An adaptive echo canceller for the transmission of compressed telephone voice

An adaptive echo canceller for the transmission of compressed telephone voice in a digital link is presented. The system is based on a TMS320C25. Measures of echo canceller performance for the running system are made and results are compared to CCITT recommendation G.165. The echo attenuation measured is noted to depend on the nature of the test signal used. It is verified that the codification and transmission processes degrade the level of echo attenuation for the system in operation.