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 simply removing CRC in traditional LTE systems renders error check and target receiver identification functions impossible.
Innovation Solution
A method that adjusts the position of bits in a bit block to generate a third bit block for radio signal transmission, using CRC bits to improve decoding accuracy and implement unequal error protection by mapping bits of different importance onto sub-channels with varying reliability, while maintaining the functions of traditional CRC through proper positional design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If polar codes use CRC bits for error checking, then decoding accuracy is improved, but transmission efficiency decreases
Solution Approach 1:
The patent segments the bit block into different types of bits (first-type bits and second-type bits) with different positions. Second-type bits are specifically designed to be associated with CRC bits, allowing the CRC functionality to be integrated into the polar code structure without simply appending separate CRC bits, thereby improving decoding accuracy while minimizing efficiency loss.
Solution Approach 2:
The patent merges the CRC error checking function with the polar code structure by integrating CRC bits into the bit block itself. Instead of treating CRC as a separate component, the invention combines error checking capabilities with the channel coding structure, allowing both functions to work together efficiently within a unified framework.
2Productivity
If polar codes remove CRC bits to improve transmission efficiency, then transmission efficiency increases, but error checking and target receiver identification functions are lost
Solution Approach 1:
The patent makes the bit block structure universal by designing bits that serve multiple functions. The second-type bits are associated with both information transmission and error checking through their relationship with CRC bits. This multi-functional design allows the same bit structure to provide both data transmission and reliability verification without requiring separate dedicated bits for each function.
Solution Approach 2:
The patent performs preliminary arrangement of bit positions before encoding and transmission. By pre-positioning second-type bits in specific locations within the bit block and establishing their association with CRC bits in advance, the system prepares the structure to inherently support error checking functionality without requiring additional processing or separate error checking mechanisms during transmission.
3Measurement precision
If bit positions are adjusted to implement unequal error protection, then decoding accuracy for important bits is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by treating different bits differently based on their importance. Second-type bits, which are associated with CRC and represent more critical information, are given special positional treatment within the bit block. This localized differentiation allows important bits to receive enhanced protection through their specific positions and associations, while less critical bits follow standard positioning, thereby achieving unequal error protection without uniformly complicating the entire system.
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.