# Detection and classification of signals

**URL:** <https://www.ruby-forum.com/t/detection-and-classification-of-signals/217119>\
**Category:** GNU Radio\
**Created:** [February 21, 2012, 10:55pm UTC](https://www.ruby-forum.com/t/detection-and-classification-of-signals/217119 "2012-02-21T22:55:18Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![dubstep](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/cdc98d/32.png) [@dubstep](https://www.ruby-forum.com/u/dubstep)\
**Post date:** [February 21, 2012, 10:55pm UTC](https://www.ruby-forum.com/t/detection-and-classification-of-signals/217119/1 "2012-02-21T22:55:18Z")

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Hi all,

I’m working an a little project using gnuradio for receiving ham radio  
psk31 signals. I can decode a signal given a rough estimate of the  
carrier frequency but I’d really like to take a big swath of bandwidth  
as the input, detect the psk31 signals, and decode them all in  
parallel.

However I don’t even know what search terms to use to find methods to  
detect the peaks, and make a guess as to whether they are psk31. What  
words should I be typing into my google searches?

My naive first attempt would be to find the peaks in the intensity  
that have about the correct width and then try to decode them, but I  
thought there might be more robust techniques out there.

Cheers,  
Ben

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**Author:** ![dabeeeenster](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed655f/32.png) [@dabeeeenster](https://www.ruby-forum.com/u/dabeeeenster)\
**Post date:** [February 21, 2012, 11:31pm UTC](https://www.ruby-forum.com/t/detection-and-classification-of-signals/217119/2 "2012-02-21T23:31:49Z")

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Ben -

Searching for “Automatic Modulation Classification (AMC)”, on Google or  
IEEExplore, will give you fairly good start =)

Related terms may be: “Peak Detection”, “Robust Statistics”, and even  
“Primary User Detection” (from the cognitive radio side of things).

Cheers,  
Ben

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**Author:** ![dabeeeenster](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed655f/32.png) [@dabeeeenster](https://www.ruby-forum.com/u/dabeeeenster)\
**Post date:** [February 21, 2012, 11:33pm UTC](https://www.ruby-forum.com/t/detection-and-classification-of-signals/217119/3 "2012-02-21T23:33:04Z")

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I’ll note that none of my suggestions are actual techniques, but just  
keywords that such techniques fall under.

If anyone is aware of actual techniques for Ben to use, that would  
probably  
be more directly helpful.

Cheers,  
Ben

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**Author:** ![dabeeeenster](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed655f/32.png) [@dabeeeenster](https://www.ruby-forum.com/u/dabeeeenster)\
**Post date:** [February 22, 2012, 6:25am UTC](https://www.ruby-forum.com/t/detection-and-classification-of-signals/217119/4 "2012-02-22T06:25:28Z")

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Wicked, thank you. That’ll go a long way towards getting me started.  
It’s frustrating when you’re so ignorant you don’t even know which  
search terms to type in.