead, in France and the UK, they
>are doing whatever it takes to get up to somewhere
>close to 3.3 b/s/Hz, in order to support HD. Their
>main handicap is the low power they want to transmit.
>
>So the inflexibility of 8-VSB is not an issue. Because
>reducing the bit rate to increase robustness is not
>where the world of TV broadcasting seems to be going.
>
>Bert
>
>
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