1424results about "Free-space transmission" patented technology

Apparatuses, systems, and methods are disclosed that provide for an agile coherent optical modem that can generate agile RF waveforms and data rates on a generic opto-electronic hardware platform. An “agile coherent optical modem” [ACOM] approach to optical communications by employing a software configurable and adaptive technologies to the transport system. The ACOM generate agile RF waveforms and data rates on a generic opto-electronic hardware platform. By employing advanced communication techniques to the optical domain such as wavelength agility, waveform agility, and symbol rate agility, it is possible to enable robust optical communications. The ACOM allows for the transport capacity of a communications link to be varied, thereby accommodating variations in transport conditions, range, opacity, etc.

An optically based location system and method of determining a location at a structure include a lighting infrastructure having lights at a structure. Each light is configured to illuminate and to transmit a respective relative or absolute terrestrial position through modulation of emitted light. An optical receiver is configured to detect the lights, to demodulate the position of detected lights, and to determine from the detection a position of the receiver. The receiver can have a conventional optical detector for determining a two-dimensional position of the receiver relative to a detected light, or can have a three-dimensional spot collimating lens and charged couple device optical detector for determining a three-dimensional position of the receiver relative to a detected light. The receiver and lights can be synchronized for converting a delay time into a distance measurement to calculate a distance between a light and the receiver.

A system for supplying power wirelessly to a remote mobile device including (i) a transmitting unit for directing radiation into the region of the mobile device, the transmitting unit having a gain medium with a front surface directed towards the space, and a retroreflector on its back surface, and (ii) a receiver unit connected with or attached to the mobile device for receiving radiation transmitted from the transmitting unit. The receiver unit includes (i) a retroreflector for reflecting part of the radiation received from the transmitting unit back in the direction of the transmitting unit, where it is amplified and retransmitted back in the direction of the receiver unit, and (ii) a power detection element for absorbing that part of the radiation not reflected by the retroreflector, and converting it to electrical power for use by the mobile device. Modulation of the transmitted beam enables it to transmit data also.

Power management for a remote antenna unit(s) (RAUs) in a distributed antenna system. Power can be managed for an RAU configured to power modules and devices that may require more power to operate than power available to the RAU. For example, the RAU may be configured to include power-consuming RAU modules to provide distributed antenna system-related services. As another example, the RAU may be configured to provide power through powered ports in the RAU to external power-consuming devices. Depending on the configuration of the RAU, the power-consuming RAU modules and/or external power-consuming devices may demand more power than is available at the RAU. In this instance, the power available at the RAU can be distributed to the power-consuming modules and devices based on the priority of services desired to be provided by the RAU.

The invention relates to a vehicle collision warning system based on optical communication, which comprises optical indicators and optical detectors and is used for the safety monitoring and the information interaction among running vehicles. The optical indicators are distributed around or on the top of a vehicle and can transmit modulated optical signals in different directions, wherein the optical signals carry the angle indication information, mounting position information and other information of the vehicle which are corresponding to the optical signals, thereby forming optical antennae. The optical detectors mounted on another vehicle can detect optical pulse signals transmitted by a certain light emitting diode (LED) of the optical indicators and then extract the carried indication angle information, mounting position information and the like; and a processing unit of the optical detector analyzes and processes the information, estimates whether an abnormal running state exists based on the change rate of light indication angle, the change rate of light intensity and the like, and outputs the result to other systems of the vehicle by a controller.

An approach is provided that uses diversity to compensate fading of free-space optical (FSO) signals propagating through an environment characterized by atmospheric scintillation. One embodiment involves collecting at least one FSO beam, demultiplexing the beam by wavelength into at least two sub-beams, detecting each sub-beam to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. Another embodiment involves collecting the FSO beam onto an array of spatially separated sub-apertures, detecting the light entering each sub-aperture to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. This second embodiment enables both electronic adaptive processing to coherently integrate across the sub-apertures and in the case of multiple transmit apertures a free space optical Multiple Input Multiple Output (MIMO) system.

Power management for a remote antenna unit(s) (RAUs) in a distributed antenna system. Power can be managed for an RAU configured to power modules and devices that may require more power to operate than power available to the RAU. For example, the RAU may be configured to include power-consuming RAU modules to provide distributed antenna system-related services. As another example, the RAU may be configured to provide power through powered ports in the RAU to external power-consuming devices. Depending on the configuration of the RAU, the power-consuming RAU modules and/or external power-consuming devices may demand more power than is available at the RAU. In this instance, the power available at the RAU can be distributed to the power-consuming modules and devices based on the priority of services desired to be provided by the RAU.

The invention discloses a laser link communication-measurement composite system. Through adoption of the laser link communication-measurement composite system, the payload weight, size and power consumption can be lowered. The laser link communication-measurement composite system is implemented by the following technical scheme: an optical antenna transmits a comprehensive optical signal to a rapid reflecting mirror through an eye lens at a transmitting end; reflected light splits a light beam of the comprehensive optical signal into two paths through a beam splitter; one path is transmitted into another beam splitter through the beam splitter to transmit the light beam into a coarse tracking module in order to extract a target position coarse miss distance, and a control voltage is applied to a two-dimensional turntable according to an embedded control algorithm; the other path of comprehensive optical signal is introduced into the field range of a fine tracking module through the beam splitter, and transmitted into the fine tracking module to extract a target position fine miss distance, the overall offset of fine field light spots is controlled, the light spots are introduced into the center of a fine tracking field to obtain target angle information, and the extracted target position fine miss distance is transmitted into a ground/satellite platform comprehensive electronic management and processing module to finish target capture and an aiming function and establish a communication link.

Disclosed herein is an LED lighting control apparatus and method based on visible light communication. The LED lighting control apparatus includes lighting information collection means for collecting status information about lighting means and environmental information about surroundings of the lighting means, and transmitting the collected information to lighting control means. The lighting information collection means includes a visible light reception processing unit for receiving the status information about the lighting means contained in a visible light signal emitted from the lighting means, a lighting information analysis unit including a plurality of environmental information sensors for detecting the environmental information about the surroundings of the lighting means, the lighting information analysis unit analyzing the environmental information detected by the environmental information sensors, and a lighting information control unit for collecting the status information and the analyzed environmental information and transmitting the collected information to the lighting control means.

A multi-modal communication system and method capable of operating underwater, at an interface such as the surface of water, and in the atmosphere using a plurality of communication modes including optical, acoustic, and radio frequency communication. The nodes include underwater vehicles, divers, buoys, aerial vehicles, and shore-based operators. In one aspect, the system and method are capable of high-speed optical and long-range acoustic communication through transitioning between communication modes dependent upon signal conditions. It is another aspect to provide a system and method designed for clandestine operation that is not easily detected when in use.

An infrared transceiver for a directed bi-directional optical data transmission through the air has a single-part or multi-part housing in which a stack of components is mounted as follows: an emitter chip for transmitting IR beams, a detector chip for receiving IR beams, and an optical system with a lens and a reflector having an optical axis for focusing the transmitted and received beams. The reflector is arranged concentrically to the optical axis and relative to the components so that transmission power and reception sensitivity of the IR transceiver are increased.

An optical fibre through which light passes is used for detecting blood leakage from a wound. The fibre may be comprised by a blood leakage detection apparatus having a light source and a photo detector in radiative communication with the respective ends of the fibre and producing an electrical signal in response to the light detected, photo detector signal amplifying means, means for detecting changes in the amplified signal over time, and alarm means, wherein a decrease in signal strength during a selected time period activates the alarm means; a corresponding method of detecting blood leakage; a device for use with the apparatus of the invention comprising the optical fibre thereof provided with coupling means at its ends and a patch of blood absorbing material.

The invention relates to a beacon optical axis precision positioning system in an atmosphere laser communication system, which is characterized by comprising an optical receiving antenna (1), a vibrating mirror (2), a dispersion prism (3), a Hartmann sensor optical axis precision positioning unit (4), a vibrating mirror controller (5), a lens (6) and a common CCD camera (7). To realize the real-time correction of the pointing direction of a beacon optical axis, the beacon optical axis precision positioning system detects a beacon light beam by a Schack Hartmann sensor with microlenses array and reconstructs a real-time wavefront image by a Zernike Polynomial mode method, thereby resolving the real pointing direction of the beacon optical axis of the atmosphere laser communication system and achieving final optical axis positioning precision exceeding 2 mu rad. If a common CCD positioned at a receiving end needs to obtain same resolution ratio and measuring precision, an optical systemof the common CCD has large volume and heavier weight; in addition, compared with the traditional platform, the invention has obviously reduced volume and weight, thereby effectively meeting the requirement of future space laser communication for the light type of an onboard platform.

A satellite laser communication compound axis light tracking device and a control method thereof are disclosed, which are mainly used for satellite laser communication terminal collimation and capture and high precision large scale tracking of a tracking system. The device adopts a compound axis system by combining a coarse tracking system and a fine tracking system, and a control method of the coarse tracking system unloading the fine tracking system. The coarse tracking system adopts a unique rotary biprism structure and has the characteristic of scanning with higher precision in a larger angel range. A capture tracking sensor adopts single CMOS sensor to carry out ternary form window with changeable view field and changeable sampling rate, and a communication tracking detector adopts a 4-quadrant detector. The invention adopts the low bandwidth rotary biprism coarse tracking system and the high bandwidth fine tracking system to carry out dynamic and self-adaptive bandwidth match to realize high dynamic range stable tracking of the compound axis system, thus having extensive application prospect in a satellite laser communication high precision laser link system.

A mobile device for receiving modulated light, an apparatus for transmitting information by modulated light and a system as well as corresponding methods are disclosed to be able to use at least parts of an illumination infrastructure for transmitting data to a mobile device. The mobile device comprises a visible light receiver for receiving modulated visible light carrying information corresponding to transmission data modulated onto visible light emitted from at least one light source and for outputting a signal based on the received modulated visible light, and a demodulator for demodulating said signal based on the received modulated visible light to extract said information corresponding to said transmission data.