A coding and modulation apparatus and method are presented. The apparatus (10) comprises an encoder (11) that encodes input data into cell words, and a modulator (12) that modulates said cell words into constellation values of a non-uniform constellation. The modulator (12) is configured to use, based on the total number M of constellation points of the constellation, the signal-to-noise ratio SNR in dB and the channel characteristics, a non-uniform constellation from a group of constellations comprising one or more of predetermined constellations defined by the constellation position vector u1 . . . v, wherein v=sqrt(M)/2−1.

Methods and devices provide a feedback message having unequal error protection. The feedback message may include channel quality indicators. The channel quality indicators may have different levels of error protection based on a transmission property.

A method for error tracking a log subsystem of a file system is provided. The method includes: when a data block of the log subsystem is recovered to an original position in the file system, calculating a verification code of the data block to obtain a second verification code; determining whether a verification result between the second verification code and a first verification code of the data block stored in a spare space in a submit block of the log subsystem in a disk is consistent; and when the verification result is inconsistent, processing the data block corresponding to the inconsistent verification result. With the above method, given that system performance is least affected, an error and a position of the error of the log subsystem of the file system can be more accurately detected to enhance the reliability of the log subsystem.

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.

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.

In accordance with embodiments, methods for data communications are disclosed. A device obtains a forward error correction (FEC) encoded bit stream. The device maps the FEC encoded bit stream to produce a set of symbols according to a bit-to-symbol mapping rule. The bit-to-symbol mapping rule comprises a first mapper bit position associated with a first mapper error protection level and a second mapper bit position associated with a second mapper error protection level. The first mapper error protection level is greater than the second mapper error protection level. The device then transmits the set of symbols in the communications system.

A storage aware memory controller and method for managing a physical storage system. A described controller includes: a system for mapping physical memory space into a memory region and a storage region; a system for applying different error protections schemes, in which a fine-grained memory fault tolerance scheme is applied to data in the memory region and a course-grained memory fault tolerance scheme is applied to data in the storage region; and an in-memory storage filesystem that compresses and stores individual pages of data in the storage region, wherein each page of data is compressed into a set of codewords that are codeword aligned such that no codeword shares compressed data from different pages, and wherein the in-memory storage filesystem stores a compression-aware logical block address (CA-LBA) for each page of data.

The present invention relates to data transmission/reception methods using a polar coding scheme, and devices for supporting same. The method for transmitting data by using polar coding in a wireless access system, according to one embodiment of the present invention, may comprise the steps of deriving Bhattacharyya parameters according to data bits input for finding noise-free channels among equivalent channels; allocating data payloads comprising data bits and cyclic redundancy check (CRC) bits to the found noise-free channels; inputting the data payloads into a polar encoder; and transmitting code bits output by the polar encoder, wherein the CRC bits may be allocated to better noise-free channels, among the noise-free channels indicated by the Bhattacharyya parameters, than the data bits.

In transmitter apparatus for a digital television broadcasting system, internet-protocol (IP) packets of digital television information are subjected to multilevel coding (MLC) before being Gray-mapped to quadrature-amplitude-modulation (QAM) constellations. The constituent codes of the MLC comprise respective low-density parity-check (LDPC) inner coding. Preferably, the LDPC inner coding is LDPC convolutional coding. The QAM constellations are used in coded orthogonal frequency-division modulation (COFDM) of plural carrier waves up-converted to a radio-frequency broadcast television channel. In receiver apparatus for the digital television broadcasting system the results of de-mapping QAM constellations recovered from demodulating the COFDM carrier waves are de-interleaved, and the LDPC constituent codes of the MLC are independently decoded in parallel with decoding results time-interleaved to recover the IP packets of digital television information.

A data storage device is disclosed comprising a storage medium. First data is encoded into a first codeword, and second data is encoded into a second codeword, wherein a first code rate of the first codeword is less than a second code rate of the second codeword. The first codeword and the second codeword are interleaved to generate an interleaved codeword that is written to the storage medium.