Polar Code Sub-Channel Ordering With Partial Reliability Sorting
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Solution Overview
Problem
Polar codes in wireless communications face challenges in efficiently selecting sub-channels for information bits and frozen bits, particularly in practical code lengths and channels, leading to suboptimal performance compared to LDPC and Turbo codes, especially in AWGN channels.
Innovation Solution
The method involves using partial-order-based sub-channel ordering to determine sub-channel reliabilities, allowing for adaptive selection of sub-channels without calculating relative reliabilities of all sub-channels, and employing a localization area for efficient sub-channel sorting and ordering, which is flexible and computationally efficient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all sub-channel reliabilities are calculated to determine optimal sub-channel selection, then coding performance is improved, but computational complexity increases significantly
Solution Approach 1:
The patent segments the sub-channels into two groups: a first group of sub-channels with higher reliability and a second group of sub-channels with lower reliability. This segmentation allows the system to select information bits from the first group and frozen bits from the second group without calculating all sub-channel reliabilities, thereby reducing computational complexity while maintaining coding performance.
Solution Approach 2:
The patent applies partial action by calculating reliabilities only for a subset of sub-channels (the first group) rather than all sub-channels. The second group is handled by default assignment as frozen bits, which reduces the computational burden while still achieving optimal coding performance through proper sub-channel selection.
2Reliability
If sub-channel ordering is optimized for practical code lengths, then error correction capability is improved, but calculation overhead increases
Solution Approach 1:
The patent performs preliminary action by pre-determining the division of sub-channels into first and second groups based on partial reliability calculations. This preliminary classification allows subsequent encoding operations to proceed efficiently without repeated calculations, reducing calculation overhead while maintaining optimized error correction capability for practical code lengths.
Data Source
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AI summary
A number K of N sub-channels that are defined by a code and that have associated reliabilities for input bits at N input bit positions, are to be selected to carry bits that are to be encoded. A localization area that includes multiple sub-channels and is located below fewer than K of the N sub-channels in a partial order of the N sub-channels is determined based on one or more coding parameters. The fewer than K sub-channels of the N sub-channels above the localization area in the partial order are selected, and a number of sub-channels from those in the localization area are also selected. The selected fewer than K sub-channels and the number of sub-channels selected from those in the localization area together include K sub-channels to carry the bits that are to be encoded.