A system for detecting a moving object is provided. The system comprises a detector module having a first antenna and a second antenna separated by a baseline distance. The system also comprises a processing module configured to receive a first signal and a second signal from the first receiving antenna and the second receiving antenna, respectively. The processing module is further configured to determine a delay rate spectrum followed by a 2D FFT for the first signal and the second signal based on a cross-correlation function and an observation time period. The delay rate spectrum is then used to detect the moving object and determine its location in terms of latitude and longitude coordinates.

The present disclosure provides techniques for improving IMU-based gesture detection by a device using ultrasonic Doppler. A method may include detecting the onset of a gesture at a first device based on motion data obtained from an IMU of the first device. An indication of the detection of the onset of the gesture may be provided to a second device. Next, a first audio signal may be received from the second device. As a result, the gesture may be identified based on the motion data and the received first audio signal. In some cases, a first token encoded within the first audio signal may be decoded and the first token may be provided to a third coordinating device. A confirmation message may be received from the third coordinating device based on the first token provided and identifying the gesture may be further based on the confirmation message.

An acoustic model determination approach for a real-time locating system is disclosed. The system includes one or more transmitting devices and one or more mobile devices. The acoustic model may be determined by deriving an acoustic representation of sub-structures within the building, and then forming the acoustic model based on the acoustic representation and the location and orientation of the static acoustic transmitting device. In another embodiment, an acoustic signal is transmitted from a static acoustic transmitting device, with the reflected signals received by the same static acoustic transmitting device in a receiving mode. Based on these received acoustic signals, the acoustic model is formed based on the reflected signals and the location and orientation of the static acoustic transmitting device.

A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.

A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.

An acoustic model determination approach for a real-time locating system is disclosed. The system includes one or more transmitting devices and one or more mobile devices. The acoustic model may be determined by deriving an acoustic representation of sub-structures within the building, and then forming the acoustic model based on the acoustic representation and the location and orientation of the static acoustic transmitting device. In another embodiment, an acoustic signal is transmitted from a static acoustic transmitting device, with the reflected signals received by the same static acoustic transmitting device in a receiving mode. Based on these received acoustic signals, the acoustic model is formed based on the reflected signals and the location and orientation of the static acoustic transmitting device.

An acoustic model determination approach for a real-time locating system is disclosed. The system includes one or more transmitting devices and one or more mobile devices. The acoustic model may be determined by deriving an acoustic representation of sub-structures within the building, and then forming the acoustic model based on the acoustic representation and the location and orientation of the static acoustic transmitting device. In another embodiment, an acoustic signal is transmitted from a static acoustic transmitting device, with the reflected signals received by the same static acoustic transmitting device in a receiving mode. Based on these received acoustic signals, the acoustic model is formed based on the reflected signals and the location and orientation of the static acoustic transmitting device.

A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.

Various presence detection techniques are disclosed. In some embodiments, a system comprises a signal generator configured to generate a signal that includes a plurality of selected frequencies that are selected from among a set of candidate frequencies, wherein inclusion or exclusion of each candidate frequency in the signal encodes a bit of information and wherein the encoded information comprises a store identifier that identifies a retail store; and a transmitter configured to transmit the signal within the retail store; wherein presence of a device in the retail store is determined in response to reception of the signal at the device and extraction of the store identifier from the received signal by decoding the received signal.

An acoustic model determination approach for a real-time locating system is disclosed. The system includes one or more transmitting devices and one or more mobile devices. The acoustic model may be determined by deriving an acoustic representation of sub-structures within the building, and then forming the acoustic model based on the acoustic representation and the location and orientation of the static acoustic transmitting device. In another embodiment, an acoustic signal is transmitted from a static acoustic transmitting device, with the reflected signals received by the same static acoustic transmitting device in a receiving mode. Based on these received acoustic signals, the acoustic model is formed based on the reflected signals and the location and orientation of the static acoustic transmitting device.