According to one embodiment, a transmitter for transmitting at least one broadcast signal having PLP (Physical Layer Pipe) data includes: a BCH (Bose-Chadhuri-Hocquenghem) encoder configured to BCH encode the PLP data; an LDPC (Low Density Parity Check) encoder configured to LDPC encode the BCH encoded PLP data and output FECFrames (Forward Error Correction Frames); a mapper configured to map data in the FECFrames onto constellations by QAM (Quadrature Amplitude Modulation) schemes; a time-interleaver configured to time-interleave the mapped data; a frame builder configured to build a signal frame including preamble symbols and data symbols; and an OFDM (Orthogonal Frequency Division Multiplexing) modulator configured to modulate data in the signal frame by an OFDM scheme. The PLP data are processed by an LDPC scheme for a long or a short LDPC FECframe. The preamble symbols include signaling information for the time-interleaved PLP data. The data symbols include the time-interleaved PLP data.