Title:
BAND DIVISION TYPE ECHO CANCELER
Document Type and Number:
Japanese Patent JP3391144
Kind Code:
B2
Abstract:
PURPOSE: To realize an efficient echo canceler using a DSP by reducing arithmetic processing quantity by band division technique.
CONSTITUTION: A received input is band-divided by a receiving analyzer 100-1 and a transmitting input is band-divided by a transmitting analyzer 100-2. The band division is executed by executing dividing/thinning processing using a polyface digital filter or the like, shifting only even channels to slots corresponding to odd channels by complex modulation and only a real number part is outputted as a band-divided real number signal. Each divided signal is inputted to each adaptive digital filter group (ADFi) 300 and canceled at its echo. Outputs from respective filter groups ADFi 300 are band-synthesized by arithmetic processing inverted from the band division in a synthesizer 200. Echo canceling can easily be executed by a DSP skilled in sum-of-product processing based upon the band division/synthesis in real number processing and an acoustic echo canceler can be economically attained by using the small number of DSPs.
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Inventors:
Kazuto Hirose
Application Number:
JP11312395A
Publication Date:
March 31, 2003
Filing Date:
May 11, 1995
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
H03H21/00; H04B3/23; (IPC1-7): H04B3/23; H03H21/00
Domestic Patent References:
| JP4123606A | ||||
| JP3243020A | ||||
| JP56132808A | ||||
| JP551707A |
Attorney, Agent or Firm:
Masami Akimoto
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