Hierarchical Beam Management Using CSI-RS in mmWave Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In mmWave wireless communication systems, managing beams effectively is challenging due to high path loss and beam mismatch, which affects signal transmission quality and coverage, particularly in areas with radio shadows.
Innovation Solution
A method for determining and managing beams by configuring primary and secondary beams using channel state information-reference signals (CSI-RS), where a user equipment (UE) receives synchronization signals or CSI-RS from a base station, reports preferred beams, and is configured with CSI-RS resources based on these beams, including information about secondary beams quasi-co-located with primary beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If beamforming is designed to control beam mismatch in mmWave communication, then signal transmission quality is improved, but device complexity increases due to elaborate beam configuration requirements
Solution Approach 1:
The beam management process is segmented into two hierarchical levels: primary beam selection from a limited set of beam pairs, and secondary beam refinement within the selected primary beam. This segmentation reduces the overall complexity by dividing the large-scale beam search into manageable stages, where the UE first identifies a primary beam pair and then performs finer-grained secondary beam selection only within that primary beam's coverage area.
Solution Approach 2:
The base station performs preliminary action by pre-configuring and transmitting a set of synchronization signal blocks (SSBs) corresponding to multiple beam pairs before the actual communication begins. This preliminary beam pair establishment provides a foundation for subsequent secondary beam refinement, reducing the real-time complexity of beam management during active communication.
2Adaptability or versatility
If hierarchical beam management with primary and secondary beams is implemented, then beam management effectiveness is improved, but information transmission overhead increases due to additional beam reporting
Solution Approach 1:
Beam information reporting is segmented into two distinct phases: primary beam reporting where the UE reports the selected primary beam pair from a limited set, and secondary beam reporting where the UE reports the preferred secondary beam index relative to the primary beam. This segmentation reduces overhead by avoiding redundant reporting of already-established primary beam information while still capturing the necessary fine-grained beam preferences.
Solution Approach 2:
The system implements partial action by having the UE report only the necessary secondary beam information (such as a secondary beam index or relative beam preference) rather than completely re-reporting all beam parameters. This partial reporting approach provides sufficient beam management information while minimizing uplink overhead.
3Measurement precision
If CSI-RS resources are configured based on secondary beams, then measurement precision is improved, but device complexity increases due to additional resource configuration management
Solution Approach 1:
CSI-RS resource configuration is segmented to align with the hierarchical beam structure: one set of CSI-RS resources is associated with primary beam measurements, and another set is associated with secondary beam measurements within the selected primary beam. This segmentation allows the UE to manage CSI-RS resources in a structured manner that mirrors the beam hierarchy, reducing the cognitive complexity of resource management while maintaining precise measurements at both levels.
Data Source
AI summary
According to one embodiment of the present specification, a method for determining a beam to be used by a terminal for communication in an mmWave communication system can be provided. Here, the method for determining a beam to be used by a terminal for communication may comprise the steps of: receiving a CSI-RS from a base station; reporting a preferred primary beam to the base station on the basis of the received CSI-RS; receiving secondary beam information from the base station on the basis of the preferred primary beam; reporting a preferred secondary beam from among the secondary beam information to the base station; and receiving a setting of a CSI-RS resource from the base station on the basis of the preferred secondary beam. Here, the secondary beam information may include the preferred primary beam and at least one secondary beam to which QCL is applied.