Software for Telecoms & Audio
V.29 Modem DSP C Code
implements the data pump function of the ITU Modem Recommendation V.29,
which provides full-duplex data transmission at rates of 9.6, 7.2, &
4.8kb/s over 4-wire leased lines. The software also allows half-duplex
transmission over the telephone network for application with Group 3 Fax.
Good error performance is assured by the use of adaptive equalisation.
at the sample interface, the code can operate at 8.0kHz and 9.6kHz sample
rates. Transmit and receive samples are transferred on a common clock,
to which the transmit clock is synchronised. The receive clock is interpolated
in the code for synchronisation to the far-end modem. At the data interface,
data is transferred in buffers under pointer control via subroutine calls.
Performance: over flat channels, near matched-filter performance is obtained. SNR for 10-6 Error Rate (Flat Channel - 4kHz BW noise):
#example figures from compiling for the TI TMS320C5000(C55x) DSP processor
Availability: NOW - sale is under licence - integration support offered