CATV Serambling And Deserambling Technology By Compressing The Synchronous Tips Of RF Signal

This paper introduces some of the well-known Scrambling and Descrambling technologies and compares their properties with each other. The Scrambling and Descrambling technologies include non-disturbing frequency method, analog base band disturbing method, the radio-frequency signal disturbing method, the digital disturbing method for the analog signal and the digital signal disturbing method, etc. After the introduction a project based on the Compression of the RF synchronous information is formulated.This project uses the Single Chip Machine MCS-51 as its fundamental controlling unit and adopts many digital chips. Scrambling is fulfilled by compressing some of the synchronous tips carried by RF signal. As the reverse procedure of Scrambling, Descrambling restores the synchronous tips to its proper place according to the controlling information transmitted from the scrambling circuit. At the fore end a computer controls the scrambling circuit through serial communication. The controlling information is sent to the descrambler after being FSK modulated. As a toll system, for authorization, it has the 1C card part.The technology of Compression of the RF synchronous information is comparatively low and secure and it can also produce high quality descrambling signals. It is suitable for the CATV development of China.