Transport Block Size Allocation for PAS-LDPC Coding Rates

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Solution Overview

Problem

The existing 5G communication systems face inefficiencies in spectral efficiency due to the use of high-order quadrature amplitude modulation (QAM) constellations, where the marginal benefits diminish due to non-linearity of the transmission medium, and enhanced channel coding and modulation schemes disrupt the effective code rate for the whole coding link, leading to inconsistencies with current MCS tables.

Innovation Solution

Implementing probabilistic amplitude shaping (PAS) combined with LDPC codes to enhance channel coding, adjusting the code rate based on channel quality indicator (CQI) reports, MCS indications, and transport block size (TBS) determination, while optimizing the labeling of constellation points to achieve balanced output probabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-order QAM constellations are used to improve spectral efficiency, then data transmission capacity increases, but the marginal benefits diminish due to non-linearity of the transmission medium

Engineering Contradiction:
Improvespectral efficiencyVSAvoidtransmission quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies probabilistic amplitude shaping (PAS) to transform the traditional uniform distribution of QAM constellation points into a non-uniform distribution. By adjusting the probability distribution parameters of amplitude levels, the system optimizes the balance between spectral efficiency and transmission reliability, achieving better performance than high-order QAM alone while mitigating the effects of channel non-linearity

Inventive Principle:
Principle #35Parameter changes

2Reliability

If enhanced channel coding schemes are implemented to improve error correction, then reliability increases, but the effective code rate for the whole coding link becomes inconsistent with current MCS tables

Engineering Contradiction:
Improveerror correction capabilityVSAvoidcoding link complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces probabilistic amplitude shaping as an intermediary layer between the channel encoder and the modulation mapper. This intermediary component transforms the coded bits into shaped symbols with optimized probability distribution, enabling the LDPC-coded system to achieve better error correction performance while maintaining compatibility with existing MCS tables through proper parameter configuration

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite coding scheme by combining LDPC codes with probabilistic amplitude shaping. This composite approach integrates the error correction strength of LDPC codes with the spectral efficiency benefits of PAS, achieving a synergistic effect that improves overall system performance while managing complexity through standardized parameter sets

Inventive Principle:
Principle #40Composite materials

3Productivity

If probabilistic amplitude shaping combined with LDPC codes is used to improve spectral efficiency, then communication performance increases by up to 2 dB, but code rate determination and TBS allocation require additional optimization

Engineering Contradiction:
Improvespectral efficiencyVSAvoidcode rate determination complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent performs preliminary optimization by pre-defining parameter sets that include code rates, modulation orders, and transport block size allocations specifically tailored for PAS-LDPC combinations. These pre-configured parameter sets enable faster and more accurate TBS determination without requiring complex real-time calculations, thus improving spectral efficiency while managing implementation complexity

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4165807B1Transport block size determination
Publication Date: 2025.09.03 ZTE CORP
  • EP4165807B1 patent drawingFigure 1A~1C
  • EP4165807B1 patent drawingFigure 1D~1H
  • EP4165807B1 patent drawingFigure 2

AI summary

The present application relates to methods, systems, and devices related to digital wireless communication, and more specifically, to techniques related to determining a transport block size. In one exemplary aspect, a method for wireless communication is disclosed. The method includes receiving, by a terminal, a first message that identifies a first coding rate and a second coding rate. The method also includes performing, by the terminal, a first operation relating to a first coding operation and using the first coding rate. The method also includes performing, by the terminal, a second operation relating to a second coding operation and using the second coding rate. The method also includes transmitting or receiving, by the terminal, a second message using information related to the first operation and/or the second operation.