Autocorrelation
Cauchy–Schwarz inequality

The Cauchy–Schwarz inequality, inequality for stochastic processes: | R X X (t 1, t 2) | 2 ≤ E E {\displaystyle \left|\operatorname {R} _{XX}(t_{1},t_{2})\right|^{2}\leq \operatorname {E} \left\operatorname {E} \left}
keywords:frequency