I suppose you have caught me out slightly lacking in precision or pedantry. A digital to analogue modulation scheme is able to exactly reconstruct the original digital signal within the design tolerances for noise and distortion. Yes, eventually a signal may degrade or be corrupted, but prior to that point the reproduction is literally and exactly perfect. That exactitude is just about the definition of a digital system. This bird system is incapable of reproducing the input image of the bird exactly. It is not a digital communication system, unless you consider the “PNG” of the bird to have not been the message being carried.
CookieOfFortune@lemmy.world 3 days ago
I thought we were being pedantic here?
Modulation schemes are characterized via a probabilistic tolerance, so even when you are within the tolerances, you can get an incorrect value at some expected rate. Note that you can even define a modulation scheme with a high error rate and be ok with that.
That’s why I take issue with the concept of an exactly perfect reproduction. Usually there are layers above the digital modulation to handle these possibility to decrease the error rates even lower.
And no, I don’t consider the PNG to be the data carried. I think the way the author does the bandwidth calculations is incorrect.
gozz@lemmy.world 2 days ago
No, I have been trying to actually be helpful and informative for people trying to understand this article and video, given that referring to what was done here as a digital system is functionally meaningless and misleading. I am pretty sure the pedantry started with you talking about CPUs being electronic.
But at this point I believe your use of language in this discussion to be so absurdly reductive that I do not think this conversation is salvageable. What you appear to take issue with seems to keep changing and refining until the argument appears to be that any system that communicates information is apparently a digital communications system, so long as you can imagine an arbitrary scheme to interpret at least one bit of information from the signal, regardless of whether that was the message intended to be communicated. It would appear we have ended up with a “digital” storage system wherein a human observes the signal and decides one bit of whether or not it looks like a bird. Though I suppose “bird” was the only symbol in the protocol, so it may actually be a zero-bit system.
If the scheme successfully communicates zero bits of information, you might as well stop bothering to listen for the signal, and miss nothing of value. In fact I should probably do exactly that with this thread.
CookieOfFortune@lemmy.world 2 days ago
This has always been my point since the beginning! There exist very low bandwidth digital communication systems in real life, with less than one bit per second. The bandwidth available should be defined where something is digital or not.
Seeing the bird in the spectrogram is quite intentional and sufficient to consider this a communications system.
It seems if instead of a bird picture, a random set of bits were encoded and then detected In the spectrogram, you’d consider this more of a digital system since instead of a human doing the check you use an algorithm?