QC-LDPC Check Matrix Construction for Large-Girth Code Search
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Solution Overview
Problem
Existing methods for constructing regular QC-LDPC codes face challenges in efficiently achieving high girth values, which are crucial for good decoding performance, especially in high bit rate and large girth scenarios, due to complex search processes and increased matrix sizes.
Innovation Solution
The method initializes a cyclic shift value matrix with specific conditions, including setting the first row and column to 0, obtaining K values with unique differences, and searching for values that satisfy the girth condition based on circulant permutation matrix dimension quantity information to construct a check matrix with improved search efficiency and reduced construction time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If classical approaches are used to design QC-LDPC codes with large girth, then good decoding performance is achieved, but the construction time and complexity increase significantly
Solution Approach 1:
The patent applies preliminary action by pre-defining the structure of the cyclic shift value matrix with specific constraints (first row and column initialized to 0, K values with unique differences) before the actual code construction. This preliminary structuring guides the subsequent search process and reduces the solution space, enabling faster construction while maintaining large girth values of 10 or 12 that ensure good decoding performance.
Solution Approach 2:
The patent changes parameters by introducing specific constraints on the cyclic shift values (requiring unique differences between any two values) and initializing specific matrix elements to 0. These parameter changes transform the general QC-LDPC code construction problem into a more constrained but efficiently solvable problem, reducing construction time while preserving the essential error correction capabilities.
2Reliability
If the girth of the check matrix is increased to improve decoding performance, then error correction capability is enhanced, but the search process becomes more complex and time-consuming
Solution Approach 1:
The patent applies segmentation by dividing the check matrix construction into structured segments: the first row and column are initialized to 0, K specific values are selected with unique difference properties, and these are placed in the second row. This segmentation creates a template that guides the completion of the remaining matrix elements, significantly reducing the search complexity while achieving large girth values that enhance error correction capability.
Solution Approach 2:
By preliminarily selecting K values that satisfy the unique difference condition and initializing the first row and column to 0, the patent creates a constrained framework that simplifies the subsequent search for remaining matrix elements. This preliminary action reduces the search space and complexity while ensuring the final matrix achieves the desired large girth for improved error correction.
3Quantity of substance
If the matrix size is increased to support high bit rate transmissions, then data capacity is improved, but the construction time and computational resources required increase
Solution Approach 1:
The patent changes parameters by imposing the unique difference constraint on cyclic shift values and initializing specific matrix elements to 0. These parameter changes create a scalable construction method that can efficiently handle larger matrix sizes required for high bit rate transmissions, as the constrained structure reduces the computational burden compared to unconstrained approaches.
Solution Approach 2:
By segmenting the matrix construction process into predefined sections (first row/column initialized to 0, second row filled with K values satisfying unique difference conditions), the patent creates a modular approach that scales efficiently. This segmentation allows systematic completion of larger matrices for high data capacity applications while maintaining manageable construction times through the guiding structure.
Data Source
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AI summary
Embodiments of the application relate to the field of communications. Disclosed are a method for constructing a regular QC-LDPC code and an electronic device. The method comprises: initializing to 0 each element in the first row and the first column of a cyclic shift matrix; obtaining K values satisfying preset conditions, the preset conditions comprising that one of the values is 0and there is no repeated number in a set consisting of the differences between any two values; assigning the K values to K elements in the second row of the cyclic shift matrix, respectively, the first element in the second row being assigned a value of 0; searching, on the basis of the dimension information of a cyclic permutation matrix, for values satisfying the girth condition for each element to be assigned, each element to be assigned referring to individual elements except those in the first row, second row, and first column; and constructing a check matrix for a regular QC-LDPC code on the basis of the cyclic shift matrix.