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Received signal stenght

Question asked by Daniel_Camara on May 19, 2015
Latest reply on Aug 7, 2015 by mhennerich

Hi people,

 

  The questions are probably dummy, but again, I want to remember you I am kind of new on this .

 

  OK I had some more time to play with the card, but I am having a little hard time here. I was trying to detect if I am receiving a signal or not, but I am not being able to.

 

  Again, based the example code, I build a filter that sums up the square of the the received values of the received I/Q and creates an history for it. I was assuming that when I send something, the values of I/Q would be significantly bigger, lets say 3 times the average noise. Then, after perceiving this difference I can start processing the signal from there on.

 

  The thing is, I made some tests and both happens:

   - When I send, the received signal is not that stronger/different than what I continuously receive, and I am considering/calling noise

   - The noise, sometimes, it is way bigger than the time I send something.

 

  I am afraid I am doing something wrong or i am not really reading the signal I am sending.  Is it my assumption wrong? I mean, does the values of I/Q, when using the "iio_buffer_refill" function, do not represent the strength of the signal? If it it is not like that, how should I do to perceive the received power?

 

The code is still messy, as it is a test code, but it is in attachment if it helps. I am using always as remote as I am more comfortable working on my machine and downloading the code through the Ethernet. So to run in send/receive mode pass the parameter "./test802.15.4.TX server receive". If you want to take a look on the osciloscope, "./test802.15.4.TX server," does not try to grab the RX so you can see the TX, working, or not working in this case .

 

  Thanks a lot people!

 

    -- Daniel

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