Time Slot Format Signaling for Partial Slots in Unlicensed Spectrum

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Solution Overview

Problem

The occurrence of partial slots during channel occupancy in unlicensed spectrum communication systems leads to adverse effects on normal communication between base stations and user equipment due to blind detection of Physical Downlink Control Channels (PDCCH) and the need for permission requests, increasing power consumption and uplink transmission delay.

Innovation Solution

A method for slot format indication is implemented, where a base station sends slot format indication information to a user equipment (UE) when a target channel is idle, indicating link formats of symbols in N slots, including partial slots, allowing the UE to transmit data without blind detection and permission requests.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the base station occupies the unlicensed spectrum channel starting from an intermediate position of a full slot, then the channel utilization efficiency is improved, but partial slots are generated which cause adverse effects on normal communication

Engineering Contradiction:
Improvechannel utilization efficiencyVSAvoidcommunication reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the slot structure into different types (first type with 14 symbols, second type with fewer than 14 symbols) based on the channel occupancy timing. This segmentation allows the system to adaptively handle both full-slot and partial-slot scenarios, resolving the contradiction between channel utilization efficiency and communication reliability by providing appropriate slot format indications for each case

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic slot format indication through higher-layer signaling that can flexibly indicate different slot formats (first type or second type) based on actual channel conditions and LBT outcomes. This dynamic adaptation enables the system to optimize channel utilization while maintaining communication reliability by selecting appropriate slot formats in real-time

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the UE performs blind detection of PDCCH and requests permission for uplink transmission in partial slots, then communication protocols are followed, but power consumption increases and uplink transmission delay occurs

Engineering Contradiction:
Improveprotocol complianceVSAvoidUE power consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by providing the UE with slot format indication information in advance through higher-layer signaling before the actual transmission occurs. This allows the UE to pre-determine whether uplink transmission is permitted without performing blind PDCCH detection or sending permission requests, thereby reducing power consumption and transmission delay while maintaining protocol compliance

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent enables the UE to self-determine the appropriate transmission behavior based on the received slot format indication information. The UE can autonomously decide whether to transmit uplink data without requiring additional interaction with the base station, thus eliminating the need for permission requests and reducing both power consumption and uplink transmission delay

Inventive Principle:
Principle #25Self-service

3Device complexity

If the slot format indication information is not provided for partial slots, then the system complexity is reduced, but the UE cannot determine the link formats of symbols in partial slots

Engineering Contradiction:
Improvesystem complexityVSAvoidslot format information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent creates a universal slot format indication mechanism that handles both full slots (first type) and partial slots (second type) through a unified higher-layer signaling approach. This multi-functional indication system provides slot format information for all slot types without requiring separate complex mechanisms, thus maintaining low system complexity while preventing information loss for partial slots

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3836671B1Time slot format indication method, apparatus, equipment, and system, and storage medium
Publication Date: 2025.10.08 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3836671B1 patent drawingFigure 1~4
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  • EP3836671B1 patent drawingFigure 8

AI summary

The present invention relates to the technical field of wireless communication, and provides a time slot format indication method, apparatus, equipment and system, and a storage medium. The method comprises: transmitting time slot format indication information to User Equipment (UE) upon detecting that a target channel is in an idle state, wherein the time slot format indication information is used for indicating upper and lower row formats of symbols in N time slots within a channel occupation period, the first time slot and/or the last time slot in the N time slots are/is a partial time slot, N is a positive integer greater than or equal to 1, the channel occupation period refers to a period occupying the target channel by a base station, and the target channel is located on a non-authorized frequency spectrum. According to the time slot format indication method provided by embodiments of the present invention, the adverse influence brought by the partial time slot in the N time slots on normal communication between the base station and the UE can be reduced.