A surface wave launcher surrounds and provides structure complimentary to an antenna and converts (transforms) a near field produced by the antenna into a cylindrical surface wave structure with a strong electric or magnetic field component parallel to a launching interface and propagating two-dimensionally from the launcher. The surface wave launcher leverages the interface found along ocean-air or ground-air to increase a field strength transmitted for a given antenna size and power available. The surface wave launcher maintains a relatively small structure compared to wavelength offering mobility to a very low frequency transmitter. Due to localization of the surface wave energy near the interface, communications using the surface wave retain a desirable low probability of detection.

There is provided a moving body including: an optical wireless communication unit configured to execute an optical wireless communication with another moving body; an object detection unit configured to detect an object around an own moving body; an object information transmission unit configured to transmit, to the other moving body, first object information including location information of the object, by the optical wireless communication or a radio wave communication; an object information receiving unit configured to receive, from the other moving body, second object information including location information of an object around the other moving body, by the optical wireless communication or the radio wave communication; and a movement control unit configured to control, based on the first object information and the second object information, a movement of the own moving body such that an object is not located on an optical axis of the optical wireless communication.

Provided is a mobile object including: a mobile object information transmitting unit configured to transmit, to another mobile object by optical wireless communication by a first optical wireless communication unit, first mobile object information including first inertial measurement information and first body control information; a mobile object information receiving unit configured to receive, from the another mobile object by optical wireless communication by the first optical wireless communication unit, second mobile object information including second inertial measurement information and second body control information; and an optical axis direction control unit configured to control a direction of an optical axis of the first optical wireless communication unit on a basis of the first mobile object information and the second mobile object information.

An underwater communication system, wherein the underwater communication system is capable of increasing a data transmission through a visible light between a surface and underwater of a swimming pool and an underwater communication method providing the data transmission between the surface and the underwater of the swimming pool are provided.

An underwater communication system, wherein the underwater communication system is capable of increasing a data transmission through a visible light between a surface and underwater of a swimming pool and an underwater communication method providing the data transmission between the surface and the underwater of the swimming pool are provided.

A decoding device is used to securely send corresponding data gathered from multiple underground sources to multiple users. The device comprises a signal receiving port connected to multiple bandwidth filters and further connected to internet access points that are assigned to end users for secure data access. The invention facilitates allowing the signal and data being transmitted through the formation of the earth to reach end users located nearby and significant distances away from the source of the transmission. A system and method utilizing the decoding device is provided.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

A receiver (30) for providing an activation signal (54) to transition a device from a dormant state to an operative state. The receiver includes a sensor (32), a super regenerative oscillator, SRO, circuit (34), and a processing device (36, 38). The sensor is one of an optical sensor, an acoustic sensor, and a magnetic field sensor, and generates detector signals (40) based on wireless signals (28) received from an external source (18). The SRO circuit is electrically coupled to the sensor to receive the detector signals, and electrically oscillates with a constant SRO frequency and with a SRO amplitude (As) that changes when a carrier frequency of the detector signal substantially matches the SRO frequency. The processing device monitors the SRO amplitude in time, and generates the activation signal when a temporal characteristic (Sc) of the monitored SRO amplitude matches a predetermined reference pattern (52).

A receiver (30) for providing an activation signal (54) to transition a device from a dormant state to an operative state. The receiver includes a sensor (32), a super regenerative oscillator, SRO, circuit (34), and a processing device (36, 38). The sensor is one of an optical sensor, an acoustic sensor, and a magnetic field sensor, and generates detector signals (40) based on wireless signals (28) received from an external source (18). The SRO circuit is electrically coupled to the sensor to receive the detector signals, and electrically oscillates with a constant SRO frequency and with a SRO amplitude (As) that changes when a carrier frequency of the detector signal substantially matches the SRO frequency. The processing device monitors the SRO amplitude in time, and generates the activation signal when a temporal characteristic (Sc) of the monitored SRO amplitude matches a predetermined reference pattern (52).