= Discrete-time signal
{title2=$x[n],\quad n\in\mathbb Z$}
A discrete-time signal assigns a value to each of a discrete collection of times, often indexed by the <integers>. Regular sampling at rate $f_s$ gives $x[n]=x(n/f_s)$, so a sinusoid with normalized frequency $f$ cycles per sample has physical <frequency> $ff_s$. Discreteness of time does not itself require the amplitudes to be quantized; rounding the values is an additional operation. The <Nyquist–Shannon sampling theorem> gives conditions for recovering a band-limited continuous <signal> from its samples.
Back to article page
