A method of processing broadcast data in a broadcast transmitter includes performing, by a Reed-Solomon (RS) encoder, RS encoding and Cyclic Redundancy Check (CRC) encoding on mobile service data and building at least primary RS frames belonging to a primary ensemble or secondary RS frames belonging to a secondary ensemble depending on RS frame mode information that indicates a single frame mode or a dual frame mode; mapping each of the built at least primary or secondary RS frames into groups, wherein each of the groups includes known data sequences, a fast information channel (FIC) segment, and transmission parameter channel (TPC) data; and transmitting a transmission frame containing the groups.