Masters Theses


"Echo is a very well known phenomenon in telephonic networks. Noticeable echo may create significant disturbance in a telephonic conversation. A Network echo canceller plays a major role in maintaining the quality of service on a telephonic network at an affordable computational complexity cost. The market place is full of advanced echo cancellation algorithms which deliver good performances.

The problem of network echo cancellation (NEC) arises mainly in Public Switching Telephone Networks (PSTN) and packet telephony networks. Here we address the NEC problem for PSTN. An adaptive filter design is explained in this thesis which delivers excellent performance for the NEC problem in PSTN networks.

The introduced adaptive design process is a multi algorithm approach for the NEC problem. The performance of the algorithm is compared to current existing algorithms such as Normalized Least Mean Squares (NLMS), Proportionate Normalized Least Mean Squares (PNLMS) and Affine Projection Algorithm (APA). The convergence properties of the adaptive filters are examined and compared. The comparison also includes the measure of efficiency of the algorithm in terms of the implementation and results"--Abstract, page iv.


Grant, Steven L.

Committee Member(s)

Zheng, Y. Rosa
Moss, Randy Hays, 1953-


Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering


Wilkens Missouri Endowment


This work was funded by the Wilkens Missouri Endowment.


University of Missouri--Rolla

Publication Date

Summer 2006

Journal article titles appearing in thesis/dissertation

  • A new multi-algorithm approach for sparse system adaptation
  • Attacking the slow final convergence rate of PNLMS
  • Multi-algorithm approach for network echo cancellation


x, 41 pages

Note about bibliography

Includes bibliographical references.


© 2006 Ashrith Deshpande, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Echo suppression (Telecommunication)
Least squares
Regression analysis -- Mathematical models
Sparse matrices
Telephone switching systems, Electronic

Thesis Number

T 9033

Print OCLC #


Link to Catalog Record

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