LDPC Parity-Column Permutation for High Code Rate Decoding
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Solution Overview
Problem
Existing LDPC codes struggle to meet performance requirements at high code rates, particularly in wireless communications systems, due to limitations in encoding and decoding efficiency.
Innovation Solution
The proposed method involves encoding an input sequence using an LDPC matrix and permuting parity check columns to adjust bit sequences, ensuring reduced puncturing and improved performance at high code rates through optimized bit rearrangement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional LDPC codes are used at high code rates, then encoding and decoding operations can be performed, but performance requirements are not met due to limitations in encoding and decoding efficiency
Solution Approach 1:
The patent segments the bit sequence into multiple groups corresponding to different column groups in the LDPC matrix. By processing and permuting these segments independently, the system optimizes the distribution of punctured bits across different groups, thereby improving overall decoding performance at high code rates while maintaining encoding efficiency.
Solution Approach 2:
The patent applies different permutation operations to different column groups based on their specific characteristics. By identifying and permuting only those groups that contain punctured bits, the system locally optimizes the bit distribution where needed rather than applying uniform processing to the entire sequence, thus improving performance without excessive computational overhead.
2Productivity
If puncturing is applied to achieve high code rates, then code rate increases, but decoding performance deteriorates due to increased errors from punctured entries
Solution Approach 1:
The patent performs permutation operations on the bit sequence before transmission to proactively address the impact of puncturing. By repositioning bits in advance based on the known puncturing pattern, the system ensures that critical information bits are not lost to puncturing, thereby maintaining decoding performance while achieving the desired high code rate.
Solution Approach 2:
The patent changes the arrangement parameters of the bit sequence by applying permutation operations to different column groups. This repositioning alters which bits are affected by puncturing, transforming the original bit distribution into an optimized distribution that maintains better decoding performance at high code rates.
3Productivity
If bit sequence permutation is applied to improve high code rate performance, then decoding efficiency improves, but device complexity increases due to additional processing steps
Solution Approach 1:
The patent divides the bit sequence into multiple column groups and applies permutation operations to specific groups rather than the entire sequence. This segmented approach reduces the computational complexity compared to full-sequence permutation while still achieving the performance benefits of optimized bit distribution for high code rates.
Solution Approach 2:
The patent applies permutation operations locally to only those column groups that contain punctured bits, rather than uniformly processing all groups. This localized processing reduces the overall computational burden and device complexity while maintaining the decoding efficiency improvements in the critical areas affected by puncturing.
Data Source
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AI summary
This application discloses an information processing method and apparatus, a communications device, and a communications system. The method includes: encoding an input sequence by using a low density parity check LDPC matrix to obtain a bit sequence D, where a base matrix of the LDPC matrix is represented by a matrix of m rows and n columns, each column corresponds to a group of Z continuous bits in the bit sequence D, and both n and Z are integers greater than 0; and obtaining an output bit sequence based on a bit sequence V, where the bit sequence V is obtained by permuting groups of bits corresponding to at least two parity check columns in the bit sequence D. According to the information processing method and apparatus, the communications device, and the communications system in this application, performance requirements of an LDPC code at a high code rate can be supported.