Cross-Carrier Symbol Muting for Aperiodic SRS Scheduling

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Solution Overview

Problem

Current communication networks, particularly in uplink carrier aggregation scenarios, face challenges in supporting aperiodic sounding reference signals (A-SRS) due to simultaneous transmission issues with PUCCH or PUSCH, and power limitations, especially in FDD+TDD FR1 scenarios, leading to decoding failures and inefficient throughput.

Innovation Solution

Implementing a symbol muting mechanism, synchronization mechanism, and scheduling suspension time to manage A-SRS transmissions in TDD FR1 carriers, ensuring minimal impact on FDD carriers by muting overlapping symbols and coordinating rank changes across carriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If aperiodic sounding reference signal (A-SRS) is transmitted simultaneously with PUCCH or PUSCH in uplink carrier aggregation, then uplink MIMO capabilities are enhanced, but decoding failures occur due to power limitations and simultaneous transmission issues

Engineering Contradiction:
Improveuplink MIMO capabilitiesVSAvoiddecoding success rate
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts the A-SRS transmission from simultaneous transmission with PUCCH/PUSCH by introducing a symbol muting mechanism. When A-SRS needs to be transmitted, the corresponding uplink symbols in FDD carriers are muted (extracted from normal operation), preventing simultaneous transmission conflicts and power limitation issues while maintaining A-SRS functionality for uplink MIMO enhancement

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If symbol muting is applied to FDD carrier uplink symbols to avoid simultaneous transmission with A-SRS, then decoding failures are reduced, but throughput is reduced due to muted symbols

Engineering Contradiction:
Improvedecoding success rateVSAvoiduplink throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies periodic action by making the symbol muting conditional and temporary. The FDD carrier symbols are muted only during specific periods when A-SRS transmission is detected in TDD FR1 carriers, and normal transmission resumes when A-SRS is not transmitted. This periodic muting approach maintains high reliability by preventing simultaneous transmission conflicts while minimizing throughput impact by limiting muting to only when necessary

Inventive Principle:
Principle #19Periodic action

3Productivity

If rank monitoring is performed in TDD FR1 carrier to detect rank decrease, then A-SRS transmission timing is optimized, but additional signaling overhead is required for coordination between carriers

Engineering Contradiction:
ImproveA-SRS transmission efficiencyVSAvoidinter-carrier coordination signaling
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary signaling mechanism where the TDD FR1 carrier (first carrier) sends indication information to the FDD carrier (second carrier) about rank changes and A-SRS transmission timing. This intermediary signaling acts as a mediator that coordinates between carriers, enabling optimized A-SRS transmission based on rank monitoring while managing the complexity through standardized indication messages

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4686134A1Device, method, apparatus and computer-readable medium for communication
Publication Date: 2026.01.28 NOKIA SOLUTIONS & NETWORKS OY
  • EP4686134A1 patent drawingFigure 1A~1B
  • EP4686134A1 patent drawingFigure 2
  • EP4686134A1 patent drawingFigure 3

AI summary

Embodiments of the present disclosure provide devices, methods, apparatus, and computer-readable media for communication. In the method, a network device monitors a change in a rank for a terminal device in a first carrier of the network device. Based on detecting a decrease in the rank, the network device transmits, to the terminal device, scheduling information for scheduling transmission of an aperiodic sounding reference signal (SRS) in the first carrier. The network device transmits, to the terminal device, first information for muting at least one predetermined symbol in an uplink slot in uplink scheduling of a second carrier of the network device, wherein the first carrier and the second carrier are used for uplink carrier aggregation for the terminal device.