摘要:
Systems and methods for decoding block and concatenated codes are provided. These include advanced iterative decoding techniques based on belief propagation algorithms, with particular advantages when applied to codes having higher density parity check matrices. Improvements are also provided for performing channel state information estimation including the use of optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics. Particular improvements are also provided for decoding HD Radio signals, including enhanced decoding of reference subcarriers based on soft-diversity combining, joint enhanced channel state information estimation, as well as iterative soft-input soft-output and list decoding of convolutional codes and Reed-Solomon codes. These and other improvements enhance the decoding of different logical channels in HD Radio systems.
摘要:
Real-time selection of interference cancellation schemes based on transmission parameters and amount of resource overlap between the desired payload and the interfering payload. Codeword level interference cancellation may be performed where the signal quality of the interfering signal indicates that the interfering payload will be decoded correctly. When performed, codeword level interference cancellation may be monitored to determine if decoding the interfering payload is converging. Other interference cancellation schemes may be selected based on the signal quality of the interfering signal or non-converging decode of the interfering payload. The number of iterations for iterative decoding in codeword level interference cancellation may be dynamically selected. The decoder output (e.g., soft bits) may be used to perform interference cancellations before the decoder is fully converged. Iterative decoding may be performed in multiple passes and soft decision output form one pass may be used to initialize the decoder for a subsequent pass.
摘要:
An encoder/decoder scheme for robust transmission of PHY layer frame control information in OFDM frames. The frame control information to be modulated onto carriers in OFDM symbols is encoded using a product encoder (100) to form a product code block/matrix that is based on a hamming code codeword set having properties of symmetry. Elements of the matrix are interleaved by an interleaver (102) so that the elements are modulated onto carriers of the symbols in diagonal groupings and with some degree of redundancy. The modulated elements are demodulated to produce soft-decision values, which are de-interleaved by a de-interleaver (180) to be re-ordered in the order of the elements prior to interleaving, and provided to a turbo product decoder (182). The decoder performs a decoding procedure, according to the properties of symmetry, on each set of soft values in fewer operations and with reduced circuitry.
摘要:
A system, method and device for error detection/estimation in OFDM communications systems is proposed. The disclosed mechanism allows an efficient error prediction in a received data block (e.g. a packet) without using error detection codes that may impair spectral efficiency (due to the overhead) especially when very small size packets are used. In order to do that, it generates a decision variable with the aim to check whether a received block has errors or not, without resorting to the use of error-detection codes.
摘要:
The present invention provides a decoding method, a decoding apparatus, and a communications system, which implement multi-level coding in a manner combining soft-decision error correction coding and hard-decision error correction coding, implement multi-level decoding in a manner combining soft-decision error correction decoding and hard-decision error correction decoding, so as to integrate advantages of the two manners: compared with a manner in which soft-decision error correction coding and decoding are performed on multiple levels, a manner in which soft-decision error correction coding and decoding are performed on only one level reduces system complexity and resource overhead; and performing hard-decision error correction coding and decoding on other levels on a basis of performing soft-decision error correction coding and decoding on one level ensures gain performance, thereby meeting a gain requirement of a high-speed optical transmission system.
摘要:
Data communication over a block-coherent channel in a communication system is described. Low-complexity demodulation techniques that allow good performance are described. A dwell syn signal (323), e.g., a set of block coherent symbols transmitted including a known symbol, e.g., a pseudo pilot symbol, are received, demodulated (204) and decoded by a joint decoder/demodulator (311 and 313) employing soft inputs, soft outputs, and interleaving of messages. Low-complexity SISO demodulator (204) is suitable for processing pseudo-pilot modulated information corresponding to each of one or more dwells (323). The low-complexity method achieves good performance when turbo equalization is used. Some decoding and demodulation embodiments include independent phase estimates and updated independent phase estimates following the extrinsic principle to generate soft symbol values and soft bits.
摘要:
A method of approximate max-log-a-posteriori decoding soft input information related to a transmitted word of a linear block code ( n , k ) and providing hard or soft output information is disclosed. The method comprises the steps of forming a reliability vector from the input information, identifying ( n-k ) linearly independent least reliable symbols and k most reliable symbols, converting a parity check matrix of the linear block code to a pseudo-systematic form with respect to the least reliable symbols, calculating extrinsic information and composite information for the most reliable symbols using the soft input information and the pseudo-systematic parity check matrix, and calculating extrinsic information for the least reliable systems using composite information for the most reliable symbols.
摘要:
Systems and methods for decoding block and concatenated codes are provided. These include advanced iterative decoding techniques based on belief propagation algorithms, with particular advantages when applied to codes having higher density parity check matrices. Improvements are also provided for performing channel state information estimation including the use of optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics. Particular improvements are also provided for decoding HD Radio signals, including enhanced decoding of reference subcarriers based on soft-diversity combining, joint enhanced channel state information estimation, as well as iterative soft-input soft-output and list decoding of convolutional codes and Reed-Solomon codes. These and other improvements enhance the decoding of different logical channels in HD Radio systems.
摘要:
Systems and methods for decoding block and concatenated codes are provided. These include advanced iterative decoding techniques based on belief propagation algorithms, with particular advantages when applied to codes having higher density parity check matrices. Improvements are also provided for performing channel state information estimation including the use of optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics. Particular improvements are also provided for decoding HD Radio signals, including enhanced decoding of reference subcarriers based on soft-diversity combining, joint enhanced channel state information estimation, as well as iterative soft-input soft-output and list decoding of convolutional codes and Reed-Solomon codes. These and other improvements enhance the decoding of different logical channels in HD Radio systems.