Dual mode LMS nonlinear data echo canceller
US4977591A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1989 |
| Grant date | Dec 11, 1990 |
| Priority date | — |
| Expiry date | Nov 17, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/238
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An adaptive nonlinear data driven echo canceller is disclosed. Unlike other approaches to nonlinear echo cancellation, the inventive echo canceller treats the nonlinearity of the echo path as nonlinear noise associated with transmitting data symbols through a linear echo path. In comparison to a conventional LMS data driven linear echo canceller, the inventive echo canceller utilizes only an additional small random access memory for storing a nonlinear function for estimating the effect of the nonlinear echo path on transmitted data symbols. The same LMS algorithm is used to estimate the linear echo path and the nonlinear function. The signal processing power of a conventional linear data driven LMS echo canceller is sufficient to implement the inventive nonlinear echo canceller and the convergence speed of the nonlinear echo canceller can be less than three times that of the conventional linear LMS echo canceller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.