Digital Signal Item
Jump to navigation
Jump to search
A Digital Signal Item is a signal item that ...
- See: Power of Two, Digital Signal Processing, Discrete-Time Signal, Discrete Set, Countable, Injective Function, Integer, Word (Computer Architecture), Word (Computer Architecture)#Word Size Choice, Fixed-Point Arithmetic, Linear Function, Companded.
References
2017
- (Wikipedia, 2017) ⇒ https://en.wikipedia.org/wiki/Digital_signal_(signal_processing) Retrieved:2017-4-7.
- In the context of digital signal processing (DSP), a digital signal is a discrete-time signal for which not only the time but also the amplitude has discrete values; in other words, its samples take on only values from a discrete set (a countable set that can be mapped one-to-one to a subset of integers). If that discrete set is finite, the discrete values can be represented with digital words of a finite width. Most commonly, these discrete values are represented as fixed-point words (either proportional to the waveform values or companded) or floating-point words. The process of analog-to-digital conversion produces a digital signal. The conversion process can be thought of as occurring in two steps:
- sampling, which produces a continuous-valued discrete-time signal, and
- quantization, which replaces each sample value by an approximation selected from a given discrete set (for example by truncating or rounding).
- It can be shown that for signal frequencies strictly below the Nyquist limit that the original continuous-valued continuous-time signal can be almost perfectly reconstructed, down to the (often very low) limit set by the quantisation.
Common practical digital signals are represented as 8-bit (256 levels), 16-bit (65,536 levels), 24-bit (16.8 million levels) and 32-bit (4.3 billion levels). But the number of quantization levels is not necessarily limited to powers of two.
- In the context of digital signal processing (DSP), a digital signal is a discrete-time signal for which not only the time but also the amplitude has discrete values; in other words, its samples take on only values from a discrete set (a countable set that can be mapped one-to-one to a subset of integers). If that discrete set is finite, the discrete values can be represented with digital words of a finite width. Most commonly, these discrete values are represented as fixed-point words (either proportional to the waveform values or companded) or floating-point words. The process of analog-to-digital conversion produces a digital signal. The conversion process can be thought of as occurring in two steps: