LDPC Encoding Scheme Selection for Variable Block Length Transmission

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Solution Overview

Problem

Existing broadcast and communication systems face challenges in maintaining high data reception quality with variable block lengths and coding rates, particularly when using LDPC codes in mobile or semi-fixed environments.

Innovation Solution

A method involving multiple coding methods, including LDPC codes with and without puncturing, is employed to adapt to variable block lengths and coding rates, using different parity check matrices for encoding and decoding processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single LDPC code with fixed block length and coding rate is used, then the system is simple to implement, but it cannot adapt to variable data amounts and different reception environments

Engineering Contradiction:

Improveadaptability to variable block lengths and coding ratesVSAvoidcomplexity of multiple coding methods

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic selection of LDPC coding methods based on reception environment and data characteristics. The system transitions from static single-code configuration to dynamic multi-code selection, allowing the coding rate and block length to adapt to varying channel conditions and data amounts, thereby resolving the contradiction between adaptability and complexity

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes key parameters of the LDPC code including block length, coding rate, and parity check matrix configuration. By providing multiple LDPC codes with different parameters and selecting appropriate ones based on reception conditions, the system achieves adaptability while managing complexity through parameter variation rather than fundamental system changes

Inventive Principle:

Principle #35Parameter changes

2Productivity

If high coding rate is used to increase data transmission efficiency, then productivity improves, but error correction performance deteriorates in mobile environments

Engineering Contradiction:

Improvedata transmission efficiencyVSAvoiderror correction performance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent dynamically adjusts the coding rate based on reception environment quality. In mobile environments with poor channel conditions, the system selects lower coding rates to prioritize reliability. In stable environments, higher coding rates are used to maximize throughput. This dynamic adjustment resolves the contradiction between productivity and reliability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies different coding rates and LDPC code configurations to different data blocks or transmission segments based on local channel conditions. Rather than using a uniform coding rate for all data, the system optimizes each transmission segment's coding parameters according to its specific reception environment, allowing simultaneous optimization of both efficiency and reliability

Inventive Principle:

Principle #3Local quality

3Reliability

If low coding rate is used to improve error correction performance, then reliability improves, but data transmission efficiency decreases

Engineering Contradiction:

Improveerror correction performanceVSAvoiddata transmission efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system dynamically selects coding rates based on channel conditions, using lower coding rates only when necessary for maintaining reliability in poor mobile environments. In better conditions, the system transitions to higher coding rates to restore transmission efficiency, thus resolving the contradiction between reliability and productivity

Inventive Principle:

Principle #15Dynamics

4Adaptability or versatility

If multiple LDPC codes with different block lengths are prepared, then adaptability to variable data amounts improves, but memory requirements and system complexity increase

Engineering Contradiction:

Improveadaptability to variable block lengthsVSAvoidmemory resources

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent designs LDPC codes with universal structures that can function across multiple block lengths. Rather than storing completely separate codes for each block length, the system uses a unified code framework that can be configured for different block lengths, reducing memory requirements while maintaining adaptability to variable data amounts

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12470323B2Transmitting device for performing an encoding process on an information bit sequence using a coding scheme selected from a coding scheme set

Publication Date: 2025.11.11 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

AI summary

One coding method of a plurality of coding methods including at least a first coding method and a second coding method is selected, an information sequence is encoded by using the selected coding method, and an encoded sequence obtained by performing predetermined processing on the information sequence is modulated and transmitted. The first coding method is a coding method having a first coding rate, for generating a first encoded sequence by performing puncturing processing on a generated first codeword by using a first parity check matrix. The second coding method is a coding method having a second coding rate, for generating a second encoded sequence by performing puncturing processing on a generated second codeword by using a second parity check matrix that is different from the first parity check matrix, the second coding rate after the puncturing process being different from the first coding rate.