Discrete-Time Signals

• On the other hand,a discrete-time signal is defined only a discrete instants of time.
• In other words, the ``time variable'' of the signal may take on only certain values.
• Usually these values are evenly spaced.
• The process of converting an analog signal into a discrete-time signal is called sampling.
• A discrete-time signal is sometimes called a sampled signal.
• Discrete-time signals are represented as a sequence of samples (real-valued numbers).

  

Figure 2.8: Discrete-time signals are defined only at discrete time instants