Subject: Re: Hilbert envelope bandwidth
From: Ramin Pichevar <Ramin.Pichevar(at)USHERBROOKE.CA>
Date: Mon, 27 Sep 2004 11:44:02 -0400
http://www.usherbrooke.ca/vers/virus-courriel
Christof,
You may have a look at pp 796-798 of the book A.V. Oppenheim, and R. W.
Schafer, "Discrete-time Signal Processig", Second Edition, which deals with
the representation of bandpass signals in the Hilbert domain. The picture
depicted there explains everything.
Hope this can help !
Cheers,
Ramin
-----Message d'origine-----
De : AUDITORY Research in Auditory Perception
[mailto:AUDITORY(at)LISTS.MCGILL.CA]De la part de Christof Faller
Envoye : 27 septembre 2004 08:02
A : AUDITORY(at)LISTS.MCGILL.CA
Objet : Hilbert envelope bandwidth
Dear list,
I am struggling with the following question:
Given a signal x(n) with
X(f) = 0 for |f| < f1 or |f| > f2
(bandpass filtered signal with bandwidth B = f2-f1)
e(n) is the Hilbert envelope of x(n) which can then be written as:
x(n) = e(n)y(n),
where y(n) is the "temporally flattened" version of x(n).
The spectrum of e(n) satisfies:
E(f) = 0 for |f| > f3
(Due to its DC offset, the evelope e(n) contains frequencies down to
zero).
==>
Can f3 be expressed as a function of B (the bandwidth of signal x)?
Any comments/suggestions are appreciated. Thanks,
Christof Faller