An apparatus for generating a broadcast signal frame, comprising a core layer bit-interleaved coded modulation, BICM, unit configured to perform bit-interleaved coded modulation, BICM, on a core layer signal; an enhanced layer bit-interleaved coded modulation, BICM, unit configured to perform bit-interleaved coded modulation, BICM, on an enhanced layer signal; an injection level controller configured to generate a power-reduced enhanced layer signal by reducing power of the enhanced layer signal after bit-interleaved coded modulation, by a scaling factor; a combiner configured to generate a multiplexed signal by combining the core layer signal and the power-reduced enhanced layer signal after bit-interleaved coded modulation, BICM, of the core layer signal and bit-interleaved coded modulation and power reduction of the enhanced layer signal; a power normalizer configured to reduce power of the multiplexed signal to a power level corresponding to the core layer signal by applying a normalizing factor to the multiplexed signal; a time interleaver configured to generate a time-interleaved signal by performing interleaving that is applied to the multiplexed signal after power normalization; and a frame builder configured to generate a broadcast signal frame including a preamble for signaling size information of Physical Layer Pipes, PLPs, within the broadcast signal frame, wherein the apparatus is configured such that the scaling factor decreases as a power reduction of the injection level controller becomes larger, and the normalizing factor increases as the power reduction of the injection level controller becomes larger. a core layer bit-interleaved coded modulation, BICM, unit configured to perform bit-interleaved coded modulation, BICM, on a core layer signal; an enhanced layer bit-interleaved coded modulation, BICM, unit configured to perform bit-interleaved coded modulation, BICM, on an enhanced layer signal; an injection level controller configured to generate a power-reduced enhanced layer signal by reducing power of the enhanced layer signal after bit-interleaved coded modulation, by a scaling factor; a combiner configured to generate a multiplexed signal by combining the core layer signal and the power-reduced enhanced layer signal after bit-interleaved coded modulation, BICM, of the core layer signal and bit-interleaved coded modulation and power reduction of the enhanced layer signal; a power normalizer configured to reduce power of the multiplexed signal to a power level corresponding to the core layer signal by applying a normalizing factor to the multiplexed signal; a time interleaver configured to generate a time-interleaved signal by performing interleaving that is applied to the multiplexed signal after power normalization; and a frame builder configured to generate a broadcast signal frame including a preamble for signaling size information of Physical Layer Pipes, PLPs, within the broadcast signal frame, wherein the apparatus is configured such that the scaling factor decreases as a power reduction of the injection level controller becomes larger, and the normalizing factor increases as the power reduction of the injection level controller becomes larger.