ABSTRACT
This chapter explains the operating principles for a bit synchronizer in general and the variations on the method and draws state diagrams for minor frame and major frame synchronization. It discusses error detecting and correcting codes for telemetry frames and packets and explains the issues involved with data sequence reassembly. Synchronization is a control process at each level. The control system tries to minimize the difference between the local reference and the received signal. Frame synchronization can start when bit synchronization has occurred. Frame synchronization is required for both the traditional telemetry frames and packet telemetry. Several differences must be considered with packet telemetry. Once the packet synchronization mark has been found, as explained above, the data must be extracted from the data packet. The probability of missing a synchronization word in the data stream is directly related to the number of bit errors the synchronization word incurs due to channel errors.
