Subband Full-Duplex HARQ Deferral for Conflict-Aware UE Feedback
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Solution Overview
Problem
The mismatch between full-duplex and half-duplex devices in wireless networks leads to scheduling issues and unnecessary deferral of Hybrid Automatic Repeat Request (HARQ) feedback, resulting in increased latency and resource wastage in Subband Full-Duplex (SBFD) networks.
Innovation Solution
Techniques for identifying conflicts between uplink resources and SBFD frame structures enable half-duplex UEs to transmit HARQ messages within downlink slots that include uplink subbands by deferring feedback to subsequent slots based on conflict conditions, using signaling and configurations to determine whether feedback deferral is necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If half-duplex UEs defer HARQ feedback to subsequent slots to avoid conflicts with SBFD frame structure, then resource conflicts are avoided, but latency increases and resource utilization deteriorates
Solution Approach 1:
The patent segments the SBFD slot into distinct uplink subbands and downlink subbands, allowing half-duplex UEs to identify and transmit HARQ feedback in uplink subbands without deferral, thereby resolving the conflict between reliability and latency
Solution Approach 2:
The patent introduces dynamic conflict condition indicators that allow the network to signal whether deferral is necessary on a per-slot basis, enabling flexible adaptation between conflict avoidance and low-latency transmission based on current network conditions
2Productivity
If half-duplex UEs assume all downlink slots contain uplink subbands and transmit HARQ feedback, then resource utilization improves, but resource conflicts and interference increase
Solution Approach 1:
The patent introduces conflict condition indicators as an intermediary signaling mechanism from the network to the UE, providing precise information about which downlink slots contain uplink subbands, thereby enabling high resource utilization without interference
Solution Approach 2:
The patent applies local quality by providing differentiated information about specific subbands within slots, allowing UEs to transmit feedback only in appropriate uplink subbands rather than universally, thus improving resource utilization while avoiding conflicts
3Productivity
If the network implements SBFD frame structure with uplink subbands in downlink slots, then spectral efficiency improves, but scheduling complexity and device compatibility issues worsen
Solution Approach 1:
The patent designs the conflict condition indicator mechanism to serve multiple functions: it signals uplink subband locations, indicates deferral requirements, and provides compatibility information for different UE types, thereby managing SBFD complexity through a universal signaling approach
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive an indication of conflict conditions for identification of conflicts between uplink feedback messages and a communication frame structure, and may receive a downlink message within a set of semi-persistent downlink resources. The downlink message may be associated with a first uplink resource for transmitting a feedback for the downlink message, where the first uplink resource is included within a subband full-duplex (SBFD) slot that includes one or more uplink subbands. The UE may then transmit the feedback message via the first uplink resource or a second uplink resource that is deferred relative to the first uplink resource based on whether feedback deferral for the downlink message is triggered in accordance with the one or more conflict conditions the second uplink resource is included within a second slot that is subsequent to the subband full-duplex slot.