Polar Code Rate Matching with Reliability-Sorted Channel Indexes
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Solution Overview
Problem
Existing wireless communication systems face high storage overheads due to the need to store numerous mother code sequences to support various code lengths and rates, which is inefficient and resource-intensive.
Innovation Solution
A method and device that utilize a puncturing/shortening proportion and a prestored sequence sorted by channel reliability or capacity to construct a target code length sequence, allowing for efficient mapping of polar-coded bits to channels, reducing storage requirements and improving bit error rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a large quantity of mother code sequences are stored to support all combinations of code lengths and code rates, then the system can support various coding requirements, but the storage overheads of the system become very large
Solution Approach 1:
The patent applies universality by using a single base mother code sequence that can serve multiple coding requirements through puncturing and shortening operations. Instead of storing separate mother code sequences for each code length and rate combination, the system uses one universal base sequence (e.g., N=512) that can be adapted to generate codes of various lengths and rates by selectively removing (puncturing) or not using (shortening) certain bits, thereby reducing storage overhead while maintaining support for diverse coding needs
Solution Approach 2:
The patent applies parameter changes by modifying the effective code length and rate parameters through puncturing and shortening operations on a fixed base mother code sequence. By changing the puncturing/shortening proportion parameter, the system can dynamically adjust the output code length and rate without changing the underlying base sequence, allowing flexible adaptation to different transmission requirements while storing only one base sequence
2Adaptability or versatility
If puncturing and shortening operations are performed on mother code sequences, then code length and rate can be adjusted, but the sorting of channel indexes may change affecting decoding performance
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the correct channel index sorting sequences for various puncturing/shortening proportions. Before actual coding operations, the system prepares lookup tables containing pre-computed optimal channel index orderings for different code configurations. When coding is performed, the system simply retrieves the appropriate pre-computed sorting sequence based on the desired code length and rate, ensuring optimal decoding performance without requiring real-time recalculation of channel reliability orders
Solution Approach 2:
The patent applies copying by creating and storing multiple copies of channel index sorting sequences, each optimized for specific puncturing/shortening proportions. Instead of computing the optimal sorting dynamically for each coding operation, the system maintains pre-computed copies of sorting sequences for different code configurations, allowing rapid selection of the appropriate sorted sequence that matches the intended puncturing/shortening operation, thereby preserving decoding performance across various code lengths and rates
Data Source
AI summary
Embodiments of the application provide a polar coding method for communicating information in a wireless network. Information bits are encoded using a polar code process to obtain a polar-coded bit sequence. A rate matched bit sequence is output based on the polar-coded bit sequence. The rate matched bit sequence includes a quantity M of bits from the polar-coded bit sequence, and the M bits from the polar-coded bit sequence correspond to M channel indexes in a channel index sequence S. The channel index sequence S is obtained based on a puncturing/shortening proportion P′ and a prestored channel index sequence S′. Channel indexes in the prestored channel index sequence S′ are sorted by channel reliability or channel capacity, and a sorting order of the M channel indexes in the channel index sequence S is the same as a sorting order of the channel indexes in the prestored channel index sequence S′.