Adaptive Polar Code Decoding for SCL Complexity Control

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Solution Overview

Problem

Conventional polar code decoding methods, such as SC and SCL, face performance issues when code length is short, leading to excessive decoding complexity and energy consumption due to fixed CRC check code lengths and survivor path quantities, which do not adapt to varying information sequence lengths or signal-to-noise ratios.

Innovation Solution

Adaptive determination of CRC check code length and survivor path quantity based on the length of the target information sequence and signal-to-noise ratio, using pre-stored mapping relationships to optimize polar code encoding and decoding processes, ensuring appropriate complexity and performance for different code lengths and channel conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed large survivor path quantity L is used in SCL decoding to ensure good performance, then decoding performance is improved, but decoding complexity and energy consumption greatly increase

Engineering Contradiction:
Improvedecoding performanceVSAvoiddecoding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the survivor path quantity L adjustable rather than fixed. The decoding device dynamically determines the appropriate value of L based on the code length N of the polar code, allowing the system to adapt the decoding complexity to match the actual performance requirements for different code lengths, thus resolving the contradiction between maintaining good performance and avoiding excessive complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter L (survivor path quantity) based on the code length N. By establishing a mapping relationship between code length and optimal survivor path quantity, the system adjusts this critical parameter to achieve the best balance between decoding performance and complexity for each specific code length scenario

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a fixed large CRC check code length is used to improve error correction capability, then reliability is improved, but encoding complexity increases

Engineering Contradiction:
Improveerror correction capabilityVSAvoidencoding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the CRC check code length dynamic by determining it based on the code length N of the polar code. This allows the encoding device to adjust the CRC length appropriately for different code lengths, ensuring sufficient error correction capability while avoiding unnecessary encoding complexity for shorter codes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the CRC check code length parameter based on the code length N, establishing an adaptive relationship where the CRC length is optimized for each code length scenario, thus resolving the contradiction between error correction capability and encoding complexity

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If conventional SC decoding is used for short code lengths, then decoding complexity is reduced, but decoding performance becomes undesirable

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

Solution Approach 1:

The patent applies dynamics by enabling the decoding device to adaptively select between SC decoding and SCL decoding based on the code length N. For short code lengths where SC decoding performance is inadequate, the system dynamically switches to SCL decoding with an appropriately adjusted survivor path quantity L, thus maintaining good performance without unnecessarily increasing complexity for all code lengths

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3442127B1Polar code encoding method and apparatus
Publication Date: 2024.02.21 HUAWEI TECH CO LTD
  • EP3442127B1 patent drawingFigure 1~3
  • EP3442127B1 patent drawingFigure 4
  • EP3442127B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention disclose a polar polar code encoding and decoding method and an apparatus. The decoding method may include: receiving, by a receive end, a polar polar code and indication information that are sent by a transmit end, where the indication information indicates that a length of the polar polar code is N; determining a survivor path quantity L of the polar polar code according to the code length N of the polar polar code and a signal-to-noise ratio SNR for receiving the polar polar code, where L is a positive integer; and performing successive cancellation list SCL decoding on the polar polar code according to the survivor path quantity L, to obtain L survivor paths, and checking at least one of the L survivor paths, to obtain a decoding result of the polar polar code. The present invention can address a prior-art disadvantage that decoding is rather complex because of a fixed survivor path quantity L for polar code decoding.