TTI Bundle Phase Continuity via Segmented UL Subframes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wireless communication systems face challenges in maintaining phase continuity during transmission time interval (TTI) bundling, particularly for low-cost devices with low data rates, leading to increased overhead and packet loss probabilities due to frequent hybrid automatic repeat request (HARQ) transmissions and power control adjustments.

Innovation Solution

Proposes methods for maintaining transmit power, timing, and frequency consistency across a segment of UL subframes within a TTI bundle, including skipping DL subframe monitoring and using virtual UL subframes to enhance phase continuity, especially for half-duplex UEs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If TTI bundling is used for low-cost devices with low data rates, then coverage is improved, but phase continuity deteriorates due to frequent HARQ transmissions and power control adjustments

Engineering Contradiction:

ImprovecoverageVSAvoidphase continuity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent segments the TTI bundle into multiple segments, where each segment maintains independent phase continuity. This allows HARQ transmissions and power control adjustments to occur at segment boundaries without disrupting the phase continuity within each segment, thus resolving the contradiction between improved coverage through TTI bundling and maintained phase continuity.

Inventive Principle:

Principle #1Segmentation

2Reliability

If frequent HARQ transmissions and power control adjustments are performed, then reliability is improved, but overhead increases and packet loss probability increases

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidoverhead

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent performs preliminary actions by establishing phase continuity maintenance mechanisms before HARQ transmissions and power control adjustments occur. By preparing the system state in advance and coordinating these operations at segment boundaries, the patent reduces the overhead associated with frequent HARQ transmissions and power control adjustments while maintaining transmission reliability.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If DL subframe monitoring is performed continuously, then channel quality is maintained, but phase continuity deteriorates during TTI bundling

Engineering Contradiction:

Improvechannel quality monitoringVSAvoidphase continuity

Core Design Contradiction:

Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent implements periodic action by scheduling DL subframe monitoring at specific intervals rather than continuously. Monitoring is performed at segment boundaries or at predetermined periods during the TTI bundle, which maintains channel quality information while allowing phase continuity to be maintained during the intervals between monitoring events.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentEP3860232B1Method and system for resource management in TTI-bundling for improved phase continuity

Publication Date: 2025.07.02 QUALCOMM INC

Figure 1~2
Figure 3
Figure 4

AI summary

Certain aspects of the present disclosure propose methods for improving phase continuity in an uplink transmit time interval (TTI) bundle. A first method may include identifying a segment of UL subframes in the TTI bundle and maintaining substantially the same transmit power/timing/frequency when transmitting data to a node over the segment of UL subframes in the TTI bundle. Another method may include ignoring reception of downlink subframes for a duration of the TTI bundle.