PDCCH Search Space Signaling Across DRX Cycles

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Solution Overview

Problem

Existing 5G wireless communication systems face challenges in efficiently managing downlink control signaling for multicast and unicast communications, particularly during discontinuous reception (DRX) cycles, leading to inefficiencies in resource allocation and reception of physical downlink control channels (PDCCHs).

Innovation Solution

The proposed solution involves receiving and transmitting downlink control information (DCI) formats outside the active time of a DRX cycle to determine the reception or transmission of PDCCHs during the next DRX cycle, utilizing first and second search space sets, allowing for flexible control of PDCCH monitoring based on specific indications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PDCCH monitoring is performed during active time of DRX cycle, then reliability of control signaling is improved, but energy consumption increases

Engineering Contradiction:

Improvecontrol signaling reception reliabilityVSAvoidUE energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system implements discontinuous reception (DRX) cycles where the UE alternates between active time for PDCCH monitoring and sleep time for energy saving. The network can dynamically indicate whether the UE should monitor PDCCH during active time of next DRX cycle, creating a periodic monitoring pattern that balances reliability and energy consumption.

Inventive Principle:

Principle #19Periodic action

2Use of energy by moving object

If PDCCH monitoring is performed outside active time of DRX cycle, then energy consumption is reduced, but control signaling reception reliability deteriorates

Engineering Contradiction:

ImproveUE energy consumptionVSAvoidcontrol signaling reception reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The network sends indication information outside the active time of current DRX cycle to prepare the UE for upcoming PDCCH monitoring in the next DRX cycle. This preliminary indication allows the UE to plan its wake-up and monitoring schedule in advance, ensuring reliable control signaling reception while minimizing energy consumption during the current cycle.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If multiple search space sets are monitored, then coverage of control signaling is improved, but device complexity increases

Engineering Contradiction:

Improvecontrol signaling coverageVSAvoidUE processing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system divides PDCCH monitoring resources into multiple search space sets (first search space sets and second search space sets) with different monitoring characteristics. The network can independently indicate monitoring requirements for each search space set group, allowing the UE to selectively monitor only relevant sets based on the indication, thereby reducing processing complexity while maintaining comprehensive coverage.

Inventive Principle:

Principle #1Segmentation

4Productivity

If PDCCH reception is indicated for next DRX cycle, then resource allocation efficiency is improved, but processing overhead increases

Engineering Contradiction:

Improveresource allocation efficiencyVSAvoidsignaling overhead

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The system combines multiple control functions into a single indication information message that simultaneously specifies PDCCH monitoring requirements for multiple search space sets and the next DRX cycle. This merging approach enables the network to efficiently allocate resources across different search space sets and time cycles while minimizing the number of separate signaling messages, thus reducing processing overhead.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12588031B2Downlink control signaling for multicast and unicast communications

Publication Date: 2026.03.24 SAMSUNG ELECTRONICS CO LTD

AI summary

Methods and apparatuses for downlink control signaling for multicast and unicast communications. A method includes receiving information for first search space sets and for second search space sets, and a physical downlink control channel (PDCCH) providing a downlink control information (DCI) format. The DCI format provides an indication for receptions of PDCCHs during an active time of a next DRX cycle according to one of: none of the first search space sets and the second search space sets, only the first search space sets, only the second search space sets, or the first search space sets and the second search space sets. The method further includes determining reception of zero or more PDCCHs for the first and second search space sets during the active time of the next DRX cycle based on the indication and receiving the PDCCHs during the active time of the next DRX cycle.