Various implementations described herein are directed to a memory device. The memory device may include a first interleaving circuit that receives data words and generates a first error correction code based on the received data words. The memory device may include a second interleaving circuit that receives the data words and generates a second error correction code based on the received data words as a complement to the first error correction code. The second interleaving circuit may interleave data bits from multiple different data words and store modified data words based on the multiple different data words.

The present invention provides an apparatus of transmitting broadcast signals, the apparatus including, an encoder for encoding service data, a frame builder for building at least one signal frame by mapping the encoded service data, a modulator for modulating data in the built at least one signal frame by an Orthogonal Frequency Division Multiplexing, OFDM, scheme and a transmitter for transmitting the broadcast signals having the modulated data.

Aspects of the disclosure provide a method for polar code puncturing. The method can include receiving a mother polar code including a sequence of coded bits, the sequence of coded bits having indices {0, . . . , N−1} and including at least a first block of coded bits having indices {0, . . . , i−1}, a second block of coded bits having indices {i, . . . , i+k−1}, a third block of coded bits having indices {i+k, i+k+k−1}, interleaving the second block of coded bits with the third block of coded bits to form a rearranged sequence of coded bits including the N coded bits, and extracting the last M coded bits from the rearranged sequence of coded bits to generate a punctured code having a length of M.

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.

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

The present invention provides a method of transmitting broadcast signals. The method includes, formatting input streams into Data Pipe (DP) data, Low-Density Parity-Check (LDPC) encoding the DP data according to a code rate, bit interleaving the LDPC encoded DP data, mapping the bit interleaved DP data onto constellations, building at least one signal frame including the mapped DP data, and modulating data in the built signal frame by an Orthogonal Frequency Division Multiplexing (OFDM) method and transmitting the broadcast signals having the modulated data, wherein the input streams include Audio/Video (A/V) data and service guide data, and wherein the Audio/Video (A/V) data and service guide data are included in first ISO base media file format (ISOBMFF) files.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 16200 and a code rate of 4/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for 64-symbol mapping.

A transmission device and reception device for digital data that have excellent resistance to noise are provided. An encoder (11-1) of this disclosure, included in a transmission device (1) of this disclosure, applies LDPC encoding to digital data using a unique check matrix for each code rate by using a check matrix in which, taking a check matrix initial value table established in advance for each code rate at a code length of 44880 bits as initial values, 1 entries of a partial matrix corresponding to an information length appropriate for a code rate of 93/120 are allocated in the column direction over a cycle of 374 columns. A demodulator (23) of this disclosure, included in a reception device (2) of this disclosure, decodes digital data encoded by the encoder (11-1).

A bit interleaving method involves applying a bit permutation process to bits of a QC-LDPC codeword made up of N cyclic blocks each including Q bits, and dividing the codeword after the permutation process into a plurality of constellation words each including M bits, the codeword being divided into F×N′/M folding sections (N′ being a subset of N selected cyclic blocks and being a multiple of M/F), each of the constellation words being associated with one of the F×N′/M folding sections, and the bit permutation process being applied such that each of the constellation words includes F bits from each of M/F different cyclic blocks in a given folding section associated with a given constellation word.

A polar code transmission method and apparatus, the method including performing, by a transmit end, polar code encoding on at least one of to-be-encoded bit sequences U to generate an encoded sequence, wherein a length of U is N, and scrambling and interleaving, by the transmit end, the encoded sequence by using a scrambling sequence S.sub.X and an interleaving matrix P.sub.X.