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.
