CSI Codebook Parameters for Multi-TRP Feedback Overhead

The patent segments the codebook into multiple components (spatial-domain basis vectors, frequency-domain basis vectors, and coefficient components). Each component handles a specific aspect of the precoding matrix representation, allowing the system to support more antenna ports and layers without proportionally increasing feedback overhead. The segmented approach enables efficient representation of large-dimensional MIMO channels by decomposing the precoding matrix into structured components that can be reported more compactly.

The patent introduces configurable codebook parameters (L, M, β) that control the dimensions and granularity of the codebook components. By adjusting these parameters, the system can adapt the codebook size and complexity to match the actual channel conditions and spectral efficiency requirements. This parameter-based control allows the system to optimize the balance between spectral efficiency and feedback overhead dynamically, rather than being constrained by fixed codebook structures.

The patent divides the precoding matrix into multiple reportable components: spatial-domain basis vectors (L vectors per TRP), frequency-domain basis vectors (M vectors), and coefficient components. This segmentation allows the UE to report channel state information in a structured manner that scales efficiently with the number of antenna ports and TRPs. Each component can be independently configured and reported, reducing the overall feedback overhead compared to reporting the complete precoding matrix directly.

The patent introduces frequency-domain basis vectors as an additional dimension to the codebook structure, complementing the traditional spatial-domain basis vectors. This two-dimensional basis (spatial × frequency) allows the system to capture channel variations in both spatial and frequency domains efficiently. By adding this dimensional structure, the patent enables compact representation of large-dimensional MIMO channels without proportionally increasing feedback overhead, as the frequency-domain basis provides a structured way to represent channel correlations across frequency.

The patent associates spatial-domain basis vectors with specific transmission reception points (TRPs), creating a segmented codebook structure where each TRP has its own set of basis vectors. This segmentation enables the UE to report CSI for multiple TRPs in a structured and organized manner, reducing reporting complexity. The association between SD basis vectors and TRPs allows the network to efficiently process and interpret the reported CSI for each TRP independently, facilitating multi-TRP operations without overwhelming reporting complexity.

The patent designs a universal codebook structure that can handle both single-TRP and multi-TRP scenarios using the same framework. The codebook parameters (L, M, β) and the basis vector components can be configured to support different numbers of TRPs and antenna ports. This universal structure eliminates the need for separate CSI reporting mechanisms for different deployment scenarios, reducing overall system complexity while maintaining the ability to support distributed MIMO and multi-TRP operations for enhanced system capacity.