Difference between revisions of "Digital signal"
Karl Jones (Talk | contribs) (→See also) |
Karl Jones (Talk | contribs) (→Subset of analog, but treated separately) |
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Although digital signals are strictly a subset of analog signals, they are usually treated as separate things. | Although digital signals are strictly a subset of analog signals, they are usually treated as separate things. | ||
| − | As a rule of thumb, a signal may be referred to as digital if system noise is never large enough to change the quantification | + | As a rule of thumb, a signal may be referred to as digital if [[system noise]] is never large enough to change the [[quantification]]. |
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| + | == Analog signals and noise == | ||
By contrast, with analog signals, [[noise]] always degrades the operation: for example the output from a [[modem]] is normally considered an analog signal. | By contrast, with analog signals, [[noise]] always degrades the operation: for example the output from a [[modem]] is normally considered an analog signal. | ||
| − | However, even with systems normally considered fully digital, during transitions, noise can become important -- [[metastability]] is one manifestation of this. | + | However, even with systems normally considered fully digital, during transitions, [[noise]] can become important -- [[metastability]] is one manifestation of this. |
== See also == | == See also == | ||
Revision as of 10:04, 19 February 2016
A digital signal is a type of analog signal that is a representation of a sequence of discrete values (a quantified signal, for example of an arbitrary bit stream, or of a digitized (sampled and analog-to-digital converted) analog signal.
Contents
Description
Digital signals are often electronic, but may be optical.
Digital signals are present in all digital electronics, notably computing equipment and telecommunications.
Subset of analog, but treated separately
Although digital signals are strictly a subset of analog signals, they are usually treated as separate things.
As a rule of thumb, a signal may be referred to as digital if system noise is never large enough to change the quantification.
Analog signals and noise
By contrast, with analog signals, noise always degrades the operation: for example the output from a modem is normally considered an analog signal.
However, even with systems normally considered fully digital, during transitions, noise can become important -- metastability is one manifestation of this.
See also
External links
- Digital signal @ Wikipedia
