Adaptive Uplink Antenna Array Codebooks for Variable Coherence
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Solution Overview
Problem
Current 5G and NR wireless communication systems lack support for MIMO codebooks for 4-port uplink transmission with variable coherence, and existing signaling methods are insufficient to identify UE capabilities for fully coherent, partially coherent, and non-coherent MIMO operations.
Innovation Solution
A method is introduced where a user equipment (UE) and base station use a precoding matrix indication field in control messages to indicate precoding matrices suitable for different coherence capabilities, allowing for the selection and use of precoding matrices that match the UE's coherence capabilities, enabling efficient uplink MIMO operations with support for fully coherent, partially coherent, and non-coherent transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single codebook is used for all coherence capabilities, then device complexity is reduced, but it cannot support UEs with different coherence capabilities (fully coherent, partially coherent, and non-coherent)
Solution Approach 1:
The codebook is segmented into multiple subsets, where each subset contains precoding matrices suitable for a specific coherence capability (fully coherent, partially coherent, or non-coherent). The network can indicate which subset to use based on the UE's coherence capability, enabling support for diverse UE types without requiring a single complex codebook to handle all cases.
Solution Approach 2:
The codebook configuration is made dynamic by allowing the network to selectively activate or indicate different codebook subsets based on the UE's coherence capability. This dynamic selection mechanism enables the system to adapt to different coherence requirements without permanently maintaining multiple complete codebooks, thus managing complexity while preserving versatility.
2Adaptability or versatility
If separate codebooks are used for different coherence capabilities, then support for various UE types is improved, but signaling overhead and system complexity increase
Solution Approach 1:
The invention extracts and separates the coherence capability indication from the main precoding matrix indication. By using a dedicated field or specific signaling mechanism to indicate the UE's coherence capability, the system can efficiently select the appropriate codebook subset without requiring extensive signaling to describe the entire codebook configuration for each UE type.
Solution Approach 2:
The codebook design employs a universal structure where a single codebook framework can serve multiple coherence capabilities through subset selection. The same codebook infrastructure is used for all UE types, but different subsets within it are activated based on the UE's coherence capability, reducing the need for completely separate codebook implementations.
3Productivity
If precoding matrices are optimized for fully coherent operation, then data rates are maximized, but UEs with partial or non-coherent operation cannot utilize these optimized matrices
Solution Approach 1:
Different subsets of precoding matrices within the codebook are optimized for different coherence capabilities. The fully coherent subset contains matrices optimized for maximum data rate with phase continuity, while other subsets contain matrices designed for partial or non-coherent operation. The network selects the appropriate subset based on the UE's coherence capability, ensuring each UE uses matrices locally optimized for its specific operation mode.
Data Source
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AI summary
A user equipment (200, 1530), configured to transmit over multiple antenna ports, receives a control message from a base station (100, 1520) in a wireless communication network. The control message includes a precoding matrix indication field configurable to at least a first and second configuration. The first configuration identifies precoding matrices in both a first set of precoding matrices and a second set of precoding matrices. The second configuration identifies precoding matrices in the second set of precoding matrices, but not in the first set of precoding matrices. The precoding matrices in the first and second set of precoding matrices are precoding matrices for transmissions from the user equipment. The first set of precoding matrices corresponds to a first coherence capability. The second set of precoding matrices corresponds to a second coherence capability. The second configuration occupies fewer information bits than the first configuration.