Dynamic PHICH Resource Allocation for LTE-A Multicarrier Transmission

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Solution Overview

Problem

In LTE-A systems, legacy UEs cannot receive HARQ acknowledgement channels in subframes without allocated PHICH resources, leading to backward compatibility issues and inefficient multicarrier transmission due to collisions with PDCCH channels.

Innovation Solution

A method and apparatus for dynamically allocating new PHICH resources in subframes without existing allocations, allowing evolved UEs to receive HARQ acknowledgments without interfering with legacy UE control channel reception, by determining the need for new PHICH resources and allocating them as necessary for transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PHICH resources are allocated in all subframes for evolved UEs, then HARQ acknowledgement reception is improved, but control channel collisions and legacy UE performance degradation occur

Engineering Contradiction:

ImproveHARQ acknowledgement receptionVSAvoidcontrol channel collisions

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically determines PHICH resource allocation on a per-subframe basis rather than statically allocating in all subframes. The base station evaluates whether PHICH transmission is needed in each subframe and allocates resources adaptively, allowing the system to balance evolved UE HARQ reception needs with legacy UE compatibility and collision avoidance

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the allocation parameter of PHICH resources from a fixed all-subframe allocation to a selective allocation based on specific conditions. By modifying the allocation pattern parameter (allocating only in subframes where needed), the system improves resource utilization while preventing control channel collisions and maintaining legacy UE performance

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If PHICH resources are allocated in all subframes, then multicarrier transmission is supported, but resource utilization efficiency deteriorates

Engineering Contradiction:

Improvemulticarrier transmission supportVSAvoidresource utilization efficiency

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

Instead of allocating PHICH resources in all subframes (excessive action), the system applies partial action by allocating resources only in subframes where PHICH transmission is actually needed. This selective allocation maintains multicarrier transmission support while avoiding waste of radio resources in subframes where PHICH is not required, thereby improving overall resource utilization efficiency

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP2735110B1Method and apparatus for transmitting HARQ acknowledgement in OFDM radio communication system

Publication Date: 2018.07.04 SAMSUNG ELECTRONICS CO LTD

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AI summary

A Physical Hybrid Automatic Repeat reQuest (ARQ) Indicator CHannel (PHICH) transmission method performed by a base station is provided. The method includes determining whether any PHICH resources are allocated to a current subframe; allocating, upon a determination that the current subframe does not have any PHICH resources allocated, a new PHICH resource; and transmitting a PHICH through the new allocated PHICH resource.