Hybrid Polar Code Construction for Short-Length Decoding
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Solution Overview
Problem
Polar codes face performance limitations, particularly in short or medium code lengths, where their decoding performance does not exceed that of Turbo codes or LDPC codes, and they have a minimal code distance, leading to error propagation and suboptimal decoding efficiency.
Innovation Solution
A hybrid Polar code is generated by selecting information bits and constructing encoding matrices based on bit reliability and weight, enhancing the code's minimum distance and decoding performance through SC or SC-List decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional Polar code encoding is used, then encoding complexity is low and Shannon capacity is achieved, but decoding performance does not exceed Turbo codes or LDPC codes for short to medium code lengths
Solution Approach 1:
The information bits are segmented into multiple groups based on their reliability metrics (such as Bhattacharyya parameters or mutual information). Different encoding strategies are applied to different groups, allowing the system to optimize decoding performance for critical bits while maintaining manageable encoding complexity.
Solution Approach 2:
Different encoding treatments are applied to different portions of the code based on local reliability characteristics. High-reliability bits receive standard Polar code encoding, while low-reliability bits are handled with enhanced encoding schemes or different matrix constructions to improve overall decoding performance.
2Reliability
If Polar code is used, then encoding complexity is low, but minimum code distance is small leading to error propagation
Solution Approach 1:
The system performs preliminary analysis of bit reliability metrics before encoding to identify which bits require enhanced protection. Based on this preliminary assessment, appropriate encoding strategies are selected in advance to ensure sufficient minimum code distance and prevent error propagation, rather than applying uniform encoding to all bits.
3Reliability
If SC decoding is used, then decoding complexity is O(N log2 N), but decoding performance is suboptimal for short to medium code lengths
Solution Approach 1:
The system changes key parameters of the Polar code construction, such as the generating matrix structure and information bit selection criteria, to optimize performance for specific code lengths. By adjusting these parameters based on the desired code length and reliability requirements, the system achieves better decoding accuracy without proportionally increasing decoding complexity.
Data Source
AI summary
Embodiments of the present invention provide a method and an apparatus for generating a hybrid Polar code. The method includes: obtaining a first matrix of N×N and a sequence that includes N bits, N rows of the first matrix correspond to the N bits in the sequence in a one-to-one manner, and N is a positive integer; determining reliability of the N bits, and determining the weight of each row in the N rows of the first matrix; selecting, according to the reliability of the N bits and the weight of the N rows of the first matrix, K bits among the N bits as information bits, or selecting, according to the reliability of the N bits and the weight of the N rows of the first matrix, K rows of the first matrix to construct a second matrix of K×N used for encoding.