CRC-Polar Encoding Using an 11-Bit Polynomial for 5G FAR Limits
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Solution Overview
Problem
Current 5G mobile communications systems face challenges in meeting the false alarm rate (FAR) requirements for channel encoding, particularly in scenarios like enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC), where existing CRC polynomials do not adequately ensure reliable communication.
Innovation Solution
The proposed solution involves performing CRC encoding using a specific CRC polynomial (D^11+D^10+D^9+D^5+1) followed by polar encoding to generate a bit sequence with 11 CRC bits, ensuring that the FAR requirement is met, which can be implemented using a shift register and either hardware or software, and is applicable to both control and data channels in uplink and downlink communications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CRC polynomials are used for channel encoding in 5G systems, then the encoding process can be performed, but the false alarm rate requirement cannot be satisfied
Solution Approach 1:
The patent changes the CRC polynomial parameter from conventional options to a specifically designed polynomial (e.g., from standard polynomials like 0x385 to custom polynomials such as 0x765 or other optimized variants). This parameter change optimizes the false alarm rate performance while maintaining compatibility with the polar encoding framework, directly resolving the contradiction between reliability and ease of implementation.
2Reliability
If CRC encoding is concatenated with polar encoding to improve reliability, then communication reliability improves, but the system complexity increases
Solution Approach 1:
The patent merges CRC encoding and polar encoding into a unified concatenated coding scheme where the CRC encoder outputs are directly fed into the polar encoder input. This integration allows the system to achieve improved reliability through the combined error detection and correction capabilities while managing complexity through standardized interface definitions and unified control mechanisms.
Solution Approach 2:
The patent applies preliminary CRC encoding to the input bits before polar encoding is performed. This preliminary action of adding CRC check bits beforehand enables the subsequent polar decoding process to benefit from both the CRC error detection capability and the polar code correction capability, achieving enhanced reliability without requiring complex post-processing adjustments.
3Reliability
If a longer CRC length is used to reduce false alarm rate, then the FAR performance improves, but the overhead and transmission time increase
Solution Approach 1:
The patent optimizes the CRC length parameter to achieve the minimum necessary length that satisfies the false alarm rate requirement. By carefully selecting the polynomial degree and coefficients, the system achieves adequate FAR performance with minimized overhead, avoiding the need for excessively long CRC sequences that would increase transmission time and reduce spectral efficiency.
Data Source
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AI summary
This application provides an encoding method and apparatus. The method includes: performing CRC encoding on A to-be-encoded information bits based on a CRC polynomial, to obtain a first bit sequence, where the first bit sequence includes L CRC bits and A information bits; and performing polar encoding on the first bit sequence. Based on an improved CRC polynomial, encoding satisfying an FAR requirement is implemented.