Michael Hartje <hartje@...> writes: > > > > > dear fellows, > the attached archive is the current version of my design of a modem with gnuradio. This modem has the objective > to enable a > very narrow-band modulation of the codec2 data > stream.Included in the archive are the* Input files for gnuradio Companion v3.5.0* Figure 1 shows the modem* Figure 2 shows the demodulator > * executable python code obtained from the GRC fileWith this modem, we can achieve with QPSK about 1.4 bits / Hz and QAM16 (OFDM) with approximately 3.2 bits / Hz.Now for the very small stream with codec2 (1400 bit / s) so we can transfer into a normal audio channel on the radio two parallel voice channels!The modem uses a structure with the > following 7 steps described below: > 1. Microphone input of the soundcard > 2. Gnuradio with Amplifier and Converter to raw > 3. File Encoder pipeline for codec24. File Encoder pipeline of codec25. Codestream process with QPSK or OFDM6. mixer up to e.g. 1 kHz > 7. Output to > > the TX (Sondkarte)Since the sound cards > have two channels, one can even send TX and RX audio streams > into the two channels - not shown.The arrangement in > the demodulator > is accordingly reversed.I myself have been > involved since 2008 with gnuradio. For the first time on the IPRT (International Packet Radio Conference) in March 2009, Darmstadt, Germany I have reported it. (www.iprt.de) > In another contribution during the > conference I have > shown a > similar modem > - but without codec2 - and discussed it in a workshop.Instructions for > use of gnuradio-companion:If you have an > older version of gnuradio allready installed, use it! If so, > you can use it since the only use of hardware is the > soundcard. (Version 3.2.2 GR and GRC is sufficient). > The shaded portions of the image is currently at time of > the picture) disabled. > The resulting > built executable > Python file > does not contain these parts.You can select the necessary parts and change the graphical elements and their parameters.<span title="Natürlich können wir den GR Entwurf auch erweitern und > zB" closure_uid_vioq7h="137" af="Natürlich können wir den GR > Entwurf auch erweitern und zB" bf="Of course, we can expand > the GR design and also as ">Of course, we can expand the GR > design and also <span title="einen Kanal mit Rauschen, > Störungen und Verzerrungen leicht implementieren." closure_uid_vioq7h="138" af="einen Kanal mit Rauschen, > Störungen und Verzerrungen leicht implementieren." bf="a > channel with noise, interference and distortion easily > implemented. ">a channel with noise, interference and > distortion can be easily implemented. <span title="Dazu entfernen wir den Funkkanal vollständig und > verbinden Modem und Demod." closure_uid_vioq7h="139" af="Dazu > entfernen wir den Funkkanal vollständig und verbinden Modem > und Demod." bf="Therefore we remove the radio channel and the > modem and connect completely Demod. ">Therefore we remove the > radio channel and connect the modem and demod via our channel > model. <span title="In GR gibt es viele Beispiele und > natürlich die erforderlichen Module in der GR-Bibliothek." closure_uid_vioq7h="140" af="In GR gibt es viele Beispiele und > natürlich die erforderlichen Module in der GR-Bibliothek." bf="In GR, there are many examples, and of course the > necessary modules in the GR library. ">In GR, there are many > examples, and of course the necessary modules are in the GR > library.I would be happy if this idea can stimulate your own experiments. > I have prepared an article for the upcoming IPRT. Does anyone want to work together with me in it? > thanks for this great development of the Codec2 that has > inspired my own experiments > Michael Hartje > DK5HH > > > > Attachment (GR-Codec2-modem.zip): application/zip, 211 KiB > > -------------------------------------------------------------------------- ---- > Write once. Port to many. > Get the SDK and tools to simplify cross-platform app development. Create > new or port existing apps to sell to consumers worldwide. Explore the > Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join > http://p.sf.net/sfu/intel-appdev > > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@... > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > Sir i cannot access the attached zip file can you mail it to me. i'll be really thankful ------------------------------------------------------------------------------ New Year. New Location. New Benefits. New Data Center in Ashburn, VA. GigeNET is offering a free month of service with a new server in Ashburn. Choose from 2 high performing configs, both with 100TB of bandwidth. Higher redundancy.Lower latency.Increased capacity.Completely compliant. http://p.sf.net/sfu/gigenet _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
