Sensing Circuitry Phase Velocity Range Measurement
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Solution Overview
Problem
Existing electronic devices with wireless circuitry face challenges in accurately detecting the distance of a moving external object due to low signal-to-noise ratios, which affects the precision of range measurement.
Innovation Solution
The electronic device employs a sensing circuitry that transmits and receives radio-frequency signals, generates beat signals by mixing transmitted and reflected signals, and uses phase velocity to resolve phase ambiguity, allowing for accurate range measurement even in low signal-to-noise ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensing circuitry uses traditional phase-based range measurement methods, then the measurement process is simple, but the measurement precision deteriorates in low signal-to-noise ratio conditions
Solution Approach 1:
The patent changes the parameter used for range measurement from direct phase measurement to phase velocity measurement. By calculating the time derivative of phase (phase velocity) instead of using absolute phase values, the system achieves more reliable measurements in low signal-to-noise ratio conditions. The phase velocity is computed as dv/dt where v is the instantaneous phase, and this derivative-based approach provides better noise immunity.
Solution Approach 2:
The patent applies preliminary smoothing or filtering to the phase signal before calculating the phase velocity. By preprocessing the phase data to reduce high-frequency noise components, the subsequent phase velocity calculation becomes more accurate. This preliminary action of smoothing the phase signal ensures that the derivative operation does not amplify noise, thereby improving measurement precision in low SNR environments.
2Reliability
If the sensing circuitry resolves phase ambiguity using only beat phase information, then the calculation is straightforward, but the reliability of range measurement deteriorates when the object is in motion
Solution Approach 1:
The patent uses feedback by incorporating the previously resolved range value into the current phase ambiguity resolution process. The phase ambiguity resolution value is calculated using the phase velocity, current beat phase, previous beat phase, and previous range value. This feedback mechanism allows the system to maintain reliable range measurements for moving objects by continuously refining the estimate based on historical data and the calculated phase velocity.
3Measurement precision
If the sensing circuitry uses phase velocity to resolve phase ambiguity, then the measurement precision improves for moving objects, but the computational complexity increases
Solution Approach 1:
The patent performs preliminary smoothing or filtering of the phase signal before calculating phase velocity. This preprocessing step reduces the computational burden by reducing noise that would otherwise require more complex filtering in subsequent stages. The smoothed phase signal is then differentiated to obtain phase velocity, achieving a balance between measurement precision and computational complexity.
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 precise range measurement between the device and an external object, even when the object is in motion, by effectively resolving phase ambiguity using phase velocity, thereby improving the accuracy and reliability of sensing operations.
Implementation Method 1
Mixer circuitry may mix the sensing signals with the reflected sensing signals to generate a series of beat signals
Implementation Method 2
The sensing receiver may generate a beat phase based on an average of the series of beat signals
Data Source
AI summary
An electronic device may include wireless circuitry with sensing circuitry that transmits radio-frequency sensing signals and receives reflected radio-frequency sensing signals. A mixer may generate a series of beat signals based on the sensing signals and the reflected sensing signals. The sensing circuitry may generate a beat phase based on an average of the series of beat signals, a set of phase values based on the series of beat signals, and a phase velocity based on the set of phase values. The sensing circuitry may resolve a phase ambiguity in the beat phase based on the phase velocity to identify a range between the electronic device and an external object. This way may allow the sensing circuitry to generate accurate ranges even in a low signal-to-noise ratio regime, such as when the external object is moving relative to the electronic device.