Polar Code Decoding with CRC-PC Outer Coding and Early Termination
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Solution Overview
Problem
Current polar coding schemes, such as CA-polar and PC polar, face challenges in providing early termination during decoding and optimizing encoding, leading to poor performance in high signal-to-noise ratios, with complex construction methods and potential errors in decoding results.
Innovation Solution
The proposed solution involves a method that performs cyclic redundancy check (CRC) and parity check encoding sequentially before polar encoding, allocating bits based on subchannel reliability, using a quasi-periodic feature of channel polarization to optimize subchannel allocation, and employing a PC-SCL decoder for error detection and correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CRC code is used as outer code in CA-polar scheme, then error detection capability is improved, but early termination capability during decoding is lost and encoding optimization space is reduced
Solution Approach 1:
The patent combines CRC code and PC code into a hybrid outer code structure. The CRC bits provide error detection while the PC bits distributed among information bits enable early termination during decoding. This merging allows both error detection capability and early termination capability to coexist, resolving the contradiction between reliability and ease of operation.
Solution Approach 2:
The patent creates a composite coding scheme by integrating two different error control codes (CRC and PC) with complementary characteristics. The CRC portion provides robust error detection while the PC portion enables decoding optimization through early termination. This composite approach leverages the strengths of both codes to simultaneously achieve high reliability and operational efficiency.
2Ease of operation
If PC code is used as outer code in PC polar scheme, then early termination capability is improved, but construction complexity increases and decoding errors may occur
Solution Approach 1:
The patent segments the outer code into distinct CRC bits and PC bits with different functions. The CRC bits are dedicated to error detection while PC bits are distributed among information bits for early termination. This segmentation simplifies the construction process by clearly defining the roles of different code components, reducing the overall construction complexity while maintaining early termination capability.
3Ease of manufacture
If CRC bit is placed at end of information bits, then error detection is simplified, but encoding optimization space is reduced and performance deteriorates in high signal-to-noise ratios
Solution Approach 1:
The patent applies different quality characteristics to different parts of the code structure. CRC bits are positioned to provide comprehensive error detection coverage, while PC bits are strategically distributed among information bits to enable early termination without compromising reliability. This local differentiation of code properties allows both simplicity in error detection and high transmission reliability to be achieved simultaneously.
Data Source
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AI summary
Embodiments of this application provide an encoding and decoding method and a terminal, and relate to the communications field, to improve polar code decoding performance. The method includes: performing, by a transmit end, a cyclic redundancy check on to-be-encoded information, to obtain first encoded information; performing, by the transmit end, parity check encoding on the first encoded information, to obtain second encoded information; and performing, by the transmit end, polar encoding on the second encoded information, to obtain third encoded information and output the third encoded information to a receive end. The embodiments of this application are applied to a scenario in which polar encoding and decoding are performed on an information bit.