# Cross correlation of complex signals in gnuradio

**URL:** <https://www.ruby-forum.com/t/cross-correlation-of-complex-signals-in-gnuradio/194550>\
**Category:** GNU Radio\
**Created:** [September 7, 2010, 12:19am UTC](https://www.ruby-forum.com/t/cross-correlation-of-complex-signals-in-gnuradio/194550 "2010-09-07T00:19:43Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![john-anes](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/22d042/32.png) [@john-anes](https://www.ruby-forum.com/u/john-anes)\
**Post date:** [September 7, 2010, 12:19am UTC](https://www.ruby-forum.com/t/cross-correlation-of-complex-signals-in-gnuradio/194550/1 "2010-09-07T00:19:43Z")

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hi,  
I want to cross-correlate two complex signals in gnuradio. is there a  
block  
to do that?

Thanks

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**Author:** ![john-anes](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/22d042/32.png) [@john-anes](https://www.ruby-forum.com/u/john-anes)\
**Post date:** [September 7, 2010, 2:01am UTC](https://www.ruby-forum.com/t/cross-correlation-of-complex-signals-in-gnuradio/194550/2 "2010-09-07T02:01:22Z")

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On 09/06/2010 06:17 PM, John A. wrote:

> hi,  
> I want to cross-correlate two complex signals in gnuradio. is there a  
> block to do that?
> 
> Thanks
> 
> * * *

Something other than a complex multiply?

That’s what I do for my simple, correlating, interferometer. Just  
multiple the two signals together.

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**Author:** ![john-anes](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/22d042/32.png) [@john-anes](https://www.ruby-forum.com/u/john-anes)\
**Post date:** [September 7, 2010, 3:02am UTC](https://www.ruby-forum.com/t/cross-correlation-of-complex-signals-in-gnuradio/194550/3 "2010-09-07T03:02:16Z")

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On Mon, Sep 6, 2010 at 7:30 PM, Marcus D. Leech [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Something other than a complex multiply?
> 
> That’s what I do for my simple, correlating, interferometer. Just multiple  
> the two signals together.

Not a native block, as such, but you’ll find a good python  
implementation in correlator.py here (I hope Martin D. doesn’t mind  
posting a link to a directory in his website here…):

> **[Index of /projects/gnuradio/mdvh/passive\_radar](https://www.olifantasia.eu/projects/gnuradio/mdvh/passive_radar/)**

Comments have some documentation, but it basically does frequency  
domain correlation (the FFT \* conj of FFT-\> IFFT thing) and works with  
complex signals. I’ve played with it a bit and it seems to work pretty  
well.

Kunal

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**Author:** ![Jonas94](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/b77776/32.png) [@Jonas94](https://www.ruby-forum.com/u/Jonas94)\
**Post date:** [February 25, 2020, 10:54am UTC](https://www.ruby-forum.com/t/cross-correlation-of-complex-signals-in-gnuradio/194550/4 "2020-02-25T10:54:42Z")

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Hi,  
I´m trying to use the correlator.py Code from [Index of /projects/gnuradio/mdvh/passive\_radar](http://www.olifantasia.com/projects/gnuradio/mdvh/passive_radar/) with Gnuradio. I installed Octave, copied the Code, (cmake …/, make, …) went well, but I have some trouble with the XML-Code for my Correlator-Block.  
Does anybody have the XML-Code for this Block or knows how to write it?

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**Author:** ![Shamoon](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/a9adbd/32.png) [@Shamoon](https://www.ruby-forum.com/u/Shamoon)\
**Post date:** [July 8, 2020, 1:59pm UTC](https://www.ruby-forum.com/t/cross-correlation-of-complex-signals-in-gnuradio/194550/5 "2020-07-08T13:59:08Z")

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In the work a method of latency measurement in software defined radio (SDR) is proposed and validated. The test setup uses customer grade GNSS modules as reference time sources and enables relative delay calculation between signals.