Re:Why you should never pay more than $10 for an HDMI cable ...
by ErrantX on Wednesday March 31, 2010 @11:46AM
(#1232073)
ugh, I hated signals theory at uni... but let me dust off that knowledge...
> All signals are analog.
I see your reasoning in saying this ("on the wire" etc.); your incorrect though. Not all signals are considered analog (which is important to the point being made)
Analog signals are generally susceptible to noise because they are usually non-recoverable; error checking is hard because it is a non-discrete continuous signal.
>It is possible to receive spurious bit errors for many reasons.
Yes, which is why error checking exists in all these systems. In the context of the wire alone, yes, it is not a case of "it just works". But in the case of the communications subsystem (i.e. the transmitter, medium, receiver) it really does either work or not work :)
Ultimately thought the phrase "it's digital; either it works or it doesnt" is making no comment about the actual signal. It's really saying: an expensive cable is not, due to the digital sub-system, likely to make any difference to error rates (or more succinctly: the performance of the error correction is better than the noise affect of the transport medium)
> All signals are analog.
I see your reasoning in saying this ("on the wire" etc.); your incorrect though. Not all signals are considered analog (which is important to the point being made)
Analog signals are generally susceptible to noise because they are usually non-recoverable; error checking is hard because it is a non-discrete continuous signal.
>It is possible to receive spurious bit errors for many reasons.
Yes, which is why error checking exists in all these systems. In the context of the wire alone, yes, it is not a case of "it just works". But in the case of the communications subsystem (i.e. the transmitter, medium, receiver) it really does either work or not work :)
Ultimately thought the phrase "it's digital; either it works or it doesnt" is making no comment about the actual signal. It's really saying: an expensive cable is not, due to the digital sub-system, likely to make any difference to error rates (or more succinctly: the performance of the error correction is better than the noise affect of the transport medium)