# Re Spectrum sensing Simulation Only **URL:** \ **Category:** GNU Radio\ **Created:** [July 30, 2014, 8:55pm UTC](https://www.ruby-forum.com/t/re-spectrum-sensing-simulation-only/231259 "2014-07-30T20:55:17Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [July 30, 2014, 8:55pm UTC](https://www.ruby-forum.com/t/re-spectrum-sensing-simulation-only/231259/1 "2014-07-30T20:55:17Z")
Hello Martin Thank you for the help. I try to run “specest\_noisy\_sinusoid\_mtm.py” (Python script is also okey for me). However it does not run “it says no module specest”. By the way I am using windows 8 OS. My goal is is to write a simple python or gnuradio code to perform the following task I have the following variables NFFT=1024 Nav=512 ampl=1 seed=1 Sampling\_rate= 10k 1. Generate any real time signal (This could be done by using "gr.noise\_source\_f (gr.GR\_GAUSSIAN, ampl, seed1)). 2. Insert throttle to control the sampling rate (i.e., gr.throttle(1, Sampling\_rate)) 3. Compute the FFT (even without windowing) (i.e., NFFT samples at a time) 4. Compute the square magnitude of x (This could be done by using gr.complex\_to\_mag\_squared(NFFT)) i.e., in matlab y=abs(x).^2 1. sum the first and second Nav samples i.e., av1=sum(y(1:512))/Nav and av2=sum(y(513:1024))/Nav 1. Then display “av1” and “av2” in a text box continuously. Note that in matlab (without GUI it is very easy task) And I feel that there should be some simple approach to do it in GNUradio Thank you again for your help * * * Tadilo Endeshaw Postdoctoral Researcher Institut National de recherche Scientifique Centre Energie Matriaux Telecommunications Place Bonaventure, 800 de la Gauchetiere Ouest, Suite 6900 H5A 1K6 Montreal, QC Canada E-mail : removed\_email\_address@domain.invalid removed\_email\_address@domain.invalid (private) Personal home page: [https://sites.google.com/site/tadilomypage/](https://sites.google.com/site/tadilomypage/) * * * From: discuss-gnuradio-bounces+tadilo.bogale=removed\_email\_address@domain.invalid [discuss-gnuradio-bounces+tadilo.bogale=removed\_email\_address@domain.invalid] On Behalf Of Martin B. [removed\_email\_address@domain.invalid] Sent: July 30, 2014 10:01 AM To: removed\_email\_address@domain.invalid Subject: Re: [Discuss-gnuradio] Spectrum sensing Simulation Only On 07/30/2014 03:37 PM, Tom R. wrote: > The easiest way to average is to use the single\_pole\_iir\_filter to > smooth out the data stream. But note that you’re coming out of the FFT > block as a vector. You can set the vector length of the single pole IIR, > but I’d have to review exactly what that means mathematically. It > probably smooths the entire vector as one as opposed to smoothing over > index i in each vector. You might have to play around with that. gr-specest might help you with that (pybombs install gr-specest, or [GitHub - kit-cel/gr-specest: A module adding spectral estimation routines to GNU Radio.](https://github.com/kit-cel/gr-specest)). M * * * Discuss-gnuradio mailing list removed\_email\_address@domain.invalid [https://lists.gnu.org/mailman/listinfo/discuss-gnuradio](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) ---
**Author:** ![BogaleS\_Tadilo\_Ende](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/85e7bf/32.png) [@BogaleS\_Tadilo\_Ende](https://www.ruby-forum.com/u/BogaleS_Tadilo_Ende)\ **Post date:** [July 30, 2014, 9:41pm UTC](https://www.ruby-forum.com/t/re-spectrum-sensing-simulation-only/231259/2 "2014-07-30T21:41:06Z")
Hi Tadilo, have you made sure that specest was correctly installed? (make && make install) Greetings, Marcus