A modulator and a modulation method using a non-uniform 16-symbol signal constellation are disclosed. The modulator includes a memory and a processor. The memory receives a codeword corresponding to a low-density parity check (LDPC) code having a code rate of 4/15. The processor maps the codeword to 16 symbols of the non-uniform 16-symbol signal constellation on a 4-bit basis.

An interleaving and mapping method and a deinterleaving and demapping method for an LDPC codeword are provided. The interleaving and mapping method comprises: performing first bit interleaving on a check part of the LDPC codeword to obtain a check bit stream; splicing an information bit part of the codeword and the check bit stream into a codeword after the first bit interleaving; dividing the codeword after the first bit interleaving into multiple consecutive bit subblocks in a predetermined length, and changing the order of the bit subblocks according to a corresponding permutation order (bit-swapping pattern) to form a codeword after second bit interleaving; dividing the codeword after the second bit interleaving into two parts, and writing the two parts into storage space in a column order respectively and reading the two parts from the storage space in a row order respectively to obtain a codeword after third bit interleaving; and performing constellation mapping on the codeword after the third bit interleaving according to a constellation diagram to obtain a symbol stream; the permutation orders (bit-swapping patterns) and the constellation diagrams used in the interleaving and mapping processing of LDPC codes with different code rates, code length and LDPC code tables are designed and optimized using theoretical analysis. The technical solution reduces the receiving threshold of the receiving end.

The present technology relates to a data processing device and a data processing method which can ensure high communication quality in data transmission using LDPC codes.

In group-wise interleaving, an LDPC code having a code length N of 64800 bits and a coding rate r of 13/15 is interleaved in a unit of a bit group of 360 bits. In group-wise deinterleaving, a sequence of bit groups of the LDPC code which has been subjected to the group-wise interleaving is returned to an original sequence. The present technology can be applied to, for example, a case in which data transmission is performed using LDPC codes.

A low density parity check (LDPC) encoder, an LDPC decoder, and an LDPC encoding method are disclosed. The LDPC encoder includes first memory, second memory, and a processor. The first memory stores an LDPC codeword having a length of 64800 and a code rate of 7/15. The second memory is initialized to 0. The processor generates the LDPC codeword corresponding to information bits by performing accumulation with respect to the second memory using a sequence corresponding to a parity check matrix (PCM).

A method and apparatus are presented for transmitting broadcast signals. Service data is encoded by an encoder. A signaling encoder encodes signaling data based on a mode of the signaling data. The signaling data is categorized to one of plural modes based on a modulation order for the signaling data. A frame builder builds at least one signal frame including the encoded service data in at least one data symbol and the encoded signaling data in at least one signaling symbol. A modulator modulates data in the at least one signal frame by an Orthogonal Frequency Division Multiplex (OFDM) scheme. A transmitter transmits the broadcast signals carrying the modulated data in the at least one signal frame. The broadcast signals further carry a bootstrap. The bootstrap includes category information indicating the mode of the signaling data in the at least one signaling symbol in the at least one signal frame.

A transmitting apparatus is provided. The transmitting apparatus includes: an encoder configured to generate a low-density parity check (LDPC) codeword by LDPC encoding based on a parity check matrix; an interleaver configured to interleave the LDPC codeword; and a modulator configured to map the interleaved LDPC codeword onto a modulation symbol, wherein the modulator is further configured to map a bit included in a predetermined bit group from among a plurality of bit groups constituting the LDPC codeword onto a predetermined bit of the modulation symbol.

The present technology relates to a data processing device and a data processing method capable of securing excellent communication quality in data transmission using an LDPC code. In group-wise interleave, an LDPC code having a code length N of 64800 bits and a coding rate r of 9/15, 11/15, or 13/15 is interleaved in units of bit groups of 360 bits. In group-wise deinterleave, a sequence of LDPC codes after the group-wise interleave is returned to an original sequence. The present technology, for example, can be applied to a case where data transmission using an LDPC code or the like is performed.

A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder which encodes input bits including outer encoded bits to generate an LDPC codeword including the input bits and parity bits to be transmitted to a receiver in a current frame; a puncturer which punctures a part of the parity bits which is not transmitted in the current frame; and an additional parity generator which selects at least a part of the parity bits to generate additional parity bits transmitted to the receiver in a previous frame of the current frame, wherein a number of the additional parity bits is determined based on a number of the outer encoded bits and a number of the parity bits left after the puncturing.

A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode input bits to generate parity bits; a parity permutator configured to group-wise interleave a plurality of bit groups including the parity bits; and a puncturer configured to select some of the parity bits in the group-wise interleaved bit groups and puncture the selected parity bits, wherein the parity permutator group-wise interleaves the bit groups such that some of the bit groups at predetermined positions in the bit groups before the group-wise interleaving are positioned serially after the group-wise interleaving and a remainder of the bit groups before the group-wise interleaving are positioned without an order after the group-wise interleaving so that the puncturer selects parity bits included in the some of the bit groups sequentially and selects parity bits included in the remainder of the bit groups without an order.

The present technology relates to a transmission device, a transmission method, a reception device, and a reception method for securing good communication quality in data transmission using an LDPC code. The LDPC coding is performed on the basis of the parity check matrix of the LDPC code with the code length N of 17280 bits and the coding rate r of 5/16, 6/16, or 7/16. The parity check matrix includes an A matrix of M1 rows and K columns expressed by a predetermined value M1 and an information length K=N×r of the LDPC code, a B matrix of M1 rows and M1 columns having a step structure, a Z matrix being a zero matrix of M1 rows and N−K−M1 columns, a C matrix of N−K−M1 rows and K+M1 columns, and a D matrix being an identity matrix of N−K−M1 rows and N−K−M1 columns. The A matrix and the C matrix are represented by a parity check matrix initial value table, and the parity check matrix initial value table is a table representing positions of elements of 1 of the A matrix and the C matrix for every 360 columns. The present technology can be applied to, for example, data transmission using an LDPC code.