Punctured Polar Code Construction for Lower Frame Error Rate

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional random puncturing methods for polar codes result in high frame error rates and poor performance, especially for short or intermediate code lengths, and have high decoding complexity compared to SC decoding.

Innovation Solution

A method and apparatus for constructing punctured polar codes by comparing phase sequence numbers with puncturing patterns to determine transition probabilities and reliability values, using the Bhattacharyya parameter and error probability to select an information bit index set, thereby improving performance and reducing frame error rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional random puncturing method is used for polar code, then the implementation is simple, but the frame error rate is high and HARQ performance is poor

Engineering Contradiction:
Improveimplementation simplicityVSAvoidframe error rate
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the puncturing pattern from random to periodic with a specific period (2t), where t is the number of punctured bits. This parameter change in the puncturing structure enables the system to achieve better frame error rate performance while maintaining implementation simplicity through the regular periodic pattern.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent pre-determines the puncturing pattern based on the code length and number of punctured bits before encoding. By calculating the periodic puncturing positions in advance and storing them as lookup tables, the system prepares the optimal puncturing configuration beforehand, avoiding the need for complex real-time decisions during encoding.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If SC decoding is used for short or intermediate code lengths, then the decoding complexity is low, but the performance is poor with high frame error rate

Engineering Contradiction:
Improvedecoding complexityVSAvoidframe error rate
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent changes the code construction parameters by determining specific information bit index sets based on code length and puncturing patterns. For short and intermediate code lengths, specific puncturing patterns and information bit selections are optimized to improve SC decoding performance without increasing complexity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If List decoding is used to improve performance over SC decoding, then the frame error rate performance is improved, but the decoding complexity is higher

Engineering Contradiction:
Improveframe error rate performanceVSAvoiddecoding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent pre-calculates and stores optimal puncturing patterns and information bit index sets for different code lengths and rates. This preliminary action enables the system to achieve List decoding-like performance by using pre-optimized configurations with SC decoding, avoiding the need for complex List decoding algorithms while maintaining improved frame error rate performance.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3142257B1Method and apparatus for constructing punctured polar code
Publication Date: 2020.08.26 HUAWEI TECH CO LTD
  • EP3142257B1 patent drawingFigure 1~2
  • EP3142257B1 patent drawingFigure 3~4
  • EP3142257B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention provide a method and an apparatus for constructing a punctured polar code, which relate to the encoding and decoding field, and can improve decoding performance of a punctured polar code and reduce a frame error rate of the punctured polar code. The method is as follows: comparing a phase sequence number of a current bit channel with a period index of a puncturing pattern to obtain a comparison result; obtaining a transition probability of the bit channel according to the comparison result and bit parity conditions of a sequence number of the bit channel in each phase; obtaining a reliability value of each bit channel according to the transition probability; and determining an information bit index set according to the reliability values. The embodiments of the present invention are used for constructing a punctured polar code.