QC-LDPC Matrix Layout for Variable 5G Code Lengths and Rates
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Solution Overview
Problem
Existing communication systems face challenges in supporting encoding and decoding of information bit sequences of varying lengths while meeting flexible code length and code rate requirements, particularly in using low-density parity-check (LDPC) codes.
Innovation Solution
The implementation of an LDPC matrix based on a base graph with specific submatrices and lifting factors, allowing for flexible code rate and length support through row and column permutations, and the use of shifting matrices to adapt to different code block lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed LDPC base matrix is used, then the decoding structure is simplified, but the system cannot support variable code lengths and code rates
Solution Approach 1:
The base matrix is divided into submatrices (A, B, C, D, E) with specific structures. Submatrix B contains a bi-diagonal structure that can be selectively used, and submatrix D can be configured with different row counts (0 ≤ mD ≤ mF) to support different code rates and lengths while maintaining a systematic approach to matrix construction
Solution Approach 2:
The patent introduces dynamic configuration capabilities where the LDPC base matrix can be adapted to different code lengths and rates through parameter selection (mA, mD, mF values) and matrix operations (row/column permutations, lifting factor Z). This allows the same base matrix structure to serve multiple coding requirements without redesigning the entire decoding architecture
2Adaptability or versatility
If multiple LDPC base matrices are designed to support different code lengths and rates, then adaptability is improved, but system complexity and implementation difficulty increase
Solution Approach 1:
A single universal base matrix structure is designed that can support multiple code lengths and rates through configuration parameters rather than requiring separate matrices for each code specification. The matrix structure with submatrices A-E and configurable dimensions allows one matrix to perform multiple coding functions
Solution Approach 2:
The patent uses parameter-based adaptation where changing values of mA (4-7), mD (0 to 38), mF (35-38), and lifting factor Z allows the same base matrix structure to generate different LDPC codes with varying lengths and rates. This parameter-driven approach simplifies implementation compared to maintaining multiple fixed matrices
Data Source
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AI summary
This application discloses an encoding method, an apparatus, a communication device, and a communication system. The method includes: encoding an input bit sequence by using a low density parity check LDPC matrix, where the LDPC matrix is obtained based on a base graph, and the base graph includes submatrices A, B, C, D, and E, where the submatrix A is a matrix including mA rows and nA columns, mA and nA are positive integers, 4≤ mA≤7, and nA =10; the submatrix B is a matrix including mA rows and mA columns, and the submatrix B includes a column whose weight is 3 and a submatrix B' having a double diagonal structure; the submatrix D includes mD rows in a matrix F, the matrix F is a matrix including mF rows and (mA + nA) columns, mD and mF are positive integers, 0≤ mD ≤ mF, and 35 ≤ mF ≤ 38; the submatrix C is an all zero matrix including mA rows and mD columns; and the submatrix E is an identity matrix including mD rows and mD columns. The encoding method, the apparatus, the communication device, and the communication system in this application can support a requirement for encoding information bit sequences of various lengths.