104results about "Error coding/decoding sychronisation" patented technology

An approach is provided for supporting signal acquisition and frame synchronization in a digital broadcast system utilizing Low Density Parity Check (LDPC) codes. Hierarchical modulation is utilized to provide backward compatibility, whereby the lower layer signal is encoded using LDPC coding. A signal is received, whereby the signal is modulated according to the hierarchical modulation scheme including an upper layer and a lower layer. The signal includes a data pattern and a coded frame. The dependency of the received signal on the upper layer modulation is removed. The modulation removed signal is correlated with multiple predetermined data patterns to determine the data pattern of the signal. The code rate of the coded frame is derived based on the determined data pattern. The above arrangement is particularly suited to a digital satellite broadcast system.

Various embodiments of the present invention provide systems and methods for identifying a reproducible location on a storage medium. As an example, a circuit is discussed that includes a data storage circuit, a pattern comparison circuit, and a threshold comparison circuit. The data storage circuit is operable to store a first set of data samples corresponding to a region of interest. The pattern comparison circuit is operable to compare a subset of the first set of data samples with a subset of a second set of data samples corresponding to the region of interest. The pattern comparison circuit is operable to yield a match value corresponding to a degree of similarity between the first set of data samples with the subset of a second set of data samples. The threshold comparison circuit is operable to indicate an anchor point based at least in part on the magnitude of the match value relative to a threshold value.

An enhanced forward error correction system is disclosed. Transmitted data is encoded into codewords in multiple dimensions. The decoding of received data by a decoder is performed in multiple passes in each dimension, with corrected data provided as an output from each pass into another decoder for the next decode pass. The encoder in one embodiment comprises a parallel inner RS(247,239) encoder or encoders and parallel outer BCH(255,247) encoder or encoders. Additional steps are added for error multiplication reduction. The system provides an approach to detect generally uncorrectable patterns for concatenated codes and provides a correction mechanism for improving error correction performance.

A system, method and computer software product are provided. One embodiment of the present invention provides a method for generating and employing numerical sequences that may be used for synchronization codes. In one embodiment of the present invention, the derivation of numerical sequences, or codes is based on an encoding algorithm. These codes enable synchronization between communicating devices, and may also be used for channelization. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

An FEC multiplexing circuit (2) has a configuration in which a first memory circuit (15) is arranged on the input stage of a first RS encoding circuit (16), a second memory circuit (17) is arranged on the input stage of a second RS encoding circuit (18), error correction encoding is performed by a combination of different data having two directions, and thereafter, error correction codes are multiplexed to generate an FEC frame. On the other hand, an FEC demultiplexing circuit (6) has a configuration in which a third memory circuit (42) is arranged on the output stage of a first RS decoding circuit (41), a fourth memory circuit (44) is arranged on the output stage of a second RS decoding circuit (43), error correction is performed by a combination of different data having two directions, and, thereafter, parallel data read from the fourth memory circuit (44) are multiplexed to reproduce original information data.

Synchronization errors in a received pulse train are detected by detecting rising or falling transitions in the pulse train, generating numbers in a repeating cycle having a length corresponding to the pulse rate, selecting the number generated when each transition is detected, and performing a predetermined operation on the selected numbers. The predetermined operation may include, for example, comparing the average values of the selected numbers in successive groups of transitions. Alternatively, the predetermined operation may include taking a difference between consecutively selected numbers to measure pulse widths in the pulse train. Synchronization error detection can be used to supplement data error detection and correction methods such as forward error correction and cyclic redundancy checks.

Method and system of adjusting a first phase shift between a first data signal and a clock signal at a sending device. First and second test signals representing firs and second test data, respectively, are transmitted to a receiving device. The test signals have respective phase shifts relative to the clock signal. An error detection code is calculated from first and second received data carried by the transmitted signals. The error detection code is transmitted from the receiving device to the sending device. An estimated first received data is calculated from the error detection code, wherein the estimated first received data are calculated under the assumption that the second received data are identical to the second test data. The first phase shift is adjusted on the basis of a comparison of the estimated first received data and the first test data.

The present invention discloses a frame boundary detection system and a synchronization system for a data stream received by an Ethernet Forward Error Correction layer. The frame boundary detection system includes a shifter, two descramblers, a syndrome generator and trapper. The error trapper includes a big-little endian mode controller for controlling the big-little endian conversion of the error trapper. If the error trapper operates in the big endian mode, the error trapper implements the function of the syndrome generator, operates at the same time with the syndrome generator, and performs a second FEC check, wherein when the shifter performs the FEC check by intercepting data with a length of one frame plus A bits, two start positions of the frame can be verified, where A is a positive integer less than a length of one frame. The invention can improve the frame boundary detection speed and the frame synchronization speed, and increase only a few hardware overheads.

A common broadcast receiver that receives cable broadcast, terrestrial broadcast, and mobile broadcast signals is provided. The common broadcast receiver includes a synchronizer for receiving any one of a cable broadcast signal, a terrestrial broadcast signal, and a mobile broadcast signal including a training signal generated by a Deterministic Trellis Reset (DTR) and inserted in a data region, and synchronizing the received broadcast signal; and a signal detector for detecting any one of the cable broadcast signal, the terrestrial broadcast signal, and the mobile broadcast signal from the synchronized broadcast signal. Hence, the mobile broadcast signal can be received and processed in addition to the cable broadcast signal and the terrestrial broadcast signal.

An encoder signal processing device detects position data at every predetermined time interval from an original signal which is an analog amount generated in an encoder according to movement of a measurement target. The encoder signal processing device includes: an approximate curve calculation unit that calculates an approximate curve of a detection error included in the original signal on the basis of the detection error of the position data at at least three or more points; an approximate error computation unit that computes an approximate value of the detection error of the position data at an arbitrary time point on the basis of the approximate curve of the detection error; and a position data correction unit that corrects the detection error of the position data at the arbitrary time point on the basis of the approximate value of the detection error of the position data.