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Re: RE: D-star, and Cute 1.7

Quoting William Leijenaar <pe1rah@yahoo.com>:

> Hi AMSATs,
> Its nothing real special on RF base, only on digital
> base.
> It takes more bandwidth and also for single user
> use... or did I miss the multi-user option ???

I was thinking that this might be a means of aquiring some
hardware through a partnership with Icom, but I see your point:
it appears to be a disadvantageous system for satellite operators.

> A better and more interresting technology is CDMA.
> This mode also uses higher bandwidth, but has no
> problems with interference from other (small band)
> signals. In CDMA mode a small band RF signal is
> deliberatly made wideband with a special digital code.
> The receiver will only receive the signal that uses
> the same code.
> Because of this the CDMA system can handle more than
> one-station using the same frequency :o) I am not sure
> if this mode can be used in ham bands, but the
> technology is quit good. All the coding and decoding
> can be made in an easy way, without DSPs and
> microprocessor logics...
> Just wondered if anyone tought about this as a
> solution for the "aligator" and interference problems.

It seems that the C-C Rider project has this in mind, or other
*DMA acronyms. See the 2004 documents at http://www.amsat.org/amsat-new/eagle/

Interestingly, this project proposes a SDR to do some of the work for it.
While the proposed IF of 90 MHz is out of the range of the SDR-1000, I
wonder if the ground station (which is planned to be developed alongside
the satellite) could be implemented through the SDR-1000. 

73, Bruce 
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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