Grant-Free Uplink Resource Ambiguity Resolution via SRS Feedback
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Solution Overview
Problem
In wireless communication systems, grant-free uplink transmission faces ambiguities regarding resource configuration and usage, especially when multiple resource sets are configured, leading to inconsistencies between terminals and base stations, particularly during RRC reconfiguration and when uplink traffic characteristics change.
Innovation Solution
A method where a terminal receives downlink control information including activation information for specific resource sets and sounding reference signal requests, transmitting the SRS as a response signal to the base station using a specific resource set, thereby performing grant-free uplink transmission and reducing ambiguity about resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If grant-free UL transmission is configured but no uplink data is transmitted, then resource configuration is established, but ambiguity occurs regarding whether UL transmission is properly configured in the UE
Solution Approach 1:
The terminal transmits an SRS signal as feedback to confirm receipt and proper configuration of grant-free UL transmission parameters. This feedback mechanism allows the base station to verify that the UE has correctly configured the grant-free transmission resources, eliminating ambiguity about whether the configuration was properly established in the UE.
2Adaptability or versatility
If multiple resource sets are configured for grant-free UL transmission, then resource flexibility is improved, but ambiguity occurs regarding which resource set is used
Solution Approach 1:
The terminal includes information indicating the selected resource set in its SRS transmission. This feedback allows the base station to identify which resource set the UE is using for grant-free UL transmission, eliminating ambiguity while maintaining the flexibility of having multiple configured resource sets available for different traffic conditions.
3Manufacturing precision
If RRC configuration process is used to change resource sets, then configuration accuracy is improved, but inconsistency may occur between terminal and base station during RRC resetting
Solution Approach 1:
The terminal transmits the SRS signal with resource set identification information before completing the full RRC reconfiguration process. This preliminary action ensures that both the base station and terminal are using the same resource set configuration, preventing inconsistency during the RRC resetting process while maintaining accurate resource allocation.
Data Source
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AI summary
Provided are a method for transmitting an uplink signal of a terminal in a wireless communication system and a terminal using the same method. The method comprises: receiving activation information that activates or deactivates a specific resource set from among a plurality of resource sets; and performing a grant-less uplink transmission using the resources belonging to the specific resource set when the activation information activates the specific resource set.