TPMI Determination for Coherent Wireless Transmission
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Solution Overview
Problem
Current wireless communication systems face challenges in determining an optimal transmit precoding matrix indication (TPMI) for codebook sets, particularly in distinguishing between different transmission capabilities such as full-coherent, partial-coherent, and non-coherent transmissions, which affects the efficiency and accuracy of data transmission.
Innovation Solution
The method involves determining a TPMI based on the transmission capability and rank, where the TPMI corresponds to specific bit lengths (up to five bits for rank one, four bits for rank two, and three bits for rank three, using predefined codebooks for each transmission type, and transmitting this information to remote units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a unified TPMI determination method is used for all transmission capabilities, then the system complexity is reduced, but the transmission accuracy and efficiency deteriorate due to inability to distinguish between full-coherent, partial-coherent, and non-coherent transmissions
Solution Approach 1:
The codebook is segmented into multiple codebook sets (first codebook set, second codebook set, third codebook set) corresponding to different transmission capabilities (full-coherent, partial-coherent, non-coherent). Each codebook set contains TPMIs optimized for its specific transmission type, allowing the system to select the appropriate codebook set based on the UE's transmission capability, thereby maintaining transmission accuracy while managing system complexity through structured organization.
2Productivity
If different codebooks are used for different transmission capabilities, then the transmission efficiency is improved, but the device complexity increases due to multiple codebook sets
Solution Approach 1:
The system performs preliminary classification of UEs into different transmission capability categories (full-coherent, partial-coherent, non-coherent) before TPMI determination. The network configures and stores multiple codebook sets in advance, each optimized for specific transmission capabilities. When determining TPMI, the system first identifies the UE's transmission capability and selects the corresponding pre-configured codebook set, avoiding real-time complex calculations and improving transmission efficiency.
3Measurement precision
If the TPMI bit length is increased to provide more granular control, then the transmission precision is improved, but the signaling overhead increases
Solution Approach 1:
Different codebook sets use different TPMI bit lengths optimized for their specific transmission capabilities. The first codebook set (full-coherent) uses 5-bit TPMIs for fine-grained control, the second codebook set (partial-coherent) uses 4-bit TPMIs, and the third codebook set (non-coherent) uses 3-bit TPMIs. This local optimization ensures that each transmission capability receives appropriate precision while minimizing overall signaling overhead by not applying uniform high precision to all cases.
Data Source
AI summary
Apparatuses, methods, and systems are disclosed for determining a TPMI for a codebook set. One method includes receiving information indicating a transmission capability of a remote unit. The method includes determining a transmit precoding matrix indication based on a rank and a codebook corresponding to the transmission capability and the rank, wherein the transmit precoding matrix indication corresponding to a rank of one includes a maximum of five bits, and the transmit precoding matrix indication corresponding to a rank of two includes a maximum of four bits. The method includes transmitting the transmit precoding matrix indication to the remote unit.