Disclosed are a modulation method, demodulation method, and apparatus for multi-user information transmission. The modulation method comprises: a transmitter determines a first modulation symbol and a second modulation symbol according to a first information bit, a second information bit, and a mapping table, the mapping table being used for determining a corresponding relation between the first information bit and the first modulation symbol and a corresponding relation between the second information bit and the second modulation symbol, each group of modulation symbols in the mapping table being superposed and mapped to a constellation diagram to achieve a Gray attribute; and the transmitter superposes the first modulation symbol and the second modulation symbol to obtain a superposed symbol.

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 receiving method for receiving a plurality of carriers and generating one or a plurality of streams. The method includes a first demodulating step of processing a first transmission signal and generating a first demodulation output; a second demodulating step of processing a second transmission signal different from the first transmission signal and generating a second demodulation output; a combining step of generating one stream based on the first demodulation output and the second demodulation output; a selecting step of selecting one among the first demodulation output and the one stream, and generating a selected stream; and a back-end processing step of generating an output for a display from the selected stream and the second demodulation output. In the selecting step, the first demodulation output is selected in a receiving mode in single channel transmission, and the one stream is selected in a receiving mode in multiple channel transmission.

A symbol phase difference compensating portion (6) calculates a first phase difference which is a phase difference between a known pattern extracted from a received signal and a true value of the known pattern and performs phase compensation for the received signal based on the first phase difference. A tentative determination portion (12) tentatively determines an output signal of the symbol phase difference compensating portion (6) to acquire an estimated value of a phase. A first phase difference acquiring portion (13) acquires a second phase difference which is a phase difference between a phase of the output signal and the estimated value of the phase acquired by the tentative determination portion (12). A first phase difference compensating portion (14) performs phase compensation for the output signal based on the second phase difference.

A receiving system of the present disclosure includes: a plurality of demodulators; an add-on generating one stream based on an output from each of the demodulators; a selector selecting and outputting one among an output from one of the demodulators, namely the demodulator, and the one stream from the add-on; and a back-end processor generating an output for a display based on an output from the selector and the other demodulators, namely the demodulators. The selector selects an output from the demodulator in a single channel transmission mode, and selects the stream from the add-on in a multiple channel transmission mode.

A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

Disclosed are a modulation method, demodulation method, and apparatus for multi-user information transmission. The modulation method comprises: a transmitter determines a first modulation symbol and a second modulation symbol according to a first information bit, a second information bit, and a mapping table, the mapping table being used for determining a corresponding relation between the first information bit and the first modulation symbol and a corresponding relation between the second information bit and the second modulation symbol, each group of modulation symbols in the mapping table being superposed and mapped to a constellation diagram to achieve a Gray attribute; and the transmitter superposes the first modulation symbol and the second modulation symbol to obtain a superposed symbol.

A digital signal processor (DSP) may include a receiver configured to receive an input signal. The DSP may include a processor component to perform carrier recovery on a set of digital signals representing a set of symbols associated with the input signal. The DSP may include an output component to provide information included in the set of digital signals representing the set of symbols. The DSP may be configured to perform, for the input signal, phase estimation with a latency of less than approximately 880 nanoseconds and having a power consumption of less than approximately 400 milliwatts at an update rate greater than approximately 4 Gigahertz. The latency being a propagation delay of the input signal.

A periodic phase modulation, having a period shorter than a symbol period, is applied as a source modulation, in addition to a symbol modulation, to signals transmitted between a transmitter and a receiver in a communication network. Symbol value elements can be sent from multiple transmitters (203, 303, 603, 703) to a receiver (607, 207) in the same symbol period can be processed on the basis of the source modulation without destructive interference. In some embodiments, the symbol value elements sent by different transmitters can be combined in the receiver. In some embodiments, symbol value elements sent by different transmitters can be distinguished in the receiver.

The present invention provides a method for hybrid scanning to reduce overhead in a beam scanning scheme in a millimeter wave (mmWave) system, and devices supporting same. The method for hybrid scanning in a wireless access system supporting millimeter wave technology, according to one embodiment of the present invention, comprises the steps of: receiving a synchronization signal to synchronize with a base station; synchronizing with the base station using the synchronization signal; receiving, from the base station, first pilot signals having different configuration patterns according to each transmitting antenna; ray-scanning using the first pilot signals; selecting a candidate beamforming port set through the ray-scanning; generating second pilot signals having different configuration patterns according to each beamforming port included in the candidate beamforming port set; and transmitting, to the base station, the second pilot signals to perform beam scanning with the base station.