TECHNICAL FIELD

The present invention relates to broadcast signal transmission/reception technology that is used in a broadcasting system and, more particularly, to a broadcast signal transmission/reception system that transmits/receives the broadcast signal using a frame including signaling fields such as a bootstrap or a preamble.

BACKGROUND ART

Bit-Interleaved Coded Modulation (BICM) is bandwidth-efficient transmission technology, and is implemented in such a manner that an error-correction coder, a bit-by-bit interleaver and a high-order modulator are combined with one another.

BICM can provide excellent performance using a simple structure because it uses a low-density parity check (LDPC) coder or a Turbo coder as the error-correction coder. Furthermore, BICM can provide high-level flexibility because it can select modulation order and the length and code rate of an error correction code in various forms. Due to these advantages, BICM has been used in broadcasting standards, such as DVB-T2 and DVB-NGH, and has a strong possibility of being used in other next-generation broadcasting systems.

Such BICM may be used not only for the transmission of data but also for the transmission of signaling information. In particular, channel encoding and modulation techniques for the transmission of signaling information need to be more robust than channel encoding and modulation techniques for the transmission of data.

Moreover, it is very important to effectively signal a structure of the preamble or an OFDM parameter for transmitting signaling information in the broadcasting telecommunication system and may determine the whole efficiency of the broadcasting telecommunication system.

DISCLOSURE

Technical Problem

An object of the present invention is to provide a new broadcast signal frame structure capable of efficiently signaling a BICM mode or an OFDM parameter of the signaling field used for transmitting signaling information in broadcast system channel.

Furthermore, an object of the present invention is to enable each service to use a proper BICM mode efficiently using signaling BICM modes which provide various SNRs.

Furthermore, an object of the present invention is to efficiently signaling a BICM mode such as constellation or a code rate, and an OFDM parameter such as a FFT size, guard interval or a pilot pattern, simultaneously.

Technical Solution

In order to accomplish the above objects, the present invention provides an apparatus for generating broadcast signal frame, including: a time interleaver configured to generate a time-interleaved signal by performing interleaving on a BICM output signal; and a frame builder configured to generate a broadcast signal frame including a bootstrap and a preamble using the time-interleaved signal.

In this case, the bootstrap may be shorter than the preamble, and have a fixed length.

In this case, the preamble may include L1-Basic and L1-Detail, and the bootstrap may include a symbol representing a structure of the L1-Basic.

In this case, the symbol may correspond to a fixed-length bit string signaling a BICM mode of the L1-Basic along with OFDM parameters of the L1-Basic.

In this case, the BICM mode may include a first mode, a second mode and a third mode for identifying QPSK and a code rate of 3/15, a fourth mode for identifying 16-NUC (Non Uniform Constellation) and a code rate of 3/15, and a fifth mode for identifying 64-NUC (Non Uniform Constellation) and a code rate of 3/15.

In this case, the first, second and third mode may use the same constellation and code rate, and correspond to various modes on parity repetition and parity puncturing sizes for different robustness.

In this case, the first mode may correspond to a mode in which the parity repetition is performed, and the second and third modes may correspond to a mode in which the parity repetition is not performed.

In this case, the parity puncturing size of the second mode may be larger than the parity puncturing size of the first mode and be smaller than the parity puncturing size of the third mode.

In this case, the symbol may correspond to a lookup table in which a preamble structure corresponding to a second guard interval length is allocated prior to a preamble structure corresponding to a first guard interval length, the second guard interval length being shorter than the first guard interval length when the FFT sizes corresponding to the OFDM parameters are the same.

In this case, the symbol may correspond to a lookup table in which the first mode, the second mode, the third mode, the fourth mode and the fifth mode are allocated in an order of robustness for the same combination of a FFT size, a guard interval length and a pilot pattern.

Furthermore, an embodiment of the present invention provides a method of generating broadcast signal frame, including: generating a time-interleaved signal by performing interleaving on a BICM output signal; and generating a broadcast signal frame including a bootstrap and a preamble using the time-interleaved signal.

In this case, the bootstrap may be shorter than the preamble, and have a fixed-length.

In this case, the preamble may include L1-Basic and L1-Detail, and the bootstrap may include a symbol representing a structure of the L1-Basic.

In this case, the symbol may correspond to a fixed-length bit string signaling a BICM mode of the L1-Basic along with OFDM parameters of the L1-Basic.

In this case, the BICM mode may include a first mode, a second mode and a third mode for identifying QPSK and a code rate of 3/15, a fourth mode for identifying 16-NUC (Non Uniform Constellation) and a code rate of 3/15, and a fifth mode for identifying 64-NUC (Non Uniform Constellation) and a code rate of 3/15.

In this case, the first, second and third mode may use the same constellation and code rate, and correspond to various modes on parity repetition and parity puncturing sizes for different robustness.

In this case, the first mode may correspond to a mode in which the parity repetition is performed, and the second and third modes may correspond to a mode in which the parity repetition is not performed.

In this case, the parity puncturing size of the second mode may be larger than the parity puncturing size of the first mode and be smaller than the parity puncturing size of the third mode.

In this case, the symbol may correspond to a lookup table in which a preamble structure corresponding to a second guard interval length is allocated prior to a preamble structure corresponding to a first guard interval length, the second guard interval length being shorter than the first guard interval length when the FFT sizes corresponding to the OFDM parameters are the same.

In this case, the symbol may correspond to a lookup table in which the first mode, the second mode, the third mode, the fourth mode and the fifth mode are allocated in an order of robustness for the same combination of a FFT size, a guard interval length and a pilot pattern.

Advantageous Effects

According to the present invention, a new broadcast signal frame structure capable of efficiently signaling a BICM mode or an OFDM parameter of the signaling field used for transmitting signaling information in broadcast system channel is provided.

Furthermore, according to the present invention, each service can use a proper BICM mode efficiently using signaling BICM modes which provide various SNRs.

Furthermore, according to the present invention, a BICM mode such as constellation or a code rate, and an OFDM parameter such as a FFT size, guard interval or a pilot pattern, can efficiently be signaled simultaneously.

