NR-PBCH Frequency Domain Mapping for UE Load Reduction

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Solution Overview

Problem

Future radio communication systems, such as 5G and NR, face challenges in reducing the load and latency of user equipment (UE) during initial access, particularly when using different numerologies and frequencies compared to existing LTE systems, and require efficient configurations for synchronization signals and broadcast channels.

Innovation Solution

The configuration of synchronization signals (NR-PSS/SSS) and broadcast channels (NR-PBCH) in a manner where NR-PBCHs are mapped to a wider frequency domain than NR-PSS/SSS, with the option to use neighboring resources for NR-PBCH transmission, reducing the bandwidth and number of SS rasters, thereby minimizing the load and latency of UEs during initial access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If NR-PBCHs are mapped to a wider frequency domain than NR-PSS/SSS, then sufficient resources for transmission are ensured, but the number of SS rasters increases and bandwidth consumption increases

Engineering Contradiction:
Improveresources for NR-PBCH transmissionVSAvoidnumber of SS rasters
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments the frequency domain resources by defining a first frequency domain for NR-PSS/SSS and a second wider frequency domain for NR-PBCH. This segmentation allows synchronization signals and broadcast channels to occupy different frequency resources, ensuring sufficient resources for NR-PBCH transmission while managing the number of SS rasters through structured frequency domain division.

Inventive Principle:
Principle #1Segmentation

2Productivity

If NR-PBCHs use neighboring resources of NR-PSS/SSS, then resource utilization is improved, but interference between signals may increase

Engineering Contradiction:
Improveresource utilizationVSAvoidsignal interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent resolves potential interference by transitioning from frequency-domain adjacency to time-domain separation. NR-PBCHs are mapped to frequency domains neighboring NR-PSS/SSS in the frequency dimension, but are transmitted in different time slots (second time domain versus first time domain), effectively eliminating interference while maximizing resource utilization.

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

3Loss of time

If the bandwidth is reduced to minimize UE load, then latency and processing load are reduced, but the number of available resources for broadcast channels decreases

Engineering Contradiction:
Improveinitial access latencyVSAvoidavailable resources for broadcast channels
Core Design Contradiction:
Loss of timeVSQuantity of substance

Solution Approach 1:

The patent implements dynamic resource allocation where the frequency domain for NR-PBCH is configured to be wider than that for NR-PSS/SSS, and the specific resource allocation can be adapted based on system conditions. This dynamic configuration allows the system to reduce UE processing load by optimizing bandwidth while maintaining sufficient resources for broadcast channel transmission through flexible frequency domain management.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3697150B1User equipment, base station and wireless communication method
Publication Date: 2024.04.17 NTT DOCOMO INC
  • EP3697150B1 patent drawingFigure 1
  • EP3697150B1 patent drawingFigure 2
  • EP3697150B1 patent drawingFigure 3

AI summary

[Summary] [Problem] The present invention is designed so that, in radio communication systems in which communication is performed using different configurations from those used in existing LTE systems, the load and/or the latency of UEs can be reduced. [Solution] A user terminal has a receiving section configured to receive a first synchronization signal (PSS), a second synchronization signal (SSS), and a broadcast channel (PBCH), and a control section configured to control, in a predetermined block that is formed by a predetermined number of symbols and a predetermined number of subcarriers, reception of the PSS and the SSS which are located in a first frequency domain, and the PBCH which is located in at least part of a second frequency domain that is broader than the first frequency domain, wherein the PBCH is located in the predetermined block in at least part of a predetermined domain that is neighbor with the SSS in the frequency direction, and the PBCH is not located in a predetermined domain that is neighbor with the PSS in the frequency direction.