QC-LDPC Encoding with Circulant Check Matrices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high coding complexity, long coding time, and large power consumption of quasi-cyclic low-density parity-check (QC-LDPC) coding schemes in channel coding methods pose challenges in efficient data transmission.
Innovation Solution
A channel coding method and apparatus that generates a check matrix H=[H a H b] for LDPC codes, where H a and H b are structured as circulant matrices, allowing for efficient calculation of the check code vector P and codeword vector C, reducing coding complexity by utilizing circulant identity matrices and segmenting operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If QC-LDPC coding scheme is used, then transmission reliability is improved, but coding complexity increases
Solution Approach 1:
The check matrix H is segmented into multiple circulant submatrixes, where each submatrix corresponds to a specific segment of the codeword. This segmentation allows the coding operation to be divided into independent parallel computations, reducing overall coding complexity while maintaining transmission reliability through the structured LDPC code design
Solution Approach 2:
The invention changes the parameter representation by using circulant matrix structures with specific shift patterns (a_ij values) instead of general dense matrices. This parameter transformation enables efficient implementation using shift-register based arithmetic, significantly reducing coding complexity while preserving the error correction performance required for reliable transmission
2Reliability
If QC-LDPC coding scheme is used, then transmission reliability is improved, but coding time increases
Solution Approach 1:
The codeword is divided into multiple segments corresponding to different circulant submatrixes in the check matrix. Each segment can be processed independently and in parallel, significantly reducing the total coding time while the LDPC structure ensures transmission reliability is maintained through systematic error correction capability
Solution Approach 2:
The check matrix is pre-structured into circulant submatrixes with predetermined shift patterns before encoding begins. This preliminary structuring allows the encoder to use pre-computed generator matrices and systematic encoding algorithms, reducing the actual coding time required during transmission while maintaining reliability
3Reliability
If QC-LDPC coding scheme is used, then transmission reliability is improved, but power consumption increases
Solution Approach 1:
The coding operation is segmented into multiple independent circulant submatrix computations that can be executed in parallel. This segmentation reduces the sequential processing time and allows for more efficient utilization of computational resources, thereby reducing power consumption while maintaining the transmission reliability benefits of LDPC codes
Solution Approach 2:
The invention replaces general-purpose matrix multiplication operations with specialized circulant matrix operations that can be implemented using shift-register based arithmetic logic. This substitution eliminates the need for complex multiplication circuits, significantly reducing power consumption while preserving the reliability performance of the QC-LDPC coding scheme
Data Source
Figure 1~2
Figure 3~4
AI summary
Embodiments of the present invention relate to the communications field, and disclose a channel coding method and apparatus, which can reduce coding complexity of low-density parity-check LDPC code. A specific solution is: obtaining information code vector M of LDPC code; generating a check matrix of the LDPC code; calculating PT according to a first formula, the information code vector M, and the check matrix H, and generating a check code vector P of the LDPC code according to PT; and generating a codeword vector C of the LDPC code according to a second formula, the information code vector M, and the check code vector P. The present invention is applied to LDPC coding.