LDPC Base Graph Segmentation for Variable Block Length Coding

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Solution Overview

Problem

Current LDPC codes in wireless communication systems face challenges in achieving high throughput with efficient hardware utilization, particularly in supporting a wide range of information block lengths and code rates, which is essential for next-generation networks like 5G New Radio.

Innovation Solution

The implementation of multiple LDPC base graphs, each associated with different information block length ranges, allowing for selection based on block length, code rate, and lift size to optimize encoding and decoding processes, thereby enhancing decoder resource utilization and throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple LDPC base graphs are maintained with overlapping information block length ranges, then the adaptability to support wide range of block lengths and code rates is improved, but the device complexity increases

Engineering Contradiction:
Improvesupport range of information block lengths and code ratesVSAvoidnumber of LDPC base graphs
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the LDPC coding space by dividing it into multiple base graphs, each optimized for specific information block length ranges and code rate ranges. This segmentation allows the system to handle diverse coding requirements with specialized graphs rather than one oversized graph, resolving the contradiction by making the complexity manageable through structured division.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic selection of LDPC base graphs based on the information block length and code rate of the incoming data. The system dynamically determines which base graph to use from the plurality of maintained graphs, allowing adaptability to varying conditions while maintaining efficient hardware utilization through selective activation of appropriate graphs.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If LDPC codes are designed to support wide range of information block lengths and code rates, then the versatility for future networks is improved, but the hardware utilization efficiency deteriorates

Engineering Contradiction:
Improverange of supported block lengths and code ratesVSAvoidhardware utilization efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

Each LDPC base graph is designed with local quality optimization, where the graph structure, lift size, and parameters are specifically tailored for its designated information block length range and code rate range. This local optimization ensures that each graph operates at peak efficiency for its intended purpose, preventing the hardware utilization deterioration that would occur with a single generalized graph.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by varying key LDPC parameters such as lift size, information block length, and code rate across different base graphs. By systematically changing these parameters to create multiple specialized graphs, the system achieves wide versatility while maintaining high hardware utilization efficiency through parameter-optimized designs for each graph.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If overlapping information block length ranges are used across LDPC base graphs, then the selection flexibility is improved, but the complexity of graph selection increases

Engineering Contradiction:
Improveselection flexibilityVSAvoidselection process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-defining overlapping information block length ranges for each LDPC base graph during system design. This preliminary structuring of ranges creates a systematic framework that guides the selection process, allowing the system to quickly determine the appropriate graph based on the incoming data's block length without requiring complex real-time analysis.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3577763A1Multiple low density parity check (LDPC) base graph design
Publication Date: 2019.12.11 QUALCOMM INC

AI summary

Aspects of the present disclosure relate to low density parity check (LDPC) coding utilizing LDPC base graphs. Two or more LDPC base graphs may be maintained that are associated with different ranges of overlapping information block lengths. A particular LDPC base graph may be selected for an information block based on the information block length of the information block. Additional metrics that may be considered when selecting the LDPC base graph may include the code rate utilized to encode the information block and/or the lift size applied to each LDPC base graph to produce the information block length of the information block.