An apparatus and method for broadcast signal frame using layered division multiplexing are disclosed. An apparatus for generating broadcast signal frame according to an embodiment of the present invention includes a combiner configured to generate a multiplexed signal by combining a core layer signal and an enhanced layer signal at different power levels; a power normalizer configured to reduce the power of the multiplexed signal to a power level corresponding to the core layer signal; a time interleaver configured to generate a time-interleaved signal by performing interleaving that is applied to both the core layer signal and the enhanced layer signal; and a frame builder configured to generate a broadcast signal frame including a preamble for signaling time interleaver information shared by the core layer signal and the enhanced layer signal, using the time-interleaved signal.

Example systems, read channels, and methods provide bit value detection from an encoded data signal using a neural network soft information detector. The neural network detector determines a set of probabilities for possible states of a data symbol from the encoded data signal. A soft output detector uses the set of probabilities for possible states of the data symbol to determine a set of bit probabilities that are iteratively exchanged as extrinsic information with an iterative decoder for making decoding decisions. The iterative decoder outputs decoded bit values for a data unit that includes the data symbol.

Proposed is a method for a terminal to decode a signal. In particular, the method for a terminal to decode a signal comprises: a step for demodulating a first low density parity check (LDPC)-coded signal; and a step for decoding a second signal obtained from the first demodulated signal through a trained neural network. The second signal is obtained by using: an output sequence generated on the basis of the trained neural network; and a log likelihood ratio (LLR) sequence of the first signal.

A method implemented in a computer system includes training a network, which is obtained by unfolding an iterative algorithm for demodulation or demodulation and decoding, using a machine learning technique with a loss function that takes into account non-Gaussianity of a log-likelihood ratio (LLR) distribution calculated from an output of the network. The method further includes producing a first set of learned parameters of that iterative algorithm.

A data encoding and decoding method for underwater acoustic networks (UANs) based on an improved online fountain code, including: in a build-up phase, subjecting all original packets to sequential encoding according to their serial numbers to generate and send encoded packets with degree 2; merging k original packets to k/8 connected components with a size of 8; performing random encoding until a largest connected component is successfully decoded; in a completion phase, sending, by a receiver, a feedback packet according to a current decoding graph; according to a feedback packet containing decoding states of all the original packets, sending, by a sender, encoded packets with degree m; and randomly selecting original packets for recursive encoding to generate and send encoded packets with degree 1 or 2; and setting, by the receiver, a threshold to restrict the number of feedback packets.

A transmission method includes mapping processing, phase change processing, and transmission processing. In the mapping processing, a plurality of first modulation signals and a plurality of second modulation signals are generated using a first mapping scheme, and a plurality of third modulation signals and a plurality of fourth modulation signals are generated using a second mapping scheme. In the phase change processing, a phase change is performed on the plurality of second modulation signals and the plurality of fourth modulation signals using all N kinds of phases. In the transmission processing, the first modulation signals and the second modulation signals are respectively transmitted at a same frequency and a same time from different antennas, and the third modulation signals and the fourth modulation signals are respectively transmitted at a same frequency and a same time from the different antennas.

The present invention is directed to data communication. More specifically, an embodiment of the present invention provides an error correction system. Input data signals are processed by a feedforward equalization module and a decision feedback back equalization module. Decisions generated by the decision feedback equalization module are processed by an error detection module, which determines error events associated with the decisions. The error detection module implements a reduced state trellis path. There are other embodiments as well.

A method, an apparatus and a system for determining stress on a low density parity check (LDPC) process for a network using orthogonal frequency division multiplexing (OFDM).

There is provided mechanisms for radio link adaptation at a transmit and receive point. A method is performed by a network node. The method includes obtaining LLR values for a block of codewords. The LLR values are output from an information decoder decoding the block of codewords. The block of codewords has been communicated over a radio link between the transmit and receive point and a terminal device. The method includes performing radio link adaptation of the radio link depending on the LLR values by selecting radio link adaptation parameter values. Which radio link adaptation parameter values to select depends on the LLR values.

A communication device (20 and 40) includes a redundant data generation unit (212a and 412a), a signal generation unit (212b, 412b, 212c, and 412c), and a transmission unit (212d and 412d). The redundant data generation unit (212a and 412a) performs error correction coding processing on combined data obtained by combining first data and second data to generate redundant data used for error correction. The signal generation unit (212b, 412b, 212c, and 412c) generates a transmission signal based on the second data and the redundant data. The transmission unit (212d and 412d) transmits the transmission signal to another communication device (20 and 40).