A stable and distortion-free echo and howling canceller [telephone networks]

Author

Chao, Jinhui ; Tsujii, Shigeo

Author_Institution

Dept. of Electr. & Electron. Eng., Tokyo Inst. of Technol., Japan

fYear

1988

fDate

11-14 Apr 1988

Firstpage

1620

Abstract

IIR (infinite-impulse-response) echo cancellers (EC) and howling cancellers (HC) have to freeze adaptation during `double talk´ (DT). However, a fixed series-parallel structure induces signal distortion. Current methods, using a fixed parallel structure or equalizer, need a stability test which costs O(N²) multiplications per sample period. A configuration of IIR EC and HC, consisting of a maximum-entropy two-channel lattice filter and its inverse filter, is proposed. It can cancel echoes and during DT eliminate the signal distortion by the fixed inverse lattice. Its stability is automatically guaranteed without the necessity of tests. The computational cost is O( N)

Keywords

echo suppression; filtering and prediction theory; telephone interference; IIR echo canceller; double talk; howling canceller; infinite-impulse-response; inverse filter; maximum-entropy two-channel lattice filter; signal distortion elimination; stability; Costs; Distortion; Echo cancellers; Equalizers; IIR filters; Lattices; Predistortion; Stability; Telephony; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on

Conference_Location

New York, NY

ISSN

1520-6149

Type

conf

DOI

10.1109/ICASSP.1988.196921

Filename

196921