On Mon, May 21, 2012 at 4:52 AM, Urban Kuhar <winn...@gmail.com> wrote: > Hi everyone! > > I've been using log power FFT block for signal power estimation. I've fed > the output of Log Power block to my custom block in which I search for peak > in power spectrum and then I sum up bins left and right from that peak until > the turn is reached. C++ code for power estimation: > > // move right from the max > iCount = iMax_index + 1; > while (in[iCount] < in[iCount-1]) > fTotalPower += in[iCount++]; > > // move left from the max > iCount = iMax_index; > while (in[iCount] > in[iCount - 1]) > fTotalPower += in[iCount--]; > > > I've set the frame rate property to 10 frames per second (each 32768 > samples) and I use sample rate of 200kSPS. What happens is that every fourth > power estimate sample has magnitude for about 1dB lower than the other > three. I've looked deeper into situation and I found out that every fourth > power spectrum from log power FFT block has about three of four bins thinner > signal and that's why the total magnitude of the signal is lower. I've tried > lower frame rate (2 frames per second) but situation doesn't change. > > Next I tried the FFT block instead of log power FFT and the problem > disappears. So I am guessing that there is some kind of problem in Log Power > FFT block. Has anyone experienced similar problem? > > Regards, > Urban
Hey Urban, Any chance you could send along a simulation that could be easily run that shows the bug? That'd help us understand the problem and find a fix. Thanks, Tom _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
