Relay Station Selection for Millimeter Wave Path Loss

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Solution Overview

Problem

In wireless communication networks, especially those using millimeter wave frequencies like 60 GHz, directional communication is hindered by obstacles, leading to significant path loss and limited coverage, making it difficult to maintain reliable data transmission beyond short distances without relay stations, and existing methods do not effectively support relay station selection in contention durations.

Innovation Solution

A communication method that involves a coordinator, source station, and destination station to select an optimal relay station through a relay search request and response process, followed by beamforming resource assignment and multi-relays channel measurement to determine the best relay for data transmission, ensuring efficient data relay even in the presence of obstacles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If directional antenna is used to transmit data at high transmission rate using millimeter wave, then transmission rate is improved, but path loss increases and coverage is limited

Engineering Contradiction:
Improvetransmission rateVSAvoidpath loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent introduces relay stations as intermediary nodes between source and destination stations. The relay stations receive signals from source stations and forward them to destination stations, enabling indirect communication paths that overcome the limitations of direct millimeter wave transmission. This mediator approach allows data to be transmitted through multiple hops, reducing the impact of path loss and extending coverage while maintaining high transmission rates on each individual link.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Area of stationary object

If relay station is used to extend coverage, then coverage is improved, but device complexity increases due to relay station selection procedure

Engineering Contradiction:
ImprovecoverageVSAvoidrelay station selection procedure
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent implements preliminary actions by having source and destination stations perform channel measurements and exchange measurement reports before actual data transmission begins. The source station identifies candidate relay stations, obtains channel state information through measurement reports, and selects the optimal relay station in advance. This preliminary selection process simplifies the overall system complexity by establishing the relay path beforehand, avoiding complex real-time selection procedures during data transmission.

Inventive Principle:
Principle #10Preliminary action

3Power

If beamforming process is used to adjust amplitude or phase of antennas, then antenna gain is improved, but difficulty of detecting and measuring increases

Engineering Contradiction:
Improveantenna gainVSAvoidbeamforming process
Core Design Contradiction:
PowerVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements feedback mechanisms where receiving stations measure channel quality and send measurement reports back to transmitting stations. The source and destination stations exchange beamforming feedback information that includes channel state measurements and quality indicators. This feedback enables the transmitting stations to adjust their beamforming parameters (amplitude and phase) based on actual channel conditions, optimizing antenna gain while keeping the measurement and control processes manageable through structured feedback exchanges.

Inventive Principle:
Principle #23Feedback

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

This method enables smooth communication between source and destination stations by selecting an optimal relay station based on beamforming results, enhancing coverage and reliability beyond the limitations of direct communication, particularly in environments with obstacles.

Implementation Method 1

a high antenna gain may be obtained by gathering a transmit power into a predetermined direction, not omni-directions, using a directional antenna

Methodology Applied
Scientific EffectBeamforming:

Implementation Method 2

an array gain may be obtained by discovering a direction of the directional antenna using a facing direction between a transmitting station and a recipient station, or by discovering the direction of the directional antenna using a beamforming process for adjusting an amplitude or a phase of each of antennas constituting an antenna array

Methodology Applied
Scientific EffectArray gain:

Data Source

PatentEP2501181B1Communication method for a coordinator, a relay device, a source device and a destination device included in a wireless network
Publication Date: 2017.12.20 ELECTRONICS & TELECOMM RES INST
  • EP2501181B1 patent drawingFigure 1
  • EP2501181B1 patent drawingFigure 2
  • EP2501181B1 patent drawingFigure 3

AI summary

Provided is a communication method of a coordinator, the method including: receiving a relay search request frame for requesting a search for at least one relay station between a destination station and a source station; and transmitting, in response to the relay search request frame, a relay search response frame including a list of the at least one relay station so that the source station selects a target relay station from the at least one relay station.