PUCCH Resource Allocation in Flexible-TDD Wireless Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, the existing methods for PUCCH resource allocation in flexible-TDD UL-DL configurations lead to PUCCH collision and inefficient resource utilization, particularly in small cells with rapidly changing traffic conditions, due to the inability to adaptively reconfigure TDD UL-DL configurations without impacting legacy UE compatibility.
Innovation Solution
A method for PUCCH resource allocation that differentiates between legacy and flexible-TDD UE configurations, using block interleaving and specified offsets to allocate PUCCH resources, allowing for flexible reconfiguration of UL-DL TDD configurations and avoiding collisions by separating DL association sets and dynamically allocating resources based on traffic demand.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If semi-static UL-DL configuration is used for legacy UE compatibility, then backward compatibility is maintained, but resource utilization efficiency deteriorates due to inability to adapt to instantaneous traffic conditions
Solution Approach 1:
The patent segments the UL-DL configuration into two parts: a semi-static reference configuration for legacy UE compatibility and a dynamic flexible configuration for traffic adaptation. This segmentation allows different UE types to operate with appropriate configurations simultaneously, resolving the contradiction between adaptability and compatibility.
Solution Approach 2:
The patent introduces a configuration indicator as an intermediary mechanism that signals the flexible TDD configuration to advanced UEs while maintaining legacy configuration for backward compatibility. This intermediary enables dynamic adaptation without disrupting legacy UE operation.
2Productivity
If flexible TDD reconfiguration is implemented for traffic adaptation, then resource utilization improves, but PUCCH collision increases due to misalignment between different UE types
Solution Approach 1:
The patent applies different PUCCH resource allocation strategies to different UE types: legacy UEs use resources based on the reference configuration while flexible UEs use resources based on the actual flexible configuration. This local differentiation prevents PUCCH collisions by ensuring each UE type uses appropriate resources for its configuration type.
Solution Approach 2:
The patent performs preliminary PUCCH resource allocation based on the reference configuration before flexible reconfiguration takes effect. This preliminary allocation ensures that legacy UEs and flexible UEs are assigned non-conflicting resources in advance, preventing PUCCH collisions.
3Ease of operation
If PUCCH resources are allocated based on reference configuration for all UEs, then legacy UE compatibility is maintained, but resource efficiency deteriorates due to reserved but unused PUCCH resources
Solution Approach 1:
The patent makes PUCCH resource allocation dynamic by allowing flexible UEs to use resources based on the actual flexible TDD configuration rather than the static reference configuration. This dynamics enables resources to be allocated according to real traffic conditions, eliminating waste while maintaining simplicity for legacy UEs.
Solution Approach 2:
The patent changes the PUCCH resource allocation parameters for flexible UEs based on the flexible TDD configuration, allowing resource indices to adapt to the actual UL-DL pattern. This parameter change enables efficient resource utilization without complicating legacy UE operation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method according to the present invention is implemented in a base station used in a wireless communications system that supports flexible-TDD (flexible-time division duplex) UL-DL (uplink-downlink) configuration. The method includes configuring a first type of user equipment (UE) with a first type of configuration; configuring a second type of UE with a second type of configuration; and receiving from a user equipment a HARQ-ACK (hybrid automatic repeat request-acknowledgement) signal according to a DL association set. The the DL association set includes: a first DL association set for a UL-DL TDD configuration used by the first type of UE; and a second DL association set for a reference UL-DL TDD configuration including a third DL association set for PUCCH resource mapping used by the second type of UE.