Method and device for training an adaptive equalizer by means of an unknown data signal in a quadrature amplitude modulation transmission system
US4227152A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 1979 |
| Grant date | Oct 7, 1980 |
| Priority date | — |
| Expiry date | May 23, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/38
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and a device for training the equalizer of a receiver used in a QAM transmission system, by means of an unknown data signal, thereby enabling in particular said equalizer to be trained in the cases described above. In accordance with the method of the present invention, in a data receiver wherein, under normal operating conditions, the data is detected with respect to a first constellation, the equalizer is trained by detecting the data with respect to a second constellation which comprises fewer points than said first constellation and by adjusting the coefficients of the equalizer by means of an error signal produced as a result of the detection operation performed with respect to the second constellation. In accordance with a first embodiment of the present invention, the second constellation is comprised of those points of the first constellation that are farthest from its center. In accordance with a second embodiment of the invention, the points of the second constellation are obtained as follows: the first constellation is divided into L sets of points S.sup.l, l=1, 2, . . . , L and a point b.sup.l of the second constellation is associated with each set S.sup.l in a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.