A transmitting system and method therein are disclosed, by which mobile service data is received and processed. The transmitting system includes an encoder, a signaling encoder, a group formatter, a transmission unit. The encoder encodes mobile data and the signaling encoder encodes signaling information. The group formatter forms data groups having the encoded mobile and signaling information. The data groups have a plurality of data blocks and specific data blocks of the plurality of data blocks include known data sequences. The transmission unit transmit broadcast signal including a parade that includes a collection of data groups having same FEC parameters. And the signaling information includes information identifying the parade and first assigned data group number for the parade to which a first assigned data group belongs.