https://github.com/argilo/gr-dsd

GNU Radio block for Digital Speech Decoder
https://github.com/argilo/gr-dsd

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GNU Radio block for Digital Speech Decoder

• Host: GitHub
• URL: https://github.com/argilo/gr-dsd
• Owner: argilo
• License: gpl-3.0
• Created: 2012-06-28T02:01:06.000Z (about 12 years ago)
• Default Branch: master
• Last Pushed: 2024-01-30T15:53:30.000Z (8 months ago)
• Last Synced: 2024-04-06T06:36:28.103Z (6 months ago)
• Topics: hacktoberfest
• Language: C++
• Homepage:
• Size: 913 KB
• Stars: 135
• Watchers: 28
• Forks: 48
• Open Issues: 12
• Metadata Files:
  • Readme: README.md
  • License: COPYING

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README

        
gr-dsd

======

Author: Clayton Smith  

Email: 

The goal of this project is to package Digital Speech Decoder (DSD) as

a GNU Radio block, so that it can be easily used with software radio

peripherals such as the Ettus Research USRP or RTL2832U-based USB TV

tuners.

Dependencies:

  * GNU Radio 3.7, 3.8, 3.9, or 3.10

  * libsndfile (libsndfile1-dev package in Ubuntu)

  * BOOST C++ source libraries (libboost-all-dev in Ubuntu)

  * libcppunit-dev

  * libitpp-dev

  * liblog4cpp5-dev

  * swig

Build instructions:

    mkdir build

    cd build

    cmake ..

    make

    sudo make install

    sudo ldconfig

After running the above commands, "DSD Block" should appear under the

"DSD" category in GNU Radio Companion, and "block_ff" will be available

in the "dsd" Python package.

The block expects 48000 samples per second input, and outputs sound at

8000 samples per second.  The input should be FM-demodulated (for

example, with GNU Radio's Quadrature Demod block) and should be between

-1 and 1 while receiving digital signals.  (A quadrature demod gain of

1.6 works well for me for EDACS Provoice.)  The input signal should

also be free of DC bias, so make sure you are tuned accurately, or

filter out DC.

To save CPU cycles, the block detects when the input is zero and avoids

sending it through DSD.  Thus it helps to put a squelch block before

gr-dsd, especially if you're using many copies of gr-dsd in parallel.

The underlying DSD and mbelib were taken from:

* https://github.com/szechyjs/dsd

* https://github.com/szechyjs/mbelib

No modifications to mbelib were required, but DSD has been modified to

bypass the sound card.  The GNU Radio block itself was adapted from the

gr-howto-write-a-block sample included with GNU Radio.

Contributions are welcome!