When I simulate the block diagram it receives perfectly, but when I add the soapy hackrf sink and source it does translate to well, the bandwidth is really short after passing the hackrf, I try fix in it but it does get bigger.

As a beginner I learn a lot from the (great!) gnr tutorials. I succesfully followed the C++ OOT tutorial.

My following challenge is to use the start() and stop() functions to activate en de-activate hardware in my own C++ OOT module when a flowgraph starts and stops.

Are there any (git) project examples (or other references) which contain .h and .cc files and use the start() and stop() functions? This would help me to understand how to use, include and syntax them in my own C++ OOT block.

Thanks for your guidance!

I have radioconda versions 3.10.10.0 and 3.10.12.0 on my Windows 11 machine. How can I add the new libraries I found on Github to Radioconda? For example gr-ais, gr,gsm, etc ...

1. As the current Constellation Decoder based on the Look Up Table(LUT) technique, I want to replace it with LLR. I believe there is a way to custom or make a new block.

2. My second idea is somehow extract the signal before decoder and handle them offline with python.

Is it possible to make log-likelihood ratio decoder on GNU Radio?

Hey, I wanted to learn gnu as thoroughly So I came up with an idea of printing the output generated by signal source of sin wave into an array and save it s that I can send it to any other person But I was actually stuck in it Could any one please letme know how to do it

I wonder have anyone try to implement Semantic Communication using the SDR with GNU Radio. If so, could you please send me the reference.

Thank you

Hey all, I'm pretty new at GNURadio and transmissions in general, so please bare with me. I'm trying to transmit using FSK with my sx1276 module on 144.39 MHz with a NUCLEO F446RE microcontroller. For my project, I want to be able to transmit live data being collected from numerous sensors. But before that, I want to verify that I'm transmitting legible and correct data (like, getting my preamble correct) before connecting my transmission system to my sensor array. I am using a SDR RTL dongle with GNURadio. I'm able to get waveforms at 144.39 MHz. I'm getting no longer padded data, but I'm getting alignment problems. I have a ham radio amateur license, btw! If you have any suggestions, we can discuss this one on one or in this post. Attached is the FSK block diagram I have, but I'm getting misaligned data. Thanks!

Does anyone have experience with building this type of project? I need a MIMO 2x2 system using a BPSK, QPSK, or any other constellation. A block diagram or transmission/reception flow using BPSK or QPSK modulation would also be helpful. We can also discuss privately. Everything is paid.

Hi all,

Maybe my question is a bit stupid since I am not very familiar with custom C++/Python blocks. I have only toyed with GNU radio on personal projects.

I was thinking about how would one implement a CDMA system where symbols are recovered by correlating a pseudorandom sequence with the incoming signal in the presence of a large doppler between the transmitter and receiver (e.g. in a satellite tracking link).

In this case the doppler effect would make the symbol stretch or expand making the correlation have more or less than the nominal (Tsymbol*sampling_frequency) number of samples. This made me a bit confused with regards to how sampling rates work in GNU radio. If I were to have multiple channels in this CDMA system at once, the input sampling rate would be the same but they would output symbols at slightly different sample rates. Does this matter or is just me overthinking the issue?

Does anyone have experience with building this type of project? I need a MIMO 2x2 system using a BPSK, QPSK, or any other constellation. A block diagram or transmission/reception flow using BPSK or QPSK modulation would also be helpful. We can also discuss privately. Everything is paid.

OK, this is a very simplified version of a problem I keep running into. I've tried very elaborate versions of this, with python blocks trying to make things flow, and they just don't. I believe I have distilled my basic question, without all the complexity, to this simple problem. Here is a flow graph that I want to work:

Here, I have some asynchronous source of "packets". It's a TCP Source, though I've tried some of the other source blocks, with no additional success. When I connect with a TCP client, what I'd like to see is that every time data arrives, it gets modulated and sent out to my transmit sink. But this is what happens:

I have proven to myself that data DOES arrive every time I press ENTER (netcat pushes data on a newline). If I put some sort of packet encoding python block in place (so I can put in preamble, sync word, header, footer, etc.), I do see each line show up. But there's clearly buffering going on that means the data only goes out every once in awhile.

This isn't good, because what if sometimes my source only wants to send one packet? It shouldn't have to guess that it needs to send three to hit some buffering threshold, and then send a few packets at once, right?

I've tried messing with max output buffers, I've created truly insane Rube Goldberg flowgraphs with blocks that send messages to selectors and try to keep a realtime flow of samples; but nothing works. The scheduler waits for more data than I give it and I can't tell it's happening in the code; or it pulls some data and then never asks my block for output again..

TL;DR -> How do I make a flowgraph that takes occasional data in from some outside source and definitely modulates and transmits them whenever they arrive?

Part of my bachelors thesis is to make a program where i can log a part of the RF spectrum but to have propper playback we had the idea of recording in ~5 min intervals and to keep file sizes down to only start recording once a threshold is reached.

while making the file sink function isnt hard at all ive been struggling with the periodic interval and the threshold. i found i could use the squelsh block with a head block but that just stops the entire program once the head block stops.

i also have no idea how to make the 5 min interval to work since i dont have much python experience and couldnt find much to work with from the built in blocks unless im missing something.

So I wanted to make a fm receiver with the demodulation done using basic blocks. I am using an RTL sdr. The demodulation seems to work, but I ended up using the FM deemphasis block after decimating to audio. However I don’t understand the sample rate here. It works great when the sample rate is set to 200e6 on the FM deemphasis, but this is obviously not the correct rate. Setting 48k, which should be the correct one, gives just noise on the audio sink. Anyone know what’s happening here?

I have 192kHz-wide SDR archives recorded as WAV files. HDSDR "plays" them and its GUI lets me pick a demodulator and a slice (say 2.4kHz wide) to USB or LSB demodulate to my PC's speaker which I can then record into a WAV file with Audacity.

But GUI is a PITA and I want to do the demodulation via command line.

file on the SDR archive WAV tells me:

RIFF (little-endian) data, WAVE audio, Microsoft PCM, 24 bit, stereo 192000 Hz

soxi on the SDR archive WAV tells me:

Channels : 2

Sample Rate : 192000

Precision : 24-bit

File Size : 1.04G

Bit Rate : 9.22M

Sample Encoding: 24-bit Signed Integer PCM

It is purely an assumption that these files are IQ.

What linux command line tool or toolchain (GNURadio, sox, or other) would let me give a frequency offset and above-format file, and produce a USB-demodulated audio WAV?

I have some sox command line skills but know little about GNURadio command line.

Tim N3QE

I have been trying to transmit data over 2.5g with these blocks and it doesn’t work but when I lower the frequency lets say like 100m it works fine any idea or help Note: I’m using blade A4 micro

I'm using 3.10.12.0 with a HackRF One. GRC is generating python code that crashes when run, but if I put "import osmosdr" before any other gnuradio imports, it runs fine.

The gnuradio I got out of macports didn't include the rather useful module, gr-digital.

Things I've learned in the last week in lieu of learning what I set out to learn, demodulation of GFSK-encoded signals:

• more than I wanted to know about macports
• more than I wanted to know about cmake
• more than I wanted to know about python import internals
• boost has gotten a lot less horrible to build but it still sucks
• building gnuradio really sucks
• how to get gdb to work on one of the newer paranoid macs
• gdb has a python mode
• what spdlib and fmt are, for some reason
• probably some other shit
• i[m so tired
• please sir may i have another sidequest

to the ether, through bullshit

I'm currently working on a group project. My role in the project is to modulate the audio file with VLF (87khz), using QPSK.

I did some learning on gnuradio, and I was able to build the modulator on gnuradio, seeing a stable constellation diagram (The audio file is compressed into .opus format, and I converted it into PCM file on a website, then send it as a file source in gnuradio).

However, when I demodulate it and connect to audio sink, i only hear sharp noise, no audio at all. Could any gnuradio experts troubleshoot the issue from my diagram?

Hi, I have recently started learning GNU Radio and I was looking at the BPSK Demodulation example (Simulation example: BPSK Demodulation) . I saw that they unpacked 8 bits when comparing the random source to the decoded output which synchronized the bits as seen below.

My intuition was that because the bits were synchronized, if I were to pack the decoded output instead of unpacking the random source, they would still be synchronized and match each other but that was not what I observed when I modified the flowchart. Why is this the case and how might I be able to recover the same random source byte stream? I hope this isn't a dumb question and I really appreciate the help.

Hello all, I've been working at this for a couple days, I swear I've put in effort, I've read the blogs and other posts on here but I cannot find a solution to my issue that works. I have recently purchased the RTL-SDR V4 from amazon, I've downloaded the latest version of GNU Radio and I've even gone through the driver install (I think, like I have them downloaded but I have no idea how to get them where I need them which could be the problem) When trying to implement the SDR GNUradio just doesn't recognize that there is anything plugged in and I get the following message in the box, attached is my test for this, any and all help is greatly appreciated!

Executing: C:\Users\mcdea\radioconda\python.exe -u C:\Users\mcdea\OneDrive\Desktop\VT SP'25\ECE 4805\rtl_test_02.py

gr-osmosdr 0.2.0.0 (0.2.0) gnuradio 3.10.10.0

built-in source types: file rtl rtl_tcp uhd miri hackrf bladerf airspy airspyhf soapy redpitaya

[INFO] [UHD] Win32; Microsoft Visual C++ version 14.2; Boost_108200; UHD_4.6.0.0-release

[1m[33m[WARNING] SoapyVOLKConverters: no VOLK config file found. Run volk_profile for best performance.[0m

[1m[33m[WARNING] Unable to scan local: -19

[0m

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_8087&PID_0029\5&3315CB79&0&7'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\ROOT_HUB30\7&28864858&0&0'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_0C45&PID_6723&MI_00\6&2E9D6633&0&0000'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_2109&PID_8817\0000000000000001'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_27C6&PID_5385&MI_00\6&295541DB&0&0000'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_0BDA&PID_2838\00000001'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_0C45&PID_6723\5&3315CB79&0&5'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_2109&PID_0817\MSFT30000000000'

libusb: info [winusb_get_device_list] The following device has no driver: 'USB\VID_0BDA&PID_2838&MI_00\7&38A180A5&0&0000'

libusb: info [winusb_get_device_list] libusb will not be able to access it

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_0BDA&PID_2838&MI_00\7&38A180A5&0&0000'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\ROOT_HUB30\4&C877C9E&0&0'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_0BDA&PID_0306\201307191000'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_2109&PID_2817\MSFT20000000000'

libusb: info [winusb_get_device_list] The following device has no driver: 'USB\VID_0BDA&PID_2838&MI_01\7&38A180A5&0&0001'

libusb: info [winusb_get_device_list] libusb will not be able to access it

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_0BDA&PID_2838&MI_01\7&38A180A5&0&0001'

libusb: info [get_guid] no DeviceInterfaceGUID registered for 'USB\VID_27C6&PID_5385\HTK32'

[1m[33m[WARNING] Unable to scan ip: -19

[0m

[1m[31m[ERROR] rtlsdr_get_device_usb_strings(0) failed[0m

Using device #0 Generic RTL2832U OEM

usb_open error -5

Traceback (most recent call last):

File "C:\Users\mcdea\OneDrive\Desktop\VT SP'25\ECE 4805\rtl_test_02.py", line 293, in <module>

main()

File "C:\Users\mcdea\OneDrive\Desktop\VT SP'25\ECE 4805\rtl_test_02.py", line 271, in main

tb = top_block_cls()

^^^^^^^^^^^^^^^

File "C:\Users\mcdea\OneDrive\Desktop\VT SP'25\ECE 4805\rtl_test_02.py", line 207, in __init__

self.osmosdr_source_0 = osmosdr.source(

^^^^^^^^^^^^^^^

RuntimeError: Failed to open rtlsdr device.

>>> Done (return code 1)

I am a newbie to GNU Radio. I am trying to use my AIRSPY mini as a source and I follow the tutorial here. I realized there are no blocks for inputting AIRSPY mini as a source, so I am thinking of using the block Soapy Custom source, but I have no idea what parameters I should enter. I tried using the Soapy AIRSPY hf source block, but that keeps giving me the error message below:

RuntimeError: Unable to open AirspyHF device

Is there anyway I can use my AIRSPY mini as a source of Gnu Radio.

Below is the code I followed on the tutorial:

Edit: I am using Windows 11 and I already installed the driver WinUSB through Zadig as shown below