Cross-Carrier Scheduling With SCS-Aware DCI Blind Detection
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Solution Overview
Problem
In wireless communication systems, particularly in 5G NR, the challenge arises when cross-carrier scheduling is performed with different subcarrier spacings (SCS) between cells, leading to uncertainty in determining the number of blind detections (BDs) for downlink control information (DCI) monitoring, which can result in unsuccessful decoding due to exceeding BD and/or CCE budgets.
Innovation Solution
The proposed solution involves configuring the UE to determine the number of BDs based on the subcarrier spacing (SCS) of at least one of the scheduling cells, ensuring successful DCI decoding within the defined limits by explicitly considering the SCS of the scheduling cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If cross-carrier scheduling is performed with different subcarrier spacings between cells, then the UE can monitor for DCI on multiple cells with different SCS configurations, but the UE may exceed the blind detection (BD) and control channel element (CCE) budgets, resulting in unsuccessful decoding
Solution Approach 1:
The patent changes the parameter used for BD determination from the SCS of the scheduled cell to the SCS of the scheduling cell. This parameter substitution resolves the contradiction by aligning the BD budget calculation with the actual monitoring requirements on the scheduling cell, preventing budget exhaustion while maintaining decoding reliability across multi-SCS carrier aggregation scenarios
Solution Approach 2:
The patent introduces the SCS of the scheduling cell as an intermediary parameter to determine the BD limit. This intermediary approach allows the system to bridge the gap between cells with different SCS configurations, enabling the UE to monitor DCI on multiple cells with different SCS while using a unified BD budget based on the scheduling cell's characteristics
2Productivity
If the UE determines the number of blind detections based on the subcarrier spacing of the scheduled cell, then the BD budget may be insufficient when monitoring DCI on scheduling cells with different SCS, but determining BD based on scheduling cell SCS requires additional configuration information
Solution Approach 1:
The patent applies the self-service principle by having the UE automatically determine the BD limit based on the SCS of the scheduling cell that is already configured for DCI monitoring. The UE uses the existing scheduling cell configuration to derive the BD budget without requiring additional separate configuration messages, thereby improving monitoring efficiency while avoiding increased configuration complexity
Data Source
AI summary
Mechanisms for cross-carrier scheduling from a first cell to a second cell in a wireless networking scheme are provided. In one aspect, a method includes receiving, from a base station (BS), a first configuration for scheduling in a first cell having a first subcarrier spacing (SCS), wherein the first configuration is associated with a first search space in the first cell. The method further includes receiving, from the BS, a second configuration for scheduling in the first cell, wherein the second configuration is associated with a second search space in a second cell, and wherein the second cell is associated with a different second SCS. The method further includes determining a number of blind detections (BDs) based on at least one of the first SCS or the second SCS, and monitoring, based on the number of BDs, for downlink control information (DCI) in the first and second search spaces.