System for high speed digital transmission in repetitive noise environment
US4845466A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1987 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Aug 17, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2203/5495
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A transceiver system for high speed, low bit-error rate data communications over a.c. power lines in the presence of repetitive impulse noise includes an a.c. power line coupling network, a power line communications modem, and a microprocessor with a memory and a programmed avoidance algorithm. The a.c. line coupling network includes a zero crossing circuit to detect the start of each a.c. cycle; a transient-voltage limiting front end to detect impluse noises above a threshold and minimize ringing, and a timing circuit to determine the time and duration of each impulse in each sampled a.c. cycle. The microprocessor records the start and stop times of impulses, repetitively scans several a.c. cycles and determines whether or not the impulses are periodic. For periodic impulses, the microprocessor blocks communication on the modem during the impulses, enabling the transceiver to transmit and receive between impulses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.