Re: [Discuss-gnuradio] How to use IQ Bal Optimize/Fix?

[Jeff Long]

1. Add a throttle after the source.

2. You are feeding the optimizer and the balancer from the original 
signal. They need to be connected to the output of the imbalance generator.

3. Whatever the scale of magnitude is in the imbalance generator, 1.0 is 
too small to see on the time plot.

4. The time plots will look different if the phase is rotated, so 
different is not necessarily wrong.

5. Add a slider to control magnitude, and you can see the optimizer adjust.



On 01/31/2018 09:21 AM, kokosz wrote:
> This is exactly what I am doing, but restored signal looks very weird 
> (its real part is close to zero). I have attached example *grc file 
> showing the problem.
>
> Dnia 31 stycznia 2018 12:34 Jeff Long <address@hidden> napisał(a):
>
>     If you put 0 in the manual fields and wire
>
>       src->optimize->iqbal
>
>     and
>
>       src->iqbal
>
>     it seems to work fine. Do you have a GRC file?
>
>     "period" is some sort of time constant, in samples. If you set it to
>     samp_rate, optimization will happen within a second. Smaller values for
>     faster response up to a point.
>
>     On 01/31/2018 05:54 AM, kokosz wrote:
>
>         Dear all,
>
>         It looks like IQ imbalance is causing problems in my
>         application, as I
>         was able to simulate real-world-like problems after adding "IQ
>         Imbalance
>         Generator" to my GRC flowgraph. So, after simulating this
>         imbalance, I
>         wanted to get rid of it with the help of "IQ Bal Optimize" and
>         "IQ Bal
>         Fix" combo. Unfortunately, I can't get it work.
>
>         As far as I understand, "IQ Bal Optimize" is automatically
>         detecting
>         settings (i.e. magnitude and phase correction values) for "IQ
>         Bal Fix"
>         and pass it to the latter block via message connection called
>         "iqbal_corr". Is this is true, I don't understand why I have to
>         manually
>         set "Magnitude" and "Phase" in "IQ Bal Fix" (otherwise I cannot
>         run the
>         flowgraph because of empty fields). I think that these fields
>         were meant
>         for making manual fix possible, but when using "IQ Bal
>         Optimize"/"IQ Bal
>         Fix" combo, message connection should be all what is necessary,
>         right?
>         Also, because of lack of detailed documentation, I am not sure
>         how to
>         interpret "Period" field in IQ Bal Optimize - what units are
>         expected here?
>
>         I am using GRC v3.7.11, compiled from source files few days ago.
>
>
>
>
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