Polar Code Auxiliary Bit Allocation by Sub-Channel Reliability
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Solution Overview
Problem
Conventional polar code construction methods face challenges in determining auxiliary bits, leading to increased decoder complexity and area overheads, which affect performance.
Innovation Solution
A method for determining auxiliary bits in polar codes by selecting sub-channels based on reliability, where information bits and auxiliary bits, including a known redundancy check (RC) bit, are positioned after information bits, reducing the number of sub-channels carrying auxiliary bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polar code construction methods are used with CRC bits for decoding assistance, then decoding reliability is improved, but decoder complexity and area overheads increase
Solution Approach 1:
The patent extracts the auxiliary bit determination function from the conventional CRC-based decoding assistance mechanism. By determining auxiliary bits directly from sub-channel reliability information without requiring full CRC calculation, the patent removes the complex CRC computation overhead while retaining the essential error detection capability, thus reducing decoder complexity while maintaining reliability
Solution Approach 2:
The patent performs preliminary determination of auxiliary bit positions based on sub-channel reliability before the actual decoding process. By pre-identifying which sub-channels will carry auxiliary bits based on their reliability metrics, the system prepares the decoding structure in advance, avoiding complex runtime calculations and reducing the computational burden during actual decoding operations
2Reliability
If conventional polar code construction methods are used with CRC bits, then error detection capability is improved, but decoder area overheads increase
Solution Approach 1:
The patent replaces the expensive, complex CRC calculation mechanism with a simpler, lighter-weight auxiliary bit determination approach. By using direct reliability-based assignment instead of full polynomial-based CRC computation, the patent achieves error detection capability with significantly reduced hardware resources and decoder area overheads
Solution Approach 2:
The patent changes the fundamental parameter of how auxiliary bits are generated - shifting from CRC polynomial calculation to direct sub-channel reliability mapping. This parameter change transforms the error detection mechanism from a computation-intensive process to a simpler selection-based approach, reducing the hardware area required while maintaining error detection functionality
3Reliability
If more sub-channels are allocated for auxiliary bits, then error correction performance is improved, but information bit transmission capacity decreases
Solution Approach 1:
The patent applies local quality by allocating auxiliary bits selectively based on the specific reliability characteristics of each sub-channel. Instead of uniformly allocating auxiliary bits across all sub-channels, the system identifies specific sub-channels with lower reliability metrics and assigns auxiliary bits only to those locations, thereby optimizing error correction where needed while preserving information bit capacity in more reliable sub-channels
Solution Approach 2:
The patent implements partial action by determining auxiliary bit allocation based on a threshold of sub-channel reliability. Rather than allocating auxiliary bits to all sub-channels or using excessive allocation, the system applies auxiliary bits only to the extent necessary - specifically to sub-channels that fall below a certain reliability threshold - thus achieving adequate error correction performance without unnecessarily reducing information bit transmission capacity
Data Source
AI summary
This application provides a method for determining an auxiliary bit of a polar code and an apparatus. The method includes: determining at least K sub-channels based on reliability of a first sub-channel set, where the K sub-channels carry information bits, S sub-channel subsets are determined based on the first sub-channel set, an ith sub-channel subset in the S sub-channel subsets includes Ji sub-channels carrying auxiliary bits and Ki sub-channels in the K sub-channels, sequence numbers of the Ji sub-channels carrying the auxiliary bits are after sequence numbers of the Ki sub-channels, and the auxiliary bits may be known redundancy check RC bits; and then performing polar encoding on the information bits and the auxiliary bits, to output polar-encoded data.