Distance Estimation Using Training Signals in Millimeter Wave Beamforming

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Solution Overview

Problem

Current methods for estimating distance between millimeter wave RF devices are sensitive to changes in transmitter and receiver gain, require calibration, and involve cooperation between devices, making them impractical for efficient wireless communication in the 60GHz band.

Innovation Solution

The use of training signals during a beamforming process, where phased array antennas transmit signals in various directions, allowing the receiving device to estimate distance based on signal power and geometric principles, minimizing the need for calibration and cooperation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If current methods for estimating distance are used, then distance estimation can be performed, but the methods are sensitive to changes in transmitter and receiver gain and require calibration

Engineering Contradiction:
Improvedistance estimation accuracyVSAvoidcalibration requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces training signals as an intermediary element that mediates between the transmitter and receiver to enable distance estimation. These training signals are specifically designed sequences transmitted by the first device and received by the second device, allowing distance calculation through correlation processing without requiring direct gain calibration between devices. The training signals serve as a reference that eliminates the need for complex calibration procedures while maintaining estimation accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses training signals that are known copies of specific sequences transmitted by the first device. The second device receives these known sequences and performs correlation processing to estimate distance. By using known copies of the transmitted signals, the system can accurately determine distance without being sensitive to gain changes, as the correlation process inherently normalizes the signal amplitude.

Inventive Principle:
Principle #26Copying

2Measurement precision

If current methods for estimating distance are used, then distance estimation can be performed, but cooperation between devices is required

Engineering Contradiction:
Improvedistance estimation accuracyVSAvoidcooperation requirements
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The training signals act as an intermediary that enables unidirectional distance estimation. The first device transmits training signals and the second device processes them to estimate distance, with the results fed back to the first device. This intermediary mechanism allows distance estimation without requiring continuous cooperation or coordination between devices, as the second device can independently process the received training signals and provide feedback.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If training signals are used during beamforming process, then distance estimation accuracy is improved and calibration requirements are reduced, but the system complexity increases

Engineering Contradiction:
Improvedistance estimation accuracyVSAvoidbeamforming processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The training signals serve multiple functions simultaneously: they enable beamforming for directional communication and provide the basis for distance estimation. By designing the training signals with specific properties (known sequences with good autocorrelation), the system achieves both beamforming capability and accurate distance estimation without requiring separate calibration procedures or additional signal exchanges, thus reducing overall system complexity despite the multi-functional requirement.

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

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 approach enables accurate distance estimation with reduced calibration and cooperation requirements, improving the efficiency and reliability of wireless communication in the 60GHz band by using training signals to determine the optimal antenna configuration for communication.

Implementation Method 1

phased array antennas transmit signals in various directions, allowing the receiving device to estimate distance based on signal power and geometric principles

Methodology Applied
Scientific EffectBeamforming: Interference

Data Source

PatentEP3254137B1Techniques for estimating distance between wireless communication devices
Publication Date: 2019.09.04 QUALCOMM INC
  • EP3254137B1 patent drawingFigure 1
  • EP3254137B1 patent drawingFigure 2
  • EP3254137B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure relate to techniques and apparatus for estimating a distance between a first and second apparatus. For example, the first apparatus may obtain a plurality of training signals received in a plurality of directions from a second apparatus and estimate, based on the plurality of training signals, a distance between the first apparatus and the second apparatus. In certain aspects, the distance may be estimated based on a ratio of receive powers of first and second training signals of the plurality of training signals.