Patent ID: 7934243

Claim:
A method of transmitting a broadcast signal in a transmitter, the method comprising: pre-processing, by a preprocessor, first service data comprising audio or video data for a mobile service, wherein the first service data is capable of being transmitted via a same channel as second service data comprising audio or video for a main service, and wherein pre-processing first service data comprises: generating, by a first encoder, a 2-dimensional Reed-Solomon (RS) frame through which the first service data is RS-Cyclic Redundancy Check (RS-CRC) encoded, wherein the RS frame is separated to a plurality of portions, wherein a size of a payload of the RS frame is 187 by N bytes, and wherein N is an integer corresponding to a length of each row of the RS frame, forming data groups of the first service data, wherein each data group includes signaling information, a plurality of known data sequences that have pre-determined values, one of the plurality of portions, second service data place holders, RS parity data place holders, and MPEG header data place holders, and wherein the signaling information includes information indicating a number of the data groups to be transmitted during a transmission frame, and removing, by a packet formatter, the second service data place holders and the RS parity data place holders and replacing the MPEG header data place holders with MPEG header data to output first service data packets including the first service data, the plurality of known data sequences, and the signaling information; multiplexing, by a multiplexer, the first service data packets and second service data packets, wherein the second service data packets include the second service data; performing, by a second encoder, systematic RS encoding on the second service data packets in the multiplexed data packets and non-systematic RS encoding on the first service data packets in the multiplexed data packets; and transmitting, by a transmission unit, a broadcast signal including the RS-encoded second service data packets and the RS-encoded first service data packets, wherein a parade of the formed data groups is transmitted during slots in the broadcast signal, the slots being basic time periods for multiplexing of the first service data and the second service data.