User Terminal PUCCH Adaptation Across Variable-Length UCI Slots

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Solution Overview

Problem

Future radio communication systems face challenges in transmitting uplink control information (UCI) in slots with varying time lengths, including UL-centric, UL-only, DL-centric, and DL-only slots, which are required to support diverse services like eMBB, mMTC, and URLLC.

Innovation Solution

A user terminal is equipped with a transmitting section to transmit UCI in multiple slots with different time lengths, controlled by an explicit instruction from a radio base station or an implicit determination, using various PUCCH configurations with distinct time lengths and waveforms to ensure effective UCI transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single PUCCH configuration is used for all slots, then device complexity is reduced, but uplink coverage and robustness deteriorate in slots with varying time lengths

Engineering Contradiction:
ImprovePUCCH configuration complexityVSAvoiduplink coverage and robustness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the PUCCH configuration into multiple distinct configurations (first PUCCH configuration and second PUCCH configuration) with different time lengths and waveforms. Each configuration is specifically designed for certain types of slots (e.g., one for UL-centric slots, another for DL-centric slots), allowing the system to adapt to varying slot structures while maintaining appropriate uplink coverage and robustness for each slot type.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic selection of PUCCH configuration based on slot type. The user terminal determines which PUCCH configuration to use in each slot according to the slot's characteristics (UL-centric, DL-centric, UL-only, or DL-only). This dynamic adaptation ensures that the appropriate time length and waveform are used for each slot type, optimizing both coverage and robustness without requiring a single complex configuration for all scenarios.

Inventive Principle:
Principle #15Dynamics

2Reliability

If PUCCH transmission time length is increased for better coverage, then uplink coverage is improved, but latency increases

Engineering Contradiction:
Improveuplink coverageVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies local quality by assigning different PUCCH configurations with different time lengths to different slot types based on their specific requirements. UL-centric slots with longer PUCCH durations are used when coverage is the priority, while DL-centric slots with shorter PUCCH durations are used when low latency is more important. This localized optimization ensures that each slot type receives the appropriate time length for its specific function, balancing coverage and latency requirements.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3537796B1User terminal and radio communications method
Publication Date: 2025.09.03 NTT DOCOMO INC
  • EP3537796B1 patent drawingFigure 1
  • EP3537796B1 patent drawingFigure 2A~2B
  • EP3537796B1 patent drawingFigure 3A~3C

AI summary

To properly transmit uplink control information (UCI) in future radio communication systems, a user terminal of the present invention is provided with a transmitting section that transmits uplink control information (UCI) in at least one of a plurality of slots with different time lengths of UL duration, and a control section that controls transmission of the UCI, where based on an explicit instruction from a radio base station or an implicit determination by the user terminal, the control section controls an uplink (UL) control channel used in transmission of the UCI.