115 results about "Symbol decoding" patented technology

The present invention provides a method of processing data in digital broadcasting system. The method includes receiving a broadcast signal including mobile broadcast service data and main broadcast service data, wherein the mobile broadcast service data configures a data group, wherein the data group is divided into a plurality of regions, wherein N number of known data sequences are inserted in some regions among the plurality of regions, and wherein a transmission parameter is inserted between a first known data sequence and a second known data sequence, among the N number of known data sequences, detecting the transmission parameter from the mobile broadcast service data, symbol-decoding the received broadcast signal included in the mobile broadcast service data in block units, based upon the detected transmission parameter, extracting a video data from the mobile broadcast service data, parsing the extracted video data by a NAL unit, obtaining NAL unit type information from parsed NAL header, obtaining extension information of a NAL header, when data of a current NAL unit indicates scalable video coded data according to the NAL unit type information, and decoding the video data using the extension information of the NAL header, wherein the extension information of the NAL header includes at least one of temporal level information, quality level information, information indicating whether inter-layer prediction is used, and dependency information of the NAL unit.

Vector signaling code communications systems rely on group transmission of code symbols using multiple signaling channels that may have differing propagation characteristics, resulting in differing received signal levels, waveforms, and symbol arrival times, and thus that should be actively monitored and adjusted to minimize differential signal characteristics. Information obtained during symbol decode may be analyzed to identify channel operational characteristics during normal operation and perform non-disruptive channel adjustments, including per-channel adjustment of sample-and-hold timing to realign code symbol groups. Initialization or start-up adjustment may also be performed using intentionally-transmitted training patterns.

Soft symbol decoder algorithms for multiple input, multiple output (MIMO) receivers reduce the search complexity by searching over fewer than all possible combinations of transmitted symbols to compute log metrics for each transmitted bit from each transmit antenna. In one algorithm, a sub-optimal set of transmitted symbols is computed and the transmitted symbols are restricted to neighboring constellation points of the sub-optimal set. In another algorithm, all constellation points are searched for every antenna except one. In yet another algorithm, constellation points are searched excluding more than one antenna. The non-searched antenna(s) can be handled by either a bit stuffing or a soft slicing technique.

A method and apparatus for multi-threaded operation of an image-based symbology reader is provided. In the method of the invention, acquired images of an encoded symbol are attempted to be decoded using a plurality of decoding engines asynchronously and substantially simultaneously in a multi-threaded processing environment. Each of the decoding engines can be directed to a specific symbology type to achieve an improved response time when reading multiple symbol types.

Decision Feedback Equalization techniques are difficult to apply in high speed communications systems, as the decoding process for a received symbol may not be completed in time to allow adaptive detection of the following symbol. Advantage may be taken of certain novel aspects of vector signaling codes to provide decision feedback to an adaptive data receiver concurrent with symbol decoding, rather than being delayed to symbol decode completion. Methods and systems are described that error correct an initial non-adaptive decoding, based on differences between the actual received signals and simulated received signals derived from the initial decoding and historical received data. Additional methods and systems are described using bounding functions to estimate an error rate with reduced computation.

A bar code reading device processing two-dimensional electronic representations in the decoding of bar code symbols, which can automatically discriminate between code symbologies such as PDF 417 code symbology and UPC code symbology. The bar code reading device may further have improved reprogramming features and improved menuing features.

This invention decodes a next significance symbol using a selected context. The invention operates in a loop for each symbol decode for a whole block until the number of decoded map elements reaches a maximum number of coefficients for the block type or a last significant coefficient marker is decoded updating loop variables accordingly. This invention counts the number of decoded significance symbols indicating a significant coefficient and stores the locations of such significant coefficients in an array. An embodiment of this invention estimates the number of significant coefficients in a block and selects the inventive method or a prior art decode method.

A digital broadcasting system and a data processing method are disclosed. A receiving system of the digital broadcasting system includes a receiving unit, a demodulator, an equalizer, a block decoder, and a RS frame decoder. The receiving unit receives a broadcast signal including mobile service data and main service data. The mobile service data may configure a RS frame. The RS frame includes at least one data packet for the mobile service data, RS parity generated based on the at least one data packet, and CRC checksum generated based on the at least one data packet and the RS parity. The demodulator converts RS frame data included in the broadcast signal received by the receiving unit into a baseband RS frame data. The equalizer performs channel equalization on the data demodulated by the demodulator. The block decoder performs symbol-decoding on the data channel-equalized by the equalizer in block units. The RS frame decoder performs CRC-decoding and RS-decoding on the decoded mobile service data in RS frame units, thereby correcting errors occurred in the mobile service data within the RS frame.

A multi-user turbo decoder combining multi-user detection and forward error correction decoding is disclosed that utilizes iterative decoding of received, interfering signals, and the construction of a decoding tree of the decoder is changed for each iteration of the decoding based on the previous conditional probability estimates of the value of the data bits of each signal making up the received, interfering signals. Before each iteration of multi-user decoding, a probability estimate is calculated that the value of the bit in a signal has a certain value for all of the data bits. Using the probability estimate a new decoding tree is constructed before each iteration of decoding such that the signal bit having the most reliable estimate is assigned to the lowest or root level of the tree. Using the probability estimate for the other signal bits, the signal bit having the next most reliable estimate is assigned to the second level of the tree, and so forth, with the signal bit having the least reliable estimate being assigned to the highest level of the tree adjacent the terminating nodes or leaves of the tree. By building the decoding tree in this manner for each iteration of symbol decoding, a reduced complexity search is more likely to include paths (and nodes) in the tree containing the correct value for the channel symbols.

Methods and systems for processing an optical signal in a communication system are disclosed. The disclosed methods yield benefits for estimation and tracking of carrier phase of received signals at a digital coherent receiver. Specifically, phase ambiguity is removed by the insertion of pilot symbols into a transmitted data stream. Pilot symbols are detected from a received signal, and carrier phase is estimated for the detected pilot symbols. If carrier phase track of received data symbols was lost, a correction is applied to recover the track. Coherent symbol decoding may be used which has not been possible with prior art techniques due to the possibility of phase tracking loss.

A PAM receiver for reproducing a baseband signal that symbol codes digital data is combined with an decision-feedback equalizer (DFE) incorporating first adaptive digital filtering as a feed-forward element and second adaptive digital filtering as a feedback element. The DFE response is supplied to symbol decoding circuitry for reproducing the digital data. A de-rotator re-samples the first adaptive digital filtering response before it is combined with the second adaptive digital filtering response to generate an equalizer response. The resulting baud-rate equalizer response is sampled at baud rate and quantized to generate baud-rate decisions that applied to the second adaptive digital filtering as input signal, for completing the decision-feedback loop. The re-sampling of the first adaptive digital filtering response by the de-rotator is controlled, so as to provide a phase-tracker that reduces phase noise and intersymbol interference, prior to the making of decisions for decision feedback.

A system and method is provided for ordering intervals rLPS and rMPS of a range to increase speed of binary symbol decoding in a binary arithmetic decoder. The method comprises the steps of: placing rLPS at a bottom of the range; enabling subtraction for rMPS to occur in parallel with comparison of rLPS and offset; and, reducing time that it takes to decode a bin. A method is also provided for performing context selection for a given syntax element, comprising the steps of: first, comparing information regarding properties of neighboring pixels with a threshold; second, adding results of threshold comparison of neighboring pixels, to provide a secondary result; and using the secondary result to select a context.

A device for decoding code symbols which are interfered with a distortion during a predetermined distortion time interval includes a reliability information generator to provide reliability information based on the code symbols and a decoder to decode the code symbols into code words. The decoder is configured to decode the code symbols based on weighted reliability information, wherein the weighted reliability information is generated from the reliability information by applying a first weight during times not coinciding with the distortion time interval, and by applying a second weight different from the first weight during times coinciding with the distortion time interval.

Disclosed is a system and method for joint source-channel encoding, symbol decoding and error correction, preferably utilizing an arithmetic encoder with operational error detection space; and a combination sequential, and arithmetic, encoded symbol decoder structure.

This application provides a flexible and efficient way to handle escape symbols during decoding of N-tuple variable length codes (VLCs). The user can request that the decoder resolve a sequence of symbols. The Huffman lookup tables can contain a field to notify the decoder if a given N-tuple VLC includes an escape symbol. For non-escape symbols, as identified by the escape indicator bit in the Huffman lookup table entry, the decoder can finish resolving the N symbols of the N-tuple without requiring a symbol-by-symbol comparison of each symbol to detect escape conditions. For escape symbols, as identified by the escape indicator bit in the Huffman lookup table entry, the decoder can either look back to the user for help, or use pre-defined logic to resolve the escape symbols. Aspects of certain embodiments enable parallelism between Huffman symbol decoding and escape condition detection without losing future expandability.

Symbol decoding errors at a receiver utilising a flash analog to digital converter (ADC) can be reduced by adjusting a reference voltage level of the ADC where a decoding error rate at the reference voltage level exceeds a threshold.

LDPC (Low Density Parity Check) coded modulation symbol decoding using non-Gray code maps for improved performance. Symbol decoding is supported by appropriately modifying an LDPC tripartite graph to eliminate the bit nodes thereby generating an LDPC bipartite graph (such that symbol nodes are appropriately mapped directly to check nodes thereby obviating the bit nodes). The edges that communicatively couple the symbol nodes to the check nodes are labeled appropriately to support symbol decoding of the LDPC coded modulation signal. In addition, the LDPC coded modulation symbol decoding can be employed to decode a signal that has been encoded using LDPC-BICM (Low Density Parity Check-Bit Interleaved Coded Modulation) encoding with non-Gray code mapping. By using the non-Gray code mapping, a performance improvement over such a system using only Gray code mapping may be achieved.

A process for improved, lossless data transformation with options for adaptive compression, multidimensional prediction, multi-symbol decoding.

A method includes the steps of: i) listing out all possibilities for first symbol of a two stream signal; ii) determining a second symbol of the two stream signal for each said first symbol listed out, iii) evaluating a metric for each said first symbol and second symbol pair, iv) determining the exact maximum log likelihood ratio for all bits associated with said first symbol using said metrics, v) decoding a codeword-1 using the maximum log likelihood ratios, vi) re-encoding said codeword-1, vii) modulating said re-encoded codeword-1, viii) subtracting said modulated re-encoded codeword-1 from said two stream signal, ix) determining metrics for all possibilities for second symbol in the signal obtained in viii, x) determining the maximum log likelihood ratios for all bits associated with second symbol, and xi) decoding said codeword-2 using the maximum log likelihood ratios for all bits associated with said second symbol.

An automatic bar code symbol reading system comprising components for carrying out object detection, scanning, photoreceiving, A/D conversion, bar code presence detection, symbol decoding, data format conversion, data storage and data transmission functions. In general, the automatic bar code symbol reading device includes a manually actuatable read-repeat switch and control system having a plurality of control centers that control the operation of the system components in accordance with preselected system control operations. Each of the control centers are responsive to control activation signals generated by certain of the system components upon the occurrence of predefined conditions. Certain of the control centers are capable overriding other control centers to provide diverse control capabilities which facilitates execution of intelligent operations and power conservation, during bar code symbol reading. In combination, control system and read-repeat switch enable the device to automatically read a previously read bar code symbol once again, or retransmit or restore symbol character data of a previously read bar code symbol, each time the read-repeat switch is depressed during the system control process of the present invention. This simple procedure can be repeated time and time again to read, in a user-controllable fashion, the same bar code symbol any number of times.

A receiver capable of decoding a symbol based on information on a previous symbol, the symbol and a next symbol in a Gaussian frequency shift keying (GFSK) communication system is provided. The receiver includes a discriminator to generate a symbol for each bit in a bit sequence, a first lookup table (LUT) to store a number of bit patterns and mapping patterns, wherein each of the bit patterns is in the form of a set of consecutive bits in the bit sequence and corresponds to a respective one of the mapping patterns, and wherein each of the mapping patterns includes a set of entries and each of the entries results from an operation of attribute values at a sample time in the waveform of a symbol, a calculator to receive a set of consecutive symbols from the discriminator and calculate a distance value between the set of consecutive symbols and each of the mapping patterns, and a comparator to identify one of the mapping patterns with a minimum distance value by comparing among the distance values from the calculator.

It is possible to linearly arrange cells and indicate particular data in the order of colors of respective sells. A code system uses an optical symbol decoding method capable of reading the color arrangement if the arrangement continuity and the linear shape are maintained. The data expression method may be other than “the order of colors.” For example, it is possible to employ a method for allocating a numeric value to each of the colors by one-to-one correspondence (R=0, B=1, etc.), a method for allocating data by a color transition (“CM”=“MY”=“YC”=0, “CY”=“YM”=“MC”=1, etc.), a method for allocating data for a combination of colors, and the like.