Polar Code Rate Adjustment for Reliable Short-Packet Decoding

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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 utilizing a specific index set pattern to place to-be-coded bits on polar channels, allowing for complementary value sets to improve data transmission reliability, thereby enhancing polar code performance.

Engineering Contradictions & Design Principles

VSEngineering 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

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter of code rate by introducing a location selection bit that dynamically adjusts the code rate. By setting different values for the location selection bit, the system can switch between different code rates (e.g., from K/N to (K-1)/N), thereby adapting to different channel conditions and packet lengths to achieve ideal performance for medium/short packets while maintaining reasonable computational complexity through polar code's inherent advantages

Inventive Principle:
Principle #35Parameter changes

2Reliability

If polar code is used for channel coding, then coding and decoding complexity is low and Shannon capacity can be obtained, but performance is insufficient for evolving communication scenarios requiring higher performance

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidperformance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent introduces dynamics into the polar code structure by making the code rate adjustable through the location selection bit. This allows the polar code to adapt dynamically to different communication scenarios, transitioning from a fixed-rate code to a flexible-rate code that can optimize performance for evolving communication demands while maintaining the low computational complexity advantage of polar codes

Inventive Principle:
Principle #15Dynamics

3Reliability

If code rate is reduced to improve data transmission reliability, then reliability increases, but code length efficiency may be affected

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial action by selectively reducing the code rate only for specific portions of the data transmission. Through the location selection bit, the system can choose to apply the reduced code rate (K-1)/N only when beneficial, while maintaining the original code rate K/N for other cases, thereby achieving improved reliability where needed without unnecessarily sacrificing transmission efficiency in all scenarios

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3910827B1Polar coding and decoding method and apparatus
Publication Date: 2023.12.13 HUAWEI TECH CO LTD
  • EP3910827B1 patent drawingFigure 1(a)~1(b)
  • EP3910827B1 patent drawingFigure 2~3
  • EP3910827B1 patent drawingFigure 4

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 the K1 to-be-coded bits. A receive end performs polar decoding on decoding information of K1 of K to-be-decoded bits based on a correspondence between K2 of the K to-be-decoded bits and an index set. 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.