Beam Management for Connected Mode Discontinuous Reception

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Solution Overview

Problem

In wireless communication systems, especially those operating at higher frequencies or using multiple beams, active beam pairs between user equipment (UE) and base stations can become misaligned during connected mode discontinuous reception (C-DRX) operations, leading to communication failures such as control channel decoding failures.

Innovation Solution

The system implements beam management procedures where a base station transmits a beam management parameter to a UE in a C-DRX OFF state, allowing the UE to monitor downlink reference signals and reconfigure the active beam pair before the next C-DRX ON duration, ensuring optimal beam alignment for improved control channel reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the UE enters C-DRX OFF state to conserve power, then power consumption is reduced, but beam alignment may deteriorate leading to communication failures

Engineering Contradiction:
Improvepower consumptionVSAvoidbeam alignment
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The base station transmits beam management parameters and reference signals to the UE before the C-DRX ON duration begins. This preliminary action ensures that beam alignment is established or refreshed in advance, so when the UE wakes up from C-DRX OFF state, the beam is already properly aligned and communication can proceed without failure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The beam management procedure is segmented into distinct phases: transmission of beam management parameters, transmission of reference signals, and beam determination. This segmentation allows the system to perform beam management tasks efficiently during specific time windows without requiring continuous operation, thus supporting power-saving C-DRX operation while maintaining beam alignment.

Inventive Principle:
Principle #1Segmentation

2Reliability

If beam management procedures are performed continuously to maintain alignment, then beam alignment is improved, but power consumption and latency increase

Engineering Contradiction:
Improvebeam alignmentVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Instead of continuous beam management, the system uses periodic action by transmitting beam management parameters and reference signals at specific intervals before C-DRX ON durations. This periodic approach maintains beam alignment reliability while avoiding the continuous power consumption and latency overhead of constant beam management operations.

Inventive Principle:
Principle #19Periodic action

3Reliability

If beam management parameters are transmitted before C-DRX ON duration, then control channel decoding reliability is improved, but transmission overhead increases

Engineering Contradiction:
Improvecontrol channel decodingVSAvoidtransmission overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The beam management parameters are extracted and transmitted separately from the main data transmission. This allows the base station to provide necessary beam alignment information in advance without burdening the control channel with excessive overhead during active C-DRX ON durations, thus improving decoding reliability while managing overhead efficiently.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3590302B1Beam management for connected mode discontinuous reception operation
Publication Date: 2022.04.27 QUALCOMM INC
  • EP3590302B1 patent drawingFigure 1
  • EP3590302B1 patent drawingFigure 2
  • EP3590302B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described. A base station may transmit a UE-specific beam management parameter to a user equipment (UE) in a connected mode discontinuous reception (C-DRX) OFF state. The UE-specific beam management parameter may indicate a time interval for reception of downlink reference signals (RSs) prior to the beginning of a next C-DRX ON state. The UE may monitor for downlink RSs, and transmit an uplink measurement report during the C-DRX OFF state, which may indicate a reconfigured active beam pair for use during the next C-DRX ON duration. In some cases, the UE may transmit uplink RSs to the base station, and the base station may reconfigure an active beam pair based on the uplink RSs. The UE may monitor for control information (e.g., in a physical downlink control channel (PDCCH)) during the next C-DRX ON duration, using the reconfigured active beam pair.