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US 9,722,633 B2Granted
Method and system for reliable data communications with adaptive multi-dimensional modulations for variable-iteration decoding
AssigneeMitsubishi Electric Research Laboratories, Inc.
InventorToshiaki Koike-Akino
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Abstract
In an advanced adaptive modulation and coding (AMC) scheme, the code rate and the parity-check matrix (PCM) for low-density parity-check (LDPC) codes are adapted according to modulation formats and variable-iteration receivers. The degree distribution for the PCM adaptation is designed by heuristic optimization to minimize the required SNR via an extrinsic information transfer (EXIT) trajectory analysis for finite-iteration decoding. The method uses dynamic window decoding by generating spatially coupled PCM for quasi-cyclic LDPC convolutional coding. The method also provides a way to jointly optimize labeling and decoding complexity for high-order and high-dimensional modulations.
Claims15
A method for adaptive modulation and coding (AMC) in a communications network, comprising steps:
- coding and decoding data using a set of codes having variable rate and multiple variable parity-check matrices (PCMs);
- and
- modulating and demodulating the data using a set of modulation formats having variable order and variable dimension, wherein the coding and the modulating are performed in a transmitter and the demodulating and the decoding are performed in a receiver,
- wherein the decoding uses a set of low-density parity-check (LDPC) codes having variable rate and variable PCM, wherein multiple PCMs have different degree distributions to achieve a minimum required SNR designed for different modulation parameters, different receiver parameters, and different coding parameters,
- wherein designing the multiple PCMs comprises steps;
- adjusting a degree distribution for variable nodes and check nodes in a bipartite graph for a given combination of the coding parameters, the modulation parameters, and the receiver parameters;
- adjusting a girth according to the adjusted degree distribution;
- and
- adapting the PCM to refine for different combinations of the modulation parameters and the receiver parameters,
- wherein adjusting the degree distribution comprises steps;
- setting up the degree distribution with average and maximum degree constraints;
- modifying a bit labeling for a high-order and high-dimensional modulation;
- analyzing mutual information updates across decoding iterations given the degree distribution by using an extrinsic information transfer (EXIT) trajectory analysis;
- searching for a required SNR achieving the mutual information of one by using a line search algorithm;
- iterating from the setting to the searching steps using heuristic optimization methods until a maximum iteration of optimizations reaches a pre-defined number;
- and
- outputting the degree distribution and the required SNR.
14 more elements
An adaptive modulation and coding (AMC) controller, comprising:
- a memory storing
- a set of codes having variable rate and multiple variable PCMs for encoding and decoding data;
- and
- a set of modulation formats having variable order and variable dimension for modulating and demodulating the data, wherein the set of modulation formats have different orders and different dimensions, further comprising;
- block-coded high-dimensional modulations, comprising 4-dimensional (4D) simplex modulation, 8D modulation based on an extended Hamming code, 16D modulation based on a Nordstrom-Robinson nonlinear code, and 24D modulation based on an extended Golay code;
- sphere-cut lattice-packed modulations, comprising 4D checker board lattice, 6D diamond lattice, 12D Coxeter-Todd lattice, 16D Barnes-Wall lattice, and 24D Leech lattice;
- space-time modulations, comprising Cayley-transformed unitary modulation, Alamouti modulation, and Reed-Muller operator modulation;
- and
- quadrature-amplitude modulations (QAM), comprising phase shift keying (PSK), and pulse-amplitude modulation (PAM);
- and
- an AMC selector for selecting a combination of one of the codes and one of the modulation formats for coding and modulating in a transmitter, and demodulation and decoding in a receiver.
8 more elements
A method for adaptive modulation and coding (AMC) in a communications network, comprising steps:
- coding and decoding data using a set of codes having variable rate and multiple variable parity-check matrices (PCMs);
- and
- modulating and demodulating the data using a set of modulation formats having variable order and variable dimension, wherein the coding and the modulating are performed in a transmitter and the demodulating and the decoding are performed in a receiver,
- wherein the set of modulation formats have different orders and different dimensions, further comprising;
- block-coded high-dimensional modulations, comprising 4-dimensional (4D) simplex modulation, 8D modulation based on an extended Hamming code, 16D modulation based on a Nordstrom-Robinson nonlinear code, and 24D modulation based on an extended Golay code;
- sphere-cut lattice-packed modulations, comprising 4D checker board lattice, 6D diamond lattice, 12D Coxeter-Todd lattice, 16D Barnes-Wall lattice, and 24D Leech lattice;
- space-time modulations, comprising Cayley-transformed unitary modulation, Alamouti modulation, and Reed-Muller operator modulation;
- and
- quadrature-amplitude modulations (QAM), comprising phase shift keying (PSK), and pulse-amplitude modulation (PAM).
6 more elements
Dependencies are inferred from the claim text.