Codebook-Based PUSCH Precoding for Layer Mapping Flexibility
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Solution Overview
Problem
Existing wireless communication systems, particularly 5G NR, face challenges in efficiently managing codebook-based Physical Uplink Shared Channel (PUSCH) transmissions due to increased transmission layers and antenna ports, leading to issues with layer mapping and codebook subset switching, which affect flexibility and adaptability to varying channel conditions.
Innovation Solution
A method and apparatus for codebook-based PUSCH transmission that includes determining the number of codewords and codeword-to-layer mapping based on the number of transmission layers, using precoding matrices for spatial multiplexing, and configuring antenna groups for coherent conditions, allowing flexible switching between different codebook subsets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of transmission layers is increased to improve data rate, then the data rate is improved, but the layer mapping complexity increases
Solution Approach 1:
The patent segments the layer mapping process by defining distinct mapping rules for different ranges of transmission layers. For 1-4 layers, a first mapping method is applied, while for 5-8 layers, a second mapping method is applied. This segmentation allows the system to handle increased data rates through higher layer counts while managing complexity by applying simplified, range-specific mapping rules rather than a single complex universal rule.
2Adaptability or versatility
If codebook subset switching is implemented to improve adaptability to channel conditions, then the adaptability is improved, but the codebook management complexity increases
Solution Approach 1:
The patent implements dynamic codebook subset switching that allows the system to adapt to varying channel conditions by selecting from multiple codebook subsets. The codebook configuration is made dynamic through DCI signaling, which enables real-time switching between different codebook subsets based on current channel state. This dynamic approach improves adaptability while managing complexity through standardized switching mechanisms and predefined codebook structures.
3Productivity
If 8TX UL operations are configured to improve wireless communication efficiency, then the communication efficiency is improved, but the antenna port mapping complexity increases
Solution Approach 1:
The patent applies local quality by configuring different antenna port mapping rules for different transmission scenarios within the 8TX UL operation. Rather than using a single complex mapping rule for all cases, the system applies specific mapping configurations tailored to different local conditions such as transmission rank, codebook subset, and layer allocation. This allows high communication efficiency through 8TX operations while managing complexity through context-specific mapping rules.
Data Source
AI summary
A method for performing codebook-based Physical Uplink Shared Channel (PUSCH) transmission by a User Equipment (UE) is provided. The method receives a Radio Resource Control (RRC) message including a PUSCH configuration indicating a codebook-based PUSCH transmission. The method receives a Downlink Control Information (DCI) format including a first field and a second field. The first field indicates an 8-port Sounding Reference Signal (SRS) resource. The second field indicates an index associated with a Transmission Precoding Matrix Indicator (TPMI) and the number of transmission layers. The method determines the number of codewords to be one or two based on the number of transmission layers. The method determines a codeword-to-layer mapping for spatial multiplexing based on the number of transmission layers and the number of codewords. The method determines a precoding matrix based on the index and the codeword-to-layer mapping. The method performs the codebook-based PUSCH transmission using the precoding matrix.