Terminal-Based CFRA Control for Multi-TRP Uplink Synchronization
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Solution Overview
Problem
In future radio communication systems, controlling uplink transmission to multiple transmission/reception points (TRPs) is challenging, which can degrade communication quality unless appropriately managed.
Innovation Solution
A terminal equipped with a receiving section to handle Contention Free Random Access (CFRA) resources for multiple TRPs and a control section to manage CFRA procedures based on received information, ensuring coordinated communication across multiple TRPs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UL transmission is performed to multiple transmission/reception points simultaneously, then communication capacity and reliability are improved, but control complexity and timing synchronization difficulty increase
Solution Approach 1:
The patent segments the control of UL transmission by introducing separate CFRA resources for each TRP. The terminal performs independent random access procedures for each transmission/reception point using dedicated preambles and time resources, allowing separate timing advance control for each TRP. This segmentation resolves the control complexity issue while maintaining the reliability benefits of multi-TRP communication.
Solution Approach 2:
The patent introduces a new dimension of control by assigning different random access occasions (time resources) to different TRPs. Instead of managing multiple TRPs within the same time-frequency resource, the system adds the time resource dimension for differentiation. This allows independent timing control for each TRP, resolving the synchronization difficulty while maintaining communication reliability.
2Measurement precision
If separate CFRA resources are allocated for each TRP, then timing advance control precision is improved, but signaling overhead and resource configuration complexity increase
Solution Approach 1:
The patent merges the timing advance control information into the random access response messages received from each TRP. Instead of separate signaling for timing advance per TRP, the timing advance information is embedded within the existing RAR structure. This reduces additional signaling overhead while maintaining precise timing control for each TRP through the random access procedure.
3Measurement precision
If random access procedures are performed for multiple TRPs, then uplink synchronization accuracy is improved, but access latency and procedure complexity increase
Solution Approach 1:
The patent applies preliminary action by pre-configuring dedicated CFRA resources (preambles and time occasions) for each TRP before the actual random access procedure. The terminal and network have predetermined the resources needed for multi-TRP access, eliminating the need for dynamic resource allocation during the access process. This reduces access latency while maintaining synchronization accuracy through the use of pre-planned dedicated resources.
Data Source
Figure 1A~1D
Figure 2A~2B
Figure 3
AI summary
A terminal according to an aspect of the present disclosure includes a receiving section that receives first information related to a Contention Free Random Access (CFRA) resource corresponding to a first transmission/reception point (TRP) and second information related to a CFRA resource corresponding to a second TRP, and a control section that controls a CFRA procedure on the first TRP based on the first information, and controls a CFRA procedure on the second TRP, based on the second information. According to an aspect of the present disclosure, even when communication is performed by using a plurality of transmission points, the communication can be appropriately performed.