Polar Encoding With Blockwise Checksum for Short-Code Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Polar codes with short or medium lengths have insufficient minimum code distance, which affects their error-detecting capability and reliability in data transmission.

Innovation Solution

The method involves processing information blocks to produce a blockwise checksum and generating an N-bit input vector with information bits, checksum bits, and frozen bits, which is then multiplied by a Polar code generator matrix, specifically an m-fold Kronecker product matrix, to produce a codeword, with the checksum bits inserted in relatively reliable positions to enhance coding performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If Polar codes with short or medium lengths are used, then the code length is reduced, but the minimum code distance becomes insufficient

Engineering Contradiction:
Improvecode lengthVSAvoidminimum code distance
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The information blocks are divided into multiple segments, and a blockwise checksum is calculated across these segments. This segmentation approach allows the checksum to span multiple code blocks, thereby increasing the minimum code distance even when individual block lengths are short or medium.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines Polar codes with a blockwise checksum mechanism to create a composite coding structure. This composite approach integrates the error-correcting capabilities of Polar codes with the error-detecting capabilities of the checksum, achieving enhanced reliability without requiring increased code length.

Inventive Principle:
Principle #40Composite materials

2Reliability

If checksum bits are inserted in reliable positions, then error-detecting capability is improved, but device complexity increases

Engineering Contradiction:
Improveerror-detecting capabilityVSAvoidcoding structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blockwise checksum is calculated in advance during the encoding process, and the checksum bits are pre-positioned in reliable channel positions before transmission. This preliminary action ensures that error-detecting capability is enhanced without requiring complex real-time processing during transmission or decoding.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent modifies the coding parameters by introducing a blockwise checksum structure with specific parameters (number of information blocks K, checksum blocks u, block length P). These parameter changes enable systematic placement of checksum bits in reliable positions, improving error-detecting capability while maintaining manageable device complexity through standardized parameterization.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3408941B1System and method for polar encoding and decoding
Publication Date: 2021.11.10 HUAWEI TECH CO LTD
  • EP3408941B1 patent drawingFigure 1
  • EP3408941B1 patent drawingFigure 2
  • EP3408941B1 patent drawingFigure 3

AI summary

Systems and methods for Polar encoding with a blockwise checksum are provided. The method involves processinga set of K information blocks to produce a blockwise checksum with u blocks, where K>=2, and u>=1, and where each information block or checksum block contains P bits. The blockwise checksum may, for example, be a Fletcher checksum. The Polar code may be based on an m-fold Kronecker product matrix. Then, an N-bit input vector is produced with P x K information bits and the P x u blockwise checksum bits, and with N-PK-Pu frozen bits, where N = 2mwhere m>=2. The N-bit input vector is processed to produce a result equivalent to multiplying the input vector by a Polar code generator matrix to produce a codeword. The codeword is then transmitted or stored.