Hi Kristoff and all, On 29 November 2011 20:41, Kristoff Bonne <[email protected]> wrote: > The development of the FEC system requires knowledge of codec2 to know > what bits are very important and what are less important.
I might be being naive here (it's a long time since I sat my digital signals classes) but if some bits are more important than others wouldn't that mean that there is some entropy in the signal which can be removed to get better compression? >> How about >> making a general-purpose mobile/handheld SDR platform, and let the soft >> modems, FEC, modulation, codecs, and applications develop as they will. > > Wait. > > For us, to start with experimenting, we do not need a SDR platform. I > now have software that turns a ARM board (like a mini2440 or a > pandaboard) into a GMSK receiver (if connected to a 9k6 port of a > radio). Next step is the sender, but that is supposted to be easier. > The kit Jan has designed allow pretty much the same thing (but is a bit > more profesional then my stuff. :-) ) and works with any PC. A general purpose handheld SDR platform would be great - but to be truly general purpose will require a linear amplifier, which is inefficient so kills battery life and is therefore a poor fit to handheld radios. If I understand correctly, envelope tracking amplifiers might help here though. To start experimenting though we have SDRs - at the cheap end there is the SoftRock for HF bands and the UHFSDR for V/UHF as well as countless more expensive models. We can also do arbitrary narrowband waveforms using sound cards and SSB radios on any frequency. GNURadio gives us a powerful platform to create modulation schemes and GRC adds a nice user interface to it. G4KLX has written GPL'd D-Star software which uses the DV-Dongle - it shouldn't be too much of a stretch to change that to codec2 instead. I don't believe that we are missing any components needed to start experimenting with codec2. All it needs is people to start playing. 73, Dan MD1CLV ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
