Base Station Asynchronous TDD Spectrum Access

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Solution Overview

Problem

In wireless communication systems, asynchronous TDD transmissions in an unlicensed radio frequency spectrum band often interfere with neighboring base stations, leading to unsuccessful CCAs and reduced uplink transmission reliability due to constrained transmit power and distance issues.

Innovation Solution

A method where a first base station monitors uplink and downlink configuration information of a second base station to identify transmission timings and prohibits access to the unlicensed spectrum during these times, ensuring asynchronous operations and minimizing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a first base station repeatedly performs CCA to gain access to an unlicensed radio frequency spectrum band, then the first base station can transmit data, but unsuccessful CCAs cause interference with uplink transmissions from mobile devices to a second base station

Engineering Contradiction:
Improvedata transmission capacityVSAvoiduplink transmission reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The first base station performs preliminary actions by monitoring uplink configuration information and downlink configuration information from the second base station before attempting CCA. This allows the first base station to identify transmission timings of uplink transmissions in advance and avoid performing CCA during these critical periods, thereby preventing interference while maintaining its own data transmission capability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The first base station uses feedback from monitoring the second base station's configuration information to adjust its CCA behavior. By continuously monitoring uplink and downlink configuration information, the first base station receives feedback about when uplink transmissions will occur and dynamically avoids CCA during those times, resolving the contradiction between maintaining productivity and ensuring reliability

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the first base station performs CCA during uplink transmissions, then spectrum access opportunities increase, but interference with vulnerable uplink transmissions occurs due to constrained transmit power and distance

Engineering Contradiction:
Improvespectrum access flexibilityVSAvoidinterference with uplink transmissions
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The first base station performs preliminary monitoring of uplink configuration information and downlink configuration information to identify transmission timings before attempting spectrum access. This preliminary action enables the base station to adapt its CCA behavior to avoid harmful interference during vulnerable uplink transmissions while maintaining spectrum access flexibility during safe periods

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The first base station changes its operational parameters by dynamically adjusting when CCA is performed based on monitored configuration information. By modifying its access pattern according to the identified transmission timings of uplink transmissions, the base station maintains adaptability while reducing harmful interference effects

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3111711B1Techniques for enabling asynchronous time division duplexing transmissions in an unlicensed radio frequency spectrum band
Publication Date: 2017.11.29 QUALCOMM INC
  • EP3111711B1 patent drawingFigure 1
  • EP3111711B1 patent drawingFigure 2
  • EP3111711B1 patent drawingFigure 3

AI summary

Techniques are described for wireless communication. One method includes monitoring, by a first base station of a first operator, for uplink configuration information and downlink configuration information associated with a second base station of at least one second operator; identifying a transmission timing of one or more uplink transmissions to the second base station of the at least one second operator based at least in part on the uplink configuration information; and prohibiting access to an unlicensed radio frequency spectrum band by the first base station of the first operator during the identified transmission timing of the one or more uplink transmissions. Transmissions of the second base station of the at least one second operator in the unlicensed radio frequency spectrum band may be asynchronous to transmissions of the first base station of the first operator in the unlicensed radio frequency spectrum band.