Uplink Beam Determination Using Reference Signal Spatial Relations
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Solution Overview
Problem
Existing beam management methods in uplink signals or channels face inefficiencies, leading to excessive signaling overhead and ineffective beam indication, particularly when downlink reference signals are absent or mismatched with uplink channels, resulting in unclear transmission beams and path loss references.
Innovation Solution
A method to determine uplink signal or channel information by selecting a reference signal based on specific preset conditions, allowing the UE to determine transmission spatial filters and path loss references using quasi co-location signals associated with PDCCH, PDSCH, or PRACH, reducing signaling overhead and improving beam alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station configures or indicates an explicit reference signal for the uplink signal or uplink channel through RRC signaling, MAC-CE signaling, or DCI, then the beam indication can be provided, but the signaling overhead becomes excessive
Solution Approach 1:
The patent makes the downlink reference signal serve multiple functions: it is used both for downlink channel estimation and for determining the uplink transmission beam through spatial relationship information. This multi-functionality eliminates the need for separate uplink beam indication signaling, thereby reducing signaling overhead while maintaining reliable beam indication.
Solution Approach 2:
The patent enables the UE to self-determine the uplink transmission beam by utilizing the spatial relationship between the uplink signal and the downlink reference signal. The UE autonomously selects the appropriate downlink reference signal from configured reference signals based on spatial relationship criteria, eliminating the need for the base station to explicitly indicate the beam through additional signaling.
2Ease of operation
If the base station uses downlink reference signals for beam indication, then the uplink transmission beam can be determined, but the beam indication becomes ineffective when downlink reference signals are absent or mismatched with uplink channels
Solution Approach 1:
The patent introduces spatial relationship information as a new parameter that links uplink signals with downlink reference signals. This parameter enables the UE to determine the appropriate downlink reference signal based on spatial characteristics, ensuring effective beam indication even when downlink reference signals are absent or mismatched with uplink channels.
Solution Approach 2:
The patent uses spatial relationship information as an intermediary to connect the uplink signal and the downlink reference signal. This intermediary enables the UE to establish the correct correspondence between uplink transmission beams and downlink reference signals, ensuring reliable beam indication in various scenarios including when downlink reference signals are absent or mismatched.
3Ease of operation
If the UE determines the transmission beam according to a downlink reference signal, then the uplink beam can be established, but the path loss reference becomes unclear when reference signals are mismatched
Solution Approach 1:
The patent uses spatial relationship information to consistently determine both the transmission beam and the path loss reference signal. By linking these two determinations through the same spatial relationship parameter, the patent ensures that when a downlink reference signal is selected for beam determination, it also serves as the clear path loss reference, eliminating the ambiguity of mismatched references.
Data Source
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AI summary
Disclosed is an information determination method and device, a first communication node, and a storage medium. The information determination method includes: in a case where a preset condition is satisfied, a reference signal is determined; and information of an uplink signal or information of anp uplink channel is determined according to the reference signal.