LDPC Base Matrix Encoding for Flexible Code Rates and Lengths
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Solution Overview
Problem
Current LDPC codes face challenges in supporting flexible code lengths and rates while maintaining encoding performance and avoiding error floors, particularly in wireless communication systems.
Innovation Solution
The design of LDPC codes using a base graph and base matrix with specific structures, including submatrices A, B, C, and E, and the use of lifting factors to generate parity bits, allows for flexible code rates and lengths, and incorporates puncturing and shortening operations to optimize encoding and decoding performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LDPC codes use a fixed base matrix structure, then encoding performance is maintained, but flexibility in code length and rate is reduced
Solution Approach 1:
The base matrix is divided into multiple submatrices (A, B, C, D, E) with specific structures. By selectively using different submatrices and combining them in different ways, the system can generate LDPC codes with various code lengths and rates while maintaining good encoding performance through the structured design of each submatrix.
Solution Approach 2:
The invention changes structural parameters of the base matrix, specifically the dimensions and configurations of submatrices A, B, C, D, and E. By adjusting these parameters, the system can support flexible code lengths and rates while the structured design ensures encoding performance is maintained across different configurations.
2Adaptability or versatility
If LDPC codes support multiple code lengths and rates, then adaptability is improved, but error floors increase
Solution Approach 1:
Different submatrices (A, B, C, D, E) are designed with specific local structures and properties optimized for different functions. By selectively activating and combining these submatrices based on the required code length and rate, the system maintains good error floor performance across multiple configurations while supporting high adaptability.
3Adaptability or versatility
If puncturing and shortening operations are applied, then code rate flexibility is improved, but encoding complexity increases
Solution Approach 1:
The base matrix is pre-designed with specific submatrix structures (A, B, C, D, E) that are optimized to work well with puncturing and shortening operations. This preliminary structural design enables flexible code rate adjustment through these operations while controlling encoding complexity, as the structured submatrices facilitate efficient encoding algorithms.
Data Source
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AI summary
This application discloses an encoding method, an apparatus, a communications device, and a communications 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 lifting factor Z and a base matrix, and the base matrix includes a row 0 to a row 4 and a column 0 to a column 26 in one of matrices shown in FIG. 3b-1A to FIG. 3b-8B, or the base matrix includes a row 0 to a row 4 and some of a column 0 to a column 26 in one of matrices shown in FIG. 3b-1A to FIG. 3b-8B. According to the encoding method, the apparatus, the communications device, and the communications system, channel coding requirements can be met.