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.

In a transmitting device, in interchanging to interchange a code bit of an LDPC code in which a code length is 16200 bits and an encoding rate is 7/15 with a symbol bit of a symbol corresponding to any of 8 signal points defined by 8PSK, when 3 bits of code bits stored in three units of storages having a storage capacity of 16200/3 bits and read bit by bit from the units of storages are allocated to one symbol, a bit b0, a bit b1, and a bit b2 are interchanged with a bit y1, a bit y0, and a bit y2, respectively. A position of the interchanged code bit obtained from data transmitted from the transmitting device is returned to an original position. The present technology is applicable to a case of transmitting data using an LDPC code, for example.

A transmitting apparatus is disclosed. The transmitting apparatus includes an encoder to perform channel encoding with respect to bits and generate a codeword, an interleaver to interleave the codeword, and a modulator to map the interleaved codeword onto a non-uniform constellation according to a modulation scheme, and the constellation may include constellation points defined based on various tables according to the modulation scheme.

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.

An FEC coder in a transmission device according to an exemplary embodiment of the present disclosure performs BCH coding and LDPC coding based on whether a code length of the LDPC coding is a 16k mode or a 64k mode. A mapper performs mapping in an I-Q coordinate to perform conversion into an FEC block, and outputs pieces of mapping data (cells). The mapper defines different non-uniform mapping patterns with respect to different code lengths even an identical coding rate is used by the FEC coder. This configuration improves a shaping gain for different error correction code lengths in a transmission technology in which modulation of the non-uniform mapping pattern is used.

A transmitting apparatus is disclosed. The transmitting apparatus includes an encoder to perform channel encoding with respect to bits and generate a codeword, an interleaver to interleave the codeword, and a modulator to map the interleaved codeword onto a non-uniform constellation according to a modulation scheme, and the constellation may include constellation points defined based on various tables according to the modulation scheme.

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, a receiving apparatus and methods of controlling these apparatuses are provided. The transmitting apparatus includes: a baseband packet generator configured to, based on an input stream including a first type stream and a second type stream, generate a baseband packet including a header and payload data corresponding to the first type stream; a frame generator configured to generate a frame including the baseband packet; a signal processor configured to perform signal-processing on the generated frame; and a transmitter configured to transmit the signal-processed frame, wherein the header includes a type of the payload data in the baseband packet and the number of the first type stream packets in the baseband packet.

An FEC coder in a transmission device according to an exemplary embodiment of the present disclosure performs BCH coding and LDPC coding based on whether a code length of the LDPC coding is a 16k mode or a 64k mode. A mapper performs mapping in an I-Q coordinate to perform conversion into an FEC block, and outputs pieces of mapping data (cells). The mapper defines different non-uniform mapping patterns with respect to different code lengths even an identical coding rate is used by the FEC coder. This configuration improves a shaping gain for different error correction code lengths in a transmission technology in which modulation of the non-uniform mapping pattern is used.

A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit.