Browse Prior Art Database

Acquisition of Synchronization Relative to a Satellite

IP.com Disclosure Number: IPCOM000083759D
Original Publication Date: 1975-Jul-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Kunzinger, CA: AUTHOR

Abstract

Stations signaling in time division multiplex (TDM) bursts relative to a satellite (in a voice/data digital communication network) acquire and keep synchronization at three levels of timing (masterframe, superframe and bit).

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Acquisition of Synchronization Relative to a Satellite

Stations signaling in time division multiplex (TDM) bursts relative to a satellite (in a voice/data digital communication network) acquire and keep synchronization at three levels of timing (masterframe, superframe and bit).

Multiple station bursts (each including multiple bits) must be timed to interleave in a frame at the satellite without overlap. A superframe consists of a fixed number of consecutive frames (e.g., 56). A master-frame consists of a fixed number of superframes (e.g., 9). In one uniquely assigned frame of each superframe, each station has an assigned slot for control burst signaling relative to the other stations.

One of the stations, operating as a reference (first-acquiring) station, utilizes its unique control burst slot to transmit unique word sequences of bits, which serve the other stations as timing references relative to the satellite for superframes and masterframes.

The other stations employ correlation detection techniques to locate these words as references, for determining their own unique control burst transmission slots in other frames of each superframe. Their own control bursts also carry unique word information for correlation detection, and permit the stations to "fine tune" their individual burst timing references with correction for satellite Doppler shifts.

This procedure and system allow for quick recovery after loss of frame- superframe-masterframe synchronization.

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