Polar Code Check-Bit Distribution for More Accurate Decoding

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Solution Overview

Problem

The decoding performance of Polar codes is poor when the code length is small or medium, leading to decreased user experience due to suboptimal decoding quality in communication systems.

Innovation Solution

An encoding/decoding method that inserts check bits into information bits, adjusts their positions based on sorting values, and performs second-level encoding, followed by decoding each bit of the second-level encoded code word to output survivor paths, allowing for distributed checking to select valid paths and improve decoding accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If SC decoding method is used for Polar codes with small or medium code length, then decoding complexity is reduced, but decoding performance deteriorates

Engineering Contradiction:
Improvedecoding complexityVSAvoiddecoding performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The code is divided into information bits and check bits, with check bits distributed throughout the code structure. This segmentation allows the decoder to verify subsets of information bits using corresponding check bits, improving decoding performance for small and medium code lengths while maintaining manageable complexity through localized verification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Check bits are inserted and positioned in advance during encoding, creating a distributed checking structure that enables the decoder to perform verification operations during the decoding process. This preliminary arrangement of check bits allows for intermediate validation of survivor paths, improving overall decoding performance without requiring more complex algorithms.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If check bits are inserted into information bits and distributed throughout the code, then decoding accuracy is improved, but encoding complexity increases

Engineering Contradiction:
Improvedecoding accuracyVSAvoidencoding complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The encoding process is segmented into distinct steps: inserting check bits into information bits, adjusting positions based on sorting values, and performing second-level encoding. This segmentation makes the encoding process more systematic and manageable, reducing the perceived complexity while achieving improved decoding accuracy through distributed check bits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Check bits are inserted and positioned in advance during the encoding process, creating a structured distribution pattern. This preliminary action establishes the checking framework before the actual encoding occurs, making the overall process more organized and easier to implement despite the additional steps involved.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3748861B1Encoding and decoding of polar codes with distributed check bits
Publication Date: 2023.12.27 HUAWEI TECH CO LTD
  • EP3748861B1 patent drawingFigure 1~2
  • EP3748861B1 patent drawingFigure 3~4
  • EP3748861B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention provide an encoding/decoding method, apparatus, and system, and relate to the communications field. The present invention may improve decoding performance and improve accuracy of a survivor path. The method includes: encoding information bits according to a first-level encoding method to obtain a first-level encoded code word; obtaining a sorting value of each check bit of the first-level encoded code word, and adjusting each check bit to a corresponding position according to the sorting value of each check bit, where the sorting value refers to a value of S when the check bit is related to first S information bits of the information bits in the first-level encoded code word, and S is a non-zero integer; and performing, according to a second-level encoding method, second-level encoding on the first-level encoded code word after positions of the check bits are adjusted, thereby obtaining a second-level encoded code word. The present invention is applicable to various communication systems.