LDPC Matrix Lifting for Flexible 5G Code Lengths and Rates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LDPC code systems face challenges in supporting diverse code block lengths and code rates, which limits their flexibility and performance in various communication systems.
Innovation Solution
The proposed method involves using a lifting factor Z and a base matrix to generate LDPC matrices suitable for different code block lengths, allowing for flexible encoding and decoding of information bit sequences, and storing parameters such as row indices, column positions, and shift values to optimize LDPC matrix construction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed LDPC matrix structure is used, then the decoding complexity is reduced, but the adaptability to different code block lengths and code rates deteriorates
Solution Approach 1:
The patent applies dynamics by making the LDPC matrix structure adjustable through the lifting factor Z. The base matrix is expanded using different lifting factors to generate full-density parity check matrices of various sizes, allowing the system to adapt to different code block lengths and code rates while maintaining a systematic approach to matrix construction that controls decoding complexity.
Solution Approach 2:
The patent changes the parameter Z (lifting factor) to generate different LDPC matrix structures. By varying Z, the system can support diverse code block lengths and code rates. The base matrix remains fixed with a systematic structure, but its expansion through different lifting factors creates adaptable code parameters without fundamentally changing the decoding algorithm complexity.
2Adaptability or versatility
If the lifting factor Z is increased to support longer code blocks, then the code length flexibility is improved, but the memory requirements and computational load increase
Solution Approach 1:
The patent segments the LDPC matrix construction into a fixed base matrix and a variable lifting factor component. The base matrix contains the essential systematic structure that remains constant, while the lifting factor Z controls the expansion scale. This segmentation allows the system to support various code lengths by simply changing Z without redesigning the entire matrix structure, thereby reducing memory requirements compared to storing multiple complete matrices.
3Reliability
If different base matrices are used for different lifting factors, then the encoding performance is optimized, but the system complexity and configuration management deteriorates
Solution Approach 1:
The patent makes the base matrix universal by designing it to work with multiple lifting factors. A single base matrix structure with systematic properties can be expanded using different lifting factors Z to support various code parameters. This universality optimizes encoding performance across different configurations while simplifying system complexity, as the same base matrix design principles apply regardless of the specific lifting factor used.
Data Source
AI summary
A low density parity check (LDPC) channel encoding method for use in a wireless communications system includes a communication device encoding an input bit sequence by using a LDPC matrix to obtain an encoded bit sequence for transmission. The LDPC matrix is obtained based on a lifting factor Z and a base matrix. The encoding method can be used in various communications systems including the fifth generation (5G) telecommunication systems, and can support various encoding requirements for information bit sequences with different code lengths.