Adaptive Multi-Beam PDCCH Monitoring for CDRX Reliability

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Solution Overview

Problem

In wireless communication systems, particularly in millimeter-wave (mmWave) systems, user equipment (UE) faces challenges in maintaining effective control channel monitoring during connected mode discontinuous reception (CDRX) operations due to potential movement or changes in orientation, which can render previously used receive beams ineffective, leading to uncertainty about which beams to monitor during subsequent ON periods.

Innovation Solution

The solution involves configuring the UE to associate specific beams with the DRX cycle periodicity, where different beams are used for short and long CDRX cycles based on the elapsed time since the last data transmission, allowing the UE to dynamically update its receive beams to maintain effective control channel monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE uses a single receive beam for control channel monitoring during CDRX operation, then the device complexity is reduced, but the reliability deteriorates due to potential movement or changes in orientation rendering the beam ineffective

Engineering Contradiction:
Improvecontrol channel monitoring reliabilityVSAvoidbeam management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the beam configuration adaptive rather than static. The UE dynamically switches between single-beam and multi-beam monitoring configurations based on CDRX cycle length and timing conditions. For short CDRX cycles, a single beam is used to minimize complexity, while for long CDRX cycles, multiple beams are configured to maintain reliability against UE movement or orientation changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of beam quantity from fixed to variable based on CDRX operation parameters. The network configures different numbers of receive beams according to the CDRX cycle length and timing, allowing the system to optimize between reliability and complexity by adjusting beam-related parameters dynamically.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the UE monitors multiple beams during CDRX operation, then the reliability of control channel monitoring is improved, but the use of energy increases due to additional monitoring activities

Engineering Contradiction:
Improvecontrol channel monitoring reliabilityVSAvoidUE energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent makes energy consumption dynamic by conditioning multi-beam monitoring on specific CDRX cycle lengths and timing conditions. The UE only activates multiple beam monitoring when necessary (for long CDRX cycles with sufficient time elapsed), avoiding unnecessary energy expenditure during short CDRX cycles where a single beam suffices.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent adjusts the parameter of active beam quantity based on CDRX operation parameters to optimize energy efficiency. By changing the number of monitored beams according to the CDRX cycle length and timing conditions, the system reduces energy consumption while maintaining adequate monitoring reliability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the UE frequently updates receive beams to adapt to movement, then the reliability of communication link is improved, but the loss of time increases due to beam switching and reconfiguration

Engineering Contradiction:
Improvecommunication link qualityVSAvoidbeam reconfiguration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by making beam updates conditional rather than frequent. The system dynamically determines whether beam reconfiguration is needed based on CDRX cycle length and timing conditions, avoiding unnecessary beam switches that would cause time loss while maintaining reliability when actually needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses preliminary action by pre-configuring multiple receive beams in advance for long CDRX cycles. The network provides the UE with a set of candidate beams before the CDRX operation begins, so that when beam switching is needed, the UE can quickly activate a pre-configured beam without time-consuming reconfiguration.

Inventive Principle:
Principle #10Preliminary action

4Ease of operation

If the UE uses a single beam for control channel monitoring, then the ease of operation is improved, but the adaptability deteriorates when UE movement or orientation changes occur

Engineering Contradiction:
Improvebeam monitoring simplicityVSAvoidbeam adaptability to movement
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent makes the beam monitoring system dynamic and adaptive. The UE operates in a simplified single-beam mode during short CDRX cycles for ease of operation, but automatically transitions to multi-beam monitoring during long CDRX cycles to adapt to potential UE movement or orientation changes, balancing simplicity and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameter of beam quantity based on CDRX conditions. The system adjusts between single-beam and multi-beam configurations according to CDRX cycle length and timing, allowing the UE to maintain ease of operation when conditions permit while gaining adaptability when movement or orientation changes are likely.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3659372B1Multi-beam physical downlink control channel (PDCCH) monitoring during connected mode discontinuous reception (CDRX) operation
Publication Date: 2023.08.23 QUALCOMM INC
  • EP3659372B1 patent drawingFigure 1
  • EP3659372B1 patent drawingFigure 2
  • EP3659372B1 patent drawingFigure 3

AI summary

Aspects of the present disclosure relate to techniques for multibeam PDCCH monitoring during CDRX operations. A BS may determine a configuration of one or more beams for a UE to monitor for receiving a downlink control channel from the BS, wherein the configuration is based, at least in part, on a monitoring window since the subframe in which the downlink control channel (e.g., PDCCH), indicates an initial UL, DL, or SL use data transmission for the UE. The BS may transmit, to the UE, an indication of the configuration. A UE may perform corresponding operations and may monitor one or more beams based on the received configuration.