Polar Coding with Complementary Index Sets for Short-Packet Reliability
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Solution Overview
Problem
Existing wireless communication systems face challenges in achieving ideal performance for medium/short packets due to high computational complexity in turbo and LDPC codes, and polar codes require higher performance to meet evolving communication demands.
Innovation Solution
A polar coding method that reduces code rate by dividing to-be-coded bits into two parts, where one part is placed on polar channels with high reliability and the other on channels with low reliability, using complementary value sets to optimize channel index placement and reduce decoding complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If turbo code or LDPC code is used for channel coding, then coding and decoding can be performed, but computational complexity is high and ideal performance cannot be achieved with limited code length for medium/short packets
Solution Approach 1:
The patent segments the K to-be-coded bits into two distinct parts: K1 information bits and K2 frozen bits. This segmentation allows the system to use polar coding with differentiated treatment of information and frozen bits, achieving better reliability for medium/short packets while maintaining manageable computational complexity through the structured approach to bit placement and decoding
2Device complexity
If polar code is used to achieve Shannon capacity with low complexity, then coding and decoding complexity is reduced, but performance is insufficient for evolving communication scenarios requiring higher performance
Solution Approach 1:
The patent applies local quality by assigning different roles to different bit positions within the polar code structure. Specifically, K2 frozen bits are placed at specific positions (determined by complementary index sets) while K1 information bits occupy other positions. This localized differentiation optimizes the code performance for specific communication scenarios without increasing overall system complexity
Solution Approach 2:
The patent changes the parameter of code rate by effectively reducing it through the introduction of K2 frozen bits among the K to-be-coded bits. This parameter change allows the polar code to achieve better performance for medium/short packets while maintaining the low complexity advantage of polar coding through the structured freezing approach
3Reliability
If code rate is reduced to improve transmission reliability, then data transmission reliability is enhanced, but code length efficiency decreases
Solution Approach 1:
The patent applies partial action by introducing only K2 frozen bits (where K2 < K) rather than freezing all bits. This partial freezing approach achieves the necessary reliability improvement for medium/short packets while maintaining reasonable code length efficiency, as the system uses just enough frozen bits to enhance reliability without excessive reduction in information transmission capacity
Data Source
AI summary
This application provides a polar coding method, a polar decoding method, and an apparatus. A transmit end obtains K to-be-coded bits and an index set including K polar channels, where a value set of K1 indexes in the set of the K indexes or a value set of K2 indexes in the set of the K indexes is determined based on a value set of K2 of the K to-be-coded bits, and the value set of the K1 indexes and the value set of the K2 indexes are complementary sets of each other; and performs polar coding on K1 to-be-coded bits. In comparison with a conventional polar coding method and a conventional polar decoding method, the polar coding method and the polar decoding method provided in this application can achieve an effect of reducing a bit rate. A simulation result indicates that the method has better performance.