Radio Link Monitoring Using Non-CRS Signals for Cell Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mobile communication systems face challenges in efficiently selecting the best cell for user equipment (UE) based on Radio Resource Management (RRM) Reference Signals (RS) other than Cell-specific Reference Signals (CRS), particularly in environments with advanced cell configurations like full-dimension MIMO, leading to suboptimal radio link quality and increased latency in initial access.
Innovation Solution
A method for UE to perform Radio Link Monitoring (RLM) using Reference Signals other than CRS, allowing for the determination of Radio Link Failure (RLF) with different conditions, and incorporating Enhanced Physical Downlink Control Channel (EPDCCH) for Downlink Control Information transmission, enabling efficient cell selection and minimizing latency through Full Dimension-Multi Input Multi Output (FD-MIMO) support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If CRS-based RLM is used for cell selection, then compatibility with existing systems is maintained, but cell selection efficiency and radio link quality in advanced cell configurations (e.g., full-dimension MIMO) deteriorate
Solution Approach 1:
The patent segments the RLM process into two distinct types: first RLM based on CRS and second RLM based on non-CRS (e.g., CSI-RS). This segmentation allows the system to maintain compatibility with existing CRS-based procedures while introducing a new monitoring mechanism optimized for advanced cell configurations, thereby resolving the contradiction between compatibility and performance.
Solution Approach 2:
The patent introduces dynamic adaptability by allowing the UE to perform both first and second RLM and determine RLF based on either or both, depending on configuration. This dynamic approach enables the system to switch between CRS-based and non-CRS-based monitoring based on the specific cell configuration and service requirements, optimizing radio link quality while maintaining backward compatibility.
2Reliability
If non-CRS reference signals are used for RLM, then cell selection efficiency and radio link quality in advanced configurations improve, but system complexity increases
Solution Approach 1:
The patent makes the RLM system universal by designing it to support both CRS-based and non-CRS-based monitoring within the same framework. The UE is configured to perform first RLM based on CRS and second RLM based on non-CRS reference signals, with the ability to determine RLF based on either or both. This multi-functional design allows the system to handle both traditional and advanced cell configurations without requiring separate systems, thereby improving radio link quality while managing system complexity through a unified approach.
3Ease of operation
If initial access process is performed without optimized RLM, then procedure simplicity is maintained, but access latency increases
Solution Approach 1:
The patent applies preliminary action by configuring the UE to perform second RLM based on non-CRS reference signals before final cell selection and initial access completion. This advance monitoring allows the UE to identify the best cell earlier in the process, reducing access latency while maintaining procedural simplicity through configured automation. The network can pre-configure the UE with non-CRS reference signal resources for RLM, enabling faster cell selection without complicating the overall access procedure.
Data Source
AI summary
Disclosed is a method for radio link monitoring in a wireless communication system and an apparatus for the method. More specifically, a method for a user equipment (UE) to perform Radio Link Monitoring (RLM) in a wireless communication system comprises performing second RLM on a cell based on a Reference Signal (RS) other than a Cell-specific Reference Signal (CRS) and determining an Radio Link Failure (RLF) with respect to the cell based on the second RLM, wherein a condition for determining an RLF applied to the second RLM is different from the condition for determining an RLF applied to CRS-based first RLM.