Re: QAM constellation script

[George Katsimaglis]

Hi,

I have already make a proposal that with fh=False a multi user CDMA can be used.

Each user will have a unique time in sawtooth shifting, the same time he can see all other Tx signals.

Each Tx will be seen as 'constant frequency' as all users shift frequency the same rate.

I do not claim that is the most efficient way, but that is technically possible.

George SV1BDS

 

On Thursday, May 4, 2023 at 11:04:42 AM GMT+3, Adrian Musceac <kantooon@droiddv.org> wrote:

On Wednesday, 3 May 2023 19:20:10 EEST Marcus Müller wrote:

> Hi George,
>
> that's a multiplicative voice scrambler!
>
> The pre-Second World war voice scrambler system "SIGSALY" [1] was kind
> of similar;
> just that the scrambling sequence came out of a noisy vacuum tube, not
> Python's random.random(), and that the combination method was taking
> samples and adding them modulo 6, instead of multiplying the phase
> (which is inherently modulo 2π).

>

That was a really nice description, thank you for taking the time to write
that. The original project is also interesting, even if we call it differently.
So to me this looks like a basic CDMA access scheme, is there really any
advantage to using it as opposed to standard FDMA as traditionally used on
QO100? From an amateur radio operator perspective.

Adrian