Sidelink MCS Selection With Network-Coded Retransmission

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Solution Overview

Problem

Existing sidelink communication systems face challenges in optimizing modulation and coding schemes (MCS) for network coding in device-to-device (D2D) networks, leading to inefficiencies in resource utilization and increased transmission collisions.

Innovation Solution

Implementing network coding with a higher MCS than normal for initial sidelink transmissions, leveraging a network coding device for retransmissions, and using a network coding request flag to facilitate reliable packet transmission, thereby reducing resource congestion and increasing spectral efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If normal MCS is used for initial sidelink transmissions, then resource utilization is efficient, but transmission reliability is insufficient and collision probability increases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidresource utilization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the MCS parameter from normal values to higher values specifically for initial sidelink transmissions. This parameter change increases transmission reliability by improving signal quality and error resistance, while the patent manages the trade-off by using network coding for retransmissions to maintain overall resource efficiency.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If higher MCS is used for initial sidelink transmissions, then spectral efficiency increases, but device complexity increases due to network coding operations

Engineering Contradiction:
Improvespectral efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a network coding device as an intermediary that performs encoding operations on packets before transmission. This intermediary handles the complex network coding computations, thereby increasing spectral efficiency through higher MCS while managing device complexity by offloading processing tasks to a dedicated network coding device.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If network coding is implemented with higher MCS, then resource congestion is reduced, but loss of information increases during encoding operations

Engineering Contradiction:
Improveresource utilizationVSAvoidinformation loss
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent implements feedback mechanisms where receiving devices send acknowledgments or negative acknowledgments back to the transmitting device based on successful packet reception. This feedback loop allows the system to adapt transmissions, request retransmissions when information is lost during network coding, and ultimately reduce resource congestion through efficient error management and resource allocation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4441937B1MCS selection for network coding in sidelink
Publication Date: 2025.12.17 QUALCOMM INC
  • EP4441937B1 patent drawingFigure 1
  • EP4441937B1 patent drawingFigure 2
  • EP4441937B1 patent drawingFigure 3

AI summary

Aspects relate to techniques for MCS selection of a packet to be network coded for sidelink communication. A transmitting UE may encode a packet using an MCS that is greater than a normal MCS that may be used for encoding the packet without network coding. The transmitting UE may then transmit the encoded packet to one or more receiving UEs and a network coding device over a sidelink data channel. The transmitting UE may further transmit a network coding request flag associated with the packet to initiate one or more retransmissions of the packet by the network coding device.