Re: [dev] Simpler WiFi alternatives

From: syg <>
Date: Mon, 15 May 2023 20:18:44 +1000


> Yep. That is true. I didn't think of that at all! But then, why do
> current WiFi, etc. work at 2.4GHz, if device speeds aren't at those
> levels?
I am not an expert but my understanding is that chips really don't
bother with sampling radio signals at those speeds, it would be
extremely costly and overkill (this is what digital oscilloscopes to,
look at their price...).

In fact, you'll have some analog pre-processing that consists in
multiplying the signal by a fundamental frequency, the carrier, to
extract a usable signal at a frequency that can actually be handled by a
general-purpose chip (simplifying massively here).

Look up IQ streams and OFDM (modulation used for wifi signals).

In short you will need some specialised hardware no matter what, the
average ADC can't handle those speeds.

> I'll try wireless transmissions of files at 10MHz then in the lower
> frequency regions. Then by replacing hardware, maybe I'll just have to
> change a single number!
Uhh... Not really, WiFi is very complex, at the GHz speed, if you don't
factor in reverberations and work around it with very complex maths and
error correction, you'll have a range of a few centimeters. That was
solved in the 90s with a very lucrative patent from CSIRO:

Hope that brings in some perspective.

- syg
Received on Mon May 15 2023 - 12:18:44 CEST

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