A system and method for locating a mobile device relative to a vehicle using mechanical waves and modulation techniques. A high frequency carrier wave that is generally inaudible to humans is modulated with a low frequency baseband signal that provides for accurate localization in order to generate a modulated signal. The modulated signal is a mechanical or pressure wave, as opposed to an electromagnetic (EM) wave, that is transmitted by one or more speaker(s) and is received by one or more microphone(s). In one example, the modulated signal is transmitted from a speaker on the mobile device (e.g., a smart phone) to a number of microphones mounted on the vehicle at specific distances apart, so as to establish multiple localization paths whose differences in phase can be used to determine the location of the mobile device, relative to the vehicle.

A transmitter is disclosed. The transmitter includes a clock configured to generate one or more output clock signals. The transmitter further includes at least one frequency divider configured to generate a plurality of divided frequencies based on the one or more output clock signals, and a modulator. The transmitter also includes at least one antenna or transducer configured to transmit modulated data. The transmitter includes a memory configured to store instructions, and at least one processor configured to execute instructions performing operations including mapping data to a decimal code value of a plurality of decimal code values, converting the decimal code value to a shrinking base system, and selecting a set of frequencies among the plurality of divided frequencies based on the code value corresponding to the shrinking base system for the decimal code value. The modulator may be configured to modulate the decimal code value using the set of frequencies.

The present teachings relate to an electronic device comprising: a first module for generating an audio signal; a second module for generating an ultrasonic signal; a mixer for generating a combined signal; a transmitter for outputting an acoustic signal dependent upon the combined signal; and, a processing means for controlling the ultrasonic signal; wherein, in response to receiving a first instruction signal for initiating the ultrasonic signal, the processing means is configured to increase the amount of the ultrasonic signal in the combined signal from an essentially zero value to a predetermined value over a predetermined enable time-period. The present teachings also relate to an electronic device configured to decrease the amount of the ultrasonic signal in the combined signal from an essentially zero value to a predetermined value over a predetermined disable time-period, and to an electronic device configured to remove the audio signal from the combined signal whilst preventing pop-noise, and to an electronic device capable of replacing the ultrasonic signal whilst minimizing the processing time. The present teachings further relate to a method for reducing the occurrence of pop noise in an acoustic signal associated with: initiating the ultrasonic signal in the combined signal, terminating the ultrasonic signal in the combined signal, terminating the audio signal in the combined signal, and replacing the ultrasonic signal in the combined signal. The present teachings also relate to a computer software product for implementing any of the method steps disclosed herein, and to a computer storage medium storing the computer software herein disclosed.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

A practically implementable robust direction-of-arrival (DoA) estimation approach that is resistant to localization errors due to mobility, multipath reflections, impulsive noise, and multiple-access interference. As part of the disclosed invention the inventors consider infrastructure-less 3D localization of autonomous underwater vehicles (AUVs) with no GPS assistance and no availability of global clock synchronization. The proposed method can be extended to challenging communication environments and applied for the localization of assets/objects in space, underground, intrabody, underwater and other complex, challenging, congested and sometimes contested environments. Each AUV leverages known-location beacon signals to self-localize and can simultaneously report its sensor data and measurement location. The approach uses two known location beacon nodes, where the beacons are single-hydrophone acoustic nodes that are deployed at known locations and transmit time-domain coded signals in a spread-spectrum fashion.

An indoor location system has acoustic wave emitters, electromagnetic emitters, and a mobile device. Each acoustic wave emitter is configured to emit an acoustic wave having an acoustic wave frequency and wavelength, and an electromagnetic signal that includes electromagnetic emitter data related to that electromagnetic emitter and data indicative of a frequency and/or wavelength of an acoustic wave emitted by the acoustic wave emitter that is associated with that electromagnetic emitter. The mobile device is configured to detect the acoustic waves and to receive the electromagnetic signals, and to determine the frequency and/or wavelength of the detected acoustic wave and to compare the determined acoustic wave frequency and/or wavelength with the data included in each received electromagnetic signal, thereby to determine which received electromagnetic emitter data was included in the electromagnetic signal which also included the data indicative of the frequency and/or wavelength of the detected acoustic wave.

Systems and methods for facilitating acoustic-based localization and motion tracking in the presence of multipath, wherein, in operation, acoustic signals are transmitted from a speaker to a microphone array, a processor coupled to the microphone array calculates the 1 D distance between a microphone and/or each microphones of the microphone array and the speaker of a user device by first filtering out multipath signals with large time-of-arrival values relative to the time-of-arrival value of the direct path signal, then extracting out the phase value of the residual multipath signals and direct path signal, using the calculated 1 D distances, the processor may then calculate the intersection of the 1 D distances to determine the 3D location of the speaker to enable sub-millimeter accuracy of 1 D distance between a microphone of a microphone array and a speaker of a user device to enable smaller separation between the microphones of the microphone array.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

A method and apparatus for locating a target in a venue is described. A backend controller activates transmitters in a venue to send burst signals using a double symmetry configuration formed of a plurality of separate transmitter groups. The backend controller activates the transmitters into a second, different configuration for bursting. The resulting location signal information from each configuration is obtained by the backend controller, which then more accurately determines the location of the target in the venue.

In many applications such as automobiles on busy highways, if a lot of vehicles on road are equipped with Doppler radars to help improve driving safety, no matter human-driven or auto-driven, if the radars use same frequency band, avoiding interference between them is a hard task. Assigning distinct frequencies is one of the solutions, however not only it wastes expensive spectrum resource, but also the task itself to dynamically assign frequency to vehicles randomly come together becomes a hard one to do. The disclosed invention of Doppler group radar will allow radar devices to work together using shared frequency band without interfering one another, without sacrificing performance, and without much increase in costs.