[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Re: Ham Radio High SPeeed data



The only readable (English) stuff I've seen on the web has been the 
technical description from CQ Ham Radio Magazine which is at:
http://www.arrl.org/tis/info/pdf/dstar.pdf

I guess the reason for using uncoded GMSK was because it was cheap and quick 
to implement.

Trevor M5AKA

>Subject: Re: [amsat-bb] Re: Ham Radio High SPeeed data
>There is an article on the D-Star system in the latest issue (June) of 
>Radio Active magazine (UK publication).
>
>Trevor M5AKA
>
>>From: Phil Karn <karn@maggie.ka9q.net>
>>Reply-To: karn@ka9q.net
>>To: bruninga@usna.edu
>>CC: amsat-bb@AMSAT.Org
>>Subject: [amsat-bb] Re: Ham Radio High SPeeed data
>>A google search for "jarl d-star" yields quite a few hits, but all of
>>the pages so far are in Japanese only.
>>
>>From what little I've seen, the system looks promising but my big
>>concern is that the physical layer may not incorporate any coding. It
>>*appears* to be just uncoded GMSK.
>>
>>This is corroborated by the sensitivity figures in Icom's Dayton
>>handout. The digital modulation requires more microvolts than FM,
>>while a well-coded signal should require less.
>>
>>This affects not only the required transmitter power, but also the
>>interference susceptibility and the amount of interference that is
>>created for others. And it affects the ability of the system to
>>withstand fading, impulse noise and multpath.
>>
>>Phil
>>
>>
>>
>>----
>>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>
>
>_________________________________________________________________
>MSN Photos is the easiest way to share and print your photos:
>http://photos.msn.com/support/worldwide.aspx
>
>----
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org


_________________________________________________________________
Join the world’s largest e-mail service with MSN Hotmail. 
http://www.hotmail.com

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home