Unique Word Detection in Digital Burst Communications

In a satellite time-division multiple-access (TDMA) system, the information is transmitted in bursts from the participating ground stations. In order to establish a time reference in each burst and to determine its origin, special code patterns called unique words (UW) are contained in the bursts. Reliable detection of the UW is the basis for keeping the stations in synchronism and providing high-quality communication links. The influence of miss and false detection of the UW on acquisition and the retention of a stable detection mode are investigated. The tolerable loss of information bursts provides criteria for the detector parameters, and for length and patterns of the UW codes. Practical results obtained during tests on an experimental system are compared with theory.