Wireless Signal Validity Determination in Carrier Aggregation
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Solution Overview
Problem
In wireless communication systems, particularly in LTE, determining the validity of signals during radio resource usage change is inefficient due to the lack of effective methods for validating downlink and uplink control information across aggregated cells with different configurations, leading to potential errors in signal transmission and reception.
Innovation Solution
A method and apparatus for a user equipment (UE) to receive and validate downlink and uplink control information by determining its validity based on the uplink-downlink configuration of the primary cell, specifically considering Time Division Duplex (TDD) modes, allowing for cross-subcarrier scheduling and ensuring accurate signal transmission and reception across aggregated cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If carrier aggregation and radio resource reconfiguration are supported to increase service capacity and flexibility, then system adaptability and service capability are improved, but signal validation complexity and error potential increase due to different uplink-downlink configurations across aggregated cells
Solution Approach 1:
The patent segments the validation process by distinguishing between fallback mode and non-fallback mode configurations. In fallback mode, the UE validates DCI based on the original uplink-downlink configuration, while in non-fallback mode, it uses the reconfigured configuration. This segmentation allows the system to support radio resource reconfiguration and carrier aggregation with different configurations without creating a single complex validation mechanism, thereby managing validation complexity while maintaining adaptability.
2Device complexity
If simultaneous reception and transmission on aggregated cells is not supported to simplify UE design, then device complexity is reduced, but communication efficiency and resource utilization deteriorate due to inability to handle overlapping subframes
Solution Approach 1:
The patent introduces dynamic validation rules that adapt based on the operation mode (fallback or non-fallback). When the UE is configured for non-simultaneous reception and transmission, the validation dynamically determines whether DCI in overlapping subframes is valid or invalid based on the specific configuration mode. This dynamic approach allows the system to maintain simplified UE design while optimizing communication efficiency through intelligent handling of overlapping subframes.
3Productivity
If downlink control information is transmitted in overlapping subframes to maximize resource utilization, then resource efficiency is improved, but signal reliability deteriorates due to potential conflicts in UEs not supporting simultaneous reception and transmission
Solution Approach 1:
The patent implements a feedback mechanism where the UE validates received DCI by checking whether the subframe configuration is valid according to its capabilities and the configured mode. The UE determines whether to accept or reject DCI in overlapping subframes based on validation results, providing feedback to the network about successful reception and interpretation of control information. This ensures reliable communication while maximizing resource utilization through selective acceptance of DCI.
Data Source
AI summary
The present invention relates to a method and an apparatus for receiving, in a wireless communication system supporting carrier aggregation and usage change of a radio resource, a signal of a terminal which does not support simultaneous reception and transmission of aggregated cells. Specifically, the method comprises the steps of: receiving downlink control information for a secondary cell on a specific radio resource corresponding to a special subframe of a primary cell and a downlink subframe of the secondary cell; and determining validity of the downlink control information according to an uplink-downlink setting of the primary cell, wherein the downlink control information is determined to be invalid if the primary cell is in non-fallback mode, and determined to be valid if the primary cell is a time division duplex (TDD) uplink-downlink setting according to fallback mode and the secondary cell is cross-carrier scheduled according to the primary cell.