PUCCH Resource Allocation for LTE-TDD HARQ Feedback
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Solution Overview
Problem
In LTE-TDD systems, the existing PDCCH-specific resource allocation schemes are not suitable for TDD systems, and the 'lowest eCCE index number plus offset' technique is not well applicable, leading to insufficient PUCCH resources for ACK/NACK feedback, especially when multiple downlink subframes are mapped to a single uplink subframe.
Innovation Solution
A method and apparatus for determining device channel resources in a TDD system, where channel resources are divided into multiple regions based on the number or potential highest number of downlink subframes with ePDCCH, allowing for efficient HARQ feedback by reallocating PUCCH resources and using the lowest eCCE index plus offset, which is suitable for TDD systems, and optionally adopting an interleaved mode for resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ePDCCH is added to PDSCH to serve more users, then the number of served users increases, but PUCCH resources for ACK/NACK feedback become insufficient
Solution Approach 1:
The patent divides channel resources into multiple channel regions based on the number of downlink subframes with ePDCCH. This segmentation allows different regions to handle different quantities of ACK/NACK feedback, effectively increasing the total capacity for user feedback while maintaining organized resource management.
2Ease of operation
If the lowest eCCE index number plus offset technique is applied, then resource allocation is simplified, but it is not well applicable to TDD system with multiple downlink subframes mapping to one uplink subframe
Solution Approach 1:
The patent applies different resource allocation strategies to different channel regions. Specifically, it uses the lowest eCCE index number plus offset technique for certain regions while employing other methods for regions handling multiple downlink subframes, allowing each region to have optimized quality suitable for its specific function.
Solution Approach 2:
The patent dynamically determines the number of channel regions based on the actual number of downlink subframes with ePDCCH. This dynamic adjustment allows the system to adapt resource allocation complexity to the actual traffic conditions, using simpler methods when appropriate and more complex methods only when necessary.
3Productivity
If multiple downlink subframes are mapped to one uplink subframe, then system capacity is improved, but resource allocation complexity and conflicts increase
Solution Approach 1:
The patent segments channel resources into multiple regions, where each region can independently handle feedback from a specific set of downlink subframes. This segmentation reduces allocation complexity by localizing the management of multiple subframes rather than handling them as a single complex resource pool.
Solution Approach 2:
The patent introduces an additional dimension to resource allocation by creating multiple channel regions along the frequency or time domain. This dimensional expansion allows the system to handle multiple downlink subframes by distributing their feedback across different regions, thereby reducing conflicts and simplifying individual region management.
Data Source
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AI summary
An objective of the present invention is to provide a method, apparatus, and equipment for determining device channel resources of a user equipment in an LTE-TDD system. The TDD system performs resource scheduling to the user equipment using an enhanced physical downlink control channel, and a physical uplink control channel as used includes channel resource(s) for feeding back a hybrid automatic repeat request of a physical downlink shared channel as scheduled by the enhanced physical downlink control channel, when the number of downlink subframes as fed back in one uplink subframe may be more than one, the channel resource(s) is divided into a plurality of channel regions based on the number of downlink subframes having the enhanced physical downlink control channel set thereon currently, or based on the potential highest number of downlink subframes having the enhanced physical downlink control channel set thereon. The present application obtains the device channel resource(s) occupied by the present user equipment in at least one channel region of the plurality of channel regions. The present invention enables the user equipment to feed back ePDCCH.