A field-programmable gate array (FPGA)-based real-time processing system applied to underwater acoustic positioning and realizing reconfigurability and multiple output is provided. The system includes a multi-interface control and command parsing module for automatically completing sample information transmission and command parsing; a finite-state machine (FSM) of sample management for calculating related data and completing splitting, flipping and writing of a sample; a parallel correlation processor group for completing, in parallel, high-performance processing operations regarding a plurality of targets; and a multiple output data former for simultaneously realizing data formation of a multiple output result and outputting a flag bit signal to the outside. A FPGA-based real-time processing control method is also provided that is applied to underwater acoustic positioning and realizing reconfigurability and multiple output. The system and the method are used, such that during a whole realization process, under multiple array elements and multiple targets, high-speed parallel correlation processing is realized, thereby solving problems in terms of real-time performance, universality and anti-noise performance, and effectively realizing high-performance correlation.

An ultrasonic transmitter apparatus is configured to transmit an ultrasonic signal that communicates a binary identifier. The apparatus includes an ultrasound transmission system and is configured to transmit an ultrasonic signal that communicates the binary identifier according to an encoding in which each bit position in the binary identifier is associated with a respective pair of frequencies and with respective first and second time positions in the ultrasonic signal. The value of the bit position in the binary identifier determines which frequency of the pair of frequencies is transmitted at the first respective time position in the ultrasonic signal, with the other frequency of the pair of frequencies being transmitted at the second respective time position in the ultrasonic signal.

A method of generating a representation of a structure includes providing an ad hoc mesh network having at least two nodes associated with the structure, obtaining time of flight data for each node in the network, and using the time of flight data to generate the representation of the structure. A method of generating a three-dimensional representation of a structure includes providing an ad hoc mesh network having at least three nodes associated with the structure, wherein at least one node is a mobile node that moves around the structure, obtaining time of flight data for each pair of nodes in the network, and using the time of flight data to generate the three-dimensional representation of the structure.

A method of generating a representation of a structure includes providing an ad hoc mesh network having at least two nodes associated with the structure, obtaining time of flight data for each node in the network, and using the time of flight data to generate the representation of the structure. A method of generating a three-dimensional representation of a structure includes providing an ad hoc mesh network having at least three nodes associated with the structure, wherein at least one node is a mobile node that moves around the structure, obtaining time of flight data for each pair of nodes in the network, and using the time of flight data to generate the three-dimensional representation of the structure.

An information provision apparatus includes: an information signal generator unit that generates an information signal containing information on a provision target; a converter unit that converts the generated information signal into a sound wave and outputs the sound wave; and a wireless communicator unit that performs wireless transmission and reception of data with a communication apparatus. Further, the information provision apparatus is enabled to receive an activation signal transmitted using a specific wireless transmission medium from a signal output apparatus. In response to that the activation signal is received, the information provision apparatus transitions into a state enabling wireless transmission and reception of data with the communication apparatus.

An information provision apparatus includes: an information signal generator unit that generates an information signal containing information on a provision target; a converter unit that converts the generated information signal into a sound wave and outputs the sound wave; and a wireless communicator unit that performs wireless transmission and reception of data with a communication apparatus. Further, the information provision apparatus is enabled to receive an activation signal transmitted using a specific wireless transmission medium from a signal output apparatus. In response to that the activation signal is received, the information provision apparatus transitions into a state enabling wireless transmission and reception of data with the communication apparatus.

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.

The present disclosure relates to a location determination system that includes acoustic transmitting devices, location tags, and a wireless mesh network, where the wireless mesh network uses battery-powered devices. A location tag receives acoustic signals (e.g., ultrasound signals) from an acoustic transmitting device. Clocks from members of the wireless mesh network are synchronized by observation of clock pairings, each clock pair formed by respective clocks in a transmitting device that transmits a message and a receiving device that receives the message. By analyzing the observed clock pairings, a best fit between the clock pairings may be determined. After selecting a reference clock, an acoustic transmission schedule may be propagated to the respective acoustic transmitting device.

The present disclosure relates to a location determination system that includes acoustic transmitting devices, location tags, and a wireless mesh network, where the wireless mesh network uses battery-powered devices. A location tag receives acoustic signals (e.g., ultrasound signals) from an acoustic transmitting device. Clocks from members of the wireless mesh network are synchronized by observation of clock pairings, each clock pair formed by respective clocks in a transmitting device that transmits a message and a receiving device that receives the message. By analyzing the observed clock pairings, a best fit between the clock pairings may be determined. After selecting a reference clock, an acoustic transmission schedule may be propagated to the respective acoustic transmitting device.

Some embodiments are directed to a system for locating an object furnished with a tag in a predetermined space. The tag is interrogatable remotely by an RFID reader. According to the invention, a zone of sound is created with an ultrasound generator. A sound wave of frequency f1f2 is present in this zone. The tag is equipped with an acoustic sensor able to sense the signals of frequency f1-f2 and this acoustic sensor is designed together with the tag to modify the content or the level of the RFID tag response signal when the acoustic sensor receives a signal of frequency f1-f2. The RFID reader is then able to locate the object in the zone of sound when it receives the modified response signal from the RFID tag or when it no longer receives any response signal from the RFID tag.