Discrete signal
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Image:Sampled.signal.png Image:Digital.signal.png A discrete signal is a signal that has been sampled from a continuous signal. Unlike a continuous signal, a discrete signal is not a continuous function but a sequence. Each value in the sequence is called a sample.
Since a discrete signal is a sequence of samples, the sampling rate must be stored separately (implicitly or explicitly) since the sampling rate cannot be extracted from the samples. This ambiguity is the basis for the establishment of the Shannon-Nyquist sampling theorem. This ambiguity also leads to problems in digital frequency.
Digital signals
A digital signal and a discrete signal are not the same thing. A digital signal is a discrete signal that has been quantized. In other words, a discrete signal has values with infinite precision while a digital signal has values with finite precision. Common practical digital signals are 8-bit (256 levels), 16-bit (65,536 levels), 32-bit (4.3 billion levels), and so on, though any number of quantization levels is possible; not just powers of two.
See also
- Aliasing, Anti-aliasing filter
- Analog-to-digital converter, Digital-to-analog converter
- Continuous signal
- Digital control
- Digital frequency
- Nyquist-Shannon sampling theorem, Nyquist-Shannon interpolation formula
- Sample (signal)
- Sampling (information theory)
- Signal (information theory)cs:Diskrétní signál