Terminal QCL Control for Multi-TRP Random Access Timing
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Solution Overview
Problem
In future radio communication systems, controlling uplink transmission to multiple transmission/reception points or non-serving cells is challenging, leading to potential degradation of communication quality.
Innovation Solution
A terminal equipped with a receiving section for first and second downlink control channels, utilizing quasi-co-location assumptions to control random access procedures per transmission/reception point, enhancing communication quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If uplink transmission is controlled for each transmission/reception point or serving cell in multi-TRP or inter-cell mobility scenarios, then communication capacity and high-speed data rates are improved, but control complexity and difficulty of managing timing advance per TRP increase
Solution Approach 1:
The patent segments the uplink transmission control by introducing separate timing advance groups (TAGs) for different transmission/reception points. Each TAG is independently managed with its own timing advance value, allowing the terminal to handle multiple TRPs without overwhelming control complexity. This segmentation enables independent timing adjustment for each TRP while maintaining overall system coordination.
Solution Approach 2:
The patent applies preliminary action by pre-configuring multiple timing advance groups and their associated parameters before actual multi-TRP operation begins. The network pre-establishes the TAG structure, assigns TRPs to specific TAGs, and provides preliminary timing advance values, so that when multi-TRP communication starts, the terminal already has the control framework in place, reducing real-time control complexity.
2Measurement precision
If random access procedure is performed per transmission/reception point to control uplink timing, then timing accuracy for each TRP is improved, but signaling overhead and procedure complexity increase
Solution Approach 1:
The patent merges the random access procedures for multiple TRPs by allowing a single random access procedure to serve multiple transmission/reception points when they share the same timing advance group. Instead of requiring separate random access procedures for each TRP, the system combines TRPs into TAGs, reducing the number of random access procedures needed while maintaining timing accuracy for each individual TRP within the group.
Solution Approach 2:
The patent makes the timing advance group structure universal by designing it to accommodate any number of TRPs and support both intra-cell and inter-cell scenarios. The TAG mechanism serves multiple functions: it manages timing for multiple TRPs, handles both serving and non-serving cells, and provides a unified framework that works across different deployment scenarios, reducing the need for scenario-specific control mechanisms.
3Reliability
If multiple timing advance groups are configured for multiple TRPs, then uplink timing control per TRP is improved, but terminal configuration complexity and memory requirements increase
Solution Approach 1:
The patent applies partial action by allowing the terminal to activate only the necessary number of timing advance groups based on the actual number of TRPs being used. Instead of requiring the terminal to always maintain maximum configuration capacity, the system activates only the required TAGs, reducing memory usage and configuration complexity while maintaining full timing control capability when needed. The terminal can dynamically adjust the number of active TAGs to match the operational requirements.
Data Source
AI summary
A terminal according to an aspect of the present disclosure includes a receiving section that receives a first downlink control channel used to trigger a random access procedure, and a control section that controls reception of a second downlink control channel used to receive a response signal in the random access procedure, based on at least one of a first QCL assumption and a second QCL assumption in a case where the random access procedure is supported per transmission/reception point, the first QCL assumption using first quasi-co-location (QCL) corresponding to the first downlink control channel, the second QCL assumption using a second QCL corresponding to a specific control resource set.