Cell Selection Based on Doppler Shift for Wireless Stability

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Solution Overview

Problem

In high-frequency radio communication environments, the movement of terminals leads to a decrease in communication performance due to factors such as Doppler shift and increased propagation loss.

Innovation Solution

A communication control apparatus and method that selects cells based on estimated Doppler shift and reception strength to optimize radio connections, using a control section to transmit control signals for improved communication performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If radio communication uses high frequency band to increase bandwidth, then communication capacity is improved, but communication performance decreases due to terminal movement and Doppler shift

Engineering Contradiction:
ImprovebandwidthVSAvoidcommunication performance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent implements dynamic cell selection by continuously monitoring Doppler shift values and reception strengths, and adjusting the selected cell based on terminal movement conditions. The control section dynamically changes the serving cell to maintain optimal communication performance despite terminal movement in high-frequency bands.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses feedback mechanisms where the terminal measures reception strength and Doppler shift in surrounding cells and reports these measurements to the base station. The base station then uses this feedback information to make informed decisions about cell selection and handover timing, optimizing communication performance.

Inventive Principle:
Principle #23Feedback

2Duration of action of stationary object

If handover is performed frequently to track terminal movement, then communication continuity is improved, but communication performance decreases due to handover timing mismatch with Doppler shift changes

Engineering Contradiction:
Improvecommunication continuityVSAvoidcommunication performance
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent performs preliminary actions by having the terminal measure and report reception strength and Doppler shift values before handover is actually executed. The base station uses these advance measurements to predict future communication quality and determines the optimal handover timing, performing the handover proactively before performance degradation occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent prepares for potential performance degradation by continuously monitoring Doppler shift trends and reception strengths. When deterioration is detected, the system initiates handover procedures in advance to cushion against the negative effects of Doppler shift, ensuring communication performance is maintained before significant degradation occurs.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Reduces the decrease in communication performance caused by terminal movement by prioritizing cells with lower Doppler shift and better reception strength, enhancing communication stability.

Implementation Method 1

selects at least one cell from among a plurality of cells based on information on a Doppler shift estimated based on an uplink reference signal in each of the plurality of cells

Methodology Applied
Scientific EffectDoppler shift: Doppler Effect

Data Source

PatentEP3962144B1Communication control device and communication control method
Publication Date: 2025.06.25 NTT DOCOMO INC
  • EP3962144B1 patent drawingFigure 1
  • EP3962144B1 patent drawingFigure 2A
  • EP3962144B1 patent drawingFigure 2B

AI summary

This communication control device is provided with: a control unit which selects at least one cell from among a plurality of cells on the basis of information relating to Doppler shifts estimated from an uplink reference signal of each of the plurality of cells; and a transmitting unit which transmits to the selected cell a control signal for controlling a wireless connection with a terminal. The communication control method includes: selecting at least one cell from among a plurality of cells on the basis of information relating to Doppler shifts estimated from an uplink reference signal of each of the plurality of cells; and transmitting to the selected cell a control signal for controlling a wireless connection with a terminal.