Multi-Kernel Polar Code Construction for Flexible Length and Low Error Rate

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Solution Overview

Problem

The original construction of polar codes restricts code lengths to powers of 2, making them insufficient for modem communication systems, and existing methods like puncturing and shortening techniques suffer from high latency, lack of structure, and performance loss.

Innovation Solution

A device and method that generate polar codes by combining reliability and minimum distance constructions using transformation matrices based on kernel matrices, allowing for flexible code length generation and improved error-rate performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If puncturing or shortening techniques are used to achieve arbitrary code lengths, then code length flexibility is improved, but implementation complexity and latency increase due to lack of structure in frozen sets and puncturing patterns

Engineering Contradiction:
Improvecode length flexibilityVSAvoidimplementation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The polar code construction is segmented into multiple kernels (e.g., T2, T3, T4) of different dimensions. Each kernel can be independently selected and combined to achieve desired code lengths. This segmentation allows systematic generation of codes with lengths not restricted to powers of 2, while maintaining structural regularity that simplifies implementation compared to ad-hoc puncturing/shortening methods.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs nested kernel structures where smaller kernels are embedded within larger transformation matrices. The transformation matrix GN is constructed as a Kronecker product of multiple kernels (e.g., G12 = T2 ⊗ T2 ⊗ T3), creating a hierarchical nested structure that enables systematic code generation with arbitrary lengths while preserving the polar code's fundamental properties and reducing implementation complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If puncturing or shortening techniques are used to achieve arbitrary code lengths, then code length flexibility is improved, but error-rate performance deteriorates

Engineering Contradiction:
Improvecode length flexibilityVSAvoiderror-rate performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The frozen sets and information sets are predetermined and systematically designed before code generation, based on the selected kernel combination. This preliminary design ensures optimal error-rate performance by pre-identifying reliable bit positions through polarization analysis, avoiding the performance degradation associated with ad-hoc puncturing or shortening applied after code generation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the fundamental parameter of kernel dimension selection to achieve arbitrary code lengths. By selecting different combinations of kernels with dimensions 2, 3, 4, etc., the total code length can be flexibly adjusted (e.g., N=12 using T2⊗T2⊗T3) while maintaining optimal error-rate performance through systematic frozen set design, avoiding the performance loss of puncturing/shortening techniques.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multi-kernel constructions are used to achieve arbitrary code lengths, then code length flexibility is improved, but construction complexity increases due to multiple kernels of different dimensions

Engineering Contradiction:
Improvecode length flexibilityVSAvoidconstruction complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent develops a universal framework using a set of standard kernels (T2, T3, T4, etc.) that can be combined in various ways to generate polar codes of arbitrary lengths. This universal kernel library approach simplifies construction complexity by providing reusable building blocks, eliminating the need to design custom codes for each length, and enabling systematic generation through Kronecker products of standardized kernels.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS11190214B2Construction of a polar code based on a distance criterion and a reliability criterion, in particular of a multi-kernel polar code
Publication Date: 2021.11.30 HUAWEI TECH CO LTD
  • US11190214B2 patent drawing
  • US11190214B2 patent drawing
  • US11190214B2 patent drawing

AI summary

The present disclosure relates to a device for generating a polar code xN of length N and dimension K on the basis of a transformation matrix GN of size N×N, wherein the transformation matrix GN is based on a first matrix GN, of size Nr×N, and on a second matrix GN<sub2>d </sub2>of size Nd×Nd, wherein N=Nr·Nd, and wherein the polar code xN is given by xN=uN·GN, wherein uN=(u0, . . . uN-1) is a vector of size N, an element ui, i=0, . . . N−1, of the vector corresponding to an information bit if i∈I, I being a set of K information bit indices, and ui=0, if i∈F, F being a set of N−K frozen bit indices.