Sidelink Relay of PDCCH Control Information Under Interference

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Solution Overview

Problem

Existing wireless communication systems, particularly in 5G networks, face challenges in ensuring reliable transmission of downlink control information (DCI) between network entities and user equipment (UE) due to interference and resource allocation inefficiencies, which affect the performance of physical downlink control channels (PDCCH).

Innovation Solution

The method involves transmitting DCI over a sidelink channel between relay UE and target UE, with search space information indicating resource allocation for PDCCH, enabling efficient communication between the network entity and the target UE.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DCI is transmitted over traditional downlink channels, then coverage is provided, but reliability is reduced due to interference and resource allocation inefficiencies

Engineering Contradiction:
ImprovePDCCH transmission reliabilityVSAvoidinterference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a relay UE as an intermediary node between the network entity and target UE. The relay UE receives DCI from the network entity and forwards it to the target UE via sidelink, thereby mediating the transmission and improving reliability by providing alternative transmission paths that avoid direct interference on traditional downlink channels.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If traditional downlink channels are used for DCI transmission, then communication is established, but resource allocation efficiency is reduced

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoidtransmission time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent transitions the DCI transmission from the traditional downlink dimension to a new sidelink dimension between UEs. By utilizing the sidelink channel for DCI forwarding and including search space information, the system creates an additional transmission dimension that improves resource allocation efficiency and reduces transmission time through more direct UE-to-UE communication.

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

Data Source

PatentEP4476857B1Improving physical downlink control channel (PDCCH) reliability using sidelink
Publication Date: 2026.02.04 QUALCOMM INC
  • EP4476857B1 patent drawingFigure 1
  • EP4476857B1 patent drawingFigure 2A
  • EP4476857B1 patent drawingFigure 2B

AI summary

Disclosed are techniques for wireless communication. In an aspect, a target user equipment (UE) receives, from a relay UE over a sidelink channel between the target UE and the relay UE, downlink control information (DCI) for a communication session between the target UE and a network entity, wherein the sidelink channel indicates search space information for a physical downlink control channel (PDCCH) between the target UE and the network entity carrying the DCI, and communicates with the network entity using a resource allocation granted by the DCI for a physical downlink channel, a physical uplink channel, or both between the target UE and the network entity based on the DCI and the search space information.