HARQ Process Configuration for Wireless Latency and Reliability

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Solution Overview

Problem

Wireless communication systems face challenges in supporting high-reliability, low-latency communications (HRLLCs) due to varying latency and reliability constraints across different service types, requiring adjustments in hybrid acknowledgment repeat request (HARQ) processes based on transmission time intervals (TTIs), timing advance (TA) values, and user equipment (UE) processing capabilities.

Innovation Solution

The system configures HARQ processes based on processing timelines, TA values, and TTI durations, with additional HARQ processes being dynamically configured to accommodate propagation delays and UE capabilities, ensuring aligned wireless transmissions and efficient error correction mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional HARQ processes are configured to accommodate propagation delays and UE capabilities, then reliability of HRLLC is improved, but device complexity increases

Engineering Contradiction:
ImproveHRLLC reliabilityVSAvoidHARQ process configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system dynamically configures the number of HARQ processes based on actual propagation delays and UE processing capabilities rather than using a fixed configuration. This allows the system to adapt the HARQ process count to match actual network conditions, improving reliability when needed while avoiding unnecessary complexity in other scenarios.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of HARQ process count based on measured propagation delays and UE capabilities. By adjusting this key parameter dynamically, the system optimizes reliability for HRLLC services while managing device complexity through conditional configuration rather than universal complexity.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If HARQ processes are optimized for HRLLC with shorter TTIs, then latency is reduced, but processing complexity at UE increases

Engineering Contradiction:
Improvecommunication latencyVSAvoidUE processing complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The system performs preliminary configuration of HARQ processes based on pre-assessed UE capabilities and network conditions. By preparing the appropriate number of HARQ processes in advance based on capability reporting, the UE avoids complex real-time decisions while still achieving low-latency performance through pre-optimized configurations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where UEs report their processing capabilities to the network, and the network responds with appropriate HARQ process configurations. This feedback loop allows the system to match processing complexity to actual UE capabilities, reducing unnecessary complexity while maintaining low latency through optimized configurations.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If timing advance values are adjusted to account for propagation delays, then transmission alignment is improved, but system complexity increases

Engineering Contradiction:
Improvetransmission timing alignmentVSAvoidtiming management complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system enables UEs to self-adjust their timing advance values based on measured propagation delays and received configuration parameters. By allowing UEs to autonomously manage their timing alignment within the configured framework, the system achieves precise transmission alignment without requiring complex centralized timing management for each UE.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3602896B1Feedback processing techniques in wireless transmissions
Publication Date: 2023.04.19 QUALCOMM INC
  • EP3602896B1 patent drawingFigure 1
  • EP3602896B1 patent drawingFigure 2
  • EP3602896B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described in which a base station may identify a processing timeline for a user equipment to transmit a HARQ feedback transmission in response to a downlink transmission and determine a configuration for a number of HARQ processes for use by the UE. The number of HARQ processes may be based on the processing timeline, a timing advance (TA) of the UE, and a duration of transmission time intervals (TTIs) for communications between the UE and the base station. The base station may transmit the configuration to the UE, and the UE may operate according to the number of configured HARQ processes.