Methods, systems and devices for lattice reduction in decision feedback equalizers for orthogonal time frequency space (OTFS) modulation are described. An exemplary wireless communication method, implementable by a wireless communication receiver apparatus, includes receiving a signal comprising information bits modulated using OTFS modulation scheme. Each delay-Doppler bin in the signal is modulated using a quadrature amplitude modulation (QAM) mapping. The method also includes estimating the information bits based on an inverse of a single error covariance matrix of the signal, with the single error covariance matrix being representative of an estimation error for all delay-Doppler bins in the signal.

Methods, systems and devices for lattice reduction in decision feedback equalizers for orthogonal time frequency space (OTFS) modulation are described. An exemplary wireless communication method, implementable by a wireless communication receiver apparatus, includes receiving a signal comprising information bits modulated using OTFS modulation scheme. Each delay-Doppler bin in the signal is modulated using a quadrature amplitude modulation (QAM) mapping. The method also includes estimating the information bits based on an inverse of a single error covariance matrix of the signal, with the single error covariance matrix being representative of an estimation error for all delay-Doppler bins in the signal.

Methods, systems and devices for lattice reduction in decision feedback equalizers for orthogonal time frequency space (OTFS) modulation are described. An exemplary wireless communication method, implementable by a wireless communication receiver apparatus, includes receiving a signal comprising information bits modulated using OTFS modulation scheme. Each delay-Doppler bin in the signal is modulated using a quadrature amplitude modulation (QAM) mapping. The method also includes estimating the information bits based on an inverse of a single error covariance matrix of the signal, with the single error covariance matrix being representative of an estimation error for all delay-Doppler bins in the signal.

A target constellation diagram determining method, a data sending method, and an apparatus are provided in accordance with the disclosure. The target constellation diagram determining method in accordance with the disclosure may include receiving, by a receiving device, training data that is generated and sent by a sending device based on each constellation point in an alternative constellation diagram. A detection region of each constellation point can then be determined based on a position of the training data in the alternative constellation diagram. A cumulative distance corresponding to the alternative constellation diagram can be obtained based on a distance between the detection regions of the constellation points. The method may include determining, based on cumulative distances corresponding to a plurality of alternative constellation diagrams, that an alternative constellation diagram with a largest cumulative distance is a target constellation diagram, and notifying the sending device of the target constellation diagram, so that the sending device modulates to-be-sent data based on the target constellation diagram.

A target constellation diagram determining method, a data sending method, and an apparatus are provided in accordance with the disclosure. The target constellation diagram determining method in accordance with the disclosure may include receiving, by a receiving device, training data that is generated and sent by a sending device based on each constellation point in an alternative constellation diagram. A detection region of each constellation point can then be determined based on a position of the training data in the alternative constellation diagram. A cumulative distance corresponding to the alternative constellation diagram can be obtained based on a distance between the detection regions of the constellation points. The method may include determining, based on cumulative distances corresponding to a plurality of alternative constellation diagrams, that an alternative constellation diagram with a largest cumulative distance is a target constellation diagram, and notifying the sending device of the target constellation diagram, so that the sending device modulates to-be-sent data based on the target constellation diagram.

Calculating path metrics, associated with respective states of an n-state trellis, by accumulating branch metrics in a sequence detector. Each path metric is represented by N bits plus a wrap-around bit for indicating wrap-around of the N-bit value of that path metric.

According to various embodiments, a joint detector/decoder device may be provided. The joint detector/decoder device may include: an input circuit configured to receive an input signal; a splitting determination circuit configured to determine whether a survivor is to be split based on a parity check criterion; and a survivor splitting circuit configured to produce a plurality of survivors of a next instance based on at least one survivor of a previous instance and based on the input signal, if it is determined that the survivor of the previous instance is to be split; wherein each survivor has an associated bit sequence.

A method for operating a receiving device includes determining reliability ratings for undecoded data streams in a received transmission, selecting an undecoded data stream in the received transmission in accordance with the determined reliability ratings, thereby producing a selected data stream, and decoding the selected data stream with a decoding trellis, thereby producing a data symbol. The method also includes updating the decoding trellis in accordance with the data symbol, and repeating the selecting, the decoding, and the updating for remaining undecoded data streams in the received transmission.