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.

Quadrature amplitude modulation (QAM) techniques for use in optical systems are described. An optical transceiver may include a modulator configured to modulate data according to a scaled set-partitioning QAM (SP-QAM) scheme. The modulator may be configured to receive a plurality of bits, associate the plurality of bits with a plurality of symbols according to the scaled (SP-QAM) scheme; and transmit the plurality of symbols over an optical channel. A demodulator in an optical receiver may receive the plurality of symbols transmitted over the optical channel and associate the received symbols with a plurality of bits according to the scaled (SP-QAM) scheme; and provide the plurality of bits to a forward error correction decoder.

Methods (C) for converting a data signal (U). The methods may comprise (i) providing an input symbol stream (IB) of input symbols (Bj), the input symbol stream (IB) being representative for the data signal (U) to be converted and (ii) applying to consecutive disjunct partial input symbol sequences (IB.sup.p) of a number of p consecutive input symbols (IBj) covering said input symbol stream (IB), a distribution matching process (DM) to generate and output a final output symbol stream (OB) or a preform thereof, wherein the distribution matching process (DM) may be formed by a preceding shell mapping process (SM) and a succeeding amplitude mapping process (AM), wherein said shell mapping process (SM) may be configured to form and output to said amplitude mapping process (AM) for each of said consecutive partial input symbol sequences (IB.sup.p) a sequence (s.sup.q) of a number of q shell indices (s), and wherein said amplitude mapping process (AM) may be configured to assign to each shell index (s) a tuple of amplitude values.

A Radio Network Node (RNN) 110 and a method therein for improving capacity in a wireless communications system 100. The RNN is configured to serve a first wireless device 120 and a second wireless device (WD) 130. The RNN assigns a shared uplink pilot signal to the first and second WDs. Further, the RNN transmits, to the first WD, an indication of how possible second data intended for the second WD will be comprised in a signal to be transmitted to the first WD. Furthermore, the RNN estimates a combined channel based on a received shared uplink pilot signal from the first WD and/or the second WD. Yet further, the RNN determines a beamforming vector for the estimated combined channel; and transmits the signal to the first WD, wherein the signal comprises first data and the possible second data, which first data is decodable only by the first WD.

A receiving apparatus includes: a first decoder configured to decode a signal transmitted through a first layer from a layered division multiplexing (LDM) signal using a parity check matrix to generate low density parity check (LDPC) information word bits and parity bits; an encoder configured to encode the LDPC information word bits, generated by decoding the signal transmitted through the first layer, using the parity check matrix to generate parity bits corresponding only to preset columns in the parity check matrix; and a second decoder configured to decode a signal obtained by removing, from the LDM signal, a signal corresponding to the LDPC information word bits generated by decoding the signal transmitted through the first layer, the parity bits generated by the encoder, and the parity bits generated by the first decoder except the parity bits generated by the encoder, thereby to generate information word bits transmitted through a second layer.

Provided are a data transmitting or receiving method and device for dual Transport Blocks (TBs), a transmitter and a receiver. Data to be transmitted is divided into two portions, where transport blocks TB1 and TB2 are generated respectively according to a corresponding predetermined Modulation Coding Scheme (MCS) for each portion. The TB1 is modulated into an amplitude weighted complex symbol sequence S1, and the TB2 is modulated into an amplitude weighted complex symbol sequence S2. The S1 and the S2 are superposed to generate a complex symbol sequence S3 corresponding to a new TB, where the complex symbol sequence S3 corresponding to the new TB possesses Gray properties. The new TB is transmitted to a receiver.

Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may determine an odd-exponent modulation constellation order for a group of bits; determine a parity bit location for the group of bits based at least in part on the odd-exponent modulation constellation order; and map the group of bits, with a parity bit in the parity bit location, to an odd-exponent modulation constellation of the odd-exponent modulation constellation order.

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.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 7/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for quadrature phase shift keying (QPSK) modulation.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 7/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for quadrature phase shift keying (QPSK) modulation.