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Digital Signal Processing (DSP) is used in a wide variety of
applications, and it is hard to find a good definition that is general.
We can start by dictionary definitions of the words:
- Digital: operating by the use of discrete signals to represent data in
the form of numbers
- Signal: a variable parameter by which information is conveyed through an
electronic circuit
- Processing: to perform operations on data according to programmed
instructions
Which leads us to a simple definition of:
Digital Signal processing: changing or analysing information which is measured as discrete
sequences of numbers
Note two unique features of Digital Signal processing as opposed to plain old ordinary digital processing:
- signals come from the real world - this intimate connection with the real world leads to many unique needs such as the need to react in real time and a need to measure signals and convert them to digital numbers
- signals are discrete - which means the information in between discrete samples is lost
The advantages of DSP are common to many digital systems and include:
Versatility:
- digital systems can be reprogrammed for other applications (at least where programmable DSP chips are used)
- digital systems can be ported to different hardware (for example a different DSP chip or board level product)
Repeatability:
- digital systems can be easily duplicated
- digital systems do not depend on strict component tolerances
- digital system responses do not drift with temperature
Simplicity:
- some things can be done more easily digitally than with analogue systems
DSP is used in a very wide variety of applications.
but most share some common features:
- they use a lot of maths (multiplying and adding signals)
- they deal with signals that come from the real world
- they require a response in a certain time
Where general purpose DSP processors are concerned, most applications deal with signal frequencies that are in the audio range.
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