NR Bit-to-Symbol Mapping Using LDPC Priority Ordering
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Solution Overview
Problem
Conventional transmission coding solutions in wireless communication networks, such as those used in 5G NR communications, do not provide the desired level of speed or customization for efficient operation, particularly in prioritizing bits within modulation symbols for error correction and reliability.
Innovation Solution
The method involves encoding a code block using a low-density parity-check (LDPC) code to generate systematic and parity bits, determining their degrees, and arranging encoded bits within modulation symbols based on relative priority, with higher priority bits mapped to more significant locations for improved reliability during transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional transmission coding solutions are used, then the system maintains simplicity and compatibility, but the transmission speed and customization capability are insufficient
Solution Approach 1:
The encoded bit stream is segmented into different priority groups (first priority bits, second priority bits, third priority bits) based on their importance for error correction. This segmentation allows selective mapping of different bit groups to different modulation symbol locations, enabling customized transmission strategies that improve overall transmission speed while maintaining necessary error protection levels.
Solution Approach 2:
Different locations within modulation symbols are assigned different quality levels (most significant bits vs. least significant bits). By mapping higher priority encoded bits to higher quality locations (most significant bits) and lower priority bits to lower quality locations (least significant bits), the system achieves customized error protection where critical bits receive enhanced protection, thereby improving transmission reliability and effective speed without uniformly increasing complexity.
2Reliability
If all encoded bits are treated equally in modulation symbols, then the mapping process is simple, but transmission reliability and error correction effectiveness are reduced
Solution Approach 1:
Before mapping encoded bits to modulation symbols, the system performs preliminary prioritization by determining the degree of each systematic and parity bit. This preliminary action assigns priority levels to different bits based on their importance for error correction, allowing the mapping process to place higher priority bits in more reliable locations within modulation symbols, thereby improving transmission reliability without adding complex real-time decision-making during transmission.
3Reliability
If higher priority bits are mapped to most significant bit locations, then error correction effectiveness improves, but the mapping complexity increases
Solution Approach 1:
The system changes the mapping parameter by using degree information of systematic and parity bits as the basis for priority determination. This parameter change transforms the mapping process from a simple sequential assignment to a degree-based priority assignment, where bits with higher degrees (more important for error correction) are mapped to most significant bit locations. This approach improves decoding accuracy while keeping the mapping rule systematic and manageable through degree-based classification.
Data Source
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AI summary
A new radio (NR) bit prioritization procedure that may be executed by a UE and a base station is disclosed, resulting in transmission and reception of modulation symbols having prioritized bits. For example, a transmitter may encode a code block using low-density parity-check code to generate a stream of encoded bits. The transmitter may arrange the encoded bits in one or more modulation symbols according to a relative priority of the encoded bits. The highest priority bits may be located in the most significant bits of the modulation symbol, and therefore be less likely to experience errors. A receiver may receive the modulation symbols and reorder the encoded bits according to the coding scheme based on the relative priority prior to decoding the encoded bits. The prioritization of the bits within the modulation symbols may provide improved block error rates over sequential mapping of encoded bits to symbols.