ADS-B as an Example for Frame Synchronization and Detection of Short Packets

We study the relation between frame synchronization and packet detection by the example of ADS-B (Automatic Dependent Surveillance - Broadcast) from the receiver perspective. We present and compare three metrics for frame synchronization and apply them at a multiple of the symbol rate in order to additionally provide clock phase synchronization. We identify a possible problem of undetected errors when applying CRC error detection to uncoded modulation for short packets and present a workaround for the ADS-B system. Finally, the combined performance of frame synchronization and packet detection, including CRC decoding is evaluated.