Long Frame Sync Words for Binary PSK Telemetry

Correlation criteria have previously been established for identifying whether a given binary sequence would be a good frame sync word for phase-shift keyed telemetry. In the past, the search for a good
K
-bit sync word has involved the application of these criteria to the entire set of 2
^K
binary
K
-tuples. It is shown that restricting this search to a much smaller subset consisting of
K
-bit prefixes of pseudonoise sequences results in sync words of comparable quality, with greatly reduced computer search times for larger values of
K
. As an example, this procedure is used to find good sync words of length 16-63; from a storage viewpoint, each of these sequences can be generated by a 5- or 6-bit linear feedback shift register.