Receiving system and method for processing digital broadcast signal in the receiving system

An apparatus for receiving a broadcast signal, the apparatus comprising:

• a receiver to receive the broadcast signal;
• a demodulator to demodulate the broadcast signal, wherein the demodulated broadcast signal includes a data unit, the data unit including one or more data blocks,
• wherein the data unit includes a variable number of data symbols having service data,
• wherein the demodulated broadcast signal further includes transmission parameter data and scattered known data in the data symbols,
• wherein the transmission parameter data includes information for representing the number of data symbols,
• wherein the scattered known data has a pattern based on a transmission mode,
• wherein the data symbols have the scattered known data based on the pattern of the scattered known data,
• wherein the scattered known data is discontinuously inserted in a data block;
• a deinterleaver to deinterleave the service data;
• a signaling decoder to decode the transmission parameter data;
• and
• a decoder to decode the deinterleaved service data.

A method for transmitting a broadcast signal by an apparatus, the method comprising:

• encoding service data;
• encoding transmission parameter data;
• modulating the encoded service data and the encoded transmission parameter data, wherein the encoded service data and the encoded transmission parameter data are included in a data unit, the data unit including one or more data blocks;
• and
• transmitting the broadcast signal including the modulated service data and the modulated transmission parameter data,
• wherein the data unit includes a variable number of data symbols having service data,
• wherein the data unit includes scattered known data in the data symbols,
• wherein the transmission parameter data includes information for the number of data symbols,
• wherein the scattered known data has a pattern based on a transmission mode,
• wherein the data symbols have the scattered known data based on the pattern of the scattered known data,
• wherein the scattered known data is discontinuously inserted in a data block.

An apparatus for transmitting a broadcast signal, the apparatus comprising:

• an encoder to encode service data;
• an signaling encoder to encode transmission parameter data;
• a modulator to modulate the encoded service data and the encoded transmission parameter data, wherein the encoded service data and the encoded transmission parameter data are included in a data unit, the data unit including one or more data blocks;
• and
• a transmitter to transmit the broadcast signal including the modulated service data and the modulated transmission parameter data,
• wherein the data unit includes a variable number of data symbols having service data,
• wherein the data unit includes scattered known data in the data symbols,
• wherein the transmission parameter data includes information for the number of data symbols,
• wherein the scattered known data has a pattern based on a transmission mode,
• wherein the data symbols have the scattered known data based on the pattern of the scattered known data,
• wherein the scattered known data is discontinuously inserted in a data block.