CSI-IM Hopping for Interference Measurement Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In CoMP systems, interference measurements using CSI-IM are less accurate due to limited resource configurations, leading to collisions and underestimation of interference, which affects CSI feedback quality, especially at cell edges where inter-cell interference is significant.
Innovation Solution
Implementing CSI-IM hopping and increasing the number of CSI-IM resources, along with pseudo-random hopping patterns, to minimize collisions and enhance interference measurement accuracy by dynamically varying the position of CSI-IM resources in time and frequency domains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If CSI-IM resources are used for interference measurements, then flexibility in supporting different interference scenarios is improved, but measurement accuracy deteriorates due to limited resource configurations and collisions
Solution Approach 1:
The invention segments the interference measurement process by dividing CSI-IM resources into multiple groups corresponding to different interference scenarios. Each group is associated with specific CoMP transmission schemes (e.g., dynamic point selection, coordinated beamforming), allowing the system to select appropriate measurement resources based on the current transmission mode, thereby improving both flexibility and accuracy
Solution Approach 2:
The invention introduces dynamic resource allocation where CSI-IM resource groups are dynamically selected and configured based on current CoMP transmission schemes and interference conditions. The network can dynamically indicate which CSI-IM resource group to use for measurements, adapting to changing channel conditions and transmission modes, thus resolving the contradiction between fixed resource limitations and measurement accuracy requirements
2Loss of substance
If the number of CSI-IM configurations is limited, then resource overhead is reduced, but interference measurement accuracy deteriorates due to collisions between CSI-IM of different nodes
Solution Approach 1:
The invention extends the CSI-IM resource space by introducing multiple dimensions including frequency domain resources, time domain resources, and code domain resources. By organizing CSI-IM resources into groups across these dimensions and applying hopping patterns, the system increases the effective number of available configurations without proportionally increasing overhead, thereby reducing collisions while maintaining resource efficiency
Solution Approach 2:
The invention implements periodic hopping patterns for CSI-IM resources where the resource allocation changes periodically according to predefined patterns. This periodic variation in resource positions across different subframes or slots reduces the probability of persistent collisions between CSI-IM of different nodes, improving measurement accuracy while maintaining a limited set of base configurations
3Measurement precision
If CRS based measurements are used, then interference measurement accuracy is improved, but resource overhead increases compared to CSI-IM
Solution Approach 1:
The invention makes CSI-IM resources multi-functional by designing them to serve both channel state information acquisition and interference measurement purposes. Through proper configuration of CSI-IM resource groups and association with different CoMP schemes, the same resource structure achieves accuracy comparable to CRS while maintaining lower overhead, as CSI-IM can be sparsely configured and shared across multiple functions
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Embodiments of providing enhanced interference measurements for CSI feedback are generally described herein. In some embodiments, CSI-IM resources are used by UE to perform interference measurements. The serving cell determines a hopping pattern for varying a position of the determined CSI-IM resources in subframes transmitted to the served UE. The determined CSI-IM resources and the determined CSI-IM resources hopping pattern are transmitted to the served UE. The serving node transmits a zero-power (ZP) CSI-RS. The serving node receives an interference measurement from the served UE based on CSI-IM and ZP CSI-RS provided to the served UE from the serving cell. Collisions between the CSI-IM of the serving node and CSI-IM of the non-serving nodes are minimized by the determined CSI-IM resources hopping pattern.