Date: Jan 25, 2013 9:30 AM
Author: Steven Lord
Subject: Re: Determination of telephone number from dtmf

"merve " <> wrote in message
> I have got a .txt file which includes dtmf and a frequency 44100 hz. I
> have to plot the original signal in time domain and then find the power
> spectrum and finally determine the telephone number. I tried to plot the
> original and i could manage, i think but the rest job is still a mystery
> for me, i mean i dont know MATLAB well. I was told to use also a
> window(rectangular, hamming,..). I need to plot power spectrum in a
> restricted time. An idea?

This sounds like homework or a school project. Because of that I recommend
asking the professor or teaching assistant who told you to use a window for
help understanding what you need to do and how to do it. That way if they
ask this on an exam, you will be prepared.

Steve Lord
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