... ≤ ⇒ i=1 n αi βi ≤ αi i=1 i=1 n βi i=1 Equality holds if αi = kβi , for i = 1, , n ∗ ∗ 2) The second equation is trivial since |xi yi | = |xi ||yi | To see this write xi and yi in polar jθxi ... it is observed both signals have the same envelope but there is a phase reversal at t = for the second signal Am2 (t) cos(2πf0 t) (right plot) This discontinuity is shown clearly in the next figure
Ngày tải lên: 05/03/2014, 19:20