A finite precision analysis of the block-gradient adaptive data-driven echo canceller

Author

Cioffi, John M. ; Ho, Mantak

Author_Institution

Dept. of Electr. Eng., Stanford Univ., CA, USA

Volume

40

Issue

5

fYear

1992

fDate

5/1/1992 12:00:00 AM

Firstpage

940

Lastpage

946

Abstract

The block-gradient (block LMS) algorithm´s finite precision performance in the data-driven echo canceller application is analyzed. From both the analysis and simulation results, it was found that the block LMS requires significantly less precision than the standard LMS algorithm. The analysis also shows how higher convergence and tracking speeds may be traded for an improvement in precision requirements. The authors derive formulae that can be used to accurately compute echo rejection levels as a function of precision, signal powers, step-size, block length, and echo canceller length. The utility of the formulae is demonstrated by showing performance levels for a typical V.32bis full-duplex voiceband modem operating at a transmission rate of 14.4 kbit/s (7200 Hz sampling rate), and for a high-speed digital subscriber line echo canceller operating at a sampling rate of 400 kHz

Keywords

data communication equipment; echo suppression; least squares approximations; modems; subscriber loops; 14.4 kbit/s; V.32bis full-duplex voiceband modem; adaptive data-driven echo canceller; block LMS algorithm; block length; block-gradient algorithm; echo canceller length; echo rejection levels; finite precision analysis; high-speed digital subscriber line; higher convergence; sampling rate; signal powers; step-size; telecommunication equipment; tracking speeds; Algorithm design and analysis; Analytical models; Computational modeling; Convergence; DSL; Echo cancellers; Least squares approximation; Modems; Performance analysis; Sampling methods;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.141459

Filename

141459