Digitales Nachrichtenübertragungssystem

摘要

The system transmits test sequences with symbols known to a receiver side. In the receiver a two-dimensional search function is formed, dependent on timer and Doppler frequency. The function is tested for the presence of a synchronising time point and the Doppler frequency of the signal. The search function is integrated in Doppler frequency direction over an integration interval, each contg. several adjacent discrete Doppler frequency values. The integrated search function is used for determining the synchronising time point and the Doppler frequency. USE/ADVANTAGE - For short wave connections etc., with improved synchronisation characteristics. Synchronisation time point is not dependent on transmission medium. Synchronisation faults less likely.