[opendtv] Re: DVB-T HDTV demo using 19.7 Mbps in a 6 Mhz channel in costa rica
- From: Bob Miller <bob@xxxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Mon, 06 Mar 2006 12:10:45 -0500
John Shutt wrote:
>----- Original Message -----
>From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
>
>
>
>>At that time, 1st generation receivers, this was robust
>>enough to beat 8-VSB in indoor tests and when close to the transmitter,
>>but the results far from the transmitter were not so different, or 8-VSB
>>had the edge (a 4 dB advantage).
>>
>>http://www.tvtechnology.com/features/On-RF/dl_8VSB_vs_cofdm_part1.shtml
>>
>>
>
>The distance reception demonstrations done by Sinclair in Baltimore in 1999
>showed NO difference in far field reception between the two. The theortical
>4 dB did not show up in practice.
>
>http://www.hdtvmagazine.com/archives/pbsbalit.html
>
>
And of the seven sites that Sinclair retested with a "marginal receiver"
after adding a front end filter COFDM beat 8-VSB in the far field being
receivable at all seven sites unlike 8-VSB that failed at one.
Lets tell it like it is, DVB-T was and is better at all distances in the
real world..
Bob Miller
>
>
>>The broadcasters might have a preference for DVB-T, if they want to use
>>DVB-H to transmit to handheld devices on the same frequency allocation
>>they use for DTT. Even though this will likely not lead to very good
>>coverage. And also, that preference might be mitigated by the reduced
>>coverage area of their DTT signal, at equal power and spectral
>>efficiency.
>>
>>
>
>And let's not forget HM-COFDM, where Stephen Long was tooling out in the
>Nevada Desert at considerably higher than the speed limit, and Mark Schubin
>couldn't lose lock except inside a closed metal transmitter cabinet on the
>NAB floor. HM-COFDM was for robustness, while DVB-H is for low power
>consumption and robustness, so I think a full power DTV station would have
>plenty of coverage for such a device. We run power levels far above what is
>run in Europe.
>
>John
>
>
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