Two-Part HARQ-ACK Feedback for Multi-Cell Latency Reduction
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Solution Overview
Problem
HARQ-ACK transmissions between non-collocated cell groups in wireless communications systems experience latency issues, disrupting HARQ operations due to backhaul communication delays.
Innovation Solution
Implementing a two-part HARQ-ACK feedback mechanism where a UE transmits first information with a smaller payload size to one cell group and second information with a specific format to another cell group, optimizing HARQ-ACK transmission across multiple cell groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional HARQ-ACK feedback is transmitted across non-collocated cell groups, then complete feedback information is conveyed, but latency increases due to backhaul communication delays
Solution Approach 1:
The patent segments the HARQ-ACK feedback into two distinct parts: first information with a smaller payload size transmitted to one cell group, and second information with a specific format transmitted to another cell group. This segmentation allows each part to be processed independently, reducing the time required for complete feedback transmission across non-collocated cell groups while maintaining reliability through the structured two-part approach.
2Loss of time
If HARQ-ACK feedback payload size is reduced for faster transmission, then latency decreases, but feedback completeness may be compromised
Solution Approach 1:
The feedback information is divided into two segments with different payload characteristics. The first information has a smaller payload size optimized for rapid transmission, while the second information includes specific format requirements for complete feedback. This segmentation resolves the contradiction by allowing reduced payload size for speed while maintaining completeness through the second part.
Solution Approach 2:
The patent introduces a dimensional distinction between the two feedback transmissions: the first transmission uses a smaller payload size dimension for speed optimization, while the second transmission uses a specific format dimension for completeness. This multi-dimensional approach allows both latency reduction and information completeness to be achieved simultaneously.
3Device complexity
If unified HARQ-ACK feedback format is used across all cell groups, then processing simplicity is maintained, but flexibility for non-collocated cell groups is reduced
Solution Approach 1:
The patent applies local quality by specifying different characteristics for different feedback transmissions: the first information has a smaller payload size suited for one cell group, while the second information has a specific format suited for another cell group. This allows each cell group to receive optimized feedback according to its specific requirements while maintaining overall processing simplicity through the structured two-part format.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive signaling indicating a configuration for communications via a first cell group and a second cell group, the first cell group comprising a first cell associated with transmission of HARQ-ACK feedback associated with the first cell group and the second cell group comprising a second cell associated with transmission of HARQ-ACK feedback associated with the second cell group. The UE may transmit first information indicative of the HARQ-ACK feedback associated with the second cell group to the second cell, the first information comprising a first payload size smaller than a full HARQ-ACK feedback payload size associated with the second cell group. The UE may transmit second information indicative of the HARQ-ACK feedback associated with the second cell group to the first cell, the second information comprising a format that is based on the first information.