Multi-TRP Codebook Reporting for Dynamic CJT CSI Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing CSI feedback for coherent joint transmission (CJT) in multi-TRP scenarios due to increased signaling overhead and lack of synchronization among TRPs, leading to suboptimal performance in multi-antenna systems.
Innovation Solution
The implementation of a dynamic point selection (DPS) mechanism for CSI reporting in multi-TRP environments, utilizing a codebook structure that allows for selective TRP participation based on CSI-RS resources, co-phasing coefficients, and spatial/frequency basis selection matrices, reducing unnecessary computations and overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multi-TRP coherent joint transmission is implemented, then communication throughput and reliability are improved, but signaling overhead and system complexity increase
Solution Approach 1:
The patent segments the multi-TRP system into independent codebook configurations for each TRP. Each TRP has its own codebook with spatial basis selection matrices, allowing the UE to independently select and report precoding information for each TRP. This segmentation reduces the overall complexity by avoiding a single large joint codebook while maintaining the benefits of multi-TRP transmission.
Solution Approach 2:
The patent implements dynamic point selection where the UE can dynamically choose which TRP(s) to use for transmission based on current channel conditions. The codebook configuration allows flexible selection of active TRPs and their corresponding precoding matrices, enabling the system to adapt to changing conditions and optimize performance while controlling complexity.
2Measurement precision
If comprehensive CSI feedback for all TRPs is reported, then transmission accuracy is improved, but signaling overhead increases
Solution Approach 1:
The patent extracts only the essential CSI feedback elements needed for multi-TRP operation. Instead of reporting complete codebook information for all TRPs, the UE reports selected spatial basis indices and co-phasing coefficients that capture the most important channel characteristics. This extraction maintains accuracy while significantly reducing overhead.
Solution Approach 2:
The patent changes the parameter representation from complete codebook matrices to compact indices and coefficients. The spatial basis selection matrices are represented by indices pointing to predefined codebook entries, and the co-phasing information is represented by compact coefficient values. This parameter transformation maintains measurement precision while reducing the quantity of feedback signaling.
3Reliability
If synchronization among multiple TRPs is achieved, then coherent joint transmission performance is improved, but system complexity and coordination overhead increase
Solution Approach 1:
The patent performs preliminary configuration of codebooks at each TRP before transmission. The spatial basis selection matrices and codebook structures are pre-defined and configured, allowing each TRP to independently prepare its precoding options. This preliminary action reduces the need for complex real-time coordination while enabling coherent joint transmission when needed.
Solution Approach 2:
The patent introduces the UE as an intermediary that performs the complex selection and coordination functions. The UE receives channel state information from multiple TRPs, independently evaluates the codebook options for each TRP, and selects the optimal combination. This shifts the coordination complexity from the network side to the UE side, simplifying TRP synchronization requirements.
Data Source
AI summary
Apparatus and methods are provided for a user equipment (UE) to perform dynamic point selection (DPS) in a wireless network. The UE receives signals from a plurality of transmission and reception points (TRPs). Different non-zero power (NZP) channel state information (CSI) reference signal (RS) resources are configured for different ones of the plurality of TRPs. The UE selects, based on the signals, one or more selected TRP of the plurality of TRPs for multiple TRP (multi-TRP) coherent joint transmission (CJT) CSI feedback. The UE configures a CSI-RS resource indicator (CRI) field in the multi-TRP CJT CSI feedback to indicate the one or more selected TRP and reports the multi-TRP CJT CSI feedback to the wireless network.