PUSCH Spatial Relation Selection for DCI 0_0 Uplink Transmission
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Solution Overview
Problem
In 3GPP Rel-17, the introduction of multiple spatial relations for PUCCH resources complicates PUSCH transmissions scheduled by DCI format 0_0, as there is no Signal Resource Indicator (SRI) field, necessitating the determination of a suitable spatial relation and pathloss RS for PUSCH transmissions when the PUCCH resource with the lowest ID is activated with at least two spatial relations.
Innovation Solution
The UE determines the spatial relation for PUSCH transmission by selecting the first spatial relation corresponding to the PUCCH resource with the lowest ID, using the pathloss RS associated with this relation, ensuring compatibility and avoiding additional signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple spatial relations are configured for PUCCH resources, then the flexibility and adaptability of uplink transmission are improved, but the complexity of determining spatial relation for PUSCH transmission increases
Solution Approach 1:
The patent extracts the spatial relation determination rule from the complex configuration by identifying a specific criterion: when multiple spatial relations are configured for a PUCCH resource, the UE shall use the first spatial relation (lowest ID) for PUSCH transmission. This extraction simplifies the decision process while maintaining the flexibility of multiple spatial relation configurations.
Solution Approach 2:
The patent applies parameter changes by establishing a clear selection rule based on spatial relation ID ordering. When multiple spatial relations are available, the system transitions from ambiguous selection to deterministic selection by prioritizing the lowest ID, thereby resolving the complexity in parameter determination.
2Quantity of substance
If DCI format 0_0 is used for PUSCH scheduling without SRI field, then the signaling overhead is reduced, but the ability to indicate specific spatial relation is lost
Solution Approach 1:
The patent implements self-service by enabling the UE to autonomously determine the spatial relation based on pre-configured PUCCH resource information. When DCI format 0_0 is used without SRI field, the UE automatically selects the first spatial relation from the configured PUCCH resource, eliminating the need for additional signaling while maintaining proper spatial relation indication.
Solution Approach 2:
The patent applies preliminary action by pre-configuring multiple spatial relations for PUCCH resources before PUSCH transmission. This preliminary configuration allows the UE to have ready-to-use spatial relation information when DCI format 0_0 is received, eliminating the need for real-time signaling and reducing overhead.
3Reliability
If the PUCCH resource with lowest ID is activated with multiple spatial relations, then the robustness of PUCCH transmission is improved, but the difficulty of determining pathloss RS increases
Solution Approach 1:
The patent extracts the pathloss RS determination rule by establishing a direct mapping: when multiple spatial relations are configured for the lowest ID PUCCH resource, the UE shall use the pathloss RS associated with the first spatial relation. This extraction simplifies the measurement and selection process while maintaining robustness through multiple spatial relation configurations.
Data Source
AI summary
Disclosed are methods for an uplink signal transmission. One embodiment of the subject application provides a method performed by a UE, including determining a spatial relation for a Physical Uplink Shared Channel transmission scheduled by Downlink Control Information format 0_0 in response to that a Physical Uplink Control Channel resource with the lowest Identification among at least one PUCCH resource configured in an active uplink bandwidth part of a serving cell is activated with at least two spatial relations, and performing the PUSCH transmission at least according to the spatial relation with a transmission power calculated based on a pathloss reference signal. Related apparatuses are also disclosed.