Sorry for the confusing explanation, but yes, I'm trying to find the average energy over frequencies.
1. What I'm doing, at least as a start, is signal detection of 802.15.4 waveform using energy detection focusing on the O-QPSK PHY operating at the 2.4 Ghz band. The O-QPSK PHY uses a 32 bit chip sequence for spreading the signal. 2. From research, I can see that other forms of detection such as matched filter detection would be a lot better for an application of this sort. However, energy detection was chosen to start with because of its lack of complexity. The focus at the moment is more on the feasibility of this approach. In the future, other approaches or methods will be considered also. Tellrell On Thu, Sep 21, 2017 at 8:40 PM, Tellrell White <rell...@gmail.com> wrote: > Thanks Marcus > > Sorry for the confusing explanation, but yes, I'm trying to find the > average energy over frequencies. > > 1. What I'm doing, at least as a start, is signal detection of 802.15.4 > waveform using energy detection focusing on the O-QPSK PHY operating at the > 2.4 Ghz band. The O-QPSK PHY uses a 32 bit chip sequence for spreading the > signal. > > 2. From research, I can see that other forms of detection such as matched > filter detection would be a lot better for an application of this sort. > However, energy detection was chosen to start with because of its lack of > complexity. The focus at the moment is more on the feasibility of this > approach. In the future, other approaches or methods will be considered > also. > > Tellrell > > > On Thu, Sep 21, 2017 at 5:36 PM, Marcus Müller <marcus.muel...@ettus.com> > wrote: > >> Hi Tellrell, >> >> I know you can find the PSD >> >> Ah, so you're actually after a PSD estimate – It wasn't clear to me what >> you were looking for, because the FFT-> frequency sink flowgraph didn't >> make sense. And you just said "average energy" (not "average energy over >> frequencies"), so I was kind of confused; sorry! >> >> So, ultimately, if the way that I'm implementing the algorithm is correct >> thus far, I'm looking for a way to display(graphically or otherwise) my >> result or the avg power. >> >> It's impossible to say whether an algorithm is correct without specifying >> what it should be doing - so maybe we need to take a step back: >> >> 1. you want to do detection of IEEE 802.15.4 signals. Which PHY are we >> talking about? There's multiple physical layers for that standard. The DSSS >> types aren't really … friendly towards energy detection at all. >> 2. pure DFT-bases spectral estimation without preprocessing or >> postprocessing is usually not the optimum method for signals that don't >> have a spectral sinc shape; they're just easy to implement. Usually, you'd >> try to detect using as much info about what the signal of interest is as >> possible – especially in the presence of other systems. >> >> Best regards, >> >> Marcus >> On 09/21/2017 11:32 AM, Tellrell White wrote: >> >> Thanks for the replies guys >> >> Marcus I know you can find the PSD of a signal in both the time and >> frequency domain. The only reason I'm choosing to use the frequency domain >> is because it was one of the earlier methods that I learned about. That's >> really all. From the archives I've read about people trying to implement >> energy detectors in GNU Radio for various applications but I never saw >> anybody display the results in any way or form. They mostly just send the >> statistics to a file sink and export to matlab or some other software for >> further processing. So, ultimately, if the way that I'm implementing the >> algorithm is correct thus far, I'm looking for a way to display(graphically >> or otherwise) my result or the avg power. >> >> Nathan would you remove the vector to stream block as well? And, why >> would you have to remove the stream to vector block? Isn't that the format >> that I want the data in? Also, how do you go about adding "vector modes" to >> the remaining blocks? >> >> Tellrell >> >> On Thu, Sep 21, 2017 at 1:30 PM, West, Nathan < >> n...@ostatemail.okstate.edu> wrote: >> >>> You can use the qt gui vector plot to plot a vector. That means removing >>> the stream to vector block. You might have to add "vector" modes to some >>> blocks to do the other operations you want. >>> >>> On Wed, Sep 20, 2017 at 6:31 PM, Tellrell White <t_whit...@yahoo.com> >>> wrote: >>> >>>> Hello Marcus >>>> You are absolutely correct. Is there an existing sink that would allow >>>> me to display avg power given some threshold ? >>>> >>>> Tellrell >>>> >>>> >>>> On Wednesday, September 20, 2017 5:54 PM, Marcus Müller < >>>> marcus.muel...@ettus.com> wrote: >>>> >>>> >>>> Hi Tellrell! >>>> Why should both plots show the same? You send in completely different >>>> signals! >>>> Best regards, >>>> Marcus >>>> >>>> On 09/20/2017 09:27 AM, Tellrell White wrote: >>>> >>>> Hello All >>>> I'm working on a project involving signal detection of an IEEE 802.15.4 >>>> waveform using energy detection. >>>> The algorithm for energy detection goes as follows: >>>> >>>> A/D conversion -> FFT -> mag^2 -> (1/N) ^ M -> threshold >>>> comparison >>>> >>>> Currently, I'm doing simulations in gnuradio companion with a focus of >>>> just trying to construct the the algorithm and get an output. Below I've >>>> attached the current flowgraph i'm using along with screen shots of the >>>> flowgraph and the outputs from the fft sinks. >>>> >>>> In the flowgraph i'm using gaussian noise as my source. I send this >>>> noise to both an FFT sink and also through the energy detection algorithm. >>>> My expectation is that both sinks will give me the same result, however, >>>> the output coming from the algorithm doesn't match the other sink and I'm >>>> currently now sure why this is. Are there some blocks I'm currently missing >>>> and/or is the FFT sink an incorrect way of trying to display the power >>>> coming from the energy detection algorithm? >>>> >>>> Any suggestions are welcome. >>>> >>>> Regards >>>> Tellrell >>>> >>>> >>>> _______________________________________________ >>>> Discuss-gnuradio mailing >>>> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>>> >>>> _______________________________________________ Discuss-gnuradio >>>> mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/ >>>> listinfo/discuss-gnuradio >>>> _______________________________________________ Discuss-gnuradio >>>> mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/ >>>> listinfo/discuss-gnuradio >>>> >>> _______________________________________________ Discuss-gnuradio >>> mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/ >>> listinfo/discuss-gnuradio >> >> _______________________________________________ >> Discuss-gnuradio mailing >> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >
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