User Terminal UL-DL Configuration Switching Timing

Solution Overview

Problem

In future radio communication systems like NR, there is a challenge in ensuring that the recognition of transmission direction between user equipment (UE) and the base station matches, especially when the UL-DL configuration is changed semi-statically in an RRC connected state, which can lead to deteriorated communication throughput and frequency use efficiency if the change timing is not appropriate.

Innovation Solution

A user terminal that includes a transmitting/receiving section and a control section to switch the UL-DL configuration based on update information notified via higher layer signaling, ensuring the change is reflected at a specific timing that satisfies given conditions, such as after receiving TDD configuration update information or RRC reconfiguration complete notifications, to align with the post-change configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the UL-DL configuration is changed semi-statically in RRC connected state, then the adaptability of the system is improved, but the reliability of transmission direction recognition deteriorates due to timing mismatch between UE and base station

Engineering Contradiction:

Improveconfiguration flexibilityVSAvoidtransmission direction recognition accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by defining specific timing rules for configuration changes to occur before they take effect. The UE is configured with advance notice of UL-DL configuration changes through RRC signaling, allowing the UE to prepare and switch configurations at predetermined timing points (e.g., at slot boundaries or frame boundaries). This ensures both the UE and base station synchronize their configuration changes, maintaining reliable transmission direction recognition while enabling flexible semi-static reconfiguration.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If the UL-DL configuration is changed semi-statically in RRC connected state, then the adaptability of the system is improved, but the communication throughput deteriorates due to improper change timing

Engineering Contradiction:

Improveconfiguration flexibilityVSAvoidcommunication throughput

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent defines specific timing rules for configuration changes to occur before they take effect. The UE is configured with advance notice of UL-DL configuration changes through RRC signaling, allowing the UE to prepare and switch configurations at predetermined timing points (e.g., at slot boundaries or frame boundaries). This ensures both the UE and base station synchronize their configuration changes, maintaining reliable transmission direction recognition while enabling flexible semi-static reconfiguration.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the UL-DL configuration is changed semi-statically in RRC connected state, then the adaptability of the system is improved, but the frequency use efficiency deteriorates due to timing mismatch

Engineering Contradiction:

Improveconfiguration flexibilityVSAvoidfrequency use efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by defining specific timing rules for configuration changes to occur before they take effect. The UE is configured with advance notice of UL-DL configuration changes through RRC signaling, allowing the UE to prepare and switch configurations at predetermined timing points (e.g., at slot boundaries or frame boundaries). This ensures both the UE and base station synchronize their configuration changes, maintaining reliable transmission direction recognition while enabling flexible semi-static reconfiguration.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11751226B2User terminal and radio communication method

Publication Date: 2023.09.05 NTT DOCOMO INC

AI summary

A user terminal according to one aspect of the present disclosure includes: a transmitting/receiving section that performs transmission and/or reception based on an Uplink-Downlink (UL-DL) configuration; and a control section that controls switching of the UL-DL configuration based on update information of the UL-DL configuration notified via a higher layer signaling, and the control section performs the switching at a timing that comes after a specific timing and satisfies a given condition. According to one aspect of the present disclosure, even when a UL-DL configuration is semi-statically configured to be changed in an RRC connected state, it is possible to reflect the change at an appropriate timing.