Skip to content
Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

LTI system

A system that is both linear and time-invariant, fully characterized by its impulse response.

An LTI system (linear, time-invariant) satisfies superposition (scaling and summing inputs scales and sums the outputs identically) and time-invariance (shifting the input shifts the output by the same amount, changing nothing else). An LTI system's response to any input is fully determined by its response to a single unit impulse, via the convolution sum (chapter 2).

See also

sequence
Read the full section →
Graph settings

Calculator