Robust adaptive filter for echo cancellation
US7031461B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 2004 |
| Grant date | Apr 18, 2006 |
| Priority date | — |
| Expiry date | Jan 19, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An adaptive filter is programmed with an algorithm based on a normalized Least Mean Squares (nLMS) algorithm that adapts each sample time. The algorithm is modified to be more efficient in a variety of DSPs by computing multiple errors, one per sample, before updating coefficients. The update equation utilizes the multiple errors to achieve adaptation at a similar performance to known nLMS algorithms that adapt each sample time but without the instability that is observed in low echo-to-near-end-noise ratio (ENR) input conditions. Varying the relaxation step size prevents divergence. The DSP utilizes either one or more MAC units.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.