摘要:
The present disclosure includes apparatus, systems and techniques relating to iterative decoder memory arrangement. A described apparatus includes a single R memory component including R banks, a Q memory component including Q banks, a channel detector memory component to store channel extrinsic information associated with current and previous codewords, and an iterative decoder communicatively coupled with the single R memory component, the Q memory component, and the channel detector memory component. The apparatus can be configured to alternate among the R banks for storing R data associated with a current codeword. The apparatus can be configured to alternate among the Q banks for storing Q data associated with a current codeword.
摘要:
The present disclosure includes apparatus, systems and techniques relating to iterative decoder memory arrangement. In some implementations, an apparatus includes a memory module to communicate with an iterative code decoder. The memory module includes a single R memory component to store R data associated with a current codeword, and R data associated with a previous codeword. The memory module includes a Q memory component to store Q data associated with the current codeword, and Q data associated with the previous codeword. The memory module includes a channel detector memory component to store channel extrinsic information.
摘要:
Systems and methods are provided for improved designs and performance for iterative decoder systems. In some embodiments, the iterative decoder may be decoupled from FIR samples through an FIR RAM, thus resulting in a less complex design and shorter processing times. In some embodiments, an intermediate memory may be used when passing information between the SOVA and LDPC of the iterative decoder. In some embodiments, the SOVA-required information may be continuously serialized from information received from the LDPC during each LDPC iteration. In some embodiments, the 1/(1+D2) precoder of the HR RLL encoder may be split into two serial, 1/(1+D) precoders. One 1/(1+D) precoder may be pulled outside of the HR RLL encoder and used in conjunction with the iterative decoder. This may allow for a 1/(1+D) precoder that may be used with the iterative decoder while maintaining the RLL constraints imposed upon the encoded information by the HR RLL encoder.
摘要:
Systems and methods are provided for improved designs and performance for iterative decoder systems. In some embodiments, the iterative decoder may be decoupled from FIR samples through an FIR RAM, thus resulting in a less complex design and shorter processing times. In some embodiments, an intermediate memory may be used when passing information between the SOVA and LDPC of the iterative decoder. In some embodiments, the SOVA-required information may be continuously serialized from information received from the LDPC during each LDPC iteration. In some embodiments, the 1/(1+D2) precoder of the HR RLL encoder may be split into two serial, 1/(1+D) precoders. One 1/(1+D) precoder may be pulled outside of the HR RLL encoder and used in conjunction with the iterative decoder. This may allow for a 1/(1+D) precoder that may be used with the iterative decoder while maintaining the RLL constraints imposed upon the encoded information by the HR RLL encoder.
摘要:
In iterative decoding, a data recovery scheme corrects for corrupted or defective data by determining reliability metrics for blocks of decoded data. Block or windowed detectors generate block reliability metrics for data blocks (rather than individual bits) of decoded data using soft information from the regular decoding mode or from new iterative decoding iterations performed during error recovery mode. An error recovery system triggers corrective decoding of selected data blocks based on the block reliability metrics, by for example, comparing the block reliability metrics to a threshold or by selecting an adjustable number of the least reliable data blocks.
摘要:
An ERSEC system that applies a level of error correction that is inversely related to susceptibility to error as indicated by a signal-to-noise ratio (SNR) profile of a channel. The SNR profile is estimated, detected or retrieved from an external source. The ERSEC system is used with any channel for which the SNRs can vary spatially, temporally or both.
摘要:
Systems and methods for constructing low-density parity check codes for holographic storage are provided. The methods include selecting parameters of a low-density parity check code, determining the number of bit processing elements and the amount of memory in an accompanying decoder, and constructing a mother matrix representation of a quasi-cyclic parity check matrix. The low-density parity check codes are optimized for performance, memory considerations, and throughput.
摘要:
Systems and methods are provided for decoding received codewords using an LDPC code. An LDPC post-processor is disclosed for performing post-processing when standard LDPC decoding fails due to a trapping set. The LDPC post-processor may direct the LDPC decoder to decode the received codeword again, but may change some of the inputs to the LDPC decoder so that the LDPC decoder does not fail in the same way. In one embodiment, the LDPC post-processor may modify the symbol positions in the received codeword that correspond to a particular unsatisfied check. In another embodiment, the LDPC post-processor may modify the messages in the decoder's iterative message algorithm that correspond to the symbol positions.
摘要:
Systems and methods for constructing low-density parity check codes for holographic storage are provided. The methods include selecting parameters of a low-density parity check code, determining the number of bit processing elements and the amount of memory in an accompanying decoder, and constructing a mother matrix representation of a quasi-cyclic parity check matrix. The low-density parity check codes are optimized for performance, memory considerations, and throughput.
摘要:
Generation of code words for error correction coding (ECC) of a channel with a non-uniform signal-to-noise ratio (SNR) is provided. A channel SNR profile is accessed, which can also include determining the channel profile. The channel profile characterizes sections of the channel having like SNR values. Each section of the channel is partitioned into a number of partitions. The number of partitions of each section equals a number of code words for the channel. The code words are generated by interleaving the partitions from each section such that an average SNR of each code word is made substantially the same as an average SNR of the channel.