Echo cancelers which cover longer impulse responses (greater than or equal to 64 ms) are desirable. Long responses create a need for more rapidly converging algorithms in order to meet the specifications for network echo cancelers devised by the ITU (International Telecommunication Union). In general, faster convergence implies a higher sensitivity to near-end disturbances, especially "double-talk". Recently, a fast converging algorithm called proportionate NLMS (normalized least mean squares) algorithm (PNLMS) has been proposed. This algorithm exploits the sparseness of the echo path. In this paper we propose a method for making the PNLMS algorithm more robust against double-talk. The slower divergence rate of these robust algorithms in combination with a standard Geigel double-talk detector improves the performance of a network echo canceler considerably during double-talk. This results in the robust PNLMS algorithm which diverges much slower than PNLMS and standard NLMS. A generalization of the robust PNLMS algorithm to a robust proportionate affine projection algorithm (APA) is also presented. It converges very fast, and unlike PNLMS, is not as dependent on the assumption of a sparse echo path response. Trade off between convergence and divergence rate is easily tuned with one parameter and the added complexity is about 7 instructions per sample.

Meeting Name

IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, 1999


Electrical and Computer Engineering

Keywords and Phrases

ITU; International Telecommunication Union; PNLMS Algorithm; Complexity; Computational Complexity; Convergence of Numerical Methods; Convergence Rate; Divergence Rate; Double-Talk Robust Fast Converging Algorithms; Echo Cancelers; Echo Suppression; Impulse Response; Least Mean Squares Methods; Near-End Disturbances; Network Echo Cancellation; Normalized Least Mean Squares; Proportionate NLMS Algorithm; Proportionate Affine Projection Algorithm; Signal Detection; Sparse Echo Path Response; Standard Geigel Double-Talk Detector; Standard NLMS; Telecommunication Networks; Transient Response

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 1999 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 1999