PUSCH Spatial Relation Mapping From Lowest-ID PUCCH Resource
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Solution Overview
Problem
Existing technologies face challenges in determining the spatial relation and pathloss reference signal for Physical Uplink Shared Channel (PUSCH) transmissions scheduled by DCI format 0_0, especially when multiple spatial relations are activated for the PUCCH resource with the lowest ID, which is not supported by the lack of a Signal Resource Indicator (SRI) field in DCI format 0_0.
Innovation Solution
The method involves determining the spatial relation for PUSCH transmission and reception based on the first spatial relation corresponding to the PUCCH resource with the lowest ID, using the pathloss reference signal (RS) associated with this relation, even when multiple spatial relations are activated for this resource.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple spatial relations are activated for the PUCCH resource with the lowest ID, then the reliability of PUSCH transmission is improved, but the device complexity increases due to the lack of SRI field in DCI format 0_0
Solution Approach 1:
The UE autonomously determines the spatial relation for PUSCH transmission by selecting the first spatial relation associated with the lowest ID PUCCH resource, without requiring additional signaling from the gNodeB. This self-service mechanism resolves the complexity issue while maintaining reliability improvement through multi-spatial relation activation.
Solution Approach 2:
The spatial relation determination is performed in advance based on pre-configured PUCCH resource information. The UE uses the pre-established mapping between PUCCH resources and spatial relations to determine the appropriate spatial relation for PUSCH transmission, avoiding real-time complex decision-making.
2Measurement precision
If the SRI field is added to DCI format 0_0 to indicate spatial relation, then the precision of spatial relation indication is improved, but the signaling overhead increases
Solution Approach 1:
The patent extracts the spatial relation indication function from a potential new SRI field and implements it through existing PUCCH resource configuration and ID mapping. By utilizing the lowest ID PUCCH resource's spatial relations, the system achieves precise spatial relation indication without requiring additional signaling fields.
Solution Approach 2:
The PUCCH resource with the lowest ID serves multiple functions: it acts as the reference for spatial relation determination, provides pathloss reference signal indication, and enables reliable PUSCH transmission. This multi-functionality eliminates the need for separate SRI field while maintaining precision.
3Measurement precision
If the pathloss RS is determined based on the determined spatial relation, then the accuracy of transmission power calculation is improved, but the measurement time increases
Solution Approach 1:
The pathloss reference signal is pre-configured and associated with the PUCCH resource in advance. The gNodeB transmits the pathloss RS before the actual PUSCH transmission, allowing the UE to calculate transmission power accurately without delaying the main transmission timeline.
Solution Approach 2:
The UE autonomously determines the pathloss RS based on the determined spatial relation and pre-configured parameters. This self-service approach allows the UE to independently calculate transmission power using existing reference signals, minimizing additional measurement time while maintaining accuracy.
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.