LDPC Matrix Structure for Flexible 5G Code Lengths and Rates
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Solution Overview
Problem
Existing LDPC code systems face challenges in supporting encoding and decoding of information bit sequences of varying lengths and meeting flexible code length and code rate requirements in communication systems.
Innovation Solution
The proposed solution involves using a specific structure for the LDPC matrix based on a base graph with submatrices A, B, C, and D, and an identity matrix E, where the base graph includes submatrix A with specific row and column configurations, submatrix B with a bi-diagonal structure, submatrix C as an all-zero matrix, and submatrix E as an identity matrix, along with a shift matrix and lifting factors to accommodate different code block lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed LDPC matrix structure is used, then decoding complexity is reduced, but adaptability to various code lengths and code rates is worsened
Solution Approach 1:
The patent applies dynamics by making the LDPC matrix structure adjustable through different lifting factors. The base matrix is expanded using a lifting factor Z to generate parity check matrices of various sizes, allowing the system to adapt to different code lengths and rates while maintaining the underlying sparse structure for manageable decoding complexity.
Solution Approach 2:
The patent changes parameters by varying the lifting factor Z and the base matrix configuration to support different code lengths and rates. By modifying these parameters, the same base structure can generate multiple specialized LDPC codes tailored to specific communication requirements without redesigning the entire matrix from scratch.
2Adaptability or versatility
If LDPC code is used to support various code block lengths, then versatility is improved, but system complexity increases
Solution Approach 1:
The patent achieves universality by designing a base matrix that can serve multiple functions through expansion with different lifting factors. A single base matrix structure can generate LDPC codes for various code block lengths and rates, eliminating the need for multiple specialized matrices and reducing overall system complexity.
3Adaptability or versatility
If flexible code rate requirements are met, then adaptability is improved, but encoding complexity increases
Solution Approach 1:
The patent uses parameter changes by adjusting the lifting factor and selecting different submatrix configurations (A, B, C, D, E) to achieve flexible code rates. This allows the system to adapt to different rate requirements while maintaining a systematic encoding approach based on the same base structure.
Data Source
AI summary
A low density parity check (LDPC) channel encoding method is used in a wireless communications system. A communication device encodes an input bit sequence by using an 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 base matrix may be one of eight exemplary designs. The encoding method can be used in various communications systems including fifth generation (5G) telecommunication systems, and can support various encoding requirements for information bit sequences with different code lengths.