An optical transmission apparatus (100) generates a second bit sequence B by encoding a first bit sequence b having forward error correction coding performed on a transmission bit sequence, maps the second bit sequence to a transmission symbol signal, and transmits an optical modulated signal generated by modulating an optical carrier wave into the transmission symbol signal. A symbol output unit (2020) generates a received symbol signal by demodulating an optical modulated signal received by an optical reception apparatus (2000). A first computation unit (2040) computes LLR(Bi) which is a log-likelihood ratio (LLR) of each bit Bi of the second bit sequence, using the received symbol signal. A second computation unit (2060) computes a log-likelihood ratio LLR(bi) of each bit bi of the first bit sequence from the LLR(Bi). A correspondence relationship between each bit of the first bit sequence and each bit of the second bit sequence is used in this computation. A decoding unit (2080) decodes the transmission bit sequence using the LLR(bi).

A storage system includes: a control processor unit, configured to: initiate a read of a raw data page, having correctable errors, calculate a raw bit error rate (RBER) (EQ1) by correcting the correctable errors to become corrected data and comparing raw data with the corrected data, and calculate a correction model characterization based on the RBER (EQ1); and a non-volatile storage array, coupled to the control processor unit, configured to store a processed data page in a physical block with the raw data page; and wherein the control processor unit is further configured to apply the correction model characterization to the raw data page in the physical block.

The disclosed technology relates to a method for improving performance of a feedback circuit comprising an amplifier and a feedback network, wherein the feedback circuit has at least one tunable component. In one aspect, the method comprises measuring first amplitude values at an input of the amplifier and second amplitude values at an output of the amplifier, estimating a linear open-loop gain of the amplifier based on both the amplitude values, estimating a linear finite gain error based on the estimated gain and the second amplitude values, subtracting the linear finite gain error from the first amplitude values to derive a set of samples containing second error information, deriving an signal-to-noise-plus-distortion ratio estimate based on the variance of the set of samples and a variance of the second amplitude values, and adjusting the feedback circuit in accordance with the signal-to-noise-plus-distortion ratio estimate.

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.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE configured to receive a plurality of beams through a plurality of different receive beam directions, each of the beams including broadcast information on a PBCH. The apparatus may be further configured to determine, for each of a subset of the received beams, a log likelihood ratio (LLR) for coded bits of the broadcast information. The apparatus may be further configured to decode the broadcast information associated with each of the subset of the received beams, and determine a refined receive beam direction based on the determined LLRs and based on whether the broadcast information associated with each of the subset of the received beams fails to decode or is successfully decoded.

A data storage device may include a memory and a controller that includes an error correction coding (ECC) decoder configured to operate in a plurality of decoding modes. The controller also includes a bit error rate estimator configured to determine, based on data received from the memory, bit error rate estimates for ECC codewords from the memory. The controller also includes a data path management unit configured to reorder the codewords based on the bit error rate estimates and to provide the reordered codewords to the ECC decoder.

Adaptive read threshold voltage tracking techniques are provided that employ bit error rate estimation based on a non-linear syndrome weight mapping. An exemplary device comprises a controller configured to determine a bit error rate for at least one of a plurality of read threshold voltages in a memory using a non-linear mapping of a syndrome weight to the bit error rate for the at least one of the plurality of read threshold voltages.

A method for optimizing non-uniform quantization thresholds of an ADC in MLSE-based receivers in an optical communication channel, according to which a Quantized Noise (QN) distortion model, in which the quantization and the channel additive noises are combined is generated. The model is applied on the channel deterministic analog states x(n) and on sequences of analog states and transition probabilities are calculated, which will be used later on to calculate the BER, from channel deterministic states and sequences of channel deterministic states into the discrete ADC quantization regions. Real value outputs of the ADC are replaced by the transition probabilities and non-uniform quantization of the ADC is performed, with thresholds that are optimized for MLSE detection, to obtain maximal statistical separation. A DSP circuit computes, the MLSE metrics and the transition probabilities of the analog states into the quantized values, for each of the channel deterministic state; and an MLSE decoder post-processes transition probabilities replacing the ADC outputs and representing analog regions, based on the derived transition probabilities.

In an illustrative example, a method includes sensing at least a portion of a representation of a convolutional low-density parity-check (CLDPC) codeword stored at a memory of a data storage device. The method further includes receiving the portion of the representation of the CLDPC codeword at a controller of the data storage device. The method further includes performing one or more management operations associated with the memory based on an estimated number of errors of the portion of the representation of the CLDPC codeword.

The present disclosure includes apparatuses and methods for estimating an error rate associated with memory. A number of embodiments include sensing data stored in a memory, performing an error detection operation on the sensed data, determining a quantity of parity violations associated with the error detection operation, and estimating an error rate associated with the memory based on the determined quantity of parity violations.