Re: [Discuss-gnuradio] Phase unwrapping

[Daniele Nicolodi]

Hello Matt,

thank for your answer. I'm aware of the problem and in my application I
can keep phase bounded, but not bounded to (-pi, +pi]  therefore I need
unwrapping to make sense of my modulation data.

If such feature does not exist in GNU radio, I hope it is not too hard
to code it myself.

Thanks. Cheers,
Daniele


On 16/06/2014 15:44, Matt Ettus wrote:
> 
> Daniele,
> 
> The problem with phase unwrapping is that it is unbounded, and will tend
> to infinity.  Once it gets very big, when you try to add a small number
> to a very big number, floating point loses precision.  Eventually,
> adding small to extremely big returns the big number unchanged.  This
> isn't that useful.
> 
> Matt
> 
> 
> 
> On Mon, Jun 16, 2014 at 2:40 PM, Daniele Nicolodi <address@hidden
> <mailto:address@hidden>> wrote:
> 
>     Hello,
> 
>     I just started to work with GNU radio for my very basic needs, so please
>     excuse my naive questions and probably my inappropriate use of the
>     jargon.
> 
>     My first trivial application of GNU radio is to simply measure the phase
>     of a phase modulated signal with an Ettus Research USRP N210 and a LFRX
>     daughter-board.
> 
>     Everything works as expected, but I haven't found a way to do phase
>     unwrapping (removing the 2pi ambiguity in the phase obtained from the
>     arctan function looking at discontinuities in the phase data). Is this
>     functionality offered somewhere, and I missed it, or should I look into
>     implementing it myself?
> 
>     Thanks. Cheers,
>     Daniele
> 
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