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.

A forward error correction and differentially encoded signal obtained via a communication channel is supplied to a soft-input soft-output (SISO) differential decoder that is bi-directionally coupled to a SISO forward error correction decoder. Over a first portion of a plurality of decoding iterations of the differentially encoded signal, the SISO differential decoder and the SISO forward error correction decoder are operated in a turbo decoding mode in which decoded messages generated by the SISO differential decoder are supplied to the SISO forward error correction decoder and forward error correction messages are supplied to the differential decoder. Over a second portion of the plurality of decoding iterations of the differentially encoded signal, the SISO forward error correction decoder is operated in a non-turbo decoding mode without any messages passing to and from the SISO differential decoder. Decoder output is obtained from the SISO forward error correction decoder.

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.

Systems and methods for decoding block and concatenated codes are provided, including channel state information estimation such as by using 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, including HD Radio receivers and systems.

A soft output detector is programmed with a first set of parameters. Soft information is generated according to the first set of parameters, including likelihood information that spans a maximum likelihood range. Error correction decoding is performed on the soft information generated according to the first set of parameters. In the event decoding is unsuccessful, the soft output detector is programmed with a second set of parameters, soft information according is generated to the second set of parameters (including likelihood information that is scaled down from the maximum likelihood range), and error correction decoding is performed on the soft information generated according to the second set of parameters.

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 such as iterative soft-input soft-output and list decoding of convolutional codes, Reed-Solomon codes and BCH codes. 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, satellite radio signals, digital audio broadcasting (DAB) signals, digital audio broadcasting plus (DAB+) signals, digital video broadcasting-handheld (DVB-H) signals, digital video broadcasting-terrestrial (DVB-T) signals, world space system signals, terrestrial-digital multimedia broadcasting (T-DMB) signals, and China mobile multimedia broadcasting (CMMB) signals. These and other improvements enhance the decoding of different digital signals.

Systems and methods for processing bit-interleaved coded modulation (BICM) signals from a BICM transmitter to generate information bit estimates of information in the BICM signals, including a decoder to generate the information bit estimates of the information in the received BICM signals and a symbol a posteriori probability (APP) generator to generate first symbol a posteriori probabilities (APPs) by processing the BICM signals based on Euclidean distances derived from the BICM signals, and further based on symbol probability log-likelihood ratios (SPLLRs) provided to the symbol APP generator by an extrinsic-information-based symbol probability log-likelihood ratio (SPLLR) generator. The SPLLR generator generates the SPLLRs directly from extrinsic information based on updated symbol APPs output from the decoder, without converting the extrinsic information into log-likelihoods (LLs), and the decoder generates the information bit estimates based on the first symbol APPs output from the symbol APP generator.

A forward error correction and differentially encoded signal obtained via a communication channel is supplied to a soft-input soft-output (SISO) differential decoder that is bi-directionally coupled to a SISO forward error correction decoder. Over a first portion of a plurality of decoding iterations of the differentially encoded signal, the SISO differential decoder and the SISO forward error correction decoder are operated in a turbo decoding mode in which decoded messages generated by the SISO differential decoder are supplied to the SISO forward error correction decoder and forward error correction messages are supplied to the differential decoder. Over a second portion of the plurality of decoding iterations of the differentially encoded signal, the SISO forward error correction decoder is operated in a non-turbo decoding mode without any messages passing to and from the SISO differential decoder. Decoder output is obtained from the SISO forward error correction decoder.

A forward error correction and differentially encoded signal obtained via a communication channel is supplied to a soft-input soft-output (SISO) differential decoder that is bi-directionally coupled to a SISO forward error correction decoder. Over a first portion of a plurality of decoding iterations of the differentially encoded signal, the SISO differential decoder and the SISO forward error correction decoder are operated in a turbo decoding mode in which decoded messages generated by the SISO differential decoder are supplied to the SISO forward error correction decoder and forward error correction messages are supplied to the differential decoder. Over a second portion of the plurality of decoding iterations of the differentially encoded signal, the SISO forward error correction decoder is operated in a non-turbo decoding mode without any messages passing to and from the SISO differential decoder. Decoder output is obtained from the SISO forward error correction decoder.

According to an embodiment, a row decoder to perform row decoding by using, as row soft input information, a row received word read as soft determination information from a non-volatile memory and to calculate row extrinsic information and a column decoder to perform column decoding by using column soft input information, which is a result of adding of the row extrinsic information to a column received word read as soft determination information from the non-volatile memory, and to calculate column extrinsic information are included. The row decoder includes a first decoder for first decoding, a second decoder for second decoding a decoding method of which is different from that of the first decoding, and a selection unit to select a decoded result based on accuracy of a decoded result of the first decoding and that of a decoded result of the second decoding and to calculate the row extrinsic information.