A signal multiplexing apparatus and method using layered division multiplexing are disclosed. A signal multiplexing apparatus according to an embodiment of the present invention includes a combiner configured to generate a multiplexed signal by combining a core layer signal and an enhanced layer signal at different power levels; a power normalizer configured to reduce the power of the multiplexed signal to a power level corresponding to the core layer signal; a time interleaver configured to generate a time-interleaved signal by performing interleaving that is applied to both the core layer signal and the enhanced layer signal; and a frame builder configured to generate a broadcast signal frame using the time-interleaved signal and L1 signaling information.

A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode input bits to generate an LDPC codeword including the input bits and parity bits to be transmitted in a current frame; a parity permutator configured to perform by group-wise interleaving a plurality of bit groups configuring the parity bits based on a group-wise interleaving pattern comprising a first pattern and a second pattern; a puncturer configured to puncture some of the parity-permutated parity bits; and an additional parity generator configured to select at least some of the punctured parity bits to generate additional parity bits to be transmitted in a previous frame of the current frame, based on the first pattern and the second pattern.

Disclosed are a broadcast signal transmitter, a broadcast signal receiver, and a method for transceiving a broadcast signal in the broadcast signal transmitter/receiver. A method for transmitting a broadcast signal comprises the following steps: signaling in-band signaling information to at least one of a service component physical layer pipe (PLP) including at least one service component of a broadcast service, a first information PLP including first service information applied to one broadcast service and a second information PLP including second service information applied commonly to a variety of broadcast services; performing the FEC encoding on data included in each PLP; performing time-interleaving on the FEC encoded data; generating a transmission frame including the time-interleaved data; and modulating the transmission frame and transmitting a broadcast signal including the modulated transmission frame.

A digital television (DTV) receiving system includes an information detector, a resampler, a timing recovery unit, and a carrier recovery unit. The information detector detects a known data sequence which is periodically inserted in a digital television (DTV) signal received from a DTV transmitting system. The resampler resamples the DTV signal at a predetermined resampling rate. The timing recovery unit performs timing recovery on the DTV signal by detecting a timing error from the resampled DTV signal using the detected known data sequence. The carrier recovery unit performs carrier recovery on the resampled DTV signal by estimating a frequency offset value of the resampled DTV signal using the detected known data sequence.

A bit interleaving method involves applying a bit permutation process to a QC LDPC codeword made up of N cyclic blocks each including Q bits, and dividing the codeword, after the bit permutation process, into a plurality of constellation words each imade up of M bits, the codeword being divided into N/M sections, each constellation word being associated with one of the N/M sections, and the bit permutation process being performed such that each of the constellation words includes one bit from each of M different cyclic blocks associated with a given section.

A method for transmitting broadcast signals by an apparatus for transmitting broadcast signals, the method includes encoding service data according to a 16200 bit codeword and a 11/15 code rate based on addresses in a parity check matrix, wherein the encoded service data comprises information bits and parity bits; building at least one signal frame by mapping the encoded service data; modulating data in the built signal frame by an Orthogonal Frequency Division Multiplexing (OFDM) scheme; and transmitting broadcast signals having the modulated data, wherein the encoding of the service data comprises: initializing the parity bits, adding the information bits to the parity bits of which addresses are based on values of entries in each row of the parity check matrix, wherein a row of the parity check matrix corresponds to a 360 bit group of the information bits.

A method pertaining to optimization of resource unit (RU) and segment parser design for aggregated and multi-RU operations in extreme high-throughput (EHT) systems involves coding data for a station (STA) to provide a stream of coded bits. The method also involves processing the stream of coded bits to provide processed bits, including parsing the stream of coded bits to a combination of multiple RUs assigned to the STA in a proportional round-robin fashion. The method further involves transmitting the processed bits to the STA over the combination of multiple RUs.

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 communication device that applies an error in an upper layer in addition to error correction in a physical layer is provided. The communication device includes an acquisition unit that acquires control information regarding forward error correction (FEC) of an upper layer and control information regarding FEC of a lower layer, an encoding-decoding unit that performs error correction encoding or decoding of an information sequence in the upper layer according to control information regarding the FEC of the upper layer, and a puncturing processing unit that performs puncturing or depuncturing in the upper layer. The information sequence after FEC encoding of the upper layer is divided into blocks, and puncturing and interleaving are performed in units of blocks.

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.