LDPC Base Matrix Segmentation for Flexible Channel Coding
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Solution Overview
Problem
Current channel coding methods, such as LDPC codes, face challenges in supporting flexible code lengths and code rates, particularly in meeting performance requirements for varying block lengths in communication systems.
Innovation Solution
The proposed solution involves using a specific structure for the LDPC matrix, including submatrices A and B with defined weights and permutations, along with lifting factors and puncture bits, to enable flexible encoding and decoding of information bit sequences, supporting different code rates and lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional LDPC code structure is used, then decoding complexity is reduced, but the ability to support flexible code lengths and code rates deteriorates
Solution Approach 1:
The LDPC base matrix is segmented into multiple submatrices (information submatrix, first parity submatrix, second parity submatrix) with different structures and functions. This segmentation allows each submatrix to be optimized independently for its specific purpose while maintaining overall flexibility in code length and rate configuration.
Solution Approach 2:
The patent employs dynamic configuration of code length and code rate by selectively using different numbers of information bits, first parity bits, and second parity bits based on communication requirements. The base matrix structure allows dynamic adjustment of operational parameters without changing the fundamental decoding architecture.
2Reliability
If the LDPC matrix is designed for high parallelism and throughput, then transmission reliability improves, but the adaptability to various block lengths deteriorates
Solution Approach 1:
The LDPC base matrix is designed as a universal structure that can support multiple code lengths and rates through systematic puncturing and shortening operations. The same base matrix framework serves multiple functions by adjusting the active portions of different submatrices, enabling both high reliability through optimized structure and adaptability through flexible configuration.
Solution Approach 2:
Different submatrices within the base matrix are assigned different local qualities and structures optimized for their specific roles. The information submatrix, first parity submatrix, and second parity submatrix each have tailored characteristics that optimize local performance while contributing to overall system reliability and adaptability.
3Adaptability or versatility
If puncture bits are added to achieve flexible code rates, then code rate adaptability improves, but encoding complexity increases
Solution Approach 1:
Puncture bit positions are predetermined and pre-configured in the base matrix structure before actual encoding operations. This preliminary arrangement of puncture patterns allows the encoder to simply select and apply pre-defined puncturing schemes rather than dynamically calculating puncture positions, thereby reducing encoding complexity while maintaining code rate flexibility.
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.