Patent ID: 8023535

Claim:
A method of transmitting a broadcast signal in a transmitter, the method comprising: encoding mobile data for an additional forward error correction (FEC), wherein the mobile data includes a cell information table (CIT) having frequency information of transmitters in adjacent cells; block processing the encoded mobile data for encoding with a specific code rate, wherein the specific code rate is either ½ or ¼; forming data groups of the encoded mobile data, each data group including the encoded mobile data, signaling information and a plurality of known data sequences, wherein at least two of the known data sequences have different lengths; forming mobile data packets including data in the data groups; multiplexing main data packets including the main data and the mobile data packets; performing systematic Reed-Solomon (RS) encoding on main data in the multiplexed data packets and non-systematic RS encoding on mobile data in the multiplexed data packets; trellis encoding the RS encoded main data and the RS encoded mobile data in a trellis encoder, wherein a memory included in the trellis encoder is initialized at a start of each known data sequence; and transmitting data groups including the trellis-encoded data, wherein the data groups are transmitted during slots, the slots being time periods for multiplexing of the mobile data and the main data.