All this is what I'm trying to find out. From the single anecdotal WRAL report plus Mark's comments it looks (vaguely) like you can get decent mobile/handheld reception with 8vsb/m/h at maybe only 1/4 to 1/3 efficiency compared to the full 19.39 mbps channel. Is WRAL in friendly broadcast terrain? Obviously more data and announcements will tell more.
But I'm still not sure at all of the other side. That is, how much FEC overhead is needed to get similar M/H reception quality on DVB-T. Is it truly 3 or more times better at mobile or does DVB-T also have to use massive extra error correction to get quality M/H reception. If so, how much?
That is, how many bits / second can reliable emerge from a moving handheld receiver using DVB-T in a 6 mhz channel, after subtracting FEC overhead?
That's assuming similar power levels, all else being equal, etc. Which of course it never is.
And of course, what about urban canyons? But I'd like to know anyway. - Tom Manfredi, Albert E wrote:
Bob Miller wrote:OH!! Then there was that thing about DVB-T not being as efficient as 8-VSB. Something about DVB-T only being capable of 18.6 Mbps while 8-VSB could handle a whopping 19.34 mbps.The problem with comparing spectral efficiency, we should always remember, is that it makes no sense at all to compare it UNLESS you include the threshold C/N ratio required for solid reception. Without the *two* numbers, you can take any position you want and rant about it. So in this case, the comparison is that with a slight drop in b/s/Hz, you are also saddled with a 3 dB increase in the required signal margin. Yes, it looks like in some modes DVB-T2 may address that issue. I'm waiting for the results with baited breath. Bert----------------------------------------------------------------------You can UNSUBSCRIBE from the OpenDTV list in two ways:- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.
-- Tom Barry trbarry@xxxxxxxxxxx ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways:- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.
