Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals

A method for receiving broadcast signals, the method comprising:

• receiving the broadcast signals and demodulating the received broadcast signals by an OFDM (Orthogonal Frequency Division Multiplex) scheme, wherein the broadcast signal includes at least one signal frame, wherein each signal frame includes a preamble generated based on a zadoff-chu sequence and broadcast data carrying at least one service;
• parsing the at least one signal frame from the demodulated broadcast signals;
• time de-interleaving the broadcast data in the parsed at least one signal frame;
• MIMO (Multi-Input Multi-Output) processing the time-deinterleaved broadcast data;
• de-mapping the MIMO processed broadcast data;
• and
• decoding the de-mapped broadcast data, wherein the at least one signal frame includes emergency alert information.

An apparatus for transmitting broadcast signals, the apparatus comprising:

• an encoder to encode broadcast data carrying at least one service;
• a mapper to map the encoded broadcast data onto constellations;
• a MIMO (Multi-Input Multi-Output) processor to process the mapped broadcast data by using a MIMO scheme;
• a time interleaver to time interleave the MIMO processed broadcast data;
• a builder to build at least one signal frame including the time interleaved DP broadcast data;
• a modulator to modulate data in the built at least one signal frame by an OFDM (Orthogonal Frequency Division Multiplex) scheme, generate a preamble based on a zadoff-chu sequence and insert the generated preamble into each signal frame;
• and
• a transmitter to transmit the broadcast signals having the modulated data,
• wherein the at least one signal frame includes emergency alert information.

An apparatus for receiving broadcast signals, the apparatus comprising:

• a receiver to receive the broadcast signals;
• a demodulator to demodulate the received broadcast signals by an OFDM (Orthogonal Frequency Division Multiplex) scheme, wherein the broadcast signal includes at least one signal frame, wherein each signal frame includes a preamble generated based on a zadoff-chu sequence and broadcast data carrying at least one service;
• a parser to parse the at least one signal frame from the demodulated broadcast signals;
• a time de-interleaver to time de-interleave the broadcast data in the parsed at least one signal frame;
• a MIMO (Multi-Input Multi-Output) processor to process the time de-interleaved broadcast data by using a MIMO scheme;
• a de-mapper to de-map the MIMO processed broadcast data;
• and
• a decoder to decode the de-mapped broadcast data, wherein the at least one signal frame includes emergency alert information.