A coding and modulation apparatus and method are presented. The apparatus comprises an encoder that encodes input data into cell words, and a modulator that modulates said cell words into constellation values of a non-uniform constellation. The modulator is configured to use, based on the total number M of constellation points of the constellation and the code rate, a non-uniform constellation from one or several groups of constellations each comprising one or more constellations.

A coding and modulation apparatus and method are presented. The apparatus comprises an encoder that encodes input data into cell words, and a modulator that modulates said cell words into constellation values of a non-uniform constellation. The modulator is configured to use, based on the total number M of constellation points of the constellation and the code rate, a non-uniform constellation from one or several groups of constellations each comprising one or more constellations.

With rapid increases in the number and spatial density of wireless messages as 5G and 6G are rolled out, it is essential that improved methods for fault-tolerant demodulation and error mitigation be developed. Disclosed herein are methods for receiving a message concatenated with a demodulation reference, determining the predetermined modulation levels of a modulation scheme, and demodulating the message by measuring the amplitude mad/or phase modulation values of each message element. The measured modulation values are then compared with the predetermined modulation levels of the modulation scheme to demodulate the message. Importantly, the message can be demodulated by determining an amplitude and phase of the raw signal for each message element, or by separating the raw signal into two orthogonal “branches” and determining the amplitudes of the two branches. By demodulating the message both ways, message faults may be identified and mitigated, according to some embodiments.

If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, the power consumption increases and the control becomes complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an encoding means for encoding digital signals to be transmitted under a predetermined transmission condition over an optical carrier wave by using one of a plurality of encoding methods; an encoding control means for selecting a predetermined encoding method corresponding to the predetermined transmission condition from among the plurality of encoding methods and causing the encoding means to operate in accordance with the predetermined encoding method; a mapping means for mapping output bit signals output from the encoding means to modulation symbols; and an optical modulation means for modulating the optical carrier wave based on symbol signals output from the mapping means.

If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, the power consumption increases and the control becomes complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an encoding means for encoding digital signals to be transmitted under a predetermined transmission condition over an optical carrier wave by using one of a plurality of encoding methods; an encoding control means for selecting a predetermined encoding method corresponding to the predetermined transmission condition from among the plurality of encoding methods and causing the encoding means to operate in accordance with the predetermined encoding method; a mapping means for mapping output bit signals output from the encoding means to modulation symbols; and an optical modulation means for modulating the optical carrier wave based on symbol signals output from the mapping means.

A method and device in a UE and a base station used for wireless communications. The UE first receives a first signaling, and then transmits a first radio signal; the first signaling is used for determining K REs, and K first-type complex numbers are used for generating a baseband signal of the first radio signal through a baseband signal generation for generating an SC-FDMA baseband signal, a modulation scheme employed by the first radio signal is π/2-BPSK, K first-type parameters respectively correspond to the K first-type complex numbers, the K REs occupy contiguous subcarriers in frequency domain. The K first-type parameters are related to a center frequency of the contiguous subcarriers occupied by the K REs, each of the K first-type parameters is related to a length of cyclic prefix of an RE onto which a corresponding first-type complex number is mapped. The present disclosure improves uplink coverage performance.

A transmitter includes: a modulation circuit that modulates a data sequence using QAM by mapping the data sequence to only four symbols each of which differs in phase by 90 degrees from an adjacent one of the four symbols and at least two of which have different amplitudes; and a transmission circuit that wirelessly transmits the data sequence mapped to the four symbols through the modulation by the modulation circuit, by assigning the data sequence mapped to the four symbols through the modulation by the modulation circuit to different subcarriers for Orthogonal Frequency Division Multiplexing (OFDM).

Methods, systems, and devices for contention-based transmissions using differential coding techniques in mobile communication technology are described. An exemplary method for wireless communication includes transmitting, by a wireless device, a payload including a first portion that is modulated using a differential coding technique and a second portion that is modulated using an amplitude-shift keying (ASK) or phase-shift keying (PSK) modulation, and where the payload includes an identity of the wireless device and at least one of a user plane data or a control plane data.

A quantum communication method, an apparatus, and a system are provided. The method includes: modulating a first symbol to an i.sup.th direction vector of a first electric wave based on a preset mapping relationship, to obtain a second electric wave; and transmitting the second electric wave, where the first electric wave supports M direction vectors, the i.sup.th direction vector of the first electric wave is one of the M direction vectors of the first electric wave, the first symbol is a symbol corresponding to first data, the i.sup.th direction vector of the first electric wave corresponds to an i.sup.th distribution result, the i.sup.th distribution result is obtained by converting the second electric wave into an energy quantum. The first symbol may be modulated to a direction vector of the first electric wave, and this application is compatible with the conventional technology.

A packet detection method is disclosed. The packet detection method includes the following operations: receiving a wireless communication signal; calculating a delay correlation function of the wireless communication signal; calculating a delay related output value and a threshold value according to the delay correlation function; and determining whether the wireless communication signal satisfies a feature of a wireless network packet or not according to the delay related output value and the threshold value.