The wiki description is pretty dated. I think the original modem had 14 carriers, but the current non-coherent modem has 16 plus the bpsk sync.
If you work backwards, the modem has to send 64-bits every 40 ms (vocoder rate). So, 64-bits at 25 Hz. But since the modem only sends 32-bits (16 carriers) it has to send two frames every 40 ms, thus, 50 Hz symbol rate, 1600 bit/s. The bpsk sync carrier being used to identify the starting frame. Steve ------------------------------------------------------------------------------ _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
