Codeword Puncturing Pattern for High-Rate BICM-ID Decoding
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Solution Overview
Problem
Existing methods for designing codes with variable code rates in wireless communication systems, particularly in BICM-ID structures based on IR codes, face challenges in supporting various code rates and maintaining normal operation at high code rates.
Innovation Solution
A method and apparatus for generating and recovering codewords that enable normal operation at high code rates in BICM-ID structures by using an IR code, which involves puncturing patterns that arrange non-punctured nodes around punctured nodes for fast convergence in iterative decoding, and inserting doping symbols to facilitate reliable decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If puncturing is performed at high code rate in BICM-ID structure based on IR code, then code rate is increased and transmission efficiency is improved, but normal operation cannot be performed and performance deteriorates
Solution Approach 1:
The patent applies local quality by differentiating the treatment of punctured and non-punctured nodes in the decoding process. Non-punctured nodes are processed with standard iterative decoding, while punctured nodes utilize a specific recovery mechanism that considers their local context (neighboring non-punctured nodes). This localized approach allows the system to maintain reliability even when significant portions of the codeword are punctured at high code rates.
Solution Approach 2:
The patent employs preliminary action by pre-arranging the puncturing pattern during code design to ensure that punctured nodes are surrounded by non-punctured nodes. This preliminary structuring of the code ensures that when decoding occurs, the recovery process can efficiently propagate information from non-punctured to punctured nodes, maintaining normal operation even at high code rates where extensive puncturing is necessary.
2Adaptability or versatility
If puncturing pattern is designed using kSR node concept, then puncturing pattern can be found for various code rates, but rate-compatible structure cannot be properly designed as low code rate pattern does not become subset of high code rate pattern
Solution Approach 1:
The patent applies segmentation by dividing the puncturing pattern design into hierarchical levels: a base pattern for low code rates and additional puncturing patterns for higher code rates. Each level builds upon the previous one, ensuring that the puncturing set for a given code rate includes all punctures from lower rates plus additional strategic punctures. This segmented approach enables rate-compatible structures where patterns nest properly across different code rates.
Solution Approach 2:
The patent implements the nested doll principle by creating puncturing patterns that are nested within each other across different code rates. The puncturing pattern for a lower code rate becomes a subset of the pattern for a higher code rate, similar to nested dolls. This nesting ensures that rate-compatible structures can be designed systematically, where each code rate's puncturing pattern contains and extends the previous rate's pattern, simplifying the overall design complexity.
3Ease of manufacture
If punctured nodes are arranged without considering convergence speed, then puncturing pattern design is simplified, but iterative decoding convergence is slow
Solution Approach 1:
The patent applies preliminary action by pre-arranging the puncturing pattern during the code design phase to optimize convergence characteristics. Specifically, punctured nodes are deliberately positioned to be surrounded by non-punctured nodes, creating a favorable structure for iterative decoding convergence. This preliminary optimization ensures fast convergence without complicating the pattern design process, as the optimal arrangement is built into the code structure itself.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the spatial distribution and density of punctured nodes based on convergence requirements. The puncturing pattern is designed with specific parameters (such as the ratio of punctured to non-punctured nodes and their spatial arrangement) that are optimized to accelerate convergence. By carefully controlling these parameters, the system achieves fast convergence while maintaining design simplicity.
Data Source
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AI summary
Disclosed are a method and an apparatus for generating a codeword, and a method and an apparatus for recovering a codeword. An encoder calculates the number of punctured symbol nodes among symbol nodes included in a codeword, punctures symbol nodes located at even or odd number positions among the symbol nodes included in the codeword, calculates the number of symbol nodes which need to be additionally punctured on the basis of the calculated number of the symbol nodes to be punctured, classifies the symbol nodes, which need to be additionally punctured, into one or more punctured node groups on the basis of the calculated number of symbol nodes which need to be punctured, determines the locations on the codeword where the one or more punctured node groups are to be arranged, and punctures the symbol nodes included in the codeword which belong to the punctured node groups according to the determined locations. A transmission unit transmits the codeword.