UE Relay Forwarding With Adaptive AF/DF for mmWave Reliability

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently and reliably transmitting messages between user equipment (UE) and base stations, particularly in millimeter wave (mmW) frequency range 2 (FR2) due to limitations in amplify and forward (AF) and decode and forward (DF) transmission schemes, which affect the successful reception of forwarded messages.

Innovation Solution

User equipment (UE) selectively employs AF, DF, or a combination of both transmission schemes based on decoding success, using cyclic redundancy check (CRC) codes and I/Q amplitude imbalance correction to forward sidelink messages to a base station, while the base station utilizes improved decoding techniques and log-likelihood radio (LLR) combining to enhance message reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If amplify and forward (AF) transmission scheme is used, then message forwarding is achieved, but thermal constraints and power availability limitations reduce successful reception likelihood

Engineering Contradiction:
Improvesuccessful reception of forwarded messageVSAvoidpower availability at UE
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic selection between AF and DF transmission schemes based on real-time decoding success determination. The relay UE adapts its transmission mode by attempting to decode the received message and selecting AF if decoding fails or DF if decoding succeeds, optimizing the balance between power consumption and reception reliability under thermal and power constraints.

Inventive Principle:
Principle #15Dynamics

2Reliability

If decode and forward (DF) transmission scheme is used, then message reliability is improved, but latency at UE and gNB increases

Engineering Contradiction:
Improvesuccessful reception of forwarded messageVSAvoidlatency at UE and gNB
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements dynamic selection between AF and DF transmission schemes based on real-time decoding success determination. The relay UE adapts its transmission mode by attempting to decode the received message and selecting AF if decoding fails or DF if decoding succeeds, optimizing the balance between power consumption and reception reliability under thermal and power constraints.

Inventive Principle:
Principle #15Dynamics

3Reliability

If single transmission scheme (AF or DF) is used, then system complexity is reduced, but message forwarding reliability is limited

Engineering Contradiction:
Improvesuccessful reception of forwarded messageVSAvoidtransmission scheme selection and combination
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic selection between AF and DF transmission schemes based on real-time decoding success determination. The relay UE adapts its transmission mode by attempting to decode the received message and selecting AF if decoding fails or DF if decoding succeeds, optimizing the balance between power consumption and reception reliability under thermal and power constraints.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission scheme parameter dynamically based on decoding success. The system transitions between two distinct operational modes (AF and DF) by evaluating the decoding outcome, allowing optimal message forwarding reliability without requiring complex multi-scheme combinations.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If adaptive transmission scheme selection is implemented, then communication efficiency and reliability are improved, but device complexity increases

Engineering Contradiction:
Improvecommunication efficiencyVSAvoiddecoding success determination and scheme selection
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic selection between AF and DF transmission schemes based on real-time decoding success determination. The relay UE adapts its transmission mode by attempting to decode the received message and selecting AF if decoding fails or DF if decoding succeeds, optimizing the balance between power consumption and reception reliability under thermal and power constraints.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the relay UE determines decoding success and uses this information to select the appropriate transmission scheme. The base station also provides feedback through improved decoding techniques and LLR combining, creating a closed-loop system that enhances communication efficiency while managing device complexity through intelligent adaptation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4085550B1Combining techniques for message forwarding in wireless communications
Publication Date: 2025.01.15 QUALCOMM INC
  • EP4085550B1 patent drawingFigure 1
  • EP4085550B1 patent drawingFigure 2
  • EP4085550B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described that allow for a first user equipment (UE) to forward a transmission from a second UE to a base station. The forwarding techniques may include the first UE performing a decoding procedure on a message received from the second UE via a sidelink communications link. Based on the results of the decoding procedure, the first UE may select an amplify and forward (AF), decode and forward (DF), or a combination thereof to forward the message from the second UE to the base station. The base station may receive the forward messages and, in some cases, a message directly from the second UE, and may determine decoding weights to use to jointly decode the two messages received at the base station.