Multi-Layer Beam CSI Feedback Quantization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communications, the existing methods for coefficient determination in multi-layer beamformed communications result in high feedback overhead and under-quantization of important beams, leading to inefficient use of channel resources due to the need for precise feedback of beam combination coefficients across multiple transmission layers.
Innovation Solution
A method where a user equipment (UE) reports high-resolution quantization feedback for the highest amplitude precoding coefficients and low-resolution feedback for the remaining non-zero power coefficients, with the total number of leading beams determined jointly across all transmission layers to optimize feedback efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-resolution quantization feedback is reported for all beams per transmission layer, then measurement precision is improved, but feedback overhead increases significantly
Solution Approach 1:
The patent applies local quality by differentiating quantization precision based on beam importance. Leading beams (with non-zero power coefficients) receive high-resolution quantization feedback, while non-leading beams receive low-resolution or zero feedback. This selective approach concentrates feedback resources on the most critical beams, achieving high measurement precision where needed while significantly reducing overall feedback overhead.
2Quantity of substance
If a fixed number of leading beams is reported per transmission layer, then feedback overhead is reduced, but important beams may be under-quantized on some layers
Solution Approach 1:
The patent transitions from per-layer beam counting to a joint approach across all transmission layers. Instead of independently determining the number of leading beams for each layer, the system identifies the total number of non-zero power coefficients across all layers and applies a unified threshold. This dimensional shift ensures that beams are selected based on their actual importance rather than layer position, preventing under-quantization while controlling feedback overhead.
Solution Approach 2:
The patent changes the parameter for beam selection from fixed per-layer counts to a dynamic total count based on non-zero power coefficients. By using the actual number of non-zero coefficients (K_total) as the selection criterion rather than a predetermined fixed number per layer, the system adapts to different channel conditions and ensures accurate quantization of truly important beams regardless of which transmission layer they belong to.
3Reliability
If more transmission layers are reported with high quantization, then communication performance is improved, but feedback overhead increases
Solution Approach 1:
The patent applies local quality by differentiating quantization precision based on beam importance. Leading beams (with non-zero power coefficients) receive high-resolution quantization feedback, while non-leading beams receive low-resolution or zero feedback. This selective approach concentrates feedback resources on the most critical beams, achieving high measurement precision where needed while significantly reducing overall feedback overhead.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described that provide for channel state information (CSI) feedback for multiple discrete Fourier transform (DFT) beams on multiple transmission layers. A user equipment (UE) may report a total number of non-zero power DFT beams across all of the transmission layers. The UE may be configured with a total number of leading beams (Ktotal) across all of the transmission layers for which to provide high quantization feedback. When the total number of non-zero DFT beams across all the transmission layers exceeds the configured total number of leading beams across all the transmission layers, the UE may report high-resolution quantization feedback for Ktotal non-zero power precoding coefficients having the highest amplitude coefficients, and may report low-resolution quantization feedback for the remaining non-zero power precoding coefficients. A base station may receive the CSI feedback to determine a precoding matrix.