Signal scrambling transmission system
US4817148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1987 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Jul 6, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03866
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
There is disclosed a signal scrambling transmission system in which the data is scrambled at the transmit end by logically combining the data with a pseudo random sequence generated by a ROM prior to transmission. The data is recovered at the receive end by logically combining the scrambled data with the same pseudo random sequence generated by a ROM. The ROM at the transmit end is divided into frames with a synchronization word and a frame count (index) word embedded in each frame. The synchronization word and index word are transmitted with each frame of data and are used to synchronize the ROM at the receive end with the incoming scrambled data. The transmit end ROM is divided into 32 frames each being 4,096 bits long. Each frame has a 27-bit synchronization word, a 5-bit index word, and 4,064 bits of pseudo random sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.