LDPC Channel Coding with Lifting for Variable 5G Block Lengths
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Solution Overview
Problem
Current LDPC codes face challenges in supporting various input lengths and coding rates, particularly for short information word lengths and fixed coding rates, due to limitations in designing effective parity check matrices that can efficiently handle variable channel conditions and inter-symbol interference in 5G communication systems.
Innovation Solution
The proposed method involves using a lifting technique combined with trapping set characteristics to design LDPC codes, where a block size and shift value sequence are identified to perform LDPC encoding and decoding, utilizing a permutation matrix of size Z×Z, enabling efficient support for various lengths and rates by optimizing the parity check matrix design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional LDPC codes are used, then encoding and decoding can be performed, but they cannot efficiently support various input lengths and coding rates particularly for short information word lengths
Solution Approach 1:
The patent changes the parameters of the parity check matrix by introducing a lifting technique that transforms a base matrix into expanded matrices with different dimensions. By varying the lifting parameter Z, the same base matrix can generate parity check matrices supporting different code lengths and rates, thereby achieving adaptability while maintaining reliability through optimized matrix structures for short lengths
2Device complexity
If a fixed parity check matrix is used, then encoding is simple, but it cannot handle variable channel conditions and inter-symbol interference in 5G systems
Solution Approach 1:
The patent segments the parity check matrix into a base matrix structure that can be systematically expanded. The base matrix is divided into sub-matrices with specific patterns, allowing independent optimization of different sections while maintaining overall adaptability to various channel conditions through the lifting expansion process
Data Source
AI summary
A pre-5th-generation (pre-5G) or 5G communication system for supporting higher data rates beyond a 4th-generation (4G) communication system, such as long term evolution (LTE) is provided. A channel encoding method in a communication or broadcasting system includes identifying an input bit size, determining a block size (Z), determining a low density parity check (LDPC) sequence to perform LDPC encoding, and performing the LDPC encoding based on the LDPC sequence and the block size.