Quasi-Cyclic LDPC Base Matrix Configuration for Flexible Code Lengths
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Solution Overview
Problem
LDPC coding and decoding processes lack flexibility in terms of code rate and code length, limiting their adaptability to various communication standards and applications.
Innovation Solution
A quasi-cyclic LDPC coding and decoding method that determines a basic matrix from a mother basic matrix set, comprising first-type and second-type elements, allowing for flexible code length and rate adjustments based on preset parameters such as transport block size, application scenarios, and channel types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional LDPC coding is used with fixed basic matrices, then the coding structure is simple and implementation is straightforward, but the code rate and code length flexibility is limited
Solution Approach 1:
The patent segments the basic matrix into multiple sub-matrices (first sub-matrix, second sub-matrix, third sub-matrix, fourth sub-matrix) that can be independently configured. Each sub-matrix can be selectively included or excluded based on the desired code rate and code length, enabling flexible adaptation without requiring completely different basic matrices for each configuration.
Solution Approach 2:
The patent introduces dynamic selection mechanisms where the transmitter and receiver can choose different basic matrices from a set of pre-defined basic matrices based on channel conditions, transport block size, and desired code rate. This dynamic adaptation allows the system to optimize performance for different operating scenarios while maintaining a relatively simple fixed structure for each individual basic matrix.
2Adaptability or versatility
If multiple basic matrices are supported to improve flexibility, then adaptability to different communication standards increases, but the complexity of selecting and managing basic matrices increases
Solution Approach 1:
The patent pre-defines multiple basic matrices with different structures and properties before communication begins. Each basic matrix is optimized for specific code rates, code lengths, or channel conditions. During operation, the system simply needs to select from these pre-configured options based on current requirements, avoiding the complexity of dynamically generating or configuring basic matrices in real-time.
Solution Approach 2:
The patent designs basic matrices with universal structures that can serve multiple functions. For example, a single basic matrix can support multiple code rates through puncturing or shortening techniques, and can be adapted to different code lengths by repeating or truncating codeword bits. This multi-functionality reduces the total number of basic matrices needed while maintaining flexibility.
Data Source
AI summary
A quasi-cyclic LDPC coding and decoding method and apparatus, and an LDPC coder and decoder. The method includes: determining from a mother basis matrix set a basis matrix used for low density parity check (LDPC) coding (S202), wherein the basis matrix used for LDPC coding includes a first-type element and a second-type element, the first-type element corresponds to an all-zero square matrix, the second-type element corresponds to a matrix obtained by means of a cyclic shift of a unit matrix according to a value of the second-type element, and dimensions of the all-zero square matrix and the unit matrix are equal; and performing LDPC coding on an information sequence to be coded according to the basis matrix used for LDPC coding, and/or performing LDPC decoding on a data sequence to be decoded according to the basis matrix used for LDPC coding (S204).