Digital time-division multiplexing system
US3995119A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 30, 1975 |
| Grant date | Nov 30, 1976 |
| Priority date | — |
| Expiry date | May 30, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/12
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Disclosed is a digital multiplexer which combines N parallel bit-synchronized digital signals, each of bit rate f.sub.1, into a single composite line signal of bit rate f.sub.2, where f.sub.2 > Nf.sub.1. Before the individual bits are interleaved, each digital signal is converted to a submultiple of the line frequency, f.sub.2. By inserting gaps having a predetermined duration and occurring at a fixed rate into each of the N digital signals, the bit rate f.sub.1 of each bit stream is increased to f.sub.2 /N. This is done without sampling any bit more than once. A multiplexer sequentially interleaves each bit from the N converted bit streams along with the gaps in each bit stream, forming the composite signal of bit rate f.sub.2. The interleaved gaps form empty time slots in the composite signal into which one or more signaling bits are added. Some of the added signaling bits carry framing information to lock the transmitter and receiver together. Thus, a composite higher-rate digital line signal consisting of interleaved information bits and signaling bits forms the time-division multiplex signal suitable for transmission over a single digital transmission path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.