Adaptive noise cancellation device
US5568558A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 1993 |
| Grant date | Oct 22, 1996 |
| Priority date | — |
| Expiry date | Dec 3, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/123
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An adaptive noise cancellation device comprises: convolution logic (10) for convolving the signal from a reference input (x) with a discretized L-tap filter to form a filtered reference signal; and logic (20) for subtracting the filtered reference signal from a signal input to form an output signal; logic for generating the filter taps as a linear combination of N basis functions each having a corresponding coefficient C.sub.k ; and logic for repeatedly determining the coefficients C.sub.k which minimize the power in the output signal (z), characterized in that N is less than the number of filter taps L and the basis functions have respective values over a portion of finite width, outside of which portion the functions are substantially zero, both in the frequency and time domains, in an embodiment they are gaussian. A full-duplex speakerphone is disclosed including such a noise cancellation device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.