摘要:
Modems, methods, and computer program products identify a signaling alphabet that is in variance with an ideal alphabet due to digital impairments and is used to decode received data symbols. In particular, a set of alphabet thresholds are established that correspond to the data symbols. The data symbols are received in an equalizer, which generates output symbols in response thereto. A collection of data symbols corresponding to a particular alphabet threshold are accumulated and an average value is computed, which is then used to replace the current value for the particular alphabet threshold to which the average value corresponds. Equalizer performance is enhanced as the improved accuracy of the alphabet thresholds results in better error information being fed back for adapting the equalizer filter coefficients.
摘要:
The present invention relates to a method for reducing data loss comprising a first computing step for computing an intermediate result for each redundancy information entity of a redundancy set by processing respectively associated data information entities of a given data set on at least two main diagonals of a parity check matrix representing an error correction coding scheme. The method further comprises a second computing step for computing the information content of the respective redundancy information entity dependent on the respective intermediate result.
摘要:
A data storage system includes an encoder subsystem comprising an error correction code encoder, a modulation encoder, and a precoder, and a decoder subsystem similarly comprising a detector, an inverse precoder, a channel decoder, and an error correction code decoder. The error correction encoder applies an error correction code to the incoming user bit stream, and the modulation encoder applies so-called modulation or constrained coding to the error correction coded bit stream. The precoder applies so-called preceding to the modulation encoded bit stream. However, this preceding is applied to selected portions of the bit stream only. There can also be a permutation step where the bit sequence is permuted after the modulation encoder before preceding is applied by the precoder. The decoder subsystem operates in the inverse manner.
摘要:
Methods and apparatus are provided for controlling writing and reading of data in an array of A storage fields of a probe-based data storage device in which data is written to and read from the array of storage fields by a corresponding array of probes. One method provides error-tolerance by exploiting the inherent parallelism of the probe storage array. A user data block to be written to the A-field array is first coded to produce a plurality of C-byte codewords, such that r·C=k1A where r is the number of codewords and k1 is an integer greater than or equal to 1. A sub-blocks of k1 bytes are produced from the codewords by selecting successive bytes of each sub-block cyclically from the r codewords. The A sub-blocks are then written via respective probes to the corresponding storage fields of the storage field array.
摘要:
Methods and apparatus are provided for controlling writing and reading of data in an array of A storage fields of a probe-based data storage device in which data is written to and read from the array of storage fields by a corresponding array of probes. One method uses the concept of sub-arrays to provide variable-rate read/write operation. Input data blocks are received for writing to the A-field array, each input data block being writable in A/k0 storage fields where k0 is an integer>=2. For successive groups of k0 blocks, the k0 blocks are written to respective sub-arrays, each of A/k0 storage fields, of the storage field array by selectively writing at one of a series of rates, ranging from 1 block at a time to k0 blocks at a time, in dependence on a desired data write-rate. The blocks can also be read from the sub-arrays by selectively reading at one of a series of rates, ranging from 1 sub-array at a time to k0 sub-arrays at a time, in dependence on a desired data read-rate.
摘要:
A method and apparatus for identifying an unwanted short message service (SMS) message from SMS messages received by a cellular mobile communication system, which comprises at least a history database (HB) for storing a set (H) of the messages received by the cellular mobile communication system. The method includes the steps of: measuring a difference in an information content between a SMS message (m) received by the cellular mobile communication system and the set (H) of messages stored in the history database (HB), and marking the SMS message (m) as being an unwanted SMS message if the difference that is measured is less than or equal to a predefined threshold value.
摘要:
Methods and apparatus are provided for controlling writing and reading of data in an array of A storage fields of a probe-based data storage device in which data is written to and read from the array of storage fields by a corresponding array of probes. One method provides error-tolerance by exploiting the inherent parallelism of the probe storage array. A user data block to be written to the A-field array is first coded to produce a plurality of C-byte codewords, such that r.C=k1.A where r is the number of codewords and k1 is an integer≧1. A sub-blocks of k1 bytes are produced from the codewords by selecting successive bytes of each sub-block cyclically from the r codewords. The A sub-blocks are then written via respective probes to the corresponding storage fields of the storage field array.
摘要翻译:提供了用于控制在基于探针的数据存储设备的A个存储区域阵列中的数据的写入和读取的方法和装置,其中通过相应的探针阵列将数据写入存储区阵列并从存储区域读取数据。 一种方法通过利用探针存储阵列的固有并行性来提供容错性。 要写入A场阵列的用户数据块首先被编码以产生多个C字节码字,使得r C = k 1 A其中r是码字数,k <1> SUB>是整数> = 1。 通过从r个码字周期性地选择每个子块的连续字节,从码字产生k 1个字节的子块。 然后通过相应的探针将A个子块写入存储字段阵列的对应存储字段。
摘要:
An apparatus that uses a lengthened equalization target filter with a matched filter metric in a Viterbi detector is disclosed. The equalization target includes a base partial response component, i.e., (1−D2), a fractional coefficient polynomial component to whiten the noise, i.e., (1+p1D+p2D2), and a time-reversed replica of the noise-whitening component. Thus, the time-reversed replica of the noise-whitening component comes from what was formerly a matched filter component.
摘要翻译:公开了一种在维特比检测器中使用具有匹配滤波器度量的延长均衡目标滤波器的装置。 均衡目标包括基本部分响应分量,即(1-D 2),用于使噪声变白的分数系数多项式分量,即(1 + p < D + p 2 D 2 O 2)和噪声增白部件的时间反转复制品。 因此,噪声增白部件的时间反转复制品来自以前的匹配滤波器部件。
摘要:
Methods and apparatus are provided for controlling writing and reading of data in an array of A storage fields of a probe-based data storage device in which data is written to and read from the array of storage fields by a corresponding array of probes. One method uses the concept of sub-arrays to provide variable-rate read/write operation. Input data blocks are received for writing to the A-field array, each input data block being writable in A/k0 storage fields where k0 is an integer ≧2. For successive groups of k0 blocks, the k0 blocks are written to respective sub-arrays, each of A/k0 storage fields, of the storage field array by selectively writing at one of a series of rates, ranging from 1 block at a time to k0 blocks at a time, in dependence on a desired data write-rate. The blocks can also be read from the sub-arrays by selectively reading at one of a series of rates, ranging from 1 sub-array at a time to k0 sub-arrays at a time, in dependence on a desired data read-rate.
摘要翻译:提供了用于控制在基于探针的数据存储设备的A个存储区域阵列中的数据的写入和读取的方法和装置,其中通过相应的探针阵列将数据写入存储区阵列并从存储区域读取数据。 一种方法使用子阵列的概念来提供可变速率的读/写操作。 接收用于写入A字阵列的输入数据块,每个输入数据块可在A / k 0存储区域中写入,其中k <0>是整数> = 2 。 对于k个块的连续组,将k个0个块写入相应的子阵列,每个A / k 0个存储场, 根据期望的数据写入速率,通过以一系列速率中的一个选择性地写入,每次从一个块到每个块块一次块。 也可以通过选择性地以一系列速率中的一种读取从子阵列中读出的块,从一个子阵列一次一个子阵列到一个子阵列,依次 以期望的数据读取速率。
摘要:
An apparatus for providing data dependent detection in a data read channel is disclosed. Parameters in a read channel are dynamically adjusted according to data dependent noise. For example, a comparison in an add-compare-select (ACS) unit of a Viterbi decoder may be adjusted or offset terms in error event filters may be biased to choose a Viterbi sequence with more transitions or to compensate for polarity dependent noise.