Dynamic TDD Reservation Signals for Interference Control

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Solution Overview

Problem

In wireless communication systems, dynamic time-division duplexing (TDD) faces challenges in efficiently managing transmission opportunities and reducing overhead costs, particularly in priority-based medium sharing schemes where low-priority link communication directions lack knowledge about high-priority transmissions, leading to inefficiencies in spectrum utilization and interference control.

Innovation Solution

The implementation of mechanisms for dynamic TDD, where a target receiver of a low-priority link can monitor reservation signals from a high-priority link to adjust its transmission, allowing for resource utilization without abandoning scheduled communications, and incorporating reduced overhead costs by placing link sharing guard periods and reservation symbols in initial portions of transmission opportunities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dynamic TDD is implemented with priority-based medium sharing, then spectrum utilization efficiency is improved, but low-priority links lack knowledge of high-priority transmissions causing interference control issues

Engineering Contradiction:
Improvespectrum utilization efficiencyVSAvoidknowledge of high-priority transmissions
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the target receiver of the low-priority link monitors for reservation signals from the high-priority link. The high-priority target receiver transmits a reservation signal indicating its intent to access the medium, providing feedback information to the low-priority transmitter. This allows the low-priority link to adjust its transmission based on the high-priority link's transmission intentions, resolving the information asymmetry while maintaining efficient spectrum utilization.

Inventive Principle:
Principle #23Feedback

2Reliability

If reservation signals are transmitted frequently to maintain interference control, then interference control is improved, but overhead costs increase

Engineering Contradiction:
Improveinterference controlVSAvoidoverhead costs
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent employs periodic action by placing reservation signals only in initial portions of transmission opportunities rather than continuously. The high-priority target receiver transmits reservation signals at specific periodic intervals (at the beginning of transmission opportunities), which is sufficient to inform low-priority links of upcoming high-priority transmissions. This periodic approach maintains reliable interference control while significantly reducing the quantity of reservation signals and associated overhead costs.

Inventive Principle:
Principle #19Periodic action

3Reliability

If low-priority links abandon scheduled communications to avoid interference, then interference control is improved, but resource utilization efficiency decreases

Engineering Contradiction:
Improveinterference controlVSAvoidresource utilization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent enables self-service by allowing low-priority transmitters to autonomously adjust their transmissions based on monitored reservation signals. Instead of forcing low-priority links to abandon scheduled communications, the system provides them with information (reservation signals) that enables them to self-adjust their transmission timing and power. This allows low-priority links to maintain resource utilization efficiency while independently controlling interference through informed transmission decisions.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3682704B1Methods and apparatus for dynamic time-division duplexing (TDD)
Publication Date: 2023.10.18 QUALCOMM INC
  • EP3682704B1 patent drawingFigure 1
  • EP3682704B1 patent drawingFigure 2
  • EP3682704B1 patent drawingFigure 3

AI summary

Wireless communication apparatus and methods related to dynamic TDD are described. In aspects, a method of wireless communication over a shared medium may include, receiving, from a base station, control information in a first portion of a transmission opportunity (TXOP), wherein the control information indicates a configuration for triggering a communication of at least one shared medium reservation signal associated with one or more remaining portions of the TXOP; and in response to receiving the control information in the first portion of the TXOP, monitoring for or transmitting the at least one shared medium reservation signal, based on the configuration.