There is provided a recording apparatus, a recording method, a reproduction apparatus, a reproduction method, a recording medium, an encoding apparatus, and a decoding apparatus which enable recording or reproduction to be easily implemented at high line density. User data is encoded into a multilevel edge code, and a multilevel code whose value changes in accordance with the multilevel edge code is recorded. The multilevel edge code is generated through state transition of a code generation model which includes a state representing the number of times that zero is consecutive corresponding to a number of ways of the number of times that zero is consecutive, which is the number of times that an edge of 0 is consecutive among edges representing a change amount from an immediately preceding value of the multilevel code of an ML value which is equal to or greater than 3, and which transitions to a state representing the number of times that zero is consecutive including 0 in a case where 0 is output, and transitions to a state representing that the number of times that zero is consecutive is 0 times in a case where one of 1 to ML−1 is output.

A symbol-determining device according to an embodiment includes: a transmission line shortening unit that multiplies each symbol value of a symbol array that is part of an input signal by a tap gain of a linear digital filter and outputs a symbol array representing a sum of values acquired through the multiplication; a transmission line estimating unit that estimates a transfer function of a transmission line using an adaptive nonlinear digital filter on the basis of a symbol array representing a state of the transmission line; an addition comparison processing unit that calculates a minimum value of a distance function in a Viterbi algorithm on the basis of a metric that is calculated on the basis of the output of the transmission line shortening unit and the transfer function; and a path tracing-back determination unit that performs symbol determination by tracing back a trellis path in the Viterbi algorithm on the basis of the minimum value of the distance function.

In described examples of a signal equalizer, a first filter stage is configured to perform adaptive equalization of crosstalk between a first signal component and a second signal component of a complex signal. A second filter stage is coupled serially to the first filter stage. The second equalizer stage is configured to perform separate adaptive equalization of the first signal component and separate adaptive equalization of the second signal component.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may perform online spur detection and mitigation scheme. The UE may identify spurs during operation, in real time, and apply cancelation and noise equalization to address identified spurs. The UE may apply a high pass filter to reference signals. During a symbol, the UE may apply the high pass filter by estimating the channel on one or more neighbor tones (e.g., tones of higher frequency and tones of lower frequency that also carry reference symbols). Because the UE may assume that a channel will generally be smooth, and that noise may vary slowly or steadily across frequency resources, the UE may compare the channel noise of a particular tone to an average or normalized channel noise of the one or more neighbor tones.

In described examples of a signal equalizer, a first filter stage is configured to perform adaptive equalization of crosstalk between a first signal component and a second signal component of a complex signal. A second filter stage is coupled serially to the first filter stage. The second equalizer stage is configured to perform separate adaptive equalization of the first signal component and separate adaptive equalization of the second signal component

This application provides a symbol processing method and related apparatus. The method includes: dividing a plurality of obtained complex-valued symbols into a plurality of sets, where each set corresponds to one transmit symbol, and the plurality of sets include a first set corresponding to a first transmit symbol; and mapping a first sequence and a second sequence to the first set, where an end position of the first sequence is a position of intercepting a cyclic prefix (CP) in the first transmit symbol, and an end position of the second sequence is an end position of the first transmit symbol. By mapping the sequences to the sets, an original cyclic prefix (CP) can be extended using a sequence with a flexible length, and flexible guard periods of different lengths can be configured for different users by adjusting the length of the sequences.

Methods, systems, and apparatus for error correction are provided. In one aspect, an error correction method includes: obtaining an output signal and an amplitude value of a feed forward equalizer (FFE), the amplitude value being a channel response amplitude value corresponding to an equivalent channel of the FFE, performing level decision on the output signal based on the amplitude value to obtain a first decision signal including (2M−1) decision symbols, M being an integer not less than 2, performing (1/(1+D)) decoding on the first decision signal to obtain a first decoded signal, determining a second decision signal based on the first decoded signal, the second decision signal including (M−1) decision symbols, determining that a burst error occurs in the second decision signal if an absolute value of the second decision signal is greater than (M−1), and correcting the burst error in the second decision signal.

A receiver for receiving a combination signal having two separate signal portions whose pulses are shifted relative to each other and/or whose carrier waves have a phase difference is configured to obtain a first series of samples using a first sampling and to obtain a second series of samples using a second sampling. The first sampling is adjusted to a symbol phase of the first signal portion, the second sampling is adjusted to a symbol phase of the second signal portion. The receiver is configured to obtain probabilities of transmission symbols of the first signal portion and probabilities of transmission symbols of the second signal portion for a plurality of sampling times based on the first and second series of samples, and to determine probabilities for transmission symbols of the first signal portion based on samples of the first sampling and estimated or calculated probabilities for transmission symbols of the second signal portion without taking into account inter-symbol interference between transmission symbols of the first signal portion in the samples of the first sampling, and determines probabilities for symbols of the second signal portion correspondingly. A corresponding method and computer program are described.

This application provides a symbol processing method and related apparatus. The method includes: dividing a plurality of obtained complex-valued symbols into a plurality of sets, where each set corresponds to one transmit symbol, and the plurality of sets include a first set corresponding to a first transmit symbol; and mapping a first sequence and a second sequence to the first set, where an end position of the first sequence is a position of intercepting a cyclic prefix (CP) in the first transmit symbol, and an end position of the second sequence is an end position of the first transmit symbol. By mapping the sequences to the sets, an original cyclic prefix (CP) can be extended using a sequence with a flexible length, and flexible guard periods of different lengths can be configured for different users by adjusting the length of the sequences.

There is described a method for communicating data, the method comprising: receiving an incomplete data stream, wherein the incomplete data stream comprises a plurality of sequences of data points having respective values and a plurality of sequences of missing data points; receiving a missing data model; determining values for each of the plurality of sequences of missing data points, comprising: selecting a sequence of missing data points that has not previously been processed, wherein the sequence of missing data points to be processed is selected as a smallest sequence of missing data points of the plurality of sequences of missing data points that have not previously been processed; processing the incomplete data stream to determine values for the selected sequence of missing data points based upon the missing data model; updating the incomplete data stream to include the determined values for the selected sequence of missing data points; and wherein values for subsequent sequences of missing data points are generated based upon the updated data stream; and outputting a corrected data stream comprising the determined values for each of the plurality of sequences of missing data points.