UWB Angle of Departure Determination via Transmit Phase Difference

Solution Overview

Problem

Existing ultra-wideband communication systems require multiple antennas or complex receiver configurations to determine the angle of arrival, which is not feasible in modern RF communication devices with a single antenna, and prior art AoA approaches are ineffective when UWB signals are transmitted by mobile devices but received by fixed installations.

Innovation Solution

A method and apparatus for determining the angle of departure of an RF signal using a single receive antenna by transmitting signal portions from two separated transmit antennas, calculating phase values, and deriving the angle of departure and Cartesian position based on the path difference and known distances between antennas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple receive antennas are used to determine angle of arrival, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

Improveangle of arrival determination accuracyVSAvoidreceiver configuration complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent inverts the traditional AoA approach by having the transmitter (with multiple antennas) determine the angle of departure, which is then used by the single-antenna receiver to calculate the angle of arrival. This inversion allows angle determination without requiring multiple receive antennas, resolving the contradiction between measurement precision and device complexity.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent uses the phase difference information from multiple transmit antennas as a proxy for what would be obtained from multiple receive antennas. By measuring the phase difference at the receiver and using it to calculate the angle, the system effectively copies the information that would be obtained from a complex multi-antenna receiver configuration.

Inventive Principle:

Principle #26Copying

2Measurement precision

If multiple receive antennas are used to determine angle of arrival, then measurement precision is improved, but manufacturing cost increases

Engineering Contradiction:

Improveangle of arrival determination accuracyVSAvoidreceiver manufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent inverts the traditional AoA approach by having the transmitter (with multiple antennas) determine the angle of departure, which is then used by the single-antenna receiver to calculate the angle of arrival. This inversion allows angle determination without requiring multiple receive antennas, resolving the contradiction between measurement precision and device complexity.

Inventive Principle:

Principle #13The other way round (Inversion)

3Adaptability or versatility

If prior art AoA approaches are used with mobile device transmission, then adaptability is improved, but measurement precision deteriorates

Engineering Contradiction:

Improvemobile device transmission compatibilityVSAvoidangle determination accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent inverts the traditional AoA approach by having the transmitter (with multiple antennas) determine the angle of departure, which is then used by the single-antenna receiver to calculate the angle of arrival. This inversion allows angle determination without requiring multiple receive antennas, resolving the contradiction between measurement precision and device complexity.

Inventive Principle:

Principle #13The other way round (Inversion)

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

Enables efficient determination of the angle of departure and position of a transmitter in UWB communication systems, improving system performance and reducing complexity and cost, while allowing UWB signal transmission by mobile devices and reception by fixed installations.

Implementation Method 1

calculate a phase from each of the signal portions received from each of the several receive antennas as a function of the complex baseband impulse response (CIR) of the channel. These phases are then used to calculate the phase differences of arrival

Methodology Applied

Scientific EffectPhase difference:

Implementation Method 2

develop a path difference value, p, as a function of the first and second phase values

Methodology Applied

Scientific EffectPath difference:

Data Source

PatentUS11128342B2Method and apparatus for determining the angle of departure

Publication Date: 2021.09.21 DECAWAVE

AI summary

An ultra-wideband (“UWB”) communication system comprising a transmitter having two transmit antennas and a receiver having a single receive antenna. Respective selected portions of the UWB signal are transmitted by the transmitter via each of transmit antennas is received at the receive antenna. By comparing the phases of the received signal portions, the phase difference of departure can be determined. From this phase difference and the known distance, d, between the transmit antennas, the Cartesian (x, y) location of the transmitter relative to the receiver can be directly determined.