Adaptive echo canceller with sparse dynamically positioned taps
US4805215A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1986 |
| Grant date | Feb 14, 1989 |
| Priority date | — |
| Expiry date | Oct 1, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/238
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
This invention relates to an echo canceller, for a transmission line, including a shift register having an input for receiving an input signal from a signal source and having a plurality of output taps for providing a plurality of equally spaced delayed signals. A tap coefficient storage memory stores a plurality of tap coefficients. A multiplier multiplies certain of the delayed signals by certain tap coefficients to produce multiplier outputs. A tap allocation circuit determines, on a tap by tap basis, how many and which of the taps are to be turned ON so that its corresponding tap coefficients are multiplied by the multiplier. A subtracter cancels echoes by subtracting the multiplier outputs from signals received on the transmission line. Taps which are turned OFF may be assigned a status of STANDBY and these taps may be activated to compensate for changes in the characteristics of the transmission line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.