Selective CRC-Polar Encoding for Short-CRC Error Floor Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, the concatenation of a Cyclic Redundancy Check (CRC) code with a polar code experiences an error floor phenomenon due to short CRC code lengths, leading to performance degradation and increased error detection failure probabilities.
Innovation Solution
The proposed method involves performing CRC coding on a determined number of information bits and polar coding on both the CRC-coded and remaining information bits, optimizing the CRC code length to improve error rate performance by adjusting the number of bits subjected to CRC coding based on the polar code's generator matrix and Hamming distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a short CRC code length is used in the CRC-polar code concatenation encoder, then the device complexity is reduced, but the error rate performance deteriorates due to error floor phenomenon
Solution Approach 1:
The patent segments the information bits into two groups: first information bits that are subjected to CRC coding and second information bits that are not. This segmentation allows the system to use a short CRC code length (reducing complexity) while still achieving good error rate performance by selectively applying CRC protection only to the most critical information bits, thereby avoiding the error floor phenomenon without requiring a long CRC code.
2Reliability
If CRC coding is performed on all information bits, then the error detection capability is improved, but the encoding complexity and overhead increase
Solution Approach 1:
Instead of applying CRC coding to all information bits (excessive action), the patent applies CRC coding only to a determined number of first information bits (partial action). This partial application of CRC coding provides sufficient error detection capability for the most critical bits while avoiding the increased complexity and overhead that would result from encoding all bits, thus resolving the contradiction between reliability and complexity.
3Reliability
If the CRC code length is increased to reduce error floor, then the error rate performance is improved, but the coding overhead and transmission efficiency decrease
Solution Approach 1:
The patent segments the information bits and applies CRC coding only to the first group of bits, allowing the use of a short CRC code length. This segmentation enables the system to achieve good error rate performance (avoiding error floor) without increasing the overall coding overhead, thereby maintaining high transmission efficiency while improving reliability.
Data Source
AI summary
An encoding method for encoding input information bits using an encoder implemented with concatenation of a CRC-α coder and a polar coder is provided. The method includes performing Cyclic Redundancy Check (CRC) coding on as many information bits as a determined number of CRC coding bits among input information bits and performing polar coding on the CRC-coded information bits and other information bits than the CRC-coded information bits.