LDPC Matrix Segmentation for Flexible Code Length and Rate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communication systems face challenges in supporting flexible code length and code rate requirements for LDPC codes, which are essential for efficient encoding and decoding in various communication systems, including 5G mobile communication systems.
Innovation Solution
The implementation of a method and apparatus that utilize a specific structure for LDPC matrices, including submatrices A and B with specific weight configurations, and the application of lifting factors to support different block lengths and code rates, allowing for flexible encoding and decoding of information bit sequences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed LDPC matrix structure is used, then the decoding algorithm is simple, but the system cannot meet flexible code length and code rate requirements
Solution Approach 1:
The LDPC matrix is segmented into multiple submatrices (e.g., information submatrix, parity submatrix, puncture submatrix) with different functions. Each submatrix can be independently configured to achieve flexible code length and code rate while maintaining a manageable overall structure that supports efficient encoding and decoding operations.
Solution Approach 2:
The patent employs dynamic configuration of the LDPC matrix structure through parameters such as lifting factor Z, code rate R, and code length N. These parameters can be adjusted according to channel conditions and communication requirements, allowing the system to adaptively change the matrix dimensions and submatrix compositions without requiring a completely different decoding algorithm.
2Adaptability or versatility
If the LDPC matrix is expanded to support various code lengths, then the system versatility improves, but the decoding complexity increases
Solution Approach 1:
Different submatrices within the LDPC matrix are designed with locally optimized properties. For example, the information submatrix may have a specific density pattern while the parity submatrix has a different pattern optimized for error correction. This local optimization allows each part to contribute efficiently to the overall decoding process while supporting variable code lengths through selective inclusion or exclusion of certain submatrices.
3Adaptability or versatility
If puncture bits are added to achieve higher code rates, then the code rate flexibility improves, but the reliability may deteriorate
Solution Approach 1:
Puncture bits are pre-allocated in specific positions within the LDPC matrix structure before encoding. The positions of these puncture bits are carefully selected in advance to minimize their impact on decoding performance. By preliminarily designing the puncture pattern based on the desired code rate, the system achieves code rate flexibility while maintaining reliability through optimized puncture placement that preserves the matrix's error-correcting capabilities.
Data Source
AI summary
This application relates to communicating information between communication devices. A channel coding method is disclosed. A communication device obtains an input sequence of K bits. The communication device encodes the input sequence using a low density parity check (LDPC) matrix H, to obtain an encoded sequence. The LDPC matrix H is determined according to a base matrix and a lifting factor Z. The base matrix includes m rows and n columns, m is greater than or equal to 5, and n is greater than or equal to 27. The lifting factor Z satisfies a relationship of 22*Z≥K. According to the encoding method provided in the embodiments, information bit sequences of a plurality of lengths can be encoded for transmission between the communication devices.