Group Common PDCCH for Cell Deactivation in Carrier Aggregation
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in transmitting and receiving control signals, particularly in systems with carrier-aggregated cells, where efficient activation and deactivation of specific cells are challenging, leading to suboptimal resource management and increased power consumption.
Innovation Solution
A method and apparatus for efficiently receiving and processing control signals in wireless communication systems, specifically by detecting deactivation signals through physical downlink control channels (PDCCH) scrambled with a common radio network temporary identifier (RNTI), which allows for the uniform deactivation of cells across multiple user equipment (UEs), including stopping operations like SRS transmission, CQI reporting, and RRM measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If individual cell deactivation signals are transmitted to each UE separately, then each UE can be precisely controlled, but signaling overhead and system complexity increase significantly
Solution Approach 1:
The patent merges multiple individual cell deactivation signals into a single group common PDCCH that can simultaneously address multiple UEs. This is achieved by using a group-common RNTI (such as G-RNTI or S-RNTI) to scramble the PDCCH, allowing one downlink control information (DCI) message to be received and processed by multiple UEs in a carrier aggregation group, thereby reducing signaling overhead while maintaining reliable control delivery
Solution Approach 2:
The patent creates a universal control channel mechanism where the group common PDCCH serves multiple functions: it can deactivate cells for multiple UEs simultaneously, work with both FDD and TDD configurations, and operate across different carrier aggregation scenarios. The use of group-common RNTI makes the PDCCH universally applicable to all UEs in the group, eliminating the need for UE-specific signaling for each deactivation command
2Reliability
If multiple PDCCH resources are allocated for cell deactivation in carrier-aggregated systems, then control coverage is improved, but resource consumption and power usage increase
Solution Approach 1:
The patent combines multiple PDCCH monitoring tasks into a single group common PDCCH reception event. Instead of requiring each UE to monitor and decode separate PDCCH resources for individual deactivation commands, all UEs in the carrier aggregation group monitor a shared group common PDCCH resource pool. This consolidation reduces the total number of PDCCH decoding operations across the group, lowering overall power consumption while maintaining adequate control coverage through the shared monitoring mechanism
3Productivity
If cell deactivation is implemented in carrier-aggregated systems with multiple cells, then resource management efficiency improves, but the complexity of managing activation/deactivation states across multiple cells increases
Solution Approach 1:
The patent segments the cell deactivation management into two distinct layers: group-common management for simultaneous deactivation of multiple cells across multiple UEs via group common PDCCH, and cell-specific management for individual cell operations. This segmentation allows the system to handle bulk deactivation operations efficiently at the group level while maintaining the ability to manage individual cell states when needed, thereby reducing overall management complexity
Solution Approach 2:
The patent introduces a new dimension of group-common RNTI-based addressing that operates parallel to the traditional UE-specific RNTI dimension. This adds a collective management layer that can simultaneously control multiple UEs and cells, transforming the management approach from one-dimensional (individual UE control) to two-dimensional (group and individual control layers), which simplifies the management of carrier aggregation scenarios
Data Source
AI summary
A method and apparatus for receiving a control signal in a wireless communication system in which a plurality of cells are merged. The method includes: receiving a signal indicating a deactivation of at least one cell from among the plurality of cells; and deactivating the at least one cell. The deactivation-indicating signal indicates the deactivation of the at least one cell to all of a plurality of user equipments configured to merge the at least one cell.