BWP Activation via Grant-Free DCI in 5G NR

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in bandwidth part activation, deactivation, and switching, particularly in 5G New Radio (NR) systems, leading to increased power consumption and latency due to continuous monitoring and reporting of channel conditions across multiple bandwidth parts (BWPs) without a grant, which is unnecessary and resource-intensive.

Innovation Solution

Implementing a method where the base station uses downlink control information (DCI) without a grant to activate or deactivate BWPs, allowing the user equipment (UE) to switch between BWPs based on traffic conditions, reducing the need for continuous monitoring and reporting, and enabling power savings and lower latency by only measuring and reporting channel state information for the actively used BWP.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the base station transmits control information to activate, deactivate or switch BWPs using DCI with grant, then the UE can switch BWPs to match data traffic, but the UE consumes unnecessary power and experiences increased latency due to continuous monitoring and decoding of PDSCH

Engineering Contradiction:
ImproveBWP switching efficiencyVSAvoidUE power consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the grant information from the DCI message, transmitting only the BWP activation/deactivation/switching control information without the associated resource grant. This allows the UE to switch BWPs based on traffic conditions without needing to continuously monitor and decode full PDSCH transmissions, thereby reducing power consumption while maintaining switching efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of transmitting complete grant information for every BWP switching operation, the patent transmits only the necessary partial information (BWP identification and activation status) in the DCI. This partial action approach reduces the amount of data the UE must process, lowering power consumption while achieving the desired BWP switching functionality

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If the UE continuously monitors and reports channel conditions of all available BWPs, then the base station can optimize transmission parameters, but the UE consumes excessive power and uses unnecessary wireless resources

Engineering Contradiction:
Improvechannel condition optimizationVSAvoidUE power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by having the UE monitor and report channel conditions only for the currently active BWP rather than all available BWPs. The base station receives this localized channel information and optimizes transmission parameters accordingly, maintaining reliability while significantly reducing UE power consumption and wireless resource usage

Inventive Principle:
Principle #3Local quality

3Measurement precision

If the UE decodes PDSCH corresponding to DCI with grant for BWP activation, then accurate channel state information is obtained, but transmission latency is increased

Engineering Contradiction:
Improvechannel state information accuracyVSAvoidBWP switching latency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary action by having the UE perform channel measurements and prepare channel state information for the target BWP in advance, before the actual BWP activation. When the DCI without grant is received, the UE can immediately switch to the indicated BWP using pre-prepared channel information, thereby reducing switching latency while maintaining measurement precision

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3692671B1Bandwidth part activation, deactivation, and switching in wireless communications
Publication Date: 2025.03.26 QUALCOMM INC
  • EP3692671B1 patent drawingFigure 1
  • EP3692671B1 patent drawingFigure 2
  • EP3692671B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described that provide for transmission of an indication of an activated bandwidth part (BWP) or component carrier (CC), or combination thereof, to a user equipment (UE) through downlink control information (DCI) that is excluding a grant of resources of the BWP or CC. A UE may establish a connection with a base station in which one or more CCs may be configured with one or more BWPs. The base station may indicate which BWP is active for a transmission in DCI that is transmitted subsequent to the configuration of the one or more CCs, and a UE may activate a corresponding BWP or CC based on the indication. In some cases, a CC may be deactivated unless the DCI indicates that at least one BWP of the CC is active.