Energy within a Digitized Pulse

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2 total messages Started by Jeffery Scott Sloka Thu, 23 Jul 1992 12:44

#131

Author: Jeffery Scott Sloka
Date: Thu, 23 Jul 1992 12:44

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Howdy.  I have two questions which I can't seem to nail down properly and I'm humbly asking for your expertise.

1.  The energy of a continuous time signal is just the integral of the square of the signal.  For a digitized signal, is it true that the energy contained is just the sum of the squares of each point?

2.  The attenuation of a signal is related to the amount that the signal decreases.  If the signal maintains its shape, is the attenuation the ratio of the two energies or is it the square root of the ratio of the energies?

Sorry to ask such basic questions but I could not find a text to confirm any of these questions in the discrete time domain.  Many thanks in advance for your replies.

	-Scott

Re: Energy within a Digitized Pulse

#132

Author: Chia-Liang Liu
Date: Fri, 24 Jul 1992 03:00

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In article <BruE1t.A8L@watserv1.waterloo.edu> jssloka@ritchie.waterloo.edu (Jeffery Scott Sloka) writes:
>Howdy.  I have two questions which I can't seem to nail down properly and
>I'm humbly asking for your expertise.

>1.  The energy of a continuous time signal is just the integral of
>the square of the signal.  For a digitized signal, is it true that
>the energy contained is just the sum of the squares of each point?

Yes, if you assume that the sampling interval, Ts, is 1.0; otherwise
you need to multiply it by Ts to get the energy.

>2.  The attenuation of a signal is related to the amount that the
>signal decreases.  If the signal maintains its shape, is the
>attenuation the ratio of the two energies or is it the square root
>of the ratio of the energies?

If your 'attenuation' is in linear scale, you need to specify it
is power (energy) or voltage (current). That's why in engineering,
engineers use 'dB' to specify 'attenuation'. If I say the attenuation
is 20 dB, it means voltage (current) is attenuated by 10 times, while
power (energy) is attenuated by 100 times.

>
>Sorry to ask such basic questions but I could not find a text to confirm any of these questions in the discrete time domain.  Many thanks in advance for your replies.
>
>	-Scott


-- 
Ka-Leung Lau ( Chia-Liang Liu )
Digital Communications Research Laboratory
Department of Electrical and Computer Engineering 
University of California, Davis (Cal Aggies)

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