Cyclically variable signal delays for acoustic echo cancellation
US9787825B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2015 |
| Grant date | Oct 10, 2017 |
| Priority date | — |
| Expiry date | Jun 30, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/002
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A multi-channel audio communication system is configured to receive highly correlated input audio signals, generated as an example by multiple microphones at a far-end site. Each input audio signal is cyclically stepped through a range of discrete delay amounts, between upper and lower limits, using a step size that is a fraction of the sample period of the input audio signals. Delay cycles applied to the different input audio signals are configured to have different phases, thereby reducing the inter-signal correlation of the input audio signals. The delayed input audio signals are then played by loudspeakers. Microphone output, which may contain sound generated by the loudspeakers, is then subjected to multi-channel acoustic echo cancellation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.