Re: [Discuss-gnuradio] Handling of IQ files

16 09:20:41 +0100 > > From: vitt...@gmail.com > > To: discuss-gnuradio@gnu.org > > Subject: Re: [Discuss-gnuradio] Handling of IQ files > > > > > Happy to read you replay Henry! > > Feel free to rip/change/upgrade my work, but let me know about ur > progress, p

Re: [Discuss-gnuradio] Handling of IQ files

the AForge .NET library.> Date: Tue, 22 Mar 2016 09:20:41 +0100 > From: vitt...@gmail.com > To: discuss-gnuradio@gnu.org > Subject: Re: [Discuss-gnuradio] Handling of IQ files > > Happy to read you replay Henry! > Feel free to rip/change/upgrade my work, but let me know abou

Re: [Discuss-gnuradio] Handling of IQ files

Happy to read you replay Henry! Feel free to rip/change/upgrade my work, but let me know about ur progress, pse! Remember that it's fairly resource hungry ( file larger that 250 Mb crashes the app also on my I7/16Gb), but it's a starting point. I think that with GNURADIO it's possible to refine

Re: [Discuss-gnuradio] Handling of IQ files

I like the concept of your program. It looks just like what I’m trying to write. Sent from Windows Mail From: Vitt Benv Sent: ‎Sunday‎, ‎March‎ ‎20‎, ‎2016 ‎4‎:‎16‎ ‎PM To: discuss-gnuradio@gnu.org Hi, this [ https://sourceforge.net/projects/automodrecog/ ] is my little effort

Re: [Discuss-gnuradio] Handling of IQ files

Hi, this [ https://sourceforge.net/projects/automodrecog/ ] is my little effort about handling IQ files. The input IQ file is recorded with HDSDR, very nice piece of sw, that as a good recording scheduler. By the way the file provided can be played with it. I do also some tests with IQ file

Re: [Discuss-gnuradio] Handling of IQ files

Ah, sorry, I sent that piece of email a bit too early. On 20.03.2016 19:07, Henry Barton wrote: > So every element of the resulting vector will hold the intensity of a > 1Hz bit of spectrum? No, not at all. The N-Point DFT gives you N evenly spaced frequencies that make up the whole Nyquist

Re: [Discuss-gnuradio] Handling of IQ files

Hi Henry, > So correlating is digitally mixing something with a predetermined > sequence? um, no. Not in the sense that I'd use "correlating". Mixing in this context is simple point-wise multiplication. > I guess, then, if you have a PSK waveform you might multiply it by > something, starting at

Re: [Discuss-gnuradio] Handling of IQ files

So every element of the resulting vector will hold the intensity of a 1Hz bit of spectrum? Also, you mentioned what would be in X, but what should vector W contain? Sent from Windows Mail From: Marcus Müller Sent: ‎Sunday‎, ‎March‎ ‎20‎, ‎2016 ‎1‎:‎57‎ ‎PM To:

Re: [Discuss-gnuradio] Handling of IQ files

Hi Henry, Look up the Discrete Fourier Transform in its Matrix form: You take a vector of samples $x$ and multiply it with a matrix $W$ to get the discrete Fourier transform of $x$, which I shall denote $X$: $X=Wx$, with $W \in \mathbb N ^{N\times N}$ (i.e. a square matrix, representing the

Re: [Discuss-gnuradio] Handling of IQ files

Yes, pretty much. With the DFT (and the continuous one) you are correlating the input waveform with harmonically related, complex sinusoids; essentially for each harmonic you mix it down to DC then sum (integrate). The FFT is different (I actually don't know how it works, other than it operates

Re: [Discuss-gnuradio] Handling of IQ files

I’ve read up on the FFT and DSP and I must say I’m impressed that multiplying two waveforms is the digital equivalent of heterodyning. Am I right in my understanding that finding frequency components (FFT-ing) is simply multiplying a series of known sine waves by your input waveform? Sent

Re: [Discuss-gnuradio] Handling of IQ files

Hi Henry, Here are a few open source applications you may find useful to reference to build your tool. rtl_power + heatmap.py (c/python) - Hard coded to use the RTL-SDRs https://github.com/keenerd/rtl-sdr/blob/master/src/rtl_power.c http://kmkeen.com/rtl-power/ rtl_power port that uses FFTW -

Re: [Discuss-gnuradio] Handling of IQ files

Hi, With gr-fosphor you just playback the file and it loops until you stop it. Plot supports averages, max and mins. Since I/Q files do not contain the actual frequency, you'll have to calibrate the plot, which is 1 sample frequency wide. gr-fosphor runs on opencl. HTH Nikos ​ On Sat, Mar 19,

Re: [Discuss-gnuradio] Handling of IQ files

On 03/19/2016 02:05 PM, Henry Barton wrote: So there’s no “read x samples, divide by y, do such-and-such, and you have a frequency-domain array” that I can average over time? Sent from Windows Mail Gnu Radio has various types of FFT blocks, filters, decimators, etc, etc.But there is no

Re: [Discuss-gnuradio] Handling of IQ files

So there’s no “read x samples, divide by y, do such-and-such, and you have a frequency-domain array” that I can average over time? Sent from Windows Mail From: Nikos Balkanas Sent: ‎Saturday‎, ‎March‎ ‎19‎, ‎2016 ‎1‎:‎31‎ ‎PM To: James Humphries Cc: Henry Barton,

Re: [Discuss-gnuradio] Handling of IQ files

Hi, I missed your second part. gr-fosphor is realtime, so It will follow whatever frequencies you have. Frequency hops show as frequency bands in a frequency spectrum. The frequency spread of a single plot, is your sampling frequency. HTH, Nikos​ On Sat, Mar 19, 2016 at 7:22 PM, James Humphries

Re: [Discuss-gnuradio] Handling of IQ files

Hi Henry, There is a script, read_complex_binary.m, that is included with gnuradio. You can use that with Octave or Matlab to read the I/Q recordings from a file as a time vector. -Trip On Sat, Mar 19, 2016 at 12:43 PM, Henry Barton wrote: > Is there any simple formula for

Re: [Discuss-gnuradio] Handling of IQ files

​Hi, Yes. gr-fosphor will do that for you. It's main takes as input a complex float I/Q file from usrp. HTH Nikos On Sat, Mar 19, 2016 at 6:43 PM, Henry Barton wrote: > Is there any simple formula for plotting spectrum (finding the intensity > of each frequency component,

[Discuss-gnuradio] Handling of IQ files

Is there any simple formula for plotting spectrum (finding the intensity of each frequency component, Hertz by Hertz) from IQ recordings? Specifically I need to know how to read an IQ file and somehow dissect clusters of samples. I’ve written programs that deal with large amounts of data from