Uplink ACK Resource Mapping for Multi-UE CCE Collision Avoidance

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Solution Overview

Problem

In 5G NR networks, the implicit signaling of uplink resources for ACK transmissions is inefficient and prone to collisions due to the use of the same CCE index for different UEs, especially in multi-user MIMO scenarios, which complicates the determination of time-frequency resources for ACK feedback.

Innovation Solution

A method for determining uplink resources for ACK transmissions in 5G NR networks by utilizing an explicit or implicit mapping process, where UEs identify resources based on additional parameters beyond the CCE index, reducing collisions and optimizing resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If implicit signaling using CCE index is used for uplink resource allocation, then device complexity is reduced, but ACK transmission collisions increase

Engineering Contradiction:
ImproveUE complexity for resource determinationVSAvoidACK transmission collision rate
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent changes the parameter used for resource mapping from only CCE index to a combination of CCE index and additional parameters (such as PRB index, resource block index, or other downlink resource allocation parameters). This parameter expansion resolves the collision problem while keeping the mapping process relatively simple.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adds another dimension to the resource mapping by introducing additional parameters beyond the CCE index. Instead of mapping ACK resources solely based on one-dimensional CCE index, the solution uses multi-dimensional parameters (CCE index + additional downlink resource parameters) to uniquely identify uplink ACK resources, thereby eliminating collisions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If explicit mapping with additional parameters is used, then ACK collision rate is reduced, but device complexity increases

Engineering Contradiction:
ImproveACK transmission collision rateVSAvoidUE complexity for resource determination
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent modifies the mapping parameters to include additional downlink resource allocation information alongside the CCE index. This parameter expansion provides sufficient information to uniquely identify uplink ACK resources without requiring complex signaling or processing mechanisms.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3639438B1Strategic mapping of uplink resources
Publication Date: 2026.03.18 QUALCOMM INC
  • EP3639438B1 patent drawingFigure 1
  • EP3639438B1 patent drawingFigure 2
  • EP3639438B1 patent drawingFigure 3

AI summary

Aspects of the disclosure relate to implied and explicit mapping of uplink (UL) resources for acknowledgement communications from a user equipment (UE). In some examples disclosed herein, implied mapping may include indexing of information elements in a downlink (DL) communication. The explicit mapping may include information elements in the DL communication configured to explicitly provide a location of an UL resource. Other aspects, embodiments, and features are also claimed and described.