A method for improving the echo suppression in a telecommunication network ion system

摘要

Undesired electrical couplings between the transmission path and the reception path of a telecommunications system and acoustic coupling between loudspeaker and microphone in the case of a subscriber terminal calling echoes, which are to be eliminated by present, echo suppression devices. In order that these present, echo suppression devices to be able to adapt to current transfer functions, is the determination of a coupling factor and of the echo delay time necessary. A significant problem in this case, the distinction between echo and mixing signals, caused by the so-called duplex communication. According to the invention, from the curve shape of the speech signal pulse trains derived, which specifically from the frequency not, however, are dependent on the amplitude of the speech signal, so that in the case of a real echo independently of the damping of the same pulse sequences in the case of the transmitted signal and at a time delay in the case of a received echo are. The agreement of the pulse sequences of the transmitted and the received signal is a characteristic for the fact that the received signal, an echo of the transmitted signal is.