A system is provided for determining the position of a mobile receiver unit (7) in an environment (1). The system comprises a plurality of transmitter units (2, 3, 4, 5) which transmit a respective phase-modulated transmitter-unit identifier, a mobile receiver unit (7), arranged to receive a signal from a transmitter unit (2, 3, 4, 5), and a processing subsystem (205; 9). The processing subsystem (205; 9) is configured to sample received signals to generate sampled data, wherein the identifier spans a transmitter-unit-identifier-bearing portion of the sampled data, obtain template data corresponding to the identifier, analyse the sampled data to determine a Doppler-induced phase deviation, adjust the template or the sampled data to change one or more phase shifts by an amount depending on the determined deviation, cross-correlate the template with the sampled data, determine a time-of-arrival of the signal, decode the identifier from the sampled data, and use the time-of-arrival and the decoded identifier to determine information relating to the position

An apparatus and method for measuring a swimmer's speed and conveying the speed to the swimmer in real time includes a plurality of ultrasonic beacons each having a transducer configured to emit ultrasonic signals in a pool or other body of water within which the swimmer is swimming. A wearable, waterproof, ultrasonic receiver worn by the swimmer, receives the ultrasonic signals and generates corresponding signal data. The receiver's microcontroller captures and uses the signal data to calculate the swimmer's position and speed in real time, and conveys this information to a wearable, waterproof, user interface device worn by the swimmer, the user interface device including a near-eye display disposed on the swimmer's googles.

An apparatus and method for measuring a swimmer's speed and conveying the speed to the swimmer in real time includes a plurality of ultrasonic beacons each having a transducer configured to emit ultrasonic signals in a pool or other body of water within which the swimmer is swimming. A wearable, waterproof, ultrasonic receiver worn by the swimmer, receives the ultrasonic signals and generates corresponding signal data. The receiver's microcontroller captures and uses the signal data to calculate the swimmer's position and speed in real time, and conveys this information to a wearable, waterproof, user interface device worn by the swimmer, the user interface device including a near-eye display disposed on the swimmer's googles.

The present disclosure relates to an acoustic position determination system that includes a mobile communication device and at least one base transmitter unit. The mobile communication device is configured to transmit and receive acoustic signals. Due to relative movements between the mobile communication device and the base transmitter unit, frequencies of the received signals shift due to Doppler effect. The mobile communication device is configured to compensate Doppler frequency shifts in the received acoustic signals prior to performing a deconvolution decoding process. The mobile communication device is further configured to compensate Doppler frequency shifts and perform deconvolution decoding process on acoustic signals received from multiple signal transmission paths.

The present disclosure relates to an acoustic position determination system that includes a mobile communication device and at least one base transmitter unit. The mobile communication device is configured to transmit and receive acoustic signals. Due to relative movements between the mobile communication device and the base transmitter unit, frequencies of the received signals shift due to Doppler effect. The mobile communication device is configured to compensate Doppler frequency shifts in the received acoustic signals prior to performing a deconvolution decoding process. The mobile communication device is further configured to compensate Doppler frequency shifts and perform deconvolution decoding process on acoustic signals received from multiple signal transmission paths.

A tracking method is disclosed. The method may include displaying visual content on a screen. A base station may be stationary with respect to the screen while the visual content is being displayed. In contrast, one or more objects may move with respect to the screen while the visual content is being displayed. The one or more objects may be tracked so that the movement thereof may be used to alter the visual content. Such tracking may involve the base station and the one or more objects sending and/or receiving one or more ultrasonic pulses. Time-difference-of-arrival and/or time-of-flight of the one or more ultrasonic pulses may then be used to estimate a relative location and/or a relative orientation of the one or more objects with respect to the base station in three dimensional space.

A tracking method is disclosed. The method may include displaying visual content on a screen. A base station may be stationary with respect to the screen while the visual content is being displayed. In contrast, one or more objects may move with respect to the screen while the visual content is being displayed. The one or more objects may be tracked so that the movement thereof may be used to alter the visual content. Such tracking may involve the base station and the one or more objects sending and/or receiving one or more ultrasonic pulses. Time-difference-of-arrival and/or time-of-flight of the one or more ultrasonic pulses may then be used to estimate a relative location and/or a relative orientation of the one or more objects with respect to the base station in three dimensional space.

According to one aspect, a system for determining a location of a device is provided. According to one embodiment, the system comprises a management component, a plurality of microphones including a first microphone and a second microphone, at least one receiving component, the at least one receiving component coupled to the plurality of microphones and configured to receive signals from the plurality of microphones related to an acoustic signal detected by the plurality of microphones, determine a first timestamp of the acoustic signal using the signals received from the first microphone, determine a second timestamp of the acoustic signal using the signals received from the second microphone, and send the first timestamp and the second timestamp to the management component, the management component being configured to receive the first timestamp and the second timestamp and calculate the location of the device using the first timestamp and the second timestamp.

According to one aspect, a system for determining a location of a device is provided. According to one embodiment, the system comprises a management component, a plurality of microphones including a first microphone and a second microphone, at least one receiving component, the at least one receiving component coupled to the plurality of microphones and configured to receive signals from the plurality of microphones related to an acoustic signal detected by the plurality of microphones, determine a first timestamp of the acoustic signal using the signals received from the first microphone, determine a second timestamp of the acoustic signal using the signals received from the second microphone, and send the first timestamp and the second timestamp to the management component, the management component being configured to receive the first timestamp and the second timestamp and calculate the location of the device using the first timestamp and the second timestamp.

Described in detail herein are methods and systems for estimating storage capacity of a storage unit disposed in a facility based on echoes detected by microphones. The microphones can detect sounds generated in the warehouse and reflected off the storage unit structures. The microphones detect the intensity of the sounds. The microphones can encode the sounds and the intensity of the sounds in time-varying electrical signals and transmit the time-varying electrical signals to a computing system. The computing system can decode the sounds and the intensity of the sounds from the time-varying electrical signals and estimate storage capacity of a storage unit from which the sounds reflected off of based on the intensity of the sounds.