LDPC Parity-Check Matrix Lifting for Variable Code Rates
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Solution Overview
Problem
Current LDPC codes face limitations in supporting various lengths and code rates due to the existing lifting method's constraints, which hinders their application in mobile communication systems requiring high data transmission compatibility.
Innovation Solution
The proposed method involves a changed lifting process that allows for the design of parity-check matrices with improved cycle characteristics, supporting various lengths and code rates by modifying the exponential transformation method to eliminate the multiple relationship between Z values, thereby enhancing the LDPC code's performance and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing lifting method is used to design parity-check matrices, then the LDPC code structure is simplified, but the code cannot support various lengths and code rates
Solution Approach 1:
The parity-check matrix is divided into multiple blocks, where each block corresponds to a specific length and code rate configuration. This segmentation allows the system to select appropriate blocks for different transmission requirements, enabling support for various lengths and code rates without redesigning the entire matrix structure.
Solution Approach 2:
The patent modifies the lifting method by introducing variable parameters that control the construction of parity-check matrices. By changing these parameters, the system can generate different matrix configurations suitable for various code lengths and rates, thereby improving adaptability while maintaining design simplicity.
2Adaptability or versatility
If the lifting method is modified to support various lengths, then the adaptability improves, but the cycle characteristics of the parity-check matrix deteriorate
Solution Approach 1:
The patent applies different construction methods to different blocks of the parity-check matrix. Specifically, certain blocks are designed with optimized cycle characteristics while others are configured for specific length support. This local optimization ensures that overall reliability is maintained even as adaptability increases.
Solution Approach 2:
The parity-check matrix is constructed as a composite structure combining multiple sub-matrices with different properties. By carefully designing the composition and arrangement of these sub-matrices, the system achieves both varied length support and good cycle characteristics through the synergistic effect of different matrix components.
3Productivity
If a sub-optimal parity-check matrix is designed, then the encoding and decoding efficiency improves, but the performance deteriorates slightly
Solution Approach 1:
The patent employs simplified construction rules for parity-check matrices that do not achieve optimal cycle characteristics but are sufficient for practical performance requirements. This partial optimization approach significantly reduces encoding and decoding complexity while maintaining acceptable performance levels for most communication scenarios.
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.