How do they manage receiving DVB-x, with 7 or 8 MHz bandwidth? Hardware decoding engine on-chip? Or is there no interleaving among the single TV-stations on one carrier, and it is enough to decode a small portion of the spectrum for being able to watch one station?
Ralph. From: [email protected] [mailto:[email protected]] On Behalf Of Nick Foster Sent: Monday, September 15, 2014 4:24 PM To: Oliver Jowett Cc: Dean Sauer; sdrrtl Subject: Re: SDR Dongle "bandwidth" - rtlsdr-airband It's important to remember these devices weren't even intended to operate in this fashion, and they almost certainly were never specified to support any given bandwidth. The ~2.4MHz sample rate is just an anecdotal number arrived at through experimentation. --n On Sep 15, 2014 6:07 AM, "Oliver Jowett" <[email protected] <mailto:[email protected]> > wrote: On 15 September 2014 10:26, Dean Sauer <[email protected] <mailto:[email protected]> > wrote: > What I am not getting is clear info on these devices.. > > Is it +- 2MHz at 2mb/s rate etc... +/- 1MHz at 2M complex samples/s. Nyquist would like to have words with you about capturing 4MHz bandwidth with 2M samples/sec! >> This spread is 3.1MHz which is so close to the upper limit of 3.2MHz you >> may just be able to scrape through, but you will definitely experience >> some packet loss. > > Here is a "limit of 3.2." Where is this coming from ? ? ? I am not > getting answers on specs.. except that some where some one already knows > these.... some how. Obviously some one has access to the NDA'd data > sheets on the chips inside that us mere mortals do not have. I really > liked things better when I could go to TI, Motorola etc. and purchase big > honking data books. :) Aye, there's the rub. It would be great to have proper specs. For the most part we don't have them. Without proper specs, most of these limits etc are just empirical limits found through trial and error. I don't think there's a secret NDA cartel (if there is, how do I join? ;-)), what you see is the end result of lots of reverse-engineering and experimentation. Oliver
