A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i×Δλ to the second precoded signal; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. Δλ satisfies π/2 radians<Δλ<π radians or π radians<Δλ<3π/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.

A modulator and a modulation method using a non-uniform 16-symbol signal constellation are disclosed. The modulator includes a memory and a processor. The memory receives a codeword corresponding to a low-density parity check (LDPC) code having a code rate of 4/15. The processor maps the codeword to 16 symbols of the non-uniform 16-symbol signal constellation on a 4-bit basis.

Methods, systems, and devices for wireless communications are described. In some systems, a transmitting device may identify one or more blocks of data for transmission to a receiving device. The transmitting device may map subsets of bits of the one or more blocks of data to a constellation of symbol points of a modulation order to obtain a set of symbols and may then transmit a signal including the set of symbols to a receiving device. In some systems, a receiving device may receive, from the transmitting device, the signal including the set of symbols associated with blocks of data. The receiving device may de-map the set of symbols according to a constellation of symbol points of a modulation order to obtain a plurality of sets of de-mapped data bits and decode a plurality of sets of de-mapped data bits to obtain the blocks of data.

The disclosure relates to a transmitting communication apparatus and a receiving communication apparatus of a non-coherent communication system. The transmitting communication apparatus is configured to communicate with the receiving communication apparatus via a communication channel. The transmitting communication apparatus comprises a processing circuitry configured to: map a sequence of data bits into a modulation symbol of a plurality of modulation symbols defined by a modulation constellation, wherein the modulation constellation is defined by a tiling of a Grassmannian manifold into a plurality of cells and a Cartesian product of a plurality of auxiliary constellations, wherein the Cartesian product of the plurality of auxiliary constellations is mapped onto each cell of the plurality of cells and each auxiliary constellation defines a plurality of auxiliary symbols. The processing circuitry is further configured to transmit a modulated signal based on the modulation symbol via the communication channel to the receiving communication apparatus.

Methods and apparatus for facilitating wireless communication using digital Quadrature Amplitude Modulation are disclosed. A mapping module electronic component of a wireless communication device utilizes a signal constellation for quadrature modulating a signal for transmission or quadrature demodulating a received signal. The signal constellation includes multiple constellation symbols and associated bit sequences. Specific signal constellations are disclosed. The signal constellations may be obtained through an optimization procedure which accounts for both phase noise and power amplifier nonlinearity.

A modulator and a modulation method using a non-uniform 16-symbol signal constellation are disclosed. The modulator includes a memory and a processor. The memory receives a codeword corresponding to a low-density parity check (LDPC) code having a code rate of 4/15. The processor maps the codeword to 16 symbols of the non-uniform 16-symbol signal constellation on a 4-bit basis.

Methods, systems, and devices for wireless communications are described. In some systems, a transmitting device may identify one or more blocks of data for transmission to a receiving device. The transmitting device may map subsets of bits of the one or more blocks of data to a constellation of symbol points of a modulation order to obtain a set of symbols and may then transmit a signal including the set of symbols to a receiving device. In some systems, a receiving device may receive, from the transmitting device, the signal including the set of symbols associated with blocks of data. The receiving device may de-map the set of symbols according to a constellation of symbol points of a modulation order to obtain a plurality of sets of de-mapped data bits and decode a plurality of sets of de-mapped data bits to obtain the blocks of data.

A modulator and a modulation method using a non-uniform 16-symbol signal constellation are disclosed. The modulator includes a memory and a processor. The memory receives a codeword corresponding to a low-density parity check (LDPC) code having a code rate of 4/15. The processor maps the codeword to 16 symbols of the non-uniform 16-symbol signal constellation on a 4-bit basis.

A modulator and a modulation method using a non-uniform 16-symbol signal constellation are disclosed. The modulator includes a memory and a processor. The memory receives a codeword corresponding to a low-density parity check (LDPC) code having a code rate of 4/15. The processor maps the codeword to 16 symbols of the non-uniform 16-symbol signal constellation on a 4-bit basis.

Probabilistic shaping quadrature amplitude modulation (QAM) based on Maxwell-Boltzmann distribution is particularly important in coherent optical communication, which can approach the Shannon limit more desirably in the case of a finite signal-to-noise ratio. However, standard coherent optical digital signal processing algorithms are not optimal for demodulation of PS higher-order QAM signals. The invention provides a probabilistic shaping QAM dynamic equalization method that intercepts multiple inner rings after clock recovery and updates the convergence radius and area of a conventional blind dynamic channel equalization algorithm using a peak density K-means clustering algorithm. The clustering algorithm gives centroid labels and a quantity of classifications required for K-means, which does not require a large number of iterations of K-means, thereby reducing the complexity and improving the accuracy. The updated decision area and decision radius reduce errors in the dynamic equalization algorithm, thereby improving the accuracy of probabilistic shaping QAM digital signal processing.