Soft-Combining HARQ for Selective Multi-User Retransmission

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in network resource utilization due to the need for retransmitting entire multi-user packets when individual transport blocks fail to decode, leading to suboptimal use of network resources.

Innovation Solution

Implementing soft-combining for hybrid automatic repeat request (HARQ) feedback, where base stations encode and transmit multi-user packets with separately encoded transport blocks, and upon receiving decoding failures, retransmit only the failed blocks, optionally incorporating new transport blocks, to optimize network resource utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If entire multi-user packets are retransmitted when individual transport blocks fail to decode, then decoding success rate is improved, but network resource utilization deteriorates

Engineering Contradiction:
Improvedecoding success rateVSAvoidnetwork resource utilization
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent segments the multi-user packet into individual transport blocks, allowing the UE to identify and request retransmission of only specific failed blocks rather than retransmitting the entire packet. This is achieved through separate encoding of each transport block and the ability to selectively request retransmission of individual blocks based on decoding results.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts only the failed transport blocks from the multi-user packet for retransmission. The UE identifies which specific transport blocks failed to decode and requests retransmission of only those blocks, leaving successfully decoded blocks out of the retransmission request, thereby optimizing network resource usage.

Inventive Principle:
Principle #2Taking out (Extraction)

2Loss of energy

If selective retransmission of failed transport blocks is implemented, then network resource utilization is improved, but system complexity increases

Engineering Contradiction:
Improvenetwork resource utilizationVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent segments the multi-user packet into individually encoded transport blocks, each with its own identification. This segmentation enables the UE to track and manage each block separately, facilitating selective retransmission requests while maintaining manageable system complexity through structured organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a feedback mechanism where the UE reports decoding results for individual transport blocks back to the base station. This feedback enables selective retransmission by informing the base station which specific blocks need retransmission, balancing complexity reduction with targeted error correction.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If separately encoded transport blocks are aggregated into combined transport block, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improveencoding precisionVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent separately encodes each transport block before aggregation, ensuring that each block maintains its own encoding integrity and can be independently decoded. This separate encoding approach improves precision while the structured aggregation process manages complexity through systematic organization of the encoded blocks.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4150823B1Soft-combining for hybrid automatic repeat request feedback
Publication Date: 2025.08.20 QUALCOMM INC
  • EP4150823B1 patent drawingFigure 1
  • EP4150823B1 patent drawingFigure 2
  • EP4150823B1 patent drawingFigure 3A

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may transmit, to a group of user equipment (UEs), a multi-user packet including a plurality of transport blocks combined into a combined transport block, wherein each transport block, of the plurality of transport blocks, is separately encoded using a particular encoding procedure and aggregated into the combined transport block; receive, from one or more UEs of the group of UEs, hybrid automatic repeat request feedback indicating a decoding failure of one or more transport blocks of the multi-user packet; and retransmit one or more packets to convey the one or more transport blocks subject to the decoding failure. Numerous other aspects are provided.