not a very experienced EE, but I was thinking about a system for high speed data transfer, and it is fairly simple conceptually, so I imagine that there must be serious flaws with the method, because to my knowledge it is not implemented, or at least not widespread. I apologize in advance for my ignorance of the subject matter (I'm just starting my learning).
The way I understand it, binary signals enclosed in a carrier wave are modulated/demodulated through a modem. I understand why this was done in the past - processors weren't that hardcore, and the hardware can only understand binary. I guess I just don't understand why it is still done this way.
If we modulate the amplitude of a wave (I think by providing the oscillator different levels of current), can we not sample this wave with some sort of analog to digital converter and process it on the CPU?
If this is possible, why stick to base 2? If we can have a unique value for each measurable amplitude, data transfer rates would skyrocket. Imagine transferring data with base 1024, or even higher. If we could accurately sample the wave (each oscillation), I don't see why the rate of transfer could be equal to the frequency of the wave times base divided by 2 bits per second (this is probably not correct mathing).
If we have a processor running in the gigahertz, and a signal in the low megahertz, it seems feasible that the processor would be able to sample and translate the data to base 2 (possibly sending to another core for translation). This way, the data rate would be limited by the processor (faster processors would lead to the utilization of higher frequencies for transfer).
Limiting factors that I can think of are how fast the current to the oscillator can be changed (for TX), how fast the analog to digital conversion can be done (read that accurate sampling is possible into the hundreds of megahertz), and the range of measurable amplitudes.
I'm aware that this question probably contains an unusal amount of stupidity, but I want to build this system and I'm wondering why I shouldn't. There has to be something major that I am missing here. What could it be? Thanks.