Overload Indicator Transmission via Phase Modulation

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Solution Overview

Problem

Wireless communication systems face interference issues due to multiple users transmitting data to base stations, which degrades system performance, and existing methods do not effectively manage interference between cells.

Innovation Solution

Transmitting overload indicators over the air to user equipment (UEs) in neighboring cells to manage interference, using phase differences between synchronization signals and reference signals, or reserving specific resources for these indicators, allowing UEs to adjust their operations based on neighboring cell loading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple users transmit data to base stations simultaneously, then system capacity and user connectivity are improved, but interference between users and cells increases, degrading system performance

Engineering Contradiction:
Improvesystem capacityVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements feedback by having base stations transmit overload indicators to UEs in neighboring cells. These UEs then adjust their uplink transmission parameters (power, timing, frequency) based on the received overload information, creating a closed-loop system that dynamically responds to interference conditions and improves overall system performance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by having base stations proactively transmit overload indicators to neighboring UEs before interference becomes severe. This advance notification allows UEs to pre-adjust their transmission parameters to avoid causing or experiencing excessive interference, thereby maintaining system performance.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If overload indicators are transmitted using existing synchronization signals, then additional dedicated signaling resources are saved, but the reliability and detectability of overload information may be compromised due to signal congestion

Engineering Contradiction:
Improvesignaling resourcesVSAvoidinformation transmission reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies universality by enabling synchronization signals to serve dual purposes: their traditional function for cell search and synchronization, and an additional function for conveying overload indicator information. This multi-functionality allows the system to transmit overload information without allocating separate dedicated signaling resources.

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

Solution Approach 2:

The patent merges the overload indicator transmission with existing synchronization signal transmissions. By combining these functions into a single signal transmission, the system efficiently utilizes available resources while maintaining the primary synchronization function intact.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If phase modulation is applied to synchronization signals for overload indication, then spectral efficiency is improved, but the complexity of signal processing and detection increases

Engineering Contradiction:
Improvespectral efficiencyVSAvoidsignal processing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modulating the phase of synchronization signals to encode overload indicator information. This approach efficiently utilizes the signal's phase parameter to convey additional information without requiring separate frequency or time resources, thereby improving spectral efficiency.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Improves system performance by enabling UEs to reduce interference and optimize their operations based on neighboring cell loading, enhancing overall network capacity and reliability.

Implementation Method 1

The overload indicator may be transmitted as a phase difference between at least one synchronization signal and a reference signal for a cell

Methodology Applied
Scientific EffectPhase modulation: Phase Modulation

Data Source

PatentEP2670073B1Method and apparatus for transmitting overload indicator over the air
Publication Date: 2018.11.28 QUALCOMM INC
  • EP2670073B1 patent drawingFigure 1
  • EP2670073B1 patent drawingFigure 2
  • EP2670073B1 patent drawingFigure 3

AI summary

Techniques for transmitting overload indicators over the air to UEs in neighbor cells are described. In one design, an overload indicator may be transmitted as a phase difference between at least one synchronization signal and a reference signal for a cell. In another design, an overload indicator may be transmitted as a phase difference between consecutive transmissions of at least one synchronization signal for a cell. In yet another design, an overload indicator may be transmitted by a cell on resources reserved for transmitting the overload indicator. In yet another design, an overload indicator may be transmitted by a cell on a low reuse channel or a broadcast channel. For all designs, a UE may receive overload indicators from neighbor cells, determine the loading of each neighbor cell based on the overload indicator for that cell, and control its operation based on the loading of the neighbor cells.