LDPC Parity-Check Matrix Lifting for Flexible Code Lengths
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Solution Overview
Problem
Current LDPC codes face limitations in supporting various lengths and code rates due to the multiple relationship of lifting values, which restricts their application in mobile communication systems requiring high data transmission compatibility.
Innovation Solution
The proposed method involves a changed lifting process where the maximum value of lifting values is defined as Zmax, and divisors of Zmax are used to determine Z values, allowing for the design of parity-check matrices without the multiple relationship constraint, thereby supporting various lengths and code rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional LDPC codes use multiple relationship of lifting values, then the code structure is simplified, but the ability to support various lengths and code rates is limited
Solution Approach 1:
The parity-check matrix is divided into multiple blocks, where each block corresponds to a specific lifting value. This segmentation allows the system to support various code lengths and rates by selectively combining different blocks, resolving the contradiction between versatility and complexity.
Solution Approach 2:
The patent changes the lifting values used in constructing the parity-check matrix based on the desired code length and rate. By dynamically selecting different lifting values (e.g., Z=12, Z=24, Z=36) for different blocks, the system achieves adaptability without requiring a completely new matrix design for each scenario.
2Productivity
If lifting values have multiple relationships, then the encoding process becomes more efficient, but the cycle characteristics of the code deteriorate
Solution Approach 1:
Different blocks of the parity-check matrix are designed with different local qualities - some blocks use lifting values optimized for encoding efficiency while others use lifting values optimized for cycle characteristics. This local differentiation allows both requirements to be satisfied simultaneously in different parts of the overall code structure.
3Device complexity
If a single parity-check matrix is designed for maximum length, then the design is simplified, but it cannot efficiently support shorter code lengths
Solution Approach 1:
The system dynamically selects and combines different blocks of the parity-check matrix based on the required code length. Rather than using a single static matrix, the encoder can adaptively choose which blocks to use, making the system efficient for both long and short codes without requiring separate designs.
Data Source
AI summary
The present invention related to a 5G or pre-5G communication system to be provided to support a higher data transmission rate since 4G communication systems like LTE. The present invention relates to a method and an apparatus for encoding a channel in a communication or broadcasting system supporting parity-check matrices having various sizes are provided. The method for encoding a channel includes determining a block size of the parity-check matrix; reading a sequence for generating the parity-check matrix, and transforming the sequence by applying a previously defined operation to the sequence based on the determined block size.