Patent ID: 7936828

Claim:
A digital television (DTV) transmitter for coding main and enhanced data for transmission, the DTV transmitter comprising: a pre-coder for pre-coding the enhanced data by coding the enhanced data for forward error correction (FEC); a packet formatter for outputting enhanced data packets, the enhanced data packets including the pre-coded enhanced data and known data sequences; a packet multiplexer for multiplexing the enhanced data packets with main data packets including the main data; an encoder for Reed-Solomon (RS) encoding the multiplexed data packets by adding first parity data to the multiplexed data packets; an interleaver for interleaving the RS-encoded data packets; a trellis encoder for trellis encoding data in the interleaved data packets, wherein at least one memory included in the trellis encoder is initialized by initialization data at each start of the interleaved known data sequences; a compatible processor for calculating second parity data based on the initialization data, replacing the first parity data with the second parity data and outputting the replaced second parity data to the trellis encoder; and a sync multiplexer for multiplexing the trellis-encoded data with segment synchronization data and field synchronization data.