Intentional aliasing of ultrasound to downconvert to audio tones
AssigneeSymbol Technologies, Inc.
InventorRussell E. Calvarese
Life of this patent
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Abstract
A method and device for aliasing ultrasound to produce audio tones includes a microphone circuit to receive an ultrasonic burst from at least one emitter in an environment. An analog-to-digital converter can convert the ultrasonic burst into a digital waveform. A digital signal processor can: provide an ultrasonic sampling frequency, alias the digital waveform with the ultrasonic sampling frequency to provide an audio signal, and detect the audio signal frequency. An amplitude of multiple audio signals can be used to locate the device within the environment.
Claims20
A mobile device providing intentional aliasing of ultrasound to produce audio tones, the method comprising the steps of:
- a microphone circuit operable to receive an ultrasonic burst broadcast from at least one emitter in an environment;
- an analog-to-digital converter coupled to microphone circuit and the operable to convert the ultrasonic burst into a digital waveform;
- and
- a digital signal processor coupled to the analog-to-digital converter and operable to:
- provide an ultrasonic sampling frequency,
- alias the digital waveform with the ultrasonic sampling frequency to provide an audio signal, and
- detect the audio signal frequency.
A mobile device providing intentional aliasing of ultrasound to produce audio tones, the device comprising:
- a microphone circuit operable to receive an ultrasonic burst broadcast from multiple emitters spatially dispersed within an environment;
- an analog-to-digital converter coupled to the microphone circuit and operable to convert the ultrasonic bursts into digital waveforms;
- a digital signal processor coupled to the analog-to-digital converter and operable to:
- provide an ultrasonic sampling frequency,
- alias the digital waveforms with the ultrasonic sampling frequency to provide audio signals, and
- detect frequencies and amplitudes of the audio signals;
- and
- a controller coupled to the digital signal processor and operable to locate the mobile device using the audio signals.
A method of intentionally aliasing ultrasound to produce audio tones, the method comprising the steps of:
- receiving an ultrasonic burst broadcast from an emitter in an environment by a mobile device;
- converting the ultrasonic burst into a digital waveform;
- providing an ultrasonic sampling frequency;
- aliasing the digital waveform with the ultrasonic sampling frequency to provide an audio signal;
- and
- detecting the audio signal frequency by the mobile device.
Dependencies are inferred from the claim text.