Distributed CRC Interleaving for Polar Code Early Stop
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Solution Overview
Problem
Existing polar code decoding methods in wireless communications systems suffer from high decoding delays and energy consumption due to the need for multiple attempts in downlink blind detection scenarios, especially for control channels, without an effective early stop mechanism.
Innovation Solution
Implement a distributed CRC mechanism with a de-interleaving sequence and CRC check operation, using a prestored interleaving sequence table to map information and CRC bits, enabling early termination of decoding when certain CRC checks fail.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional CRC encoding is used without distributed mechanism, then decoding completeness is ensured, but decoding delay and energy consumption increase due to inability to stop early
Solution Approach 1:
The patent divides the CRC check into distributed segments by inserting check bits at multiple positions throughout the encoded bit sequence rather than concentrating all CRC bits at the end. This segmentation allows the decoder to perform incremental CRC checks at different stages of decoding, enabling early termination when errors are detected, thus reducing decoding delay while maintaining reliability through distributed verification points
Solution Approach 2:
The patent performs preliminary CRC check preparations by pre-calculating and inserting distributed check bits during the encoding phase. These check bits are strategically placed throughout the bit sequence to enable future early stopping decisions during decoding, allowing the system to prepare verification capabilities in advance before actual decoding occurs
2Reliability
If multiple decoding attempts are performed in downlink blind detection, then decoding reliability is improved, but energy consumption increases
Solution Approach 1:
The patent implements feedback mechanisms through distributed CRC check bits that provide continuous verification information during the decoding process. When a CRC check fails at any distributed check point, the decoder receives immediate feedback to terminate decoding attempts, avoiding unnecessary energy consumption from continuing to decode failed transmissions while maintaining reliability through multiple verification opportunities
3Productivity
If distributed CRC encoding with interleaving is used, then early stop capability is achieved, but device complexity increases
Solution Approach 1:
The patent segments the CRC encoding process by distributing check bits at multiple positions in the bit sequence using interleaving techniques. This segmentation transforms a single complex CRC operation into multiple simpler distributed check points, enabling early stopping capability that improves decoding efficiency while the modular segmented structure helps manage encoding complexity through systematic distribution patterns
Data Source
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AI summary
This application provides a channel encoding method and apparatus. The method includes: obtaining A to-be-encoded information bits; mapping the A to-be-encoded information bits and L CRC bits to a first bit sequence based on an interleaving sequence, where the L CRC bits are obtained based on the A to-be-encoded information bits and a CRC polynomial, the interleaving sequence is obtained from a prestored interleaving sequence table or is obtained based on a maximum-length interleaving sequence, A+L is less than or equal to Kmax, and Kmax is a length of the maximum-length interleaving sequence; and encoding the first bit sequence. In this way, not only an encoding delay can be reduced, but also decoding has an early stop capability, so that decoding can end in advance, thereby reducing a decoding delay.