Polar Channel Coding With CRC Bit Mapping for Unequal Protection
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Solution Overview
Problem
Polar codes in wireless communication systems face efficiency issues when used without Cyclic Redundancy Check (CRC) bits, particularly in low information bit scenarios, leading to decreased transmission efficiency compared to Tail-Biting Convolutional Codes, and removing CRC bits compromises error checking and target receiver identification functions in traditional LTE systems.
Innovation Solution
A method that generates a third bit block by combining first and second bit blocks, where the position of bits in the third block is adjusted based on the number of associated bits in the first block, allowing for unequal error protection and improved decoding accuracy by using CRC bits as both an outer code and for error checking and target receiver identification, while maintaining the functionality of traditional CRC functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CRC bits are removed from polar code to improve transmission efficiency, then transmission efficiency increases, but error checking and target receiver identification functions are lost
Solution Approach 1:
The patent applies multi-functionality by enabling CRC bits to serve dual purposes: as outer code for error correction in polar coding and as error checking/target receiver identification code in traditional LTE functions. This allows the same CRC bits to simultaneously improve transmission efficiency through polar code integration while maintaining traditional error checking and identification capabilities, thereby resolving the contradiction between improved efficiency and preserved reliability functions.
2Reliability
If CRC bits are used in polar code for low information bit scenarios, then error protection is improved, but transmission efficiency decreases compared to Tail-Biting Convolutional Codes
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the position of CRC bits within the bit block based on the number of information bits. This optimization allows the system to adapt the CRC bit positioning to different transmission scenarios, improving transmission efficiency while maintaining error protection capabilities. The parameter adjustment enables polar codes with CRC to outperform Tail-Biting Convolutional Codes in low information bit scenarios by optimizing the code structure rather than simply adding overhead.
3Reliability
If position of bits in third bit block is adjusted based on number of associated bits, then unequal error protection is achieved, but decoding complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-determining and optimizing the position mapping rules between the first bit block and the third bit block before transmission. The position of each bit in the third bit block is pre-calculated based on the number of associated bits in the first bit block, creating a deterministic mapping relationship. This preliminary optimization of bit positioning enables unequal error protection across different bit positions while maintaining manageable decoding complexity, as the mapping rules are established in advance rather than requiring complex real-time calculations during decoding.
Data Source
AI summary
The disclosure discloses a method and device in UE and a base station for channel coding. A first node first determines a first bit block and then transmits a first radio signal, wherein bits of the first bit block are used to generate bits of a second bit block, a third bit block comprises bits of the second bit block and the first bit block, and the third bit block is used to generate the first radio signal. The first bit block, the second bit block and the third bit block comprise P1, P2 and P3 bits, respectively.