A broadcast signal transmitter is disclosed. A broadcast signal transmitter according to an embodiment of the present invention comprises an input formatting module configured to perform baseband formatting and to output at least one PLP (Physical Layer Pipe) data; a BICM (Bit Interleaved Coded Modulation) module configured to perform an error correction process on the PLP data; a framing and interleaving module configured to interleave the PLP data and to generate a signal frame; and a waveform generating module configured to generate a broadcast signal by inserting a preamble into the signal frame and performing OFDM modulation.