-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Basically, yes, but that's communication theory. I'd refer you to Kammeyer -- Nachrichtenübertragung, but that's a German book. I guess Proakis would be a fine source, too, but I don't have his book at hand right now.
Anyway, ADB-S should *define* the pulse shape. Best look into Nick's gr-airmodes code for matched filtering; the matched filter directly gives you the transmission filter. (But that's even more signal theory) Greetings, Marcus On 30.01.2014 10:44, Andrew Rich wrote: > Thanks Marcus > > Pulse shape and repetition frequency determine bandwidth then ? > > Square is the worst - gausian is better ? > > - Andrew - > > > ----- Original Message ----- From: "Marcus Müller" > <[email protected]> To: "Andrew Rich" <[email protected]> > Cc: <[email protected]> Sent: Thursday, January 30, 2014 > 5:27 PM Subject: Re: Modulation question > > > Hi Andrew, > > just a quick heads-up: I nearly missed your message because it was > hidden in another thread, since you seem to have hit reply and > changed subject and text; however, my mail client recognized the > In-Reply-To header, and sorted you in - please directly write mails > unless you actually mean to reply. > > So now for your question >>>> Ads-b uses a 1 MHz pulse position modulation scheme > On 30.01.2014 01:22, Andrew Rich wrote: >>>> Ads-b uses a 1 MHz pulse position modulation scheme >>>> >>>> Is this possible to create on gnu ? > GNU Radio is only a software radio framework. Basically you can do > anything with it that can be done in baseband signal of a sample > rate that your ADC/DAC and mixers (and analog filters, amps and so > on) support. With gr-air-modes there is a comfortable receiver > implemented in GNU Radio, and as a not-to-rough simplification you > can transmit everything with a software radio that you can receive > with one. > >>>> >>>> Is it the data rate that makes the spectrum wide ? 7 MHz ? > Ok, I don't really understand your question, could you please > elaborate? Reception of ADB-S works quite well with a 4MHz sampling > bandwidth, but I'm not quite sure on the technical requirements of > ADB-S transmission. > > The actual bandwidth of PPM systems of course depends on pulse > shape and pulse frequency. > > Hope I was able to help a little, Marcus > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJS6iLnAAoJEAFxB7BbsDrLl+wIAJKGfJS0AT3b6WTRdCcm+14B lgGOBuTPqpf/3loOqZpoPiAkbUetxrJMk4QtCjbnru5DOKI/cJV7vPwsyL/vAyM2 MzDgvVrCL0n91fk7iWnEYG/1PrPwJJcoJIdxBL7oBr4b2DHqg6Delsdbai9YK1B3 FY+6kjKnwUQNdVeEK3G7ifxotUEvEDfrz7pul84HfP6MqZA59CXCsatPgnUTtl6P TqIRjbyZNQXePdoBfdmmDA9PiM4FXhAMc7oQEDmsBrlG6wpYqEZSo4xoJbQ2SIEw gVPpX/tfBWPhIBtnZCGdQlmKLCmKK7SK4lUbfztdieLV4Jip1m7s9+RjalpnmHc= =riRq -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
