LTE-U Uplink Resource Reservation for Reliable LBT Access

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Solution Overview

Problem

There is a lack of a specific solution for scheduling and accessing unlicensed spectrum resources in LTE systems, leading to potential interference and channel access failures among different wireless communication systems, particularly in a time division multiplexing mode.

Innovation Solution

A method and apparatus for scheduling uplink transmission resources in LTE-U systems, where a base station determines and notifies user equipment (UE) about reserved resources for Listen Before Talk (LBT) operations over unlicensed carriers, ensuring UE does not transmit signals over these resources, thereby allowing fair access in a time division multiplexing mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If UE transmits uplink signal continuously over unlicensed carrier to improve data transmission efficiency, then productivity increases, but other UEs fail to access channel due to LBT operations being blocked, worsening reliability

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidchannel access reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The base station performs preliminary scheduling of LBT resources before actual data transmission. It determines in advance which resources should be reserved for LBT operations and notifies UEs through uplink grants, ensuring that LBT opportunities are prepared beforehand and preventing transmission blocking

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The uplink transmission resources are segmented into two distinct parts: data transmission resources and LBT operation resources. This segmentation allows UEs to perform LBT operations on reserved resources without interfering with data transmission on other resources, resolving the conflict between continuous transmission and channel access opportunities

Inventive Principle:
Principle #1Segmentation

2Productivity

If base station schedules multiple UEs in time division multiplexing mode over unlicensed carrier to improve resource utilization, then productivity increases, but channel access fails for subsequently scheduled UE, worsening reliability

Engineering Contradiction:
Improveresource utilizationVSAvoidchannel access reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The base station performs preliminary scheduling of LBT resources before actual data transmission. It determines in advance which resources should be reserved for LBT operations and notifies UEs through uplink grants, ensuring that LBT opportunities are prepared beforehand and preventing transmission blocking

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

LBT resources are allocated periodically in the time division multiplexing schedule. The base station inserts LBT reservation notifications at regular intervals in the uplink grant signaling, ensuring that subsequently scheduled UEs have periodic opportunities to perform LBT operations and access the channel

Inventive Principle:
Principle #19Periodic action

3Ease of operation

If no resource reservation mechanism is implemented to simplify system operation, then ease of operation improves, but channel access failures occur in TDM mode, worsening reliability

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidchannel access reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The base station performs preliminary scheduling of LBT resources before actual data transmission. It determines in advance which resources should be reserved for LBT operations and notifies UEs through uplink grants, ensuring that LBT opportunities are prepared beforehand and preventing transmission blocking

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The base station acts as an intermediary that manages the conflict between continuous transmission and LBT operations. By controlling the resource reservation through uplink grant signaling, it automates the LBT scheduling process, maintaining ease of operation while ensuring reliable channel access for multiple UEs

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3355614B1Uplink transmission resource scheduling method and device, and uplink transmission method and device
Publication Date: 2026.04.22 DATANG MOBILE COMM EQUIP CO LTD
  • EP3355614B1 patent drawingFigure 1~2
  • EP3355614B1 patent drawingFigure 3~4
  • EP3355614B1 patent drawingFigure 5~7

AI summary

Disclosed are an uplink transmission resource scheduling method and device, and an uplink transmission method and device, which are used for reserving an uplink transmission resource on an unlicensed carrier, enabling a user equipment (UE) not to transmit an uplink signal on the reserved resource and avoiding a case in which the scheduled UE cannot access a channel, and can realize time division multiplexing of uplink transmission resources on the unlicensed carrier. An uplink transmission resource scheduling method provided by the present application comprises: a base station determines a reserved resource in an uplink subframe, the reserved resource being a transmission resource on an unlicensed carrier; and the base station sends a notification about the reserved resource in the uplink subframe to a UE.