Generating a half rate/quarter rate flag stream for enhanced VSB decoder

摘要

A system and method are provided for generating a flag stream that is used to mark the half rate and quarter rate bytes in an enhanced vestigial sideband (eVSB) data stream. The flag generator includes a buffer, a counter, and an interleaver. The buffer receives map data from a map decoder. The map data indicates the number of half rate and quarter rate packets that are present in a given eVSB data frame. The map data also includes a multiplexer option bit that indicates how the half rate and quarter rate packets are multiplexed in the eVSB data frame. The flag generator uses the map data to generate a flag stream that marks the bytes of the eVSB data frame for accurately separating the half rate data and the quarter rate data.