Multichannel echo canceller with a compander

US6498850B1 · kind B1 · utility

Assignee

• ALCATEL · FR

Inventors

• Michael D. Walker · San Francisco, US
• Hans Jurgen Matt · Waiblingen, DE
• Armin Mann · Sachsenheim, DE
• Fritz Weinschenk · Esslingen am Neckar, DE
• Holger Söhnle · Herxheim, DE

Key dates

• Filing date: Mar 31, 1999
• Grant date: Dec 24, 2002
• Expiry date: Mar 31, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B3/23
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A compander circuit (20) for echo cancellation in telecommunications apparatus with an estimator module (21) for estimating an echo coupling and a delay of a line echo and a characteristic module (23) with an associated multiplier (24) for controlling the short-time output level of zout(k) as a function of the short-time input level of zin(k) is characterized in that at all inputs and outputs of the compander circuit (20), a plurality of N communications channels are applied and outputted, respectively, at an N-fold clock rate as compared with a single communications channel; that all memory units in the compander circuit (20) are designed as multiplexer-buffer-demultiplexer (MBD) units (30); and that a modulo-N counter (26) is provided which controls all MBD units (30) so that in each of the MBD units (30), always the same memory cell (351, 352, 35N) assigned to a particular communications channel is addressed.