Re: Does complex conjugate invert IQ ?

2021-12-14 Thread Daniel Estévez 
Indeed. Also, in case that's a long read (I think it's interesting 
anyhow), the bottom line is that IQ swap and complex conjugate are 
basically "the same" operation for most purposes.


This is because if the swap is S(a+bi) = b+ai and the conjugate is 
C(a+bi) = a-bi, then S(z) = iC(z), so we see that the only difference 
between both operations is a 90º phase rotation.


Both of these operations accomplish flipping the frequency axis, which 
is probably the main reason one would use them.


Best,

Daniel.

El 13/12/21 a las 17:14, Albin Stigö escribió:

This might be of interest.

https://www.dsprelated.com/showarticle/51.php 




--Albin

On Mon, Dec 13, 2021, 16:45 Cyrille Morin > wrote:


Hi,

You could use a "Complex to Float" to separate the I and Q
components, followed by a "Float to Complex", inverting the re and
im inputs.


Le 13/12/2021 à 16:31, Rachida SAROUI a écrit :

Thank you for responding, but what I meant by invert is swapping
the I and Q components of the signal.

Le lun. 13 déc. 2021 à 16:25, Fabian Schwartau mailto:fab...@opencode.eu>> a écrit :

Complex conjugate only inverts the imaginary (Q) part of the
signal.
If you want to invert both, just multiply with -1.

Am 13.12.21 um 16:22 schrieb Rachida SAROUI:
> Hi everyone,
>
> I need to invert the I and Q of a complex signal. Does the
block complex
> conjugate do the job?
>
> Thank you
>






OpenPGP_signature
Description: OpenPGP digital signature

Re: Does complex conjugate invert IQ ?

2021-12-14 Thread Marcus D. Leech 

On 2021-12-13 11:14, Albin Stigö wrote:

This might be of interest.

https://www.dsprelated.com/showarticle/51.php


The attached shows that a complex-conjugate will nicely effect a 
frequency inversion, if that's what is wanted.




inversion.grc
Description: application/gnuradio-grc

Re: Does complex conjugate invert IQ ?

2021-12-13 Thread Johannes Demel 

Hi,

I assume the "Swap IQ" block is exactly what you're looking for.
https://wiki.gnuradio.org/index.php/Swap_IQ

Cheers
Johannes

On 13.12.21 16:39, Cyrille Morin wrote:

Hi,

You could use a "Complex to Float" to separate the I and Q components, 
followed by a "Float to Complex", inverting the re and im inputs.



Le 13/12/2021 à 16:31, Rachida SAROUI a écrit :
Thank you for responding, but what I meant by invert is swapping the I 
and Q components of the signal.


Le lun. 13 déc. 2021 à 16:25, Fabian Schwartau > a écrit :


Complex conjugate only inverts the imaginary (Q) part of the signal.
If you want to invert both, just multiply with -1.

Am 13.12.21 um 16:22 schrieb Rachida SAROUI:
> Hi everyone,
>
> I need to invert the I and Q of a complex signal. Does the block
complex
> conjugate do the job?
>
> Thank you
>

Re: Does complex conjugate invert IQ ?

2021-12-13 Thread Albin Stigö 
This might be of interest.

https://www.dsprelated.com/showarticle/51.php


--Albin

On Mon, Dec 13, 2021, 16:45 Cyrille Morin 
wrote:

> Hi,
>
> You could use a "Complex to Float" to separate the I and Q components,
> followed by a "Float to Complex", inverting the re and im inputs.
>
>
> Le 13/12/2021 à 16:31, Rachida SAROUI a écrit :
>
> Thank you for responding, but what I meant by invert is swapping the I
> and Q components of the signal.
>
> Le lun. 13 déc. 2021 à 16:25, Fabian Schwartau  a
> écrit :
>
>> Complex conjugate only inverts the imaginary (Q) part of the signal.
>> If you want to invert both, just multiply with -1.
>>
>> Am 13.12.21 um 16:22 schrieb Rachida SAROUI:
>> > Hi everyone,
>> >
>> > I need to invert the I and Q of a complex signal. Does the block
>> complex
>> > conjugate do the job?
>> >
>> > Thank you
>> >
>>
>>
>>

Re: Does complex conjugate invert IQ ?

2021-12-13 Thread Cyrille Morin 

Hi,

You could use a "Complex to Float" to separate the I and Q components, 
followed by a "Float to Complex", inverting the re and im inputs.



Le 13/12/2021 à 16:31, Rachida SAROUI a écrit :
Thank you for responding, but what I meant by invert is swapping the I 
and Q components of the signal.


Le lun. 13 déc. 2021 à 16:25, Fabian Schwartau > a écrit :


Complex conjugate only inverts the imaginary (Q) part of the signal.
If you want to invert both, just multiply with -1.

Am 13.12.21 um 16:22 schrieb Rachida SAROUI:
> Hi everyone,
>
> I need to invert the I and Q of a complex signal. Does the block
complex
> conjugate do the job?
>
> Thank you
>

Re: Does complex conjugate invert IQ ?

2021-12-13 Thread Martin Luelf 

Dear Rachida,

in order to do that, use the "complex to float" and "float to complex" 
blocks and connect the re output to the im input and the im output to 
the re input.


Yours
Martin


On 13.12.21 16:31, Rachida SAROUI wrote:
Thank you for responding, but what I meant by invert is swapping the I 
and Q components of the signal.


Le lun. 13 déc. 2021 à 16:25, Fabian Schwartau > a écrit :


Complex conjugate only inverts the imaginary (Q) part of the signal.
If you want to invert both, just multiply with -1.

Am 13.12.21 um 16:22 schrieb Rachida SAROUI:
 > Hi everyone,
 >
 > I need to invert the I and Q of a complex signal. Does the block
complex
 > conjugate do the job?
 >
 > Thank you
 >

Re: Does complex conjugate invert IQ ?

2021-12-13 Thread Rachida SAROUI 
Thank you for responding, but what I meant by invert is swapping the I and
Q components of the signal.

Le lun. 13 déc. 2021 à 16:25, Fabian Schwartau  a
écrit :

> Complex conjugate only inverts the imaginary (Q) part of the signal.
> If you want to invert both, just multiply with -1.
>
> Am 13.12.21 um 16:22 schrieb Rachida SAROUI:
> > Hi everyone,
> >
> > I need to invert the I and Q of a complex signal. Does the block complex
> > conjugate do the job?
> >
> > Thank you
> >
>
>
>

Re: Does complex conjugate invert IQ ?

2021-12-13 Thread Fabian Schwartau 

Complex conjugate only inverts the imaginary (Q) part of the signal.
If you want to invert both, just multiply with -1.

Am 13.12.21 um 16:22 schrieb Rachida SAROUI:

Hi everyone,

I need to invert the I and Q of a complex signal. Does the block complex 
conjugate do the job?


Thank you

Does complex conjugate invert IQ ?

2021-12-13 Thread Rachida SAROUI 
Hi everyone,

I need to invert the I and Q of a complex signal. Does the block complex
conjugate do the job?

Thank you