An LSI Implementation of an ISDN Echo Canceller: Design and Network Aspects

This paper describes a single/chip VLSI implementation of aU-interface system component called transceiver with echo cancelling (TEC). The transceiver is implemented with the adaptive echo cancelling method and is combined with a decision feedback equalizer. The algorithms are based on the sign algorithm, but have been considerably improved by using an adaptive reference level. Besides the transceiver functions, functions for activation/deactivation, maintenance, and test are also included in the chip.