PUSCH ACK Search Space Control During Repetitive Uplink Transmission

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Solution Overview

Problem

In wireless communication networks, repetitive PUSCH transmissions without corresponding ACK feedback lead to unnecessary resource waste and increased power consumption at the UE, due to inefficient search space scanning during repetitive transmission.

Innovation Solution

The UE receives downlink control information (DCI) indicating different search spaces for ACK feedback, allowing it to stop repetitive PUSCH transmissions upon receiving ACK, thereby reducing unnecessary scanning and conserving power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE continuously performs repetitive PUSCH transmissions without receiving ACK feedback, then the transmission reliability is improved, but the power consumption increases and network resources are wasted

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback mechanism where the UE monitors downlink control information (DCI) in specific search spaces during repetitive PUSCH transmissions. When an ACK feedback is detected in the monitored search space, the UE terminates the repetitive transmissions. This feedback-based approach resolves the contradiction by enabling reliable transmission completion detection while preventing unnecessary continuous transmissions that waste power and resources.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the search space monitoring behavior based on transmission state. During repetitive PUSCH transmissions, the UE selectively monitors specific search spaces (e.g., type0-PDCCH or type1-PDCCH) rather than all search spaces continuously. This dynamic monitoring strategy allows the system to maintain transmission reliability through selective ACK detection while reducing power consumption by avoiding continuous full-search space scanning.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the UE scans all search spaces for ACK feedback during repetitive PUSCH transmissions, then the ACK detection reliability is improved, but the processing complexity and power consumption increase

Engineering Contradiction:
ImproveACK detection reliabilityVSAvoidsearch space scanning complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by differentiating the monitoring behavior across different search spaces. Instead of uniformly scanning all search spaces with the same intensity, the UE focuses monitoring resources on specific search spaces (type0-PDCCH or type1-PDCCH) that are more likely to contain ACK feedback during repetitive transmissions. This localized monitoring approach maintains ACK detection reliability while significantly reducing processing complexity compared to exhaustive scanning of all search spaces.

Inventive Principle:
Principle #3Local quality

3Use of energy by moving object

If the UE terminates repetitive PUSCH transmissions early upon receiving ACK, then the power consumption is reduced, but the risk of premature termination increases

Engineering Contradiction:
Improvepower consumptionVSAvoidtransmission reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces an intermediary verification mechanism where the UE uses specific DCI formats (format 1_0 or format 1_1) with particular field configurations as intermediaries to confirm ACK feedback before terminating transmissions. The monitoring of specific search spaces (type0-PDCCH or type1-PDCCH) acts as an intermediary layer that filters and validates feedback signals, reducing the risk of misinterpretation while enabling timely termination when genuine ACK feedback is received, thus balancing power savings with transmission reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3665811B1Transmitting and receiving controlling information in wireless communications
Publication Date: 2025.12.10 ZTE CORP
  • EP3665811B1 patent drawingFigure 1~2
  • EP3665811B1 patent drawingFigure 3~4
  • EP3665811B1 patent drawingFigure 5~6

AI summary

This disclosure provides techniques for reducing waste of user equipment (UE) resources caused in transmission of a Physical Uplink Shared Channel (PUSCH) when a UE conducts searching for downlink control information (DCI) outside of a PUSCH transmission. This disclosure defines a first search space on the basis of an existing second search space that was used to receive DCI information to schedule a PUSCH. The first search space can be used to obtain a DCI having an ACK feedback. This disclosure provides systems and methods for determining the location of the first search space to receive a second DCI having ACK feedback during a PUSCH repetitive transmission and whether the second search space should be used for the second DCI instead. Outside of the PUSCH transmission, the UE receives DCI in the second search space, decreasing the unnecessary searching of DCI and increasing network efficiency.