A channel encoding method in a communication or broadcasting system is provided. The channel encoding method includes reading a first sequence corresponding to a parity check matrix, converting the first sequence to a second sequence by applying a certain rule to a block size corresponding to a parity check matrix and the first sequence, and encoding information bits based on the second sequence. The block size has at least two different integer values.

A descrambler receives data from a memory device. The descrambler calculates a sub-syndrome weight for multiple bits in each of the plurality of descrambled sequences using a set parity check matrix to generate multiple sub-syndrome weights, one for each of the plurality of descrambled sequences. The descrambler selects a sub-syndrome weight among the multiple sub-syndrome weights. The descrambler determines, as a correct scrambler sequence for descrambling the data, a scrambler sequence corresponding to the selected sub-syndrome weight, among the plurality of scrambler sequences.

A transmitting system, receiving system, and a method of processing broadcast signals are disclosed. The method for processing a broadcast signal in a broadcast receiver comprises receiving a DTV signal including a data group, the data group including mobile service data, segmented known data sequences, long known data sequences and transmission parameter data, compensating carrier frequency offset of the DTV signal and channel-equalizing the carrier frequency offset compensated DTV signal using at least one of the long known data sequences and segmented known data sequences in the data group of the DTV signal, wherein the channel-equalizing includes performing a Error Correction (FEC) decoding on data located between the segmented known data sequences, and estimating Channel Impulse Response (CIR) using the FEC decoded data as known data.

[Problem] Encoding and decoding techniques capable of speeding up an error-correction decoding process utilizing channel polarization are provided. [Solution] In an encoding device, the information bit sequence is input on division for each designated bit length; error-correction encoding is performed on an information block of the designated bit length to generate L M-bit codes, each M-bit code having a predetermined bit length M; the L M-bit codes are converted into M L-bit blocks each having a predetermined bit length of L; the M L-bit blocks are Polar-converted to M L-bit codes, each L-bit code having a bit length of L, through channel polarization processing; and division of the information bit sequence is determined based on channel polarization information.

A Viterbi traceback processing method, system, and apparatus are provided wherein a first Viterbi traceback processing operation (MUX 514) is performed on a first survivor path metric (TMV1) by selecting, in response to a back track state (INDEX 0), a first output data bit (Ti1) for the first survivor path metric, wherein a plurality of Viterbi traceback processing operations (MUX 512, 513) are performed on respective portions of an additional survivor path metric (TMV2A, TMV2B) by selecting, in response to a shifted back track state (INDEX 1), candidate data bits (Tn1, Tn2) for the additional survivor path metric, wherein a multiplexer (MUX 518) controlled by the first output data bit selects between the candidate data bits to generate an additional output data bit (Ti2) for the additional survivor path metric such that the Viterbi traceback processing operations are performed in parallel to produce the output data bits.

A channel encoding method in a communication or broadcasting system is provided. The channel encoding method includes reading a first sequence corresponding to a parity check matrix, converting the first sequence to a second sequence by applying a certain rule to a block size corresponding to a parity check matrix and the first sequence, and encoding information bits based on the second sequence. The block size has at least two different integer values.

Provided are a transmitter and a method for transmitting a data block in a wireless communication system. The method comprises the following steps: deciding the number of bits (s) and encoders (N.sub.ES) to allocate to one axis of a signal constellation; encoding an information bit based on the s and the N.sub.ES and generating a coded block; parsing the coded block based on the s and the N.sub.ES and generating a plurality of frequency sub-blocks; and transmitting the plurality of frequency sub-blocks to a receiver.

A channel encoding method in a communication or broadcasting system is provided. The channel encoding method includes reading a first sequence corresponding to a parity check matrix, converting the first sequence to a second sequence by applying a certain rule to a block size corresponding to a parity check matrix and the first sequence, and encoding information bits based on the second sequence. The block size has at least two different integer values.

A digital system, components and method are configured with nonvolatile memory for storing digital data using codewords. The data is stored in the memory using multiple bits per memory cell of the memory. A code efficiency, for purposes of write operations and read operations relating to the memory, can be changed on a codeword to codeword basis based on input parameters. The code efficiency can change based on changing any one of the input parameters including bit density that is stored by the memory. Storing and reading fractional bit densities is described.

Techniques are presented for mapping a digital data sequence into a signal point sequence for transmission. The signal point sequence belongs to a set of possible signal point sequences. In one example, a digital data sequence is received. Forbidden branch flags that forbid certain signal points in the possible signal points sequences are applied. The signal point sequence is selected from a subset of all the possible signal point sequences based on the digital data sequence. The subset is defined by the forbidden branch flags.