Discrete-time signal

Discrete-time signals ($x[n]$) are signals of independent variables $n\in \mathbb{Z}$, where $n$ denotes discrete time. The signal is only defined at integer times of $n$, and never in-between.

We can get discrete-time signals via regular sampling of a continuous-time signal $x$. For a sampling period $T_s$ (how often we sample the CT signal):

$$x_s[n]=x(t){|}_{t=n{T}_s}=x(n{T}_s)$$

For example, video sees 30 samples per second. CD audio sees 44 100 samples per second. For a high-frequency signal, we want to sample enough times to accurately reconstruct it (else we may get something inaccurate or a DC signal).

In MATLAB, we can plot with stem(t, y).

Sub-pages

• Discrete-time Fourier series
• Discrete-time Fourier transform
• Discrete-time system
  • Difference equation