CSI-RS Time Allocation for DRX Power Savings

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Solution Overview

Problem

In next-generation wireless communications systems, user equipment (UE) experiences power consumption issues and measurement failures due to discontinuous reception (DRX) patterns, as it cannot receive channel state information-reference signals (CSI-RS) during off durations, necessitating additional power to receive these signals.

Innovation Solution

The proposed solution involves synchronizing the sending time of CSI-RS with the on duration period of UE, ensuring the reference signals are received within the active periods, thereby reducing power consumption and measurement failures by configuring CSI-RS resources based on overlapping on duration periods of multiple UEs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If UE uses discontinuous reception (DRX) pattern to reduce power consumption, then power consumption is reduced, but UE cannot receive CSI-RS during off duration periods

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

Solution Approach 1:

The network device pre-configures CSI-RS sending time points to coincide with UE's on duration periods before actual measurements occur. This preliminary alignment ensures that measurement signals are transmitted only when the UE is actively listening, eliminating the need for the UE to wake up during off duration periods specifically for measurements, thus maintaining measurement reliability while preserving power savings.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts CSI-RS transmission timing based on UE DRX patterns. The network device configures different sending time points for different UEs according to their specific on duration schedules, making the measurement system adaptable to individual UE power saving patterns rather than using a fixed transmission schedule.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If CSI-RS are sent at fixed time-frequency positions, then measurement consistency is improved, but UE may miss these signals during off duration periods

Engineering Contradiction:
Improvemeasurement consistencyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The invention changes the time parameter of CSI-RS transmission from fixed positions to dynamically configured positions that align with UE on duration periods. The network device determines and configures specific sending time points for each UE based on their DRX patterns, transforming the static transmission schedule into a dynamic one that adapts to UE activity patterns.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If UE wakes up periodically to monitor PDCCH and read paging information, then communication reliability is improved, but power consumption increases

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

Solution Approach 1:

The invention merges CSI-RS measurement operations with the UE's existing on duration periods when the UE is already awake to monitor PDCCH and read paging information. By aligning measurement opportunities with these mandatory wake periods, the system combines multiple functions (paging reception, control channel monitoring, and channel state measurement) into a single active period, avoiding additional wake-ups and reducing overall power consumption while maintaining communication reliability.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3661099B1Time allocation method and apparatus
Publication Date: 2025.03.26 HUAWEI TECH CO LTD
  • EP3661099B1 patent drawingFigure 1
  • EP3661099B1 patent drawingFigure 2
  • EP3661099B1 patent drawingFigure 3A~3D

AI summary

This application provides a time configuration method, a network device, and a terminal. A sending time of a reference signal is determined according to an on duration period, or an on duration period is determined according to a sending time of a reference signal, so that the sending time of the reference signal is associated with the on duration period, to avoid a technical problem that UE cannot receive the reference signal, or UE needs to frequently wake up to receive the reference signal.