DC restoration circuit for a radio receiver
US6661858B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Sep 12, 2000 |
| Grant date | Dec 9, 2003 |
| Priority date | — |
| Expiry date | Mar 27, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/061
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
This invention relates to communications (radio) receiver circuitry and, in particular, to circuitry for eliminating a varying DC distortion component of a demodulated received information signal such as comprising data packets. This invention uses an adaptive filter, and a corresponding adaptive (equalization) feedback signal, to remove a slow varying (exponential) DC component of the signal. In the decoding circuitry of a receiver the adaptive filter (e.g. an LMS filter) compares the outputs of an integrate and dump component to adapted outputs of a decision component in order to produce an error signal which inherently corresponds to the varying DC component of the symbol stream. This equalizing adaptive error signal is fed back and subtracted from the symbol integral stream to remove the varying DC component therefrom and thereby restore the information packet to a level DC bias condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.