CSI-IM Resource Configuration for MU-MIMO Interference Measurement
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Solution Overview
Problem
Current wireless communication systems, particularly in LTE Release-10, face challenges in supporting multi-user MIMO (MU-MIMO) due to limitations in interference measurement resources and feedback mechanisms, which affect the determination of reliable modulation and coding schemes for multiple users.
Innovation Solution
The configuration of CSI-IM resources for enhanced downlink measurements allows user equipment (UE) to identify and measure interference, determining whether to use a subset of frequency resources for interference measurement and sending feedback based on these measurements, thereby improving MU-MIMO performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If interference measurement is performed using all frequency resources, then measurement accuracy is improved, but feedback overhead and processing complexity increase
Solution Approach 1:
The patent segments the frequency resources into subsets and configures multiple CSI-IM resources corresponding to different subsets. The UE performs interference measurements on each subset separately and reports multiple CSI reports, each corresponding to a specific frequency subset. This segmentation allows the system to balance measurement accuracy with feedback overhead by selectively measuring and reporting on subsets rather than all resources at once.
Solution Approach 2:
The patent implements partial action by allowing the UE to measure interference on a subset of frequency resources rather than all resources. The network can configure the UE to measure only specific subsets of CSI-IM resources based on scheduling decisions, reducing the measurement and feedback burden while maintaining sufficient accuracy for MU-MIMO operations.
2Measurement precision
If interference measurement is performed on all downlink subframes, then measurement completeness is improved, but measurement overhead and latency increase
Solution Approach 1:
The patent implements periodic action by configuring CSI-IM resources to appear periodically in downlink subframes according to a predefined pattern. The UE performs interference measurements on these periodically occurring CSI-IM resources rather than continuously monitoring all subframes. This periodic structure reduces measurement overhead and latency while maintaining adequate measurement completeness for MU-MIMO scheduling decisions.
3Adaptability or versatility
If multiple CSI-IM resources are configured for different frequency subsets, then frequency-selective interference measurement capability is improved, but configuration complexity increases
Solution Approach 1:
The patent applies universality by designing a unified CSI-IM resource configuration framework that can serve multiple purposes. The same CSI-IM resource configuration structure is used whether the UE measures on a single frequency subset or multiple subsets. The configuration parameters and measurement procedures remain consistent across different deployment scenarios, reducing the effective complexity despite the enhanced frequency-selective capability.
Data Source
AI summary
Apparatuses and methods for indicating and performing interference measurements. A method for performing interference measurements includes identifying a CSI-IM configuration for the UE to perform interference measurement. The method includes determining whether the CSI-IM configuration includes a subset of a total number of frequency resources configured for CSI-IM in the wireless communication system. The method includes measuring interference based on the identified CSI-IM configuration. Additionally, the method includes sending feedback based on the measured interference. The method for performing interference measurements may also include determining whether to perform interference measurements based on all downlink subframes or only a portion of the downlink subframes. Additionally, the method may include performing interference measurement based on the subframe determination.