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

Trevor AKA m5aka at yahoo.co.uk
Sun Aug 21 11:41:31 UTC 2005


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
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--- 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
> 



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