Error tracking loop
US5406587A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 1993 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | Feb 8, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/02
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A circuit for error correcting a received complex data signal comprises a synchronous detector for recovering an in-phase data component from the received signal and a Hilbert transform filter for estimating the related quadrature component from the recovered in-phase data component, the recovered in-phase data component including a periodically recurring reference signal. A decision feedback loop is periodically operable in response to the reference signal for initially error correcting a selected characteristic of the received signal at a first relatively rapid rate and for subsequently error correcting the selected characteristic at a rate which is less than the first rate and which is dependent upon the estimated S/N ratio of the received signal. In one embodiment, phase errors are corrected at a rate which is also directly related to the value of the estimated quadrature component. In another embodiment, amplitude errors, e.g. gain and offset, are corrected at a rate which is inversely related to the value of the estimated quadrature component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.