Transmission mode detection in a modulated communication system
US5289476A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1991 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | May 10, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0057
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A power line communication (PLC) apparatus wherein transmission mode information is encoded into each data packet while maintaining immunity from single bit errors. In the present invention, a power line communication system includes a transmitter/receiver (i.e. transceiver) which is coupled to a power distribution network. Data is transmitted through the power line by the transceiver in packets. The transceiver includes a preamble generator which creates a preamble for each of the data packets and a preamble decoder that decodes the preamble of a data packet and determines word sync for the packet. The preamble generated by the preamble generator consists of a carrier detect interval, a carrier sync interval, a bit sync interval, and a word sync pattern. The transceiver may select either BPSK or QPSK transmission modes on a data packet by data packet basis by encoding information into the packet preamble. Transmission mode information is encoded into the preamble using one of two seven-bit cross compatible word sync patterns for each data packet. Thus, one word sync pattern is used to define a BPSK transmission while the other word sync pattern is used to define a QPSK transmissio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.