公开(公告)号：AU3194489A

公开(公告)日：1989-09-06

申请号：AU3194489

申请日：1989-02-17

Applicant: NOISE CANCELLATION TECHNOLOGIES INC

Inventor： GARDNER JOHN W ,  ZIEGLER ELDON W JR

IPC: F01N1/00 ,  F01N1/06 ,  F01N1/08 ,  F01N1/22 ,  G10K11/178

公开(公告)号：AU6616490A

公开(公告)日：1991-05-16

申请号：AU6616490

申请日：1990-10-16

Applicant: NOISE CANCELLATION TECHNOLOGIES INC

Inventor： ZIEGLER ELDON W JR ,  GARDNER JOHN W

IPC: H03H21/00 ,  H04B1/10 ,  H04B3/00 ,  H03B1/00 ,  H03K5/00

Abstract: An in wire active cancelling system cancels undesirable repetitive signal components from a primary electronics signal controlling desired intelligent signal components and undesirable repetitive signal components. The primary electronic signal is fed as an input to an electronic mixer. A second input to the electronic mixer is a repetitive cancelling signal which is applied by the mixer to cancel the undesirable repetitive signal component from the primary signal without interfering with passage of the primary signal intelligent signal components. The repetitive cancellation signal is developed from a residual signal developed by the mixer and a timing signal obtained from a timing signal generator.

公开(公告)号：AU7240491A

公开(公告)日：1991-09-03

申请号：AU7240491

申请日：1991-02-07

Applicant: NOISE CANCELLATION TECHNOLOGIES INC

Inventor： ZIEGLER ELDON W JR

IPC: G10K11/178 ,  H03H21/00 ,  H04B3/04 ,  G06F15/31

Abstract: A digital virtual earth active cancellation system which receives a phenomena input signal representing residual phenomena to be cancelled and has an adaptive filter which generates a cancellation signal. A system impulse response is convolved with the cancellation signal and is subtracted from the input signal to produce an estimate of noise. This substantially eliminates the problems associated with destructive feedback due to phase shifts. The residual signal is used to control an adaptive filter that receives the estimated noise as an input. The adaptive filter produces the cancellation signal by filtering the estimated noise with filter weights that are adapted using the residual signal and the estimated noise convolved with the system impulse response.