Polar-LDPC Concatenated Coding with Interleaving for Better Decoding
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Solution Overview
Problem
Current concatenated codes in channel encoding and decoding suffer from low decoding performance and inflexible construction, particularly in schemes involving polar codes and low-density parity-check (LDPC) codes.
Innovation Solution
A concatenated code encoding and decoding method that combines a polar code as an outer code with an optimized low-density parity-check (ER-LDPC) code as an inner code, utilizing a specialized interleaver and iterative soft information decoding to enhance decoding performance and flexibility across varying code lengths and rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional concatenated codes (polar code + LDPC code) are used, then encoding gain is improved, but decoding performance is insufficient
Solution Approach 1:
The patent segments the concatenated code structure into distinct outer code (polar code) and inner code (optimized LDPC code) components, with the outer code handling error correction and the inner code handling noise reduction. This segmentation allows each code type to operate at its optimal performance point, resolving the contradiction between achieving high decoding performance and maintaining manageable structural complexity.
Solution Approach 2:
The patent applies local quality by optimizing specific parameters of the LDPC code (such as check matrix construction and row weight distribution) to work synergistically with the polar code. The inner LDPC code is specifically optimized with certain structural properties that complement the outer polar code's characteristics, thereby improving overall decoding performance without proportionally increasing complexity.
2Reliability
If code concatenation scheme is implemented, then encoding gain is achieved, but flexibility in adapting to different code lengths and rates is reduced
Solution Approach 1:
The patent implements dynamics by making the concatenated code structure adaptable to different code lengths and rates. The outer polar code and inner LDPC code can be independently configured with different lengths and rates, allowing the system to dynamically adjust to various communication requirements. The interleaving structure between the two codes can also be adapted to different configurations, providing flexibility while maintaining encoding gain.
3Reliability
If polar code and LDPC code are concatenated, then noise reduction capability is improved, but error transmission and correlation increase
Solution Approach 1:
The patent introduces an interleaving structure as an intermediary between the outer polar code and inner LDPC code. This interleaver redistributes the encoded bits from the polar code before passing them to the LDPC code, effectively breaking up error patterns and reducing error correlation. The interleaver acts as a mediator that prevents error propagation while maintaining the noise reduction benefits of the concatenated structure.
Data Source
AI summary
This application provides example concatenated code encoding and decoding methods. In one example method, polar code encoding is performed on a to-be-encoded message bit sequence based on a frozen bit set and a message bit set that are of a first polar code, to obtain a first encoded code word whose length is N_o. The first encoded code word is interleaved to obtain a second encoded code word, and optimized low-density parity-check (LDPC) code encoding is performed on the second encoded code word to obtain a concatenated code word. Interleaving includes both outer interleaving and inner interleaving. The concatenated code word is then outputted.