438results about "Checking code calculations" patented technology

A channel has a first and a second end. The first end of the channel is coupled to a transmitter. The channel is capable of transmitting symbols selected from a symbol set from the first end to the second end. The channel exhibits incomplete error introduction properties. A code comprises a set of code words. The elements of the set of code words are one or more code symbols long. The code symbols are members of the symbol set. The minimum modified Hamming separation between the elements of the set of code words in light of the error introduction properties of the channel is greater than the minimum Hamming distance between the elements of the set of code words. A memory device, a method of using the channel, and a method of generating the code are also described.

The present invention relates to a method for reducing data loss comprising a first computing step for computing an intermediate result for each redundancy information entity of a redundancy set by processing respectively associated data information entities of a given data set on at least two main diagonals of a parity check matrix representing an error correction coding scheme. The method further comprises a second computing step for computing the information content of the respective redundancy information entity dependent on the respective intermediate result.

A digital television transmitting system includes a frame encoder, a block processor, a group formatter, and a multiplexer. The frame encoder forms an enhanced data frame and encodes the data frame for error correction and for error detection. The block processor further encodes the encoded data frame at a rate of ½ or ¼, and the group formatter divides the encoded data frame into a plurality of enhanced data blocks and maps the divided data blocks into a plurality of enhanced data groups, respectively. The multiplexer multiplexes the enhanced data groups with main data.

In one embodiment, the present patent application comprises a method and apparatus to generate low rate protographs from high rate protographs, comprising copying a base graph; permuting end points of edges of a same type in copies of the base graph to produce a permuted graph; and pruning systematic input nodes in the permuted graph and the edges connected to them. In another embodiment, the present patent application comprises a method and apparatus to generate high-rate codes from low-rate codes, comprising puncturing a subset of codeword bits, wherein the step of puncturing a subset of codeword bits comprises regular-irregular puncturing the subset of codeword bits, random puncturing variable nodes, or progressive node puncturing variable nodes to obtain a desired code from a preceding code.

A method constructs a code, wherein the code is a large-girth quasi-cyclic low-density parity-check code. A base matrix is selected for the code. A cost matrix corresponding to the base matrix is determined. A single element in the base is changed repeatedly maximize a reduction in cost. A parity check matrix is constructing for the code from the base matrix when the cost is zero, and an information block is encoded as a code word using the parity check matrix in an encoder.