A multiple access method, a multiple access transmitter, and a multiple access receiver includes performing, by a transmitter, channel coding on a bit sequence to determine a coded sequence. The method also includes interleaving and/or scrambling the coded sequence, and performing multidimensional constellation modulation on the interleaved and/or scrambled sequence; performing grid mapping on the modulated symbol sequence to determine a mapped sequence, and transmitting the mapped sequence. The method also includes receiving, by a receiver, mixed signals from multiple transmitters, the mixed signals are obtained by performing, by each of the multiple transmitters, interleaving and/or scrambling, multidimensional constellation modulation and grid mapping on data. The method further includes decoding, by the receiver, mixed information according to interleaver information and/or scrambler information, multidimensional constellation information and grid mapping pattern information corresponding to each transmitter to obtain data corresponding to each transmitter.

Architectures for inter-converting bitstreams and symbol streams of PAM and/or QAM constellations of different sizes that are not base-2 integers. Some of such constellations may be Gray-coded, and the constellation mapping may be performed to achieve an equiprobable distribution of different constellation symbols. Some embodiments may be compatible with FEC schemes. In an example embodiment, a transmitter DSP may employ a conventional constellation mapper preceded by an electronic encoder programmed to exclude some constellation-symbol labels from the bitstream applied to the mapper. In different embodiments, the electronic encoder may employ a CCDM and/or a long-division operation to select some amplitudes of the constellation and to exclude others. At least some embodiments are beneficially capable of achieving a smaller gap to the Shannon limit than comparable conventional solutions.

Encoder circuit encodes information bits using 2.sup.2N signal points. The encoder circuit includes: symbol mapper that allocates each symbol of frame including information bits, first code and second code to a corresponding signal point among 2.sup.2N signal points according to mapping pattern; converter that converts information bits in other bit strings among N bit strings forming the frame excluding MSB string by using probabilistic shaping; first encoder that generates the first code from information bits in MSB string and the information bits converted by the converter; and second encoder that generates the second code from the information bits in MSB string and the first code. In the mapping pattern, values of bits corresponding to the other bit strings are arranged symmetrically in the constellation, and each pair of adjacent signal points on the constellation are different from each other in terms of value of bit corresponding to MSB string.

A transmitting apparatus for modulating data based on a predetermined 2.sup.q-QAM constellation and a receiving apparatus and method for demodulating a signal based on the predetermined 2.sup.q-QAM constellation, wherein the last q-2 bits corresponding to a quadrant of the predetermined 2.sup.q-QAM constellation are same with a gray code of a 2.sup.q-2-QAM constellation, the last q-2 bits corresponding to the remaining quadrants of the predetermined 2.sup.q-QAM constellation are determined by performing symmetric transformation for the last q-2 bits of the quadrant of the predetermined 2.sup.q-QAM around the x-axis or the y-axis.

The present disclosure relates to a 5G or pre-5G communication system to be provided for supporting a higher data transfer rate beyond a 4G communication system such as LTE. The present invention relates to a NOMA system based FQAM connection method and an apparatus therefor. The present invention can increase the user transfer rate at a cell boundary. The scheduling method in a wireless communication system, according to an embodiment of the present invention, comprises a step of receiving a signal-to-interference-noise ratio (SINR) value and an alpha value from a terminal; a step of determining, on the basis of the SINR value and the alpha value, a Gaussian SINR value; a step of pairing users on the basis of the Gaussian SINR value; and a step of re-computing MCS on the basis of a re-computed alpha value.

A method by which a terminal demodulates a signal in a wireless access system according to one embodiment of the present invention comprises the steps of: receiving a modulation signal having a modulation order of 2.sup.m (m is a natural number); determining a first demodulation constellation arrangement corresponding to a k.sup.th (k is an even number among natural numbers of m or less) bit among m numbers of bits; determining a second demodulation constellation arrangement corresponding to an nth (n is an odd number among natural numbers of m or less) bit among the m numbers of bits; and demodulating the received modulation signal by using the first and second demodulation constellation arrangements, wherein the first constellation arrangement can have a pattern in which a square matrix having a size of 2.sup.(m/2+1)−(k/2) is repeated.

A telecommunication method which includes mapping, by a mapper, input data to points of a constellation, modulating, by a modulator, points of the constellation to generate modulated symbols, and transmitting a radio signal representative of the modulated symbols. The constellation includes a set of N points, the coordinates of which expressed in polar form α.sub.n X e.sup.jφn, n = 1,..., N, referred to as polar coordinates, are determined such that a.sub.n+1 = a.sub.n + p, p > 0, the real number being the pitch amplitude of the constellation.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.

The present disclosure relates to a communication method and system for converging a 5.sup.th-Generation (5G) communication system for supporting higher data rates beyond a 4.sup.th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. Embodiments of the present invention provide a multiple access method, a multiple access transmitter and a multiple access receiver. The multiple access method comprises the steps of: performing, by a transmitter, channel coding on a bit sequence to determine a coded sequence; interleaving and/or scrambling the coded sequence, and performing multidimensional constellation modulation on the interleaved and/or scrambled sequence; performing grid mapping on the modulated symbol sequence to determine a mapped sequence, and transmitting the mapped sequence; receiving, by a receiver, mixed signals from multiple transmitters, the mixed signals are obtained by performing, by each of the multiple transmitters, interleaving and/or scrambling, multidimensional constellation modulation and grid mapping on data; and, decoding, by the receiver, mixed information according to interleaver information and/or scrambler information, multidimensional constellation information and grid mapping pattern information corresponding to each transmitter to obtain data corresponding to each transmitter.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.