Digital broadcast transmitter and receiver and method for processing stream thereof

A digital broadcast receiver comprising:

• a receiver which receives a transport stream transmitted from a digital broadcast transmitter;
• an additional data stream detector which determines whether the received transport stream includes an additional data stream with an additional error correction coding;
• and
• a processor which processes the additional data stream if the transport stream includes the additional data stream,
• wherein if the transport stream includes the additional data stream, the transport stream includes a training signal which resets memories used for trellis-encoding at a predetermined time, and
• wherein the additional data stream detector determines whether the transport stream includes the additional data stream according to whether forward error correction (FEC) coding is performed with respect to a predetermined symbol of the field sync signal.