Multi-Layer CRC Coding with Distinct Polynomials for Error Detection
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Solution Overview
Problem
The use of the same generator polynomials for CRC coders in wireless communication systems leads to undetected error events at both levels of CRC checking, resulting in incorrect data being accepted as correct.
Innovation Solution
Employing different generator polynomials for CRC encoding the transport block and segmented code blocks, with specific examples provided, such as degree-24 polynomials that share at most a factor of (D+1, and using reciprocal polynomials, to improve error detection capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the same generator polynomial is used for both transport block CRC and code block CRC encoding, then the system complexity is reduced and ease of manufacture is improved, but undetected error events occur at both levels of CRC checking resulting in incorrect data acceptance
Solution Approach 1:
The patent applies local quality by using different generator polynomials for different levels of CRC encoding. Specifically, a first generator polynomial is used for transport block CRC encoding while a second, different generator polynomial is used for code block CRC encoding. This differentiation ensures that errors detected at the code block level cannot necessarily pass through to the transport block level, thereby eliminating undetected error events while maintaining manageable system complexity through the use of standardized polynomial selection.
2Reliability
If different generator polynomials are used for CRC encoding transport block and code blocks, then error detection capability is improved, but device complexity increases
Solution Approach 1:
The patent implements parameter changes by modifying the generator polynomial parameter used in CRC encoding. Instead of using the same polynomial for both transport block and code block encoding, the system changes the polynomial parameter to different values (e.g., different degree-24 polynomials) at different encoding levels. This parameter differentiation enhances error detection capability while the complexity increase is mitigated by selecting from a predefined set of standardized polynomials.
Data Source
AI summary
A communication device is disclosed. The device is configured to generate a first block of first cyclic redundancy check (CRC) parity bits on a transport block wherein the first block of CRC parity bits is based on a first generator polynomial, to attach the first block of CRC parity bits to the transport block and to segment the transport block into multiple code blocks. The processor is also configured to generate a second block of CRC parity bits on each code block wherein each of the second blocks of CRC parity bits is based on a second generator polynomial that is different than the first generator polynomial. The first and second generator polynomials have a common degree. A second block of CRC parity bits is attached to each code block, and the code blocks are concatenated after channel encoding.