Hi Dani, IIRC the highest rate LDPC code in codec2 is rate 0.8. BTW codec2 or LPCNet won't require any FEC at that BER.
QAM might be useful for that channel. - David > Hi David, > > I did a real world test of the 8PSK modem the other day and got 7e-4 BER > without FEC. I'm thinking about adding a very light FEC (very high rate, > higher than 9/10) to correct the few errors that appear. Are there such > very high rate LDPC codes in codec2? What I've seen is more reasonable > and conventional, on the order of 8/9. If not, I'm thinking of adding > something more simple, such as a Reed-Solomon code with only a few > parity check bytes. > > The idea is not only to be able to transmit codec2 through this modem > (it is clear that this is very easy, since there is more than enough > Eb/N0 on this channel), but also other kinds of data, such as images > (people are using some old Japanese 1k2 GMSK modem to send digital SSTV, > and this could be improved a lot in terms of speed with this modem). > > The fun thing is that the channel of the QO-100 narrowband transponder > is bandwidth limited rather than SNR limited. According to the "rules" > we can use up to 2.7kHz and 52dB CN0. > > 73, > > Dani. > > > > > > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
