PRS Muting Patterns for 5G Positioning Accuracy

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G networks, face challenges in efficiently managing positioning reference signals (PRS) due to overlapping transmissions from different cells, leading to interference and reduced accuracy in user equipment (UE) positioning, especially in heterogeneous networks with macro and small cell base stations.

Innovation Solution

Implementing semi-persistent or aperiodic muting patterns for PRS transmissions, allowing cells to mute specific PRS occasions, thereby reducing interference and improving the detectability of weak signals from neighboring cells, and using on-demand muting configurations triggered by DCI or MAC control elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If positioning reference signals are transmitted continuously from all cells, then coverage and signal availability are improved, but interference increases and positioning accuracy deteriorates

Engineering Contradiction:
Improvesignal availabilityVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements periodic muting patterns where PRS transmissions are selectively silenced at specific time occasions according to predefined muting sequences. This periodic action reduces interference between neighboring cells while maintaining signal availability during non-muted occasions, thereby resolving the contradiction between continuous coverage and positioning accuracy.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent configures muting patterns in advance before positioning measurements are performed. The network pre-defines which cells will mute their PRS transmissions at which time occasions, allowing UEs to anticipate and prepare for interference-free measurement opportunities. This preliminary configuration ensures both signal availability and measurement precision are optimized.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If muting patterns are applied to reduce interference, then positioning accuracy is improved, but signal coverage and detectability worsen

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsignal detectability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies muting patterns selectively to specific cells and specific time occasions rather than universally across all cells continuously. Each cell's muting behavior is locally optimized based on its interference impact on neighboring cells, ensuring that positioning accuracy is improved in affected areas while signal coverage is maintained in other areas and times.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

By implementing periodic muting rather than continuous muting, the system ensures that PRS signals are available for detection during non-muted occasions. This periodic transmission pattern maintains signal detectability and coverage while providing regular interference-free measurement opportunities to improve positioning accuracy.

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If semi-persistent or aperiodic muting is implemented, then interference management is improved, but system complexity increases

Engineering Contradiction:
Improveinterference managementVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs self-service mechanisms where UEs autonomously determine which PRS occasions to measure based on received muting pattern indications. The network provides the muting configuration, and UEs independently apply this information to select appropriate measurement occasions without requiring complex centralized coordination or real-time signaling, thereby managing interference while limiting system complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Muting patterns are configured in advance and provided to UEs before measurements are needed. This preliminary configuration allows UEs to pre-determine their measurement strategy based on known muting patterns, simplifying the real-time operation and reducing the complexity of dynamic interference management during actual positioning measurements.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3909187B1Positioning reference signal muting patterns with semi-persistent or aperiodic timing behavior
Publication Date: 2024.09.04 QUALCOMM INC
  • EP3909187B1 patent drawingFigure 1
  • EP3909187B1 patent drawingFigure 2A
  • EP3909187B1 patent drawingFigure 2B

AI summary

Disclosed are techniques for muting positioning reference signals. In aspects, a location server sends, to a user equipment, a plurality of positioning reference signal configurations and one or more positioning reference signal muting configurations associated with a transmission-reception point (TRP) identifier and/or a positioning reference signal ID. A first TRP sends, to the UE, a command triggering at least one positioning reference signal muting configuration, wherein the triggered positioning reference signal muting configuration indicates that: the one or more positioning reference signals of the one or more positioning reference signal occasions of at least one positioning reference signal configuration are not being transmitted, or the one or more positioning reference signals of the one or more positioning reference signal occasions of all of the plurality of positioning reference signal configurations are not being transmitted, and mutes positioning reference signals according to the triggered positioning reference signal muting configurations.