The disclosure provides for a method for reacquiring a communication link between a first communication device and a second communication device. The method includes using one or more processors of the first communication device to receive historical data related to the first communication device and an environment surrounding the first communication device. The one or more processors are then used to determine one or more trends in the historical data related to fading of the communication link. Based on the one or more trends, the one or more processors are used to determine a starting time and an initial search direction for a search for the communication link. The one or more processors then execute the search at the starting time from the initial search direction.

A receiver is configured to extract a clock signal superimposed on a detection signal of light propagated to determine whether or not SNR of the detection signal is lower than SNR at which the detection signal can be demodulated; compensate a signal value of the detection signal by using a filter coefficient and output a detection signal after signal value compensation; and calculate, as the filter coefficient, a filter coefficient in which a signal value of a detection signal output from the adaptive filter is a reference value when it is determined that there is no SNR degradation, and changes the filter coefficient to a stored filter coefficient when it is determined that SNR degradation occurs.

A method and apparatus to control optical communication between proximal devices, providing autonomous data transfer sessions that include optically-represented datagram (e.g., QR code™) presentations, is disclosed. Optical control signals sent between a viewing device and a presenting device enable control of the presenting device without physical contact during initiation, performance, and termination of the transfer session. Advancement between datagrams is provided by control signals indicated by changes in relative orientation, changes in relative position, and gestural relative motion between the proximal devices.

A display device includes imaging unit (101) to generate a captured image, image recognizer (102) to recognize whether or not the captured image contains a reception terminal, light emitter (106) to emit light in accordance with a modulation signal, and transmission controller (103) and light emission controller (105) to control driving of light emitter (106) based on a result recognized by image recognizer (102).

An apparatus embodiment includes a remote control interface unit configured to accept an appliance control code carried in a radio frequency signal transmitted from a smart phone, extract the appliance control code from the radio frequency signal, send the extracted appliance control code to an optical frequency interface, and initiate transmission of an optical frequency signal including the appliance control code to an appliance configured to receive signals from an optical remote control.

Wireless communication using germicidal light frequencies is a system and method for transmitting and receiving data using Far-UVC light. The system communicates data using Far-UVC light of a germicidal wavelength. Far UV is a specific spectrum of UV light. The ultraviolet spectrum is a band of electromagnetic radiation with higher energy, thus shorter wavelengths, than visible light. With respect to this system, the UV light wavelengths of interest are Far-UVC for solar-blind data-carrying frequencies in the THz range to provide a UVGI function.

An inventive rotatable optical short-range transceiver has: a support which is rotatable around a rotation axis, an optical receiver which is arranged at the support on the rotation axis to receive an optical reception signal from a first direction, an optical transmitter which is arranged at the support to be adjacent to the optical receiver to emit an optical transmission signal in a second direction, and an optical transmission/reception unit which is configured to allow interruption-free rotatable optical data communication, wherein the optical transmission/reception unit is arranged at the support above the optical receiver and extends over the optical receiver and the optical transmitter, and wherein the optical transmission/reception unit has a support structure for mounting at the support, which is implemented integrally with the optical transmission/reception unit.

Disclosed herein are methods, devices, and systems for providing timing and bandwidth management of ultra-wideband, wireless data channels (including radio frequency and wireless optical data channels). According to one embodiment, a hub apparatus is disclosed for providing out-of-band bandwidth management for a free-space-optical (FSO) data channel associated with a first device. The hub apparatus includes a processor, a memory coupled with the processor, an FSO transmitter coupled with the processor, and an FSO receiver coupled with the processor. The FSO transmitter may be configured to transmit a control signal comprising timing information and bandwidth management information.

A second transceiver (22) includes a guide light source (22c), a photorefractive crystal (22a), and a frequency control unit (22e). The guide light source (22c) emits guide light (Y3). A double phase conjugate mirror (22m) is formed in a crystal (22a) by scattering of reference signal light (Y1), which has a frequency different from that of the guide light and is incident on the crystal via space (15) after being transmitted from a first transceiver (21) which is a transceiver on the other side, and the guide light that is incident on the crystal in a reverse direction to that of the reference signal light. A frequency control unit (22e) couples the reference signal light emitted from the crystal (22a), which is phase-conjugate light of the guide light generated by the mirror (22m), to an optical fiber (13b).

A passenger vehicle optical communication system includes a source vehicle including a light source and an endpoint vehicle including a camera. The source vehicle transmits a series of patterns using the light source to communicate, as one example, state information to the endpoint vehicle.