Presence Detection via Phase Difference Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current presence detection methods in control devices, such as pulse radar systems, face limitations in accurately determining user presence due to short signal transmission and reflection times, which can lead to inaccurate readings and inefficient power management.
Innovation Solution
A system comprising a transmitter, in-phase divider, reference transmission line, transmitting and receiving antennas, combiner, and receiver that splits and compares signals to detect phase differences caused by user presence, allowing for accurate presence detection and reduced power consumption by powering down devices when not in use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pulse radar system is used for presence detection, then the system can detect user presence, but the measurement accuracy is insufficient due to short transmission and reflection times
Solution Approach 1:
The patent employs continuous wave (CW) signals instead of pulsed signals, allowing periodic measurement of phase differences over extended time intervals. This enables accurate detection of user presence by comparing phase shifts of continuous reference and received signals, overcoming the time limitation of pulsed radar systems.
Solution Approach 2:
The patent changes the measurement parameter from time-of-flight (unsuitable for short distances) to phase difference of continuous waves. By measuring phase shifts rather than transmission time, the system achieves high precision presence detection even when the user is very close to the device.
2Loss of energy
If presence detection is implemented to enable power management, then power consumption can be reduced by powering down devices, but the system complexity increases
Solution Approach 1:
The patent integrates presence detection functionality into the existing wireless communication signal path, allowing the same transmitter and receiver to serve both communication and presence detection purposes. This multi-functionality approach avoids adding separate dedicated presence detection hardware, thereby limiting the increase in system complexity.
Solution Approach 2:
The patent introduces a phase detector as an intermediary component that processes the difference between reference and received signals to generate presence detection information. This intermediary approach enables power management decisions based on simple phase comparison rather than requiring complex radar processing systems.
3Measurement precision
If phase difference measurement is used for presence detection, then accurate detection can be achieved, but additional signal processing components are required
Solution Approach 1:
The patent extracts only the essential phase difference information from the received signal by comparing it with a reference signal. By focusing solely on phase comparison rather than full signal processing, the system achieves accurate presence detection with minimal additional processing complexity.
Solution Approach 2:
The patent creates a reference signal that copies the transmitted signal characteristics and uses it for comparison with the received signal. This reference copy enables simple phase difference measurement without requiring complex processing of the original transmitted signal.
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 reliable presence detection and minimizes power consumption by determining the presence of an object or body through phase difference analysis, allowing devices to be powered up only when needed, without requiring additional devices and using existing components.
Implementation Method 1
a transmitter configured to emit a signal
Implementation Method 2
a receiving antenna operable to receive a second transmission signal broadcast from the transmitting antenna
Implementation Method 3
a combiner operable to receive the first transmission signal from the reference transmission line and the second transmission signal from the receiving antenna
Implementation Method 4
a receiver operable to compare the first transmission signal and the second transmission signal and generate a compared signal
Data Source
AI summary
Embodiments of the invention are directed to control devices configured for use with computing devices. More specifically, the present invention relates to methods and devices for performing presence detection of an object body near a device. The methods and devices described herein may include comparing a reference signal against an over the air signal to determine whether a phase difference exists between the reference signal and the over the air signal. The existence of a phase difference may be indicative of a object or body in proximity to the device.