LTE-A Anchor Block for Stable Carrier Aggregation Transitions
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Solution Overview
Problem
In LTE communication systems, during transitions where the Carrier Indicator Field (CIF) is switched or the number of component carrier aggregations changes, there is uncertainty about the mobile station's state, leading to potential failures in blind decoding and misidentification of component carriers, resulting in unstable communication.
Innovation Solution
A radio communication system is designed with an overlapping configuration of two communication systems, where one system uses a fixed fundamental frequency block as an anchor to maintain communication stability during CIF transitions and changes in component carrier aggregations, by mapping user common and user-specific control information to dedicated search spaces and using a DCI configuration that supports LTE operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If CIF is added to DCI configuration to support carrier aggregation, then adaptability to different component carriers is improved, but device complexity increases and reliability deteriorates during transition periods
Solution Approach 1:
The patent segments the DCI configuration into two distinct modes: with CIF and without CIF. During transition periods when RRC reconfiguration is in progress, the system uses the segment without CIF to maintain stability, while after reconfiguration completes, it switches to the segment with CIF to support carrier aggregation. This segmentation allows the system to maintain reliability during transitions while preserving adaptability when needed.
Solution Approach 2:
The patent implements dynamic switching between DCI configurations with and without CIF based on the RRC reconfiguration state. The system dynamically adjusts the DCI format used for downlink control information, selecting the appropriate configuration mode according to whether the mobile station has completed reconfiguration. This dynamic adaptation resolves the contradiction by providing the right configuration at the right time.
2Adaptability or versatility
If RRC signaling is used to switch CIF configuration, then adaptability is improved, but loss of time occurs during the reconfiguration interval
Solution Approach 1:
The patent applies preliminary action by preparing both DCI configuration modes (with and without CIF) in advance. The base station pre-configures the mobile station with both options through RRC signaling, so that during the reconfiguration interval, the system can immediately switch to the pre-prepared configuration without CIF, avoiding communication interruptions. This eliminates the time loss during transition while maintaining adaptability.
3Adaptability or versatility
If blind decoding is performed with CIF added, then adaptability to carrier aggregation is improved, but measurement precision deteriorates due to decoding failures during transition
Solution Approach 1:
The patent applies local quality by making the DCI configuration quality context-dependent. During transition periods (local context of RRC reconfiguration), the system uses DCI without CIF to ensure accurate blind decoding. After reconfiguration completes, it switches to DCI with CIF for carrier aggregation support. This local adaptation of configuration quality resolves the contradiction between adaptability and decoding precision.
Data Source
AI summary
The present invention maintains communication even during a transition period in which ON/OFF of the CIF is switched by higher layer signaling or during a transition period in which the number of component carrier aggregations is increased/decreased. In a radio communication system in which an LTE-A system, in which an LTE-A system to add or remove the frequency band to assign for communication between a base station apparatus (20) and a mobile terminal apparatus (10) on a per component carrier basis, and an LTE system to perform communication between the base station apparatus (20) and the mobile terminal apparatus (10) using one fixed fundamental frequency block, are arranged in an overlapping manner, in the LTE-A system, one of the fundamental frequency blocks assigned to the mobile terminal apparatus (10) is determined as an anchor block, and the anchor block supports the same operation as in the LTE system.