LDPC Puncturing Pattern for Flexible Code Rates and Decoding
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Solution Overview
Problem
Current LDPC code systems, such as DVB-S2, have limited flexibility and extendibility due to fixed codeword lengths, requiring separate parity-check matrices for different data rates, which reduces memory efficiency and complicates adaptation to varying communication system requirements.
Innovation Solution
The method employs puncturing and shortening techniques to generate LDPC codes with varying codeword lengths from a given parity-check matrix, using a structured LDPC code, allowing for efficient support of multiple codeword lengths without additional storage, by selectively omitting bits and adjusting the code rate, while maintaining decoding reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate parity-check matrices are used for different data rates, then code performance is maintained, but memory efficiency deteriorates and system complexity increases
Solution Approach 1:
The patent applies universality by designing a single base parity-check matrix that can serve multiple code rates through puncturing operations. The same base matrix H is used to generate codes for different data rates by selectively removing columns, eliminating the need for separate matrices for each rate while maintaining decoding performance.
Solution Approach 2:
The patent segments the base parity-check matrix by dividing it into information bit columns and parity bit columns. This segmentation allows selective puncturing of parity columns to achieve different code rates, enabling one matrix to support multiple rates through systematic column removal while preserving the fundamental code structure.
2Reliability
If fixed codeword lengths are used, then decoding reliability is maintained, but adaptability to varying data rates deteriorates
Solution Approach 1:
The patent applies dynamics by making the code rate adjustable through selective puncturing of the base matrix. The system can dynamically adapt to different data rate requirements by removing different numbers of parity columns from the base matrix, transforming a static fixed-rate system into a flexible multi-rate system while preserving decoding reliability.
Solution Approach 2:
The patent changes the code rate parameter by puncturing different proportions of parity bits from the base matrix. By varying the puncturing pattern and density, the system generates codes with different rates from the same base matrix, enabling parameter adaptation without changing the fundamental code structure or sacrificing decoding performance.
3Adaptability or versatility
If multiple parity-check matrices are stored for different codeword lengths, then support for various data rates is achieved, but memory efficiency deteriorates
Solution Approach 1:
The patent merges multiple rate-specific parity-check matrices into a single base parity-check matrix. Instead of storing separate matrices for different data rates, the system stores one comprehensive base matrix that contains all necessary information to generate codes for various rates through puncturing, significantly reducing memory requirements while maintaining support for multiple data rates.
Data Source
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AI summary
An apparatus and a method for channel decoding using a Low-Density Parity-Check (LDPC) code, the method comprising: demodulating a signal transmitted from a transmitter; determining position information of the punctured parity bits by estimating information about a predetermined order of parity bit sets to be punctured and the number of parity bit sets ; and decoding data using the position information of the punctured parity bits, wherein determining position of punctured parity bits comprises, determining a number of parity bits to be punctured; and determining a number of parity bit sets to be punctured based on the determined number of parity bits to be punctured; and acquiring a predetermined order of parity bit sets, wherein the predetermined order of parity bit sets is determined as 27, 13, 29, 32, 5, 0, 11, 21, 33, 20, 25, 28, 18, 35, 8, 3, 9, 31, 22, 24, 7, 14, 17, 4, 2, 26, 16, 34, 19, 10, 12, 23, 1, 6, 30, 15..