Re: [linrad] Question about time delay compensation

[Alberto di Bene <dibene@xxxxxxxxxxx]

Robert,
   how I am intending to proceed is the following:
Given that what must be compensated for is a fixed delay caused by the 
hardware
of the sound card, I will place a slider in a "Calibration" panel, where 
the user can
finely adjust the time delay, and in real time see the effect of his 
adjustment on the
spectrogram. This will need a steady carrier as input, and the 
adjustment will be
done for the maximum rejection of the unwanted sideband. The spectrogram can
be adjusted for more than 130 dB of dynamic range, so the visual adjustment
shouldn't be too difficult. This will require from me to compute the 
h(k) coefficients
of the allpass filter also in almost real time, but that should be possible.

The paper you couldn't load is on:

http://wwwtvs.et.tudelft.nl/P&N/people/TON/pdf/PIMRC'98%20Coenen.pdf

probably you will see this link underlined only up to the apostrophe 
following PIMRC.
If this is the case, just copy manually with the mouse all of the row, 
up to the final .pdf
and paste it into the address line of the browser. In this way it should 
work.

73  Alberto  I2PHD
-------------------------------------------------------------------

Robert McGwier wrote:

> Alberto:
>
> I possibly was not careful enough when I wrote.  I suggested
> that you find the amount of correction in the frequency domain
> and that it be applied in an interpolated or upsampled version
> of the signal where you only apply the upsampling filter
> (again in the time domain) at the correct phase.  The upsampling
> filter can and should be dynamic since it can correct for amplitude
> and frequency dependent distortions determined in step 1.  My approach
> would be to do the interpolation in the time domain as specified
> in the papers you list. I cannot get the last paper to load and
> since you say it is the most interesting, I would like to get
> a copy of it.
>
>
> Good luck,
> Bob
>  



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