Apparatus and method for reducing errors in data caused by noise through use of blanking
US5463662A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1994 |
| Grant date | Oct 31, 1995 |
| Priority date | — |
| Expiry date | Apr 8, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2203/547
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus for snubbing or blanking digital signals representing a band of signals that includes an encoded carrier signal transmitted over a power line. An average signal level is compared with the instantaneous signal level to develop a blanking circuit control signal. Additionally, snubbing occurs in the circuit which determines the average signal level to prevent noise from building-up the average signal level. A hold-off signal is used in this circuit to prevent the average signal level from being latched permanently low. A unique infinite impulse filter subtracts out the D.C. offset thereby improving the dynamic range of the blanking. Additionally, the average signal level is used by AGC logic to control the gain at the front end of the apparatus. The state and switching of the AGC is controlled to minimize errors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.