PHICH Resource Allocation Offset for Carrier Aggregation Collisions
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Solution Overview
Problem
In LTE communication systems, PHICH collisions occur when multiple uplink carriers are scheduled from the same downlink carrier, complicating resource allocation and requiring modifications to PHICH group and sequence calculations, which can limit the range of achievable PHICH sequence numbers.
Innovation Solution
Modifying the PHICH sequence calculation by adding an offset value to the resource block numbering, allowing unique PHICH resources to be determined without altering the PHICH group, thereby avoiding collisions and ensuring compatibility with existing systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple uplink carriers are scheduled from the same downlink carrier, then carrier aggregation capability is improved, but PHICH collisions occur and resource allocation becomes complex
Solution Approach 1:
The patent segments the PHICH resource allocation by introducing a carrier-specific offset value that divides the PHICH sequence numbers into distinct ranges for each uplink carrier. This segmentation prevents collisions by ensuring that each carrier uses a unique subset of PHICH resources, allowing multiple carriers to be scheduled from the same downlink carrier without resource conflicts.
Solution Approach 2:
The patent applies local quality by making the PHICH sequence number calculation carrier-specific through the offset value. Each uplink carrier receives a customized PHICH resource allocation based on its identity, while the overall PHICH group structure remains unchanged. This localized customization enables multiple carriers to coexist without collisions.
2Reliability
If PHICH group and sequence calculations are modified to avoid collisions, then PHICH resource uniqueness is improved, but backward compatibility with LTE Rel-8 is compromised
Solution Approach 1:
The patent introduces dynamic flexibility by making the offset value configurable rather than fixed. The offset can be dynamically adjusted based on the carrier configuration, allowing the system to adapt to different carrier aggregation scenarios while maintaining compatibility with existing LTE Rel-8 implementations when offset values are set to zero or default configurations.
Solution Approach 2:
The patent changes the parameter of PHICH sequence number calculation by introducing an offset value that can be configured per carrier. This parameter change allows the system to differentiate between multiple carriers without fundamentally altering the PHICH structure, thus maintaining backward compatibility while achieving resource uniqueness.
3Adaptability or versatility
If offset value is added to PHICH sequence calculation, then PHICH sequence range is improved, but calculation complexity increases
Solution Approach 1:
The patent applies partial action by adding the offset value only to the PHICH sequence number calculation rather than redesigning the entire PHICH resource allocation mechanism. This partial modification expands the usable PHICH sequence range while keeping the overall calculation structure simple and manageable.
Data Source
AI summary
Methods and apparatus for organizing reception on a channel by a user equipment are disclosed. A method includes determining a channel group based on a first physical resource block index of a physical uplink shared channel and a cyclic shift of uplink demodulation reference signals, without an offset value; determining a channel sequence based on the first physical resource block index, the cyclic shift, and the offset value; and determining a reception resource according to the channel group and the channel sequence.