Timeline for Is Gnuradio `file sink` data time domain data or frequency domain data?
Current License: CC BY-SA 4.0
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| Mar 22, 2022 at 15:03 | history | edited | user21417 | CC BY-SA 4.0 |
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| Mar 18, 2022 at 18:54 | comment | added | user21417 | Data is data. I have no idea what real-world information might be in the stream. All we know is that the stream is organized in a particular manner, and then it is vectorized or not. See: wiki.gnuradio.org/index.php?title=FFT I bet you could modify this flowgraph to see what happens when you compare the same stream when it has been interpreted in the time domain via IFFT and a GUI sink. | |
| Mar 18, 2022 at 18:41 | comment | added | kittygirl |
Is data in your above comments correlated to voltage?If yes,I think I can take data as time domain data.
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| Mar 18, 2022 at 18:37 | comment | added | user21417 | In short, the data leaving or entering a block is just data. It is arranged as vectors or streams of n-bit floats or complex or whatever. And there may be "lossy" conversions that can be made. But the data itself is not really in a "domain". You can treat the output of the FFT block as time or freq domain data for sure. But it's really just a vector of data that can be fed to a block that knows what to do with data arranged in that manner. (or not, it's up to you to make sure the block is given what it needs and the right properties are set to get the result you want.) | |
| Mar 18, 2022 at 18:30 | comment | added | user21417 | The FFT block can do forward or reverse. Reverse is the Inverse FFT. Since the operations are symmetric they put it in a single block. To be clear: these blocks are not really converting from one domain to another. They are interpreting domain agnostic data to a particular domain, just like the GUI Sinks do when they are displaying the data as various domains. As for if you can take the output of Forward FFT and feed it into a Reverse FFT -- this is something I have not tried. Some data conversion just to get the vectors right might be required, but as long as the data is there it should work. | |
| Mar 18, 2022 at 18:27 | comment | added | kittygirl |
so,if grc_iq_data is not time domain data,how can I run fft(grc_iq_data to get frequency domain data?
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| Mar 18, 2022 at 18:17 | comment | added | user21417 | That sounds like a different question! However, you take a vector of floats or complex values and either calculate the FFT or the IFFT with that block -- the domain is how you interpret the data, not the data itself. To convert from the FFT output you may need to convert to a different output. For example, to get the magnitude. | |
| Mar 18, 2022 at 17:55 | vote | accept | kittygirl | ||
| Mar 18, 2022 at 17:46 | comment | added | kittygirl |
I can get frequency domain data after fft(grc_iq_data),how to get time domain data when I do time domain analysis?I think ifft(fft(grc_iq_data)) is same as grc_iq_data.
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| Mar 16, 2022 at 19:58 | history | edited | user21417 | CC BY-SA 4.0 |
Fixup typo in typical GR variable name
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| Mar 16, 2022 at 14:39 | history | edited | user21417 | CC BY-SA 4.0 |
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| Mar 16, 2022 at 13:51 | history | edited | user21417 | CC BY-SA 4.0 |
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| Mar 16, 2022 at 13:45 | history | answered | user21417 | CC BY-SA 4.0 |