Cascaded equalizer technique
US4233683A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 31, 1978 |
| Grant date | Nov 11, 1980 |
| Priority date | — |
| Expiry date | Jan 31, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03038
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Equipment-generated and dynamic crosstalk are effectively compensated by a signal equalization technique which involves the cascading of equalizers of respectively different lengths and respectively different loop gains. The first equalizer to which a received data sequence is applied is a long equalizer having a large number of stages, the term long being relative to the time dispersion of the high frequency channel. The gain of this long equalizer is adjusted to a low value that is consistent with the basic acquisition requirements of the transmission system, but is such that it averages through rapid variations of the high frequency channel. The second equalizer is short relative to the first but is sufficiently long to cover the span of the time dispersion of the high frequency channel. The first equalizer includes a data storage device which receives and stores successively received data samples. Each data sample is multiplied by a controllable weighting factor and the weighted samples are summed to provide an estimate of a received data signal. This estimate is then supplied to the second equalizer which may either be of the form of a transversal equalizer, like the first, or…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.