Methods and communication apparatuses are presented for bit-to-symbol mapping. The method for bit-to-symbol mapping according to one example of the present invention includes: obtaining a plurality of base constellation maps; and mapping an input bit sequence by using the plurality of base constellation maps to generate symbols to be transmitted.

Provided is a transmission method that improves data reception quality in radio transmission using a single-carrier scheme and/or a multi-carrier scheme. The transmission method includes: generating a plurality of first modulated signals and a plurality of second modulated signals from transmission data, the plurality of first modulated signals being signals generated using a 16QAM modulation scheme, and the plurality of second modulated signals being signals generated using uniform constellation 64QAM modulation; generating, from the plurality of first modulated signals and the plurality of second modulated signals, a plurality of first signal-processed signals and a plurality of second signal-processed signals which satisfy a predetermined equation; and changing the predetermined equation when a 64QAM modulation used to generate the plurality of second modulated signals is switched from the uniform constellation 64QAM modulation to a non-uniform constellation 64QAM modulation.

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.

Provided is a transmission method that improves data reception quality in radio transmission using a single-carrier scheme and/or a multi-carrier scheme. The transmission method includes: generating a plurality of first modulated signals and a plurality of second modulated signals from transmission data, the plurality of first modulated signals being signals generated using a 16 QAM modulation scheme, and the plurality of second modulated signals being signals generated using uniform constellation 64 QAM modulation; generating, from the plurality of first modulated signals and the plurality of second modulated signals, a plurality of first signal-processed signals and a plurality of second signal-processed signals which satisfy a predetermined equation; and changing the predetermined equation when a 64 QAM modulation used to generate the plurality of second modulated signals is switched from the uniform constellation 64 QAM modulation to a non-uniform constellation 64 QAM modulation.

A method (C) for converting a data signal (U). The method comprises processes of (i) providing an input bit stream (IB) of input bits (IBj), the input bit stream (IB) being representative for the underlying data signal (U) to be converted, and (ii) applying to consecutive disjunct partial input bit sequences (IB.sup.k) of a number of k consecutive input bits (IBj) covering said input bit stream (IB) a distribution matching process (DM) to generate and output a final output bit stream (OB) or a preform thereof. The distribution matching process (DM) is formed by a quadrant constellation shaping process (QS) and configured to map a respective partial input bit sequence (IB.sup.k) to a constellation point of a four-dimensional 2.sup.4.Math.m-QAM constellationin particular conveying two distinct polarizations for each of an in-phase and a quadrature componentwith I and m being fixed natural numbers and with k and m fulfilling the relation 4.Math.mk.

Methods and communication apparatuses are presented for bit-to-symbol mapping. The method for bit-to-symbol mapping according to one example of the present invention includes: obtaining a plurality of base constellation maps; and mapping an input bit sequence by using the plurality of base constellation maps to generate symbols to be transmitted

A simple construction for a family of non-uniform APSK constellations by the radial isomorphism between squares to circles is provided. The mutual information values indicate gains of at least 0.5 dB up to 1.5 dB with respect to the state of the art, such as the DVB-S2X constellations with 256 symbols. The invention also provides for a low-complexity detector of high-order modulated signals.

Provided is a transmission method that improves data reception quality in radio transmission using a single-carrier scheme and/or a multi-carrier scheme. The transmission method includes: generating a plurality of first modulated signals and a plurality of second modulated signals from transmission data, the plurality of first modulated signals being signals generated using a 16QAM modulation scheme, and the plurality of second modulated signals being signals generated using uniform constellation 64QAM modulation; generating, from the plurality of first modulated signals and the plurality of second modulated signals, a plurality of first signal-processed signals and a plurality of second signal-processed signals which satisfy a predetermined equation; and changing the predetermined equation when a 64QAM modulation used to generate the plurality of second modulated signals is switched from the uniform constellation 64QAM modulation to a non-uniform constellation 64QAM modulation.

A method (C) for converting a data signal (U). The method comprises processes of (i) providing an input bit stream (IB) of input bits (IBj), the input bit stream (IB) being representative for the underlying data signal (U) to be converted, and (ii) applying to consecutive disjunct partial input bit sequences (IB.sup.k) of a number of k consecutive input bits (IBj) covering said input bit stream (IB) a distribution matching process (DM) to generate and output a final output bit stream (OB) or a preform thereof. The distribution matching process (DM) is formed by a quadrant constellation shaping process (QS) and configured to map a respective partial input bit sequence (IB.sup.k) to a constellation point of a four-dimensional 2.sup.4.Math.m-QAM constellationin particular conveying two distinct polarizations for each of an in-phase and a quadrature componentwith I and m being fixed natural numbers and with k and m fulfilling the relation 4.Math.mk.

A method, system, and apparatus for encoding a data for transmission across a communication link, the comprising encoding the data into a constellation; wherein the constellation is of a power 2.sup.n; wherein n is an odd number; wherein encoding the constellation creates outer constellation points forming a square at an edge of the constellation.