Abstract:
A method and apparatus to reproduce and/or record data from and/or to an optical recording medium. The method includes detecting a wobble signal from the optical recording medium, predicting a wobble channel state from the detected wobble signal, detecting an information signal from the optical recording medium, predicting an information channel state from the detected information signal. If a damaged section is discovered from the optical recording medium, the information signal is decoded based on the information on the wobble channel state or the information on the information channel state. Accordingly, data can be reproduced more effectively by predicting a channel state of an information (RF) signal and a channel state of a wobble signal.
Abstract:
An apparatus and method for constructing a low density parity check matrix. A p-th positive-shift block is generated by shifting all elements of an identity matrix p times to the right; a p-th negative-shift block is generated by shifting all elements of the identity matrix p times to the left; and one or more pairs of different p-th positive- and negative-shift blocks symmetrically arranged in the vertical direction are horizontally arranged.
Abstract:
The present invention relates to a method of independently generating row parity information and column parity information in an encoding process using a low density parity check (LDPC) matrix. The method comprises: generating code word vectors by generating column parity information using a parity check matrix and message information; selecting code word bits for generating row parity information among code word bits in the generated code word vectors; and generating the row parity information using the selected code word bits, wherein the selecting of the code word bits comprises: excluding code word bits related to the generation of other row parity information. Accordingly, independent parity information can be generated by generating row parity information on the basis of code word bits without related to generation of column parity information.
Abstract:
A method of improving the error correcting performance using low-density parity check (LDPC) encoding includes, making an LDPC matrix by arranging non-zero matrices in a series of blockwise columns not to overlap with one another, making at least one LDPC codeword block by generating parity information based on the LDPC matrix, making an error correcting block by accumulating the LDPC codeword block, and interleaving the error correcting block. Accordingly, it is possible to improve the burst error correcting performance in a communications/high-density recording medium system.
Abstract:
A technique for sensor network, Machine to Machine (M2M), Machine Type Communication (MTC), Internet of Things (IoT) is provided. The present disclosure can be applied to intelligent services (smart homes, smart buildings, smart cities, smart cars or connected cars, health care, digital education, retail, security and safety service) based on the technique. A method for operating a user equipment (UE) is provided. The method includes receiving a first signal comprising a first category identification (ID) and a first unique ID from a first beacon device, determining a distance from the first beacon device based on the first signal, if the distance is below a threshold, registering the first category ID, and if a second signal comprising the registered first category ID from a second beacon device, displaying information corresponding to a second unique ID of the second signal.
Abstract:
Provided are a wearable display device and a light guide element thereof, the display device including: a display element configured to project a first light forming a virtual image; and a light guide element configured to guide the first light from the display element and a second light input from outside of the wearable display device to a predetermined position. The light guide element includes: a first optical surface facing the display element; a second optical surface and a third optical surface configured to reflect the first light input through the first optical surface; and a fourth optical surface configured to reflect the reflected first light to the predetermined position. The first to third optical surfaces are flat surfaces, and the fourth optical surface is a rotationally asymmetric reflective surface.
Abstract:
An iterative decoding apparatus includes a channel detection unit receiving an input signal derived from an output signal of a channel and detecting a channel signal from the input signal by using a soft value; a channel decoding unit receiving the detected channel signal from the channel detection unit and decoding the detected channel signal by using a soft value; a pseudo-channel block unit receiving the decoded channel signal from the channel decoding unit and adding a channel effect to the decoded channel signal to obtain a channel-effect-added signal; and a signal mixing unit mixing the channel-effect-added signal from the pseudo-channel block unit with the output signal of the channel to obtain the input signal and providing the input signal to the channel detection unit.
Abstract:
A method of and an apparatus for generating a block-based low density parity check (LDPC) matrix, where calculation of an inverse matrix is not necessary and back-substitution is possible over the entire matrix area, and a recording medium having recorded thereon code for implementing the method. An area of the LDPC matrix is vertically divided based on respective lengths of first and second parity bit vectors and, a block-based matrix is generated such that a double diagonal matrix is arranged in an upper portion of an area corresponding to the second parity bit vector among areas into which the LDPC matrix is vertically divided., The area of the LDPC matrix is horizontally divided based on a position of the double diagonal matrix, and block-based matrices are generated in the divided areas of the LDPC matrix, to satisfy a condition that column weights (Wc) are uniform.
Abstract:
The present invention relates to an error correction method and apparatus for determining whether an error exists in a decoded binary signal and correcting the error if the error exists in a decoding apparatus using a low density parity check (LDPC). The method comprises: generating a resultant matrix (m*1) by performing an XOR operation and a modular 2 operation with respect to an LDPC matrix (m*n) and a code word vector (n*1); determining whether a decoding of the code word vector succeeded on the basis of the resultant matrix; and if it is determined that the decoding failed, detecting a code word bit, in which an error is generated, in the code word vector on the basis of correlations of components of the LDPC matrix, code word vector, and resultant matrix. Accordingly, the decoding apparatus using the LDPC can prevent a small number of errors from causing a total block to be determined as a decoding failure and correct an error when it is determined that only one bit error exists.