QC-LDPC Base Matrix Construction for Low Code Rate Convergence
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Solution Overview
Problem
Existing QC-LDPC codes in the 802.11n standard lack low code rates, such as 1/6, 1/4, and 1/3, which are necessary for improved performance in low signal-to-noise ratio and long-distance transmission environments.
Innovation Solution
A method for constructing a base matrix for QC-LDPC codes, which involves determining the number of columns and rows based on the code rate, maximizing row weights, and performing convergence calculations to ensure the base matrix converges, thereby enabling the design of permutation matrices for 1/6, 1/4, and 1/3 code rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If QC-LDPC codes are designed for low code rates (1/6, 1/4, 1/3), then performance in low signal-to-noise ratio and long-distance transmission environments is improved, but the complexity of constructing the base matrix increases
Solution Approach 1:
The base matrix construction is divided into multiple stages: determining matrix dimensions based on code rate, setting row weight parameters, generating the systematic bit part, and performing convergence calculations. This segmentation makes the complex construction process more manageable and systematic.
Solution Approach 2:
The patent performs preliminary actions by pre-determining the number of rows and columns based on code rate, pre-setting the row weight parameters (dc and dc-1), and pre-defining the total weight range before actual matrix generation. This preliminary configuration simplifies subsequent construction steps.
2Productivity
If the row weights are maximized with values of dc or dc−1, then the convergence calculation efficiency is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies different row weight values (dc and dc-1) to different rows of the base matrix based on specific requirements. This local differentiation allows optimization of convergence calculation while maintaining overall performance, rather than using a uniform row weight across all rows.
Solution Approach 2:
The patent changes the row weight parameter from a single fixed value to two possible values (dc and dc-1), allowing flexible adjustment of matrix properties. This parameter variation enables better convergence behavior while controlling the total weight within a specified range.
3Reliability
If the total weight range of the base matrix is controlled, then the code performance is improved, but the flexibility in matrix design is reduced
Solution Approach 1:
The patent introduces dynamics by allowing the distribution of row weights (dc and dc-1) to be adjusted based on the total weight range requirement. The systematic bit part is generated dynamically to meet the weight constraints while maintaining code performance, rather than using a static fixed structure.
Data Source
AI summary
A method of constructing a base matrix of a permutation matrix, device and medium. The method includes: determining a number Ns of columns corresponding to systematic bits and a number Nrow of rows of the base matrix according to a code rate of the permutation matrix; determining a maximum row weight dc and a total weight range Tweight of the base matrix, wherein the row weight is dc or dc−1; according to Tweight and Nrow, determining a first range R1 of rows with weights of dc−1 and a second range R2 of rows with weights of dc in the base matrix; according to Nrow, Tweight, R1 and R2, filling the systematic bit part in an initial base matrix corresponding to the base matrix to obtain an intermediate base matrix; and performing convergence calculation on it to determine whether it converges, and determining it as the base matrix if it converges.