Patent ID: 7881408

Claim:
A digital broadcast receiving system, comprising: a tuner receiving a DTV signal comprising main service data and mobile service data multiplexed with the main service data, wherein the DTV signal results from generating a second data by de-interleaving a first data group by a DTV transmitter, the first data group including a plurality of segments in a plurality of regions, an Nth segment in a first region having place holders for main service data and K mobile service data bytes, an (N+1)th segment in the first region having place holders for main service data and L mobile service data bytes, an (N+2)th segment in the first region having place holders for main service data and M mobile service data bytes, an Oth segment in a second region having X mobile service data bytes, an (O+1)th segment in the second region having Y mobile service data bytes, and an (O+2)th segment in the second region having Z mobile service data bytes, wherein the variables K, L, M, N , O, X, Y, Z are integers greater than 0, K<L<M, X=Y=Z, and N<O, each packet in the second data group having a length of 207 bytes; a known data detector detecting known data information inserted and transmitted from a digital broadcast transmitting system and using the known data information to estimate an initial frequency offset; a carrier recovery unit obtaining initial synchronization by using the initial frequency offset, and detecting a frequency offset from the received signal by using the known data information so as to perform carrier recovery; and a timing recovery unit detecting timing error information from the received signal by using the known data information so as to perform timing recovery.