LDPC Base Matrix Structure for Flexible Code Length and Rate
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Solution Overview
Problem
Existing channel coding methods, such as LDPC codes, face challenges in supporting flexible code length and code rate requirements in communication systems, which can impact encoding performance and error floor performance.
Innovation Solution
The proposed solution involves using a specific structure for the LDPC matrix, including submatrices A and B, with specific weights and configurations, to support various code lengths and rates. This structure allows for the use of different lifting factors Z to accommodate different block lengths, enabling flexible code rate and length requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LDPC codes are used for channel coding, then throughput and channel transmission reliability are improved, but flexibility in supporting various code lengths and code rates deteriorates
Solution Approach 1:
The LDPC base matrix is divided into multiple submatrices (first submatrix, second submatrix, third submatrix, fourth submatrix) with different structures and functions. This segmentation allows each submatrix to be optimized for specific code rates and lengths, enabling flexible adaptation while maintaining high throughput through specialized structures like the bi-diagonal structure in the second submatrix.
Solution Approach 2:
The patent employs parameter changes by varying the lifting factor Z to generate different code lengths from a single base matrix structure. By changing Z while maintaining the same base matrix configuration, the system can support multiple code lengths (e.g., 512, 1024, 2048 bits) and code rates without redesigning the entire coding scheme, thus achieving flexibility while preserving throughput performance.
2Reliability
If a specific LDPC base matrix structure is used, then encoding and decoding performance is improved, but adaptability to different code lengths and code rates deteriorates
Solution Approach 1:
The designed LDPC base matrix serves multiple functions simultaneously: it supports various code rates (1/3, 1/2, 2/3, 3/4, 5/6) through different submatrix configurations, accommodates multiple code lengths via lifting factor variation, and maintains high encoding/decoding performance through optimized structures like the bi-diagonal structure. This multi-functionality resolves the contradiction between specialized performance optimization and general adaptability.
Solution Approach 2:
The base matrix structure is designed to be dynamic and reconfigurable. Different submatrices can be activated or deactivated based on the required code rate and length, allowing the same base matrix to adapt to different communication conditions while maintaining optimal performance characteristics for each configuration.
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.