Polar Code Puncturing by Channel Grouping for Rate Matching
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Solution Overview
Problem
Conventional rate matching methods for polar codes, such as puncturing or shortening, result in performance loss when the mother code has a large quantity of information bits, as they directly puncture or shorten the code, leading to inefficiencies in achieving the target code length.
Innovation Solution
A method and apparatus for rate matching in polar codes that determine specific bit positions for puncturing or shortening based on polarization channel reliability and code weight, allowing for targeted bit removal to achieve the desired code length without recalculating reliability, thereby reducing complexity and performance loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional puncturing or shortening is used for rate matching when the mother code has a large quantity of information bits, then the target code length is achieved, but performance loss occurs
Solution Approach 1:
The patent segments the N polarization channels into multiple groups based on reliability and code weight characteristics. Instead of uniformly puncturing or shortening all channels, the method selectively processes different groups, dividing the rate matching operation into manageable segments that preserve performance while reducing overall complexity.
Solution Approach 2:
The patent applies different rate matching strategies to different groups of polarization channels based on their local characteristics (reliability and code weight). High-reliability channels with appropriate code weights are preserved, while lower-priority channels are punctured or shortened, achieving local optimization that improves overall rate matching performance.
2Device complexity
If direct puncturing or shortening is applied to the mother code, then the code length is adjusted to target length, but recalculating reliability increases complexity
Solution Approach 1:
The patent performs preliminary grouping of polarization channels based on reliability and code weight before the rate matching operation. This preliminary classification allows the system to determine which channels to puncture or shorten without needing to recalculate reliability after rate matching, significantly reducing decoding complexity while maintaining efficiency.
Solution Approach 2:
The patent changes the approach from recalculating reliability parameters after rate matching to using pre-determined grouping based on reliability and code weight. By changing the parameter selection strategy to use initial reliability values and code weights for grouping decisions, the system avoids redundant calculations and reduces overall complexity.
Data Source
AI summary
Embodiments of the present disclosure provide a rate matching method and an apparatus. The method includes performing, by a sending apparatus, encoding using a polar code to obtain a first encoded sequence whose length is N. A sequence number of a polarization channel may range from 0 to N−1. The method includes determining, by the sending apparatus, P1 to-be-punctured bit positions. The method includes performing puncturing at the P1 bit positions in the first encoded sequence to obtain rate-matched encoded bits. The P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to PT1−1, PT1 to 3N/8−1, and/or N/2 to 5N/8−1, PT1 is a threshold of a quantity of to-be-punctured bit positions, and PT1≤N/4. The method includes sending the rate-matched encoded bits.