D2D User Equipment Time Adjustment for Signal Interference

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Solution Overview

Problem

In device-to-device (D2D) communication, interference occurs when multiple user equipment (UEs) send data signals in the same subframe, affecting the accuracy rate of signal reception due to differing time adjustment amounts.

Innovation Solution

A method where a first UE acquires scheduling assignment signals from a second UE and at least one third UE, determines a first time adjustment amount that is not less than the maximum time adjustment amount, and receives data signals based on this adjusted time, thereby reducing interference between UEs with larger and smaller time adjustment amounts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple UEs send data signals in the same subframe, then the air interface resource utilization is improved, but interference between data signals increases and reception accuracy deteriorates

Engineering Contradiction:
Improveair interface resource utilizationVSAvoidinterference between data signals
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The receive end performs preliminary actions by acquiring SA signals from multiple transmit ends before receiving data signals, determining time adjustment amounts in advance, and preparing reception time points beforehand. This preliminary preparation enables the receive end to properly handle multiple simultaneous transmissions by pre-calculating the necessary time adjustments for each transmit end.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the time parameter by introducing time adjustment amounts that are determined based on SA signals. Each transmit end's data signal is received at a different adjusted time point, transforming the reception process from a fixed time-based approach to a dynamic time-adjustment approach, thereby resolving interference while maintaining resource utilization.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a fixed time adjustment amount is used for receiving data signals, then the reception process is simplified, but interference from other UEs with different time adjustments cannot be avoided

Engineering Contradiction:
Improvereception process simplicityVSAvoiddata signal reception accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention dynamically changes the time adjustment parameter based on SA signal information from multiple transmit ends. Instead of using a fixed time adjustment, the receive end determines specific time adjustment amounts for each transmit end, adapting the reception timing to accommodate multiple simultaneous transmissions with different timing characteristics.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The SA signal acts as feedback information that provides timing characteristics of transmit ends. The receive end uses this feedback to determine appropriate time adjustment amounts, creating a closed-loop system where timing information is continuously adjusted based on the actual transmission conditions of multiple UEs.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2988558B1Data signal transmission method and user device
Publication Date: 2019.08.14 HUAWEI TECH CO LTD
  • EP2988558B1 patent drawingFigure 1A~1B
  • EP2988558B1 patent drawingFigure 1C~2
  • EP2988558B1 patent drawingFigure 3

AI summary

Embodiments of the present invention provide a method for transmitting a data signal and a user equipment, where the method includes: acquiring, by a first user equipment, a scheduling assignment signal sent by a second user equipment and a scheduling assignment signal sent by at least one third user equipment, where the second user equipment is a user equipment that performs D2D communication with the first user equipment; determining, by the first user equipment, a first time adjustment amount according to a time adjustment amount included in the acquired scheduling assignment signal, where the first time adjustment amount is not less than the time adjustment amount included in the scheduling assignment signal sent by the second user equipment; and receiving, by the first user equipment according to the first time adjustment amount and subframe information that is included in the scheduling assignment signal sent by the second user equipment, a data signal sent by the second user equipment. According to the embodiments of the present invention, interference between signals can be reduced and even avoided when multiple user equipments send data signals in a same subframe, and a transmission effect and receiving accuracy rate of a data signal are improved.