Apparatus and method for sending and receiving broadcast signals

A broadcast signal receiver, comprising:

• a demodulator to demodulate a broadcast signal;
• a pilot detector to detect pilots from the broadcast signal;
• a de-framer to de-frame a signal frame of the broadcast signal and to extract Physical Layer Pipe (PLP) data, the signal frame comprising a preamble and at least one subframe;
• wherein the subframe comprises data symbols and at least one Subframe Boundary Symbol (SBS), the data symbols comprising Scattered Pilots (SPs), and the SBS comprises data cells and subframe boundary pilots,
• the data cells of the SBS comprise active data cells and null cells,
• the active data cells are at a center and each half of the null cells are at each band edge within data carrier indices, and the de-framer determining
• a number of the active data cells of the SBS for an Fast Fourier Transform (FFT) size and an SP pattern is determined based on a coefficient to control a number of carriers and an SP boosting parameter for a boosted power level of the SPs;
• a de-interleaver configured to bit de-interleave the PLP data;
• and
• a decoder configured to decode the PLP data.

A method for receiving a broadcast signal, comprising:

• demodulating the broadcast signal;
• detecting pilots from the broadcast signal;
• de-framing a signal frame of the broadcast signal and extracting Physical Layer Pipe (PLP) data, the signal frame comprising a preamble and at least one subframe;
• the subframe comprises data symbols and at least one Subframe Boundary Symbol (SBS), the data symbols comprising Scattered Pilots (SPs), and the SBS comprises data cells and subframe boundary pilots,
• the data cells of the SBS comprise active data cells and null cells,
• the active data cells are at a center and each half of the null cells are at each band edge within data carrier indices, and the de-framing includes determining
• a number of the active data cells of the SBS for an Fast Fourier Transform (FFT) size and an SP pattern is determined based on a coefficient to control a number of carriers and an SP boosting parameter for a boosted power level of the SPs;
• bit de-interleaving the PLP data, and
• decoding the PLP data.