Order Tray | Contact Us | Home | SIG Lists

[hfsig] What can you do with an OFDM signal in a 3.5 KHz band pass?

DuBose Walt Civ AETC CONS/LGCA Walt.DuBose at RANDOLPH.AF.MIL
Mon Aug 22 14:27:52 UTC 2005


Its interesting to do a Google Search on STANAG 

Also see http://www.linuxjournal.com/comment/reply/6299 "Radio E-mail in
West Africa: The Complete Version"...remote networking with high-frequency
(HF) radio and qmail.

Perhaps the "system" we are looking for is already in place.

Walt/K5YFW

-----Original Message-----
From: hfsig-bounces at lists.tapr.org
[mailto:hfsig-bounces at lists.tapr.org]On Behalf Of Trevor AKA
Sent: Sunday, August 21, 2005 6:42 AM
To: TAPR HF Modes SIG Mailing List
Subject: RE: [hfsig] What can you do with an OFDM signal in a 3.5 KHz
band pass?


Raw data rates of up to 12800 kbps have available commercially for a number
of
years now using standard HF SSB rigs. There are several products available
using MIL-STD-188-110B waveforms an example is
http://www.rapidm.com/rm6.shtml 
Sure they drop down to lower speed if the path isn't great, but on many
paths
the higher rates are viable.

However, I am not aware of any Amateur implementation of these waveforms,
has
anybody tried ? For some of our HF bands I believe there are valid arguments
for resticting b/w to 1.8 kHz or less but for 28 MHz there is no reason why
3.5
kHz or 7.5 kHz shouldn't be used.

73 Trevor M5AKA
----------------
Daily Amateur Radio RSS News Service: http://www.southgatearc.org/
Add News Service to your Website: http://www.southgatearc.org/rss/index.htm
Add News Service to your PC: http://www.southgatearc.org/rss/newsreader.htm
Upload Your News Items: http://www.southgatearc.org/news/your_news.htm
----------------

--- tattje <tattje at planet.nl> wrote:

> RE: [hfsig] What can you do with an OFDM signal in a 3.5 KHz bandpass?The
> POTS will give you 56 kbit/sec in the same bandwidth.
> Using OFDM some channels will not be available, fec is not enough, so one
> has to spread the info over all the channels.
> Reread the fs-1052, why do you think are so many different throughput
speeds
> defined?
> 10 kbits in 3 kHz? Forget it, may be sometimes, but not always.
> HF is a naughty channel,
> Regards
> Henk
>   -----Oorspronkelijk bericht-----
>   Van: hfsig-bounces at lists.tapr.org
> [mailto:hfsig-bounces at lists.tapr.org]Namens DuBose Walt Civ AETC CONS/LGCA
>   Verzonden: vrijdag 19 augustus 2005 22:25
>   Aan: 'TAPR HF Modes SIG Mailing List'
>   Onderwerp: RE: [hfsig] What can you do with an OFDM signal in a 3.5 KHz
> band pass?
> 
> 
>   When talking to EOC, disaster relief and military contingency personnel
> about HF data modes, they no longer ask how many words per minute is it,
now
> they are asking how many pages per minute is your capability.
> 
>   We can no longer think in WPM capability; but rather, pages per minute
> (ppm).
> 
>   73,
> 
>   Walt/K5YFW
> 
>   -----Original Message-----
>   From: hfsig-bounces at lists.tapr.org
[mailto:hfsig-bounces at lists.tapr.org]On
> Behalf Of DuBose Walt Civ AETC CONS/LGCA
>   Sent: Friday, August 19, 2005 2:41 PM
>   To: 'hfsig at lists.tapr.org'
>   Subject: [hfsig] What can you do with an OFDM signal in a 3.5 KHz
> bandpass?
> 
> 
> 
>   What can you do (what RAW throughput) can you get in a 3.5 Khz bandwidth
> using an OFDM mode?
>   Here's what I found using some figures based on the FS-1052, Appendix A
> modem.
>   Your User Throughput will be determined on how much RAW througput you
use
> for FEC.
>   Walt/K5YFW
> 
> 
> > _______________________________________________
> hfsig mailing list
> hfsig at lists.tapr.org
> https://lists.tapr.org/cgi-bin/mailman/listinfo/hfsig
> 



------------- Chelmsford Amateur Radio Society -------------
Support Essex Air Ambulance - Apply for the Chelmsford Award 
         See CARS website http://www.g0mwt.org.uk/
------------------------------------------------------------


		
___________________________________________________________ 
How much free photo storage do you get? Store your holiday 
snaps for FREE with Yahoo! Photos http://uk.photos.yahoo.com

_______________________________________________
hfsig mailing list
hfsig at lists.tapr.org
https://lists.tapr.org/cgi-bin/mailman/listinfo/hfsig
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.tapr.org/pipermail/hfsig/attachments/20050822/23fb3e11/attachment.htm 


More information about the hfsig mailing list