Dedicated Downlink Control Channels for Flexible Carrier Aggregation
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Solution Overview
Problem
Existing wireless communication systems face challenges in managing flexible spectrum usage, deployment strategies, and operation, particularly in scenarios where a wireless transmit/receive unit (WTRU) is connected to multiple access points simultaneously, leading to issues with power reduction and inter-carrier interference.
Innovation Solution
Implementing a flexible radio access communication system that allows for varying spectrum sizes, duplexing methods, TTI lengths, and transmission types, along with resource element and channel configurations to optimize spectrum utilization and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a WTRU is connected to multiple access points simultaneously, then spectrum utilization and connectivity flexibility are improved, but frequency synchronization and uplink timing alignment become difficult to maintain
Solution Approach 1:
The patent segments the control channel into multiple instances across different access points, allowing the WTRU to receive control information from multiple APs independently. This segmentation enables connectivity flexibility while maintaining synchronization reliability through distributed control
Solution Approach 2:
The patent introduces dynamic control channel configuration where the control channel can be adaptively allocated across different time-frequency resources based on the number of connected access points. This dynamic adjustment allows the system to maintain synchronization while supporting multiple connectivity scenarios
2Adaptability or versatility
If spectrum aggregation of non-adjacent carriers is implemented, then spectrum utilization is improved, but system complexity and interference management increase
Solution Approach 1:
The patent creates a universal control channel structure that can operate across different spectrum configurations (adjacent and non-adjacent carriers). The control channel design is multi-functional, supporting both contiguous and fragmented spectrum aggregation without requiring separate processing paths
Solution Approach 2:
The patent changes the parameter of control channel resource allocation to be flexible and adaptive. The control channel can be configured with different bandwidths, locations, and densities based on the specific spectrum aggregation scenario, reducing system complexity by using a unified adaptive approach rather than multiple fixed configurations
3Reliability
If control channel resources are increased to support multiple access points, then control information reliability is improved, but available resources for data transmission are reduced
Solution Approach 1:
The patent applies partial action by allocating control channel resources selectively rather than uniformly across all bandwidth. The control channel is configured with sufficient resources to maintain reliability for multiple AP connections, while avoiding excessive allocation that would unnecessarily reduce data transmission capacity
Solution Approach 2:
The patent implements dynamic control channel resource allocation that adjusts the amount of control resources based on the actual number of connected access points and traffic conditions. This dynamic approach ensures control information reliability is maintained at the minimum necessary level, preserving maximum resources for data transmission
Data Source
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AI summary
Systems, methods, and instrumentalities may be disclosed for implementing a flexible radio access communication system. A flexible radio access communication system may be supported using spectrum of varying size, including aggregation of non-adjacent carriers in the same and/or in different frequency bands. A wireless transmit/receive unit (WTRU) may receive a first transmission via a common downlink control channel. The first transmission may include first control information. The first control information may include information regarding the configuration of a first dedicated downlink control channel of one or more dedicated control channels. The WTRU may receive a second transmission via the first dedicated downlink control channel of the dedicated control channels. The second transmission may include second control information. The second control information may be associated with a transmission of a first transmission type. The dedicated downlink control channels may be used for providing control information associated with different types of transmissions.