Narrowband PBCH Allocation for 5 MHz NR Terminals

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Solution Overview

Problem

Existing 5G NR systems do not support bandwidths of 5 MHz or less, leading to issues in transmitting and receiving channels or signals between radio base stations and UEs.

Innovation Solution

The proposed solution involves a terminal and radio base station that allocate and receive resource blocks differently when a bandwidth of 5 MHz or less is applied, using a second channel bandwidth that is narrower than the first, and adjusting the position and spacing of synchronization and control channels to accommodate the reduced bandwidth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If a bandwidth of 5 MHz or less is used, then low latency use cases (smart grids, railway mobile communication) are supported, but conventional channel and signal formats cannot be transmitted or received between radio base stations and UEs

Engineering Contradiction:
ImprovelatencyVSAvoidchannel transmission reliability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent changes the bandwidth parameter from the conventional 5 MHz or wider to 5 MHz or less, enabling support for low latency use cases. Simultaneously, it adjusts the resource block allocation parameters and synchronization signal block configurations to accommodate the narrower bandwidth, ensuring that channel and signal transmission remains reliable despite the parameter change.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a second channel bandwidth narrower than the first channel bandwidth is applied, then narrow bandwidth scenarios are supported, but resource block allocation and channel positioning become complex

Engineering Contradiction:
Improvebandwidth adaptabilityVSAvoidresource block allocation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic resource block allocation where the number and positioning of resource blocks are adjusted based on the applied bandwidth. The system dynamically configures the resource block structure to match the second channel bandwidth, simplifying the allocation process while maintaining bandwidth adaptability. The synchronization signal block positions are also dynamically determined based on the bandwidth configuration.

Inventive Principle:
Principle #15Dynamics

3Reliability

If resource blocks are excluded from the first channel bandwidth to form remaining resource blocks, then proper signal transmission is enabled, but the occupied bandwidth creates transmission issues

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidoccupied bandwidth
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent segments the resource blocks into different groups based on their allocation patterns. By excluding certain resource blocks from the first channel bandwidth configuration, it creates remaining resource blocks that are specifically allocated for the second channel bandwidth. This segmentation enables proper signal transmission within the narrower bandwidth while managing the occupied bandwidth effectively.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4615103A1Terminal, wireless base station, and wireless communication method
Publication Date: 2025.09.10 NTT DOCOMO INC
  • EP4615103A1 patent drawingFigure 1
  • EP4615103A1 patent drawingFigure 2
  • EP4615103A1 patent drawingFigure 3

AI summary

A terminal includes a reception unit that receives a physical broadcast channel to which one or more resource blocks are allocated, and a control unit that assumes, when a second channel bandwidth narrower than a first channel bandwidth is applied, the physical broadcast channel, to which a remaining resource block is allocated which is obtained by excluding a part of the resource blocks corresponding to the first channel bandwidth.