Thank you for your support. You will find sequels by my colleagues and myself in the 2020 European GNU Radio Days tutorials, including kzfaq.info/get/bejne/qqeGpK99l6uYmH0.html and kzfaq.info/get/bejne/kNtggcp6y77SZJc.html

Absolutely, thank you for correcting, I should have been more careful when proofreading the video.

Indeed it is my belief that GNU Radio is an invaluable teaching tool with hands on experiments on sometimes plainfully abstract concepts of discrete time digital signal processing. For more teaching material on GNU Radio for teaching basic concepts of digital communications: jmfriedt.free.fr/#L3

Thank you for the positive feedback. GNU Radio is only a library easing prototyping of discrete time signal processing algorithms, DoA being a phase analysis of the signal being received by multiple separate antennas connected to a coherent (same local oscillator) receiver, GNU Radio is indeed well suited. See Balint Seeber's past presentations or T. Collins' @ kzfaq.info/get/bejne/lbtyg7maltzUYqc.html

Tutorials 2 and 3 should be uploaded prior to the actual conference to be held June 24th, 2021. The tutorials are mostly independent and the numbering only follows the program schedule: tutorial 4 can be tackled before 2 and 3 are uploaded. Best, JM

If running the flowgraph through Python is not limiting your bandwidth, then saving raw data is as simple as connecting a Source (OsmoSDR, USRP) to a File Sink. If multiple streams are to be interleaved, then Sources -> Interleave -> File Sink. The drawback of this approach is 1/ the scheduler might limit the bandwidth and 2/ the floating point number storage will increase the file size (8 bytes/complex number), which might be an issue when saving high datarates to RAMdisk. You will find an example at github.com/jmfriedt/sentinel1_pbr/ of streaming 8-bit I/Q data from 2 channels to a file saved as 2-bytes/sample (I and Q), optimizing storage size and bandwidth, but not using GNU Radio (raw UHD access).

@@europeangnuradiodays1445 Thanks for your reply. Is there any sourch that combines DSP and various methods with GNU radio?

@@kmoraitakis40 I realize I was mistaken when mentioning interleaving in the source to file program I mentioned above. *Either* we are using UHD source and sinking straight to file without relying on GNU Radio (my example, inspired from github.com/EttusResearch/uhd/blob/master/host/examples) *or* using GNU Radio with all its processing functions with datastream organized by the scheduler and the associated overhead: in this case gr-uhd must be used as shown at github.com/gnuradio/gnuradio/tree/master/gr-uhd/examples/c%2B%2B Apologies for the confusion.

could you point to the timestamp in the video you are referring to? I would not dare compare GPS and FM broadcast signals, so I must have misrepresented my thoughts in the discussion, apologies for the confusion, I hope I can clarify what I meant if pointed to the right part of the presentation.

@@europeangnuradiodays1445 04:08

@@reddamasio OK I understand the confusion. I am addressing here the "ideal" SDR architecture -- connecting an antenna straight to the ADC input -- with the practical SDR architecture of antenna-mixer for frequency transposition-low pass filtering-ADC input. I am justifying why the "SDR dream" of sampling the whole RF and microwave band with a single ADC might not be wise due to the limited dynamic range, since the weak GPS signal (as an example) would be overwhelmed by the strong FM band signal when sampling from DC to 1.57542 GHz (hence including the 88-108 MHz FM band), whereas transposing the GPS band to baseband by mixing with 1575.42 MHz, then low pass filtering (eg. 1.023 MHz low pass filter for GPS L1 but anything that will remove the frequency components MHz to 10s of MHz from the GPS frequency) and then sampling will cancel strong signals and compensate for the limited quantization capability of SDR. So ADC quantization limits the dynamic range between the strongest and weakest signal in the sampled band, and justifies the practical architecture of transposing-low pass-sampling as opposed to the most flexible approach of sampling the antenna output. Anyway an antenna acts as a bandpass filter and would not allow all signals from DC to 1.57542 GHz from being sampled, but this is not addressed in this discussion (except if using atoms as antennas as described in the fascinating www.nist.gov/publications/multi-band-rydberg-atom-based-receiverantenna-amfm-stereo-reception but that is well beyond this discussion)