[Intro] Typical signals-1

  BASICS

Signal is a function of time that carries information. 

e.g). voltage, current, audio, etc

Therefore, signals are expressed as analog or digital signal, and various measured values such as sound, electromagnetic waves, images, or sensor output values may be expressed. →"Signal Processing"

 

 

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"Analog" and "Continuous" are terms related to signals that are often confused. However, these two terms are different and explain different concepts.

 

•  Analog signal:
  An analog signal means a signal that can have a continuous value. These values typically represent physical phenomena, such as temperature, pressure, or voltage. An important feature of analog signals is that they can take any value within the range of values. For example, an analog voltage signal between 0V and 5V can take any value within this range.
  
  
• Continuous signal:
  A continuous signal means a continuous signal with respect to time. In other words, continuous signals are defined at all time points. Contrasts with discrete signals. Discrete signals are only defined at certain time points and not at the time points between them.

Important to understand the difference between these two concepts is that "analog" is related to the value of the signal and "continuous" is related to the time at which the signal is defined. Therefore, analog signals can be either continuous or discrete. Digital signals, on the other hand, have discrete values, but these values can be in continuous time or in discrete time.

 

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The "Digital" and "Discrete" signals also represent different concepts, but they are often confused. Let's look at the difference.

 

• Digital signal:
  A digital signal means a signal consisting of discrete values. A digital signal takes a value from a particular set of values, such as {0,1} (binary digital signals). Digital signals are widely used in digital systems such as computers, and the value of the signal is expressed in a certain number of bits.
  
  
• Discrete signal:
  Discrete signals mean discrete signals with respect to time. In other words, discrete signals are defined only at certain discrete time points and not at the time between them. The values of discrete signals can be either continuous or discrete. This is a major difference from digital signals. The value of a digital signal is always discrete.

In summary, "discrete" is related to the nature of the time at which the signal is defined, and "digital" is related to the nature of the value of the signal. Digital signals consist of discrete values, and are often defined even at discrete time points. Therefore, digital signals can be seen as special cases of discrete signals.