Patent ID: 8045591

Claim:
A method of transmitting a broadcast signal in a transmitter, the method comprising: encoding mobile data for an additional forward error correction (FEC); block processing the encoded mobile data by a specific code rate of ½; forming data groups including the block processed mobile data, each of the data groups further including signaling information and a plurality of known data sequences, wherein at least two of the plurality of known data sequences have different lengths, and wherein the signaling information includes information for a plurality of Reed-Solomon (RS) code modes for the mobile data and information for a plurality of serial concatenated convolutional code (SCCC) modes for the mobile data, wherein one of the plurality of SCCC modes indicates the specific code rate, wherein each of the data groups further includes a plurality of areas and the signaling information is inserted into a specific area of the plurality of areas; forming a mobile data packet including data in the data groups; multiplexing a main data packet including main data and the mobile data packet; performing systematic RS encoding on the main data in the multiplexed packets and non-systematic RS encoding on the mobile data in the multiplexed packets; trellis encoding the RS encoded main data and 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 within slots, the slots being basic time periods for multiplexing the mobile data and the main data.