Abstract: Methods and systems for relaying an optical signal from a remote control to a remote-controlled device such as a home entertainment device or a security device. Embodiments include at least one optical receiver and a plurality of optical transmitters. The optical transmitter positioned with an unobstructed line-of-sight to the home entertainment device is identified and the data encoded in the optical signal from the remote control is sent to that transmitter. A second optical signal that is substantially identical to the first is then generated at the optical transmitter and communicated to the home entertainment device.

Abstract: A data transmission network comprising: a base comprising: a base light source and a base light detector; a plurality of nodes, each node comprising a node light source and a node light detector; and a plurality of optical fibers arranged to form a optical fiber network. Each optical fiber is arranged to receive light from the base light source, transmit the light received from the base light source to one or more of the node light detectors via an air gap, receive light from one or more of the node light sources via an air gap, and transmit the light received from the node light source(s) towards the base light detector.

Abstract: Intrapersonal communication systems and methods that provide an optical digital signal link between two or more local devices are disclosed. In some embodiments, the system includes a first signal converter disposed at a first end of the optical digital signal link and configured to convert between electrical digital signals from a first local device and optical digital signals from the optical digital signal link. The system can include an optical connector having a non-contact portion configured to couple optical digital signals between the first signal converter and the optical digital signal link across a gap. The system can include a second signal converter disposed at a second end of the optical digital signal link and configured to convert between electrical digital signals from the second local device and optical digital signals from the optical digital signal link.

Abstract: Lighting systems, apparatus, and methods are disclosed, which employ optical transmission of two-dimensional control signals to manipulate lighting elements. The lighting apparatus can include a projector with an IR LED array to wirelessly transmit pixel information onto a target space. The pixel information controls lighting elements within the target space. The two-dimensional control signals can includes subareas corresponding to lighting elements in a control array. The lighting elements can be lights producing light of desired wavelengths including infrared and/or visible wavelengths. LEDs can be used as light sources in exemplary embodiments.

Abstract: A Multiple-Input-Multiple-Output (MIMO) data transmit-receive protocol that can be used with an arbitrary light array, including one or more lights, that transmits light to a light receiver having an image sensor, including a large number of light sensing pixels. The protocol supports two primary protocol or coding modes in which the light array may transmit: spatial coding and space-time coding. The protocol is constructed upon the use of efficient start-frame-delimiters (SFDs) and data-delimiters (DDs). The lights may be implemented to transmit the SFDs, the data delimiters, and data bits as modulated light. The light may be modulated in accordance with a modulation technique referred to as frequency shift on-off keying (FSOOK).

Abstract: Embodiments relate to methods, devices, and computer-implemented methods for receiving a modulated signal transmitted from at least one signal emitter. The method can include receiving at least one image that comprises image data representing the modulated signal received as radiation emitted from the at least one signal emitter, wherein the radiation represented in the image data comprises at least one period of the modulated signal and wherein the at least one image was captured by a camera of a computing device while a field of view of the camera was moving relative to the at least one signal emitter; analyzing, by at least one processor, the at least one image; extracting, based on the analyzing, the image data representing the radiation; and determining, from the image data that was extracted, the modulated signal transmitted by the at least one signal emitter.

Abstract: An electronic device may include wireless circuitry such as infrared sources that control external equipment such as televisions and set-top boxes. An infrared source may be mounted within an electronic device housing in a visually inconspicuous location such as in a connector port. A button may be provided with transparent structures that allow infrared light to pass through the button. A removable accessory port may be provided with an infrared transmitter accessory that allows an electronic device to serve as a remote control device. Portions of an electronic device housing may be provided with thin housing walls or holes that are too small to be noticeable to the naked eye to serve as windows for infrared light. An audio port may serve as an infrared light window. Gasket structures, bezel structures, and the edges of displays and other planar glass members may be used in transmitting infrared light.

Abstract: A spatial light transmitter of a content supplying system stores ID information of its own and emits spatial light on which the ID information is superimposed from a light emitting portion. A spatial light receiver is used by being connected to a handheld terminal and receives spatial light emitted from the spatial light transmitter. When a user carries the handheld terminal and moves close to the spatial light transmitter, the spatial light receiver receives spatial light emitted from the spatial light transmitter, and ID information obtaining means of the spatial light receiver obtains the ID information which is superimposed on spatial light from a light receiving signal of the light receiving portion, thereby outputting the ID information to the handheld terminal. Alternatively, the ID information obtaining means of the handheld terminal obtains the ID information on the basis of the light receiving signal, and the handheld terminal reproduces the content selected on the basis of the ID information.

Abstract: The spatial light communication device is constituted with a spatial light transmitter which is installed in a fixed manner in a plurality of places, stores preset ID information of its own and has a light emitting portion for emitting spatial light on which the ID information is superimposed, and a spatial light receiver which is connected to a handheld terminal, has a light receiving portion for receiving spatial light emitted from the light emitting portion of the spatial light transmitter and also has a light receiving circuit for amplifying and outputting a light receiving signal of the light receiving portion. The spatial light receiver is provided with a connector portion which is connected to a microphone input terminal of the handheld terminal as a terminal for outputting a light receiving output signal of the light receiving circuit to the handheld terminal.

Abstract: An information communication method includes: setting an exposure time of an image sensor so that, in an image obtained by capturing a subject by the image sensor, a bright line corresponding to an exposure line included in the image sensor appears according to a change in luminance of the subject; capturing the subject that changes in luminance by the image sensor with the set exposure time, to obtain the image including the bright line; and obtaining information by demodulating data specified by a pattern of the bright line included in the obtained image.

Abstract: Distributed communications systems employing one or more free-space-optics (FSO) links, and related components and methods are disclosed. In one embodiment, a distributed communications system is provided in which one or more links of a communications path located between a central unit and a remote unit include FSO provided by one or more FSO components. The FSO component(s) can replace optical fiber (or copper) cable assembly and the associated electrical/optical and optical/electrical converter circuitry. Note that FSO and fiber cable links may be used in a mixed fashion depending on the particular requirements of a given installation project for a distributed communications system. Use of such FSO components may allow temporary installations to be effectuated with greater ease and more economically since physical cable is not required for the FSO portion of the communications path.

Abstract: Proposed is a light module (110) comprising at least two primary light sources (111,112,113) capable of emitting a primary color light. This allows the light module to emit light having intensity (Y) and color coordinates (x,y) through additive color mixing of the constituent primary colors. The light module further comprises an modulator (115) capable of modulating the primary light sources enabling embedment of data in the light emitted. The modulator (115) is arranged to modulate the color coordinates of the light emitted for embedding the data. This is especially advantageous as the sensitivity of the human eye to changes in color is lower than to changes in intensity. The invention thus advantageously allows embedding the data into the light emitted from the light modules (110) of an illumination system (100) without reducing the performance of its primary function as an aid to human vision.

Abstract: A method and system for transferring data comprising : an entangled photon source for producing first and second entangled photons associated with a receiver and a sender, respectively; a Bell state measurement device for performing a joint Bell state measurement on the second entangled photon and the at least one qubit; the Bell state measurement device outputting two bits of data to be used at the receiver; a transmission channel for transmitting two bits from the outcome of the Bell state measurement device to the receiver; a unitary transformation device for performing a unitary transformation operation on the first entangled photon based upon the value of the two bits of data; at least one detector for detecting encoded information from the first entangled photon; at least one processor operating to determine whether or not to transmit portions of data from a sequential successive qubit based upon the preceding qubit.

Abstract: A data center for executing a data processing application includes processing units, sub-units or servers. Each of the processing units, sub-units or servers can execute a part or all of the data processing application. The processing units, sub-units or servers are electrical disjoint with respect to data communications, but can communicate with each other over free space optical links.

Abstract: An LED light and communication system is in communication with a broadband over power line communications system. The LED light and communication system includes at least one optical transceiver. The optical transceiver includes a light support having a plurality of light emitting diodes and at least one photodetector attached thereto, and a processor. The processor is in communication with the light emitting diodes and the at least one photodetector. The processor is constructed and arranged to generate a communication signal.

Abstract: A visible light communication method and terminal are provided for communicating with a visible light coordinator which discriminates between at least one communication area cell that includes at least one light source and a boundary area positioned between the communication area cell and another communication area cell adjacent to the communication cell area, and which provides time division visible light communication. Data of the visible light communication terminal is received from the visible light coordinator using a first time slot in a first communication area cell determined according to a position of the visible light communication terminal. The visible light coordinator is communicated with using a second time slot assigned from the visible light coordinator, when the visible light communication terminal is located in a boundary area of the first communication area cell. The second time slot has not been assigned to the visible light communication terminal.

Abstract: An optically-connected system is disclosed for exchanging data among industrial automation devices, that is composed of a plurality of connection modules, where each module comprises at least two pairs of optical transmitters and receivers on the main side, and one optical receiver on the opposing main side, that are opposite with respect to another pair of transmitters and receivers in a following module; and where each one of the transmitters and receivers is adapted to communicate with industrial automation devices to cooperate for exchanging data between modules, sending one interrogation signal requesting an identity of the module and the receiver is adapted to send to each corresponding response signal containing characteristics of the receiver.

Abstract: A VCSEL array device formed of a monolithic array of raised VCSELs on an electrical contact and raised inactive regions connected to the electrical contact. The VCSELs can be spaced symmetrically or asymmetrically, in a manner to improve power or speed, or in phase and in parallel. The raised VCSELs and raised inactive regions are positioned between the electrical contact and an electrical waveguide. The VCSELs may be separated into subarrays and each VCSEL may be covered with an integrated or bonded microlens for directing light without external lenses. The microlenses may be offset to collect or collimate light and may be shaped to form various lens profiles.

Abstract: LEDs that transmit or receive data in a VLC may create a flickering effect which is observed when the human eye is able to perceive the fluctuations of the light intensity in a LED. To prevent flickering, the LEDs may emit light based on a pattern of data and energy intervals. During the data intervals, a LED transmitting a message sends one or more data symbols to receiving LEDs. The receiving LEDs, however, are reversed bias and do not emit light. During the energy intervals, any LED in the VLC system may emit light. Each LED uses the energy interval to compensate for the light transmitted (or not transmitted) during the data interval. The combination of data and energy levels results in an observer seeing light with a constant intensity rather than changing intensity.

Abstract: An apparatus for transmitting Visible Light Communication (VLC) data, in which a data processor processes data to be transmitted, a modulator modulates data received from the data processor into a signal for VLC, a light output unit outputs light of a predetermined color and includes in the light a signal of any selected one characteristic among signals of two different characteristics, and a light output controller selects at least one of the signals of different characteristics, and controls the light output unit so that a signal from the modulator is output through the signal of the selected characteristic.

Abstract: An indirect optical free-space communications system provides broadband transmission of high-speed data in transportation vehicles such as aircraft. The system includes a transmitter with a light source that can be modulated and a receiver with a photo detector, adapted to receive light that is emitted from the transmitter and to convert it into an electric signal. The transmitter and the receiver are directed onto at least one common surface, which reflects the light emitted from the transmitter before it reaches the receiver. The free space communications system is cellular and includes several cells, each of which has a transmitter and at least one corresponding receiver. The cells are configured in such a way that crosstalk with a respective adjoining cell is prevented. The cells are thus independent of one another.

Abstract: Systems and methods are disclosed for use in conjunction with a standardized electrical connector of a conventional light bulb or tube with one or more light emitting diodes (LEDs) electrically coupled to at least one electrical connector compatible with a conventional light connector, wherein the LEDs include at least one multiband-type ultra-wideband (UWB) transceiver having one or more optical channels defined using one or more OFDM bands; and a controller coupled to the LEDs, the controller adjusting LED light output and communicating with the optical network using the optical transmitter and receiver. In other embodiments, the LEDs include at least one optical transmitter and receiver optically coupled to an optical network using at least one LED with a first mode to generate light and a second mode to receive optical transmissions using ambient light.

Abstract: A modular connector assembly is provided that has both an electrical coupling configuration that complies with the RJ-45 wiring standard and an optical coupling configuration that provides the assembly with optical communications capabilities. In addition, the modular connector assembly is configured to have backwards compatibility with existing 8P8C jacks and plugs that implement the RJ-45 wiring standard. Consequently, the modular connector assembly may be used to communicate optical data signals at higher data rates (e.g., 10 Gb/s and higher) or to communicate electrical data signals at lower data rates (e.g., 1 Gb/s).

Abstract: According to one embodiment, a receiver includes an image sensor, a synchronization controller, and a data generator. The image sensor detects a visible ray having a lattice-shaped emission pattern. The synchronization controller determines whether it is necessary to generate data based on a first synchronized visible ray located at a first lattice corner of the emission pattern and a second synchronized visible ray located at a second lattice corner. The second lattice corner is an opposite corner to the first lattice corner. The data generator generates the data corresponding to a data visible ray located at a lattice point other than the first lattice corner and the second lattice corner when the synchronization controller determines that it is necessary to generate the data.

Abstract: According to one embodiment, a visible-light communication apparatus includes an image input unit, a calculation unit, a preamble detection unit, a bit train detection unit, and a reception unit. The image input unit is configured to input image data generated by photographing a source of visible light carrying data. The calculation unit is configured to generate, from the image data, luminance data about an image at a designated position. The preamble detection unit is configured to detect a preamble at the head of the data, on the basis of the luminance data. The bit train detection unit is configured to detect the data bit train from the image data, in accordance with the preamble. The reception unit is configured to reproduce the data from the data bit train.

Abstract: A system for delivering optical power over an optical conduit includes at least one than one optical power source delivering multiple optical power forms at least partially over a free space.

Abstract: An optical power beam transmission systems, with a directional light transmitter and receiver. The transmitter contains an amplifying laser medium, and this together with a retroreflector in the receiver, forms a laser resonator. When lasing sets in, the receiver can extract optical power through an output coupler and convert it to electrical power. The gain medium may be a disc having a thickness substantially smaller than its lateral dimensions. The laser resonator is operated as a stable resonator to ensure safe operation. This is achieved by use of an adaptive optical element, for reducing the diameter of the energy beam impinging on the gain medium, thereby increasing the overlap between the energy beam and the gain medium. As the transmitter-receiver distance is changed, such as by movement of the receiver, the adaptive optical element focal length changes to ensure that the cavity remains within its stability zone.

Abstract: Visible light data communication with a sufficient transmission speed is performed using a general-purpose and cost-advantageous blue-light-excitation-type white LED without using a blue color filter while preventing the element from being damaged. When transmission data is inputted to a driving waveform generation unit (110) in a transmitter (100), the driving waveform generation unit (110) and a multi-gray scale driving unit (120) generate a multi-gray scale driving signal, which is supplied to the blue-light-excitation-type white LED (140) and allows the blue-light-excitation-type white LED (140) to emit light. A light signal outputted from the blue-light-excitation-type white LED (140) is collected by a lens or the like, is made incident into a PD (210) in a receiver (200), and is converted to a current signal. The current signal is converted into a voltage signal in a trans-impedance amplifier (212).

Abstract: Systems and methods for visible light communication are disclosed. In part, illumination devices and related systems and methods are disclosed that can be used for general illumination, lighting control systems, or other applications. The illumination devices synchronize preferentially to the AC mains to produce time division multiplexed channels in which control information can be communicated optically by the same light source that is producing illumination. Such illumination devices preferentially comprise LEDs for producing illumination, transmitting data, detecting ambient light, and receiving data, however, other light sources and detectors can be used. The physical layer can be used with a variety of protocols, such as ZigBee, from the Media ACcess (MAC) layer and higher.

Abstract: A data transmission system is provided with a transmission unit, a receiving unit, transmission paths, and a delay unit. The delay unit is disposed on a transmission path along which a high-speed signal is transmitted, and delays the transmission of the high-speed signal with respect to a low-speed signal. When the high-speed signal is transmitted from a section b2 to c along the transmission path, a delay time of ?t occurs with respect to when the high-speed signal is transmitted from a section a to b1 along the transmission path. In other words, the phase of the high-speed signal transmitted from section b2 to c is shifted with respect to the phase of the high-speed signal transmitted from section a to b1. Consequently, a time interval in which an EMI peak value occurs can be reduced, thereby enabling the probability of an EMI peak value occurring to be reduced.

Abstract: A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a plurality of active beam steering device are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where an active beam steering device is deployed with each of the one or more detectors, and determines, for each of the detected signals, if the detected signal is out of focus from a focus point. The method applies a corrective signal to each active beam steering device that corresponds to a detected terahertz signal that is out of focus from the focus point, wherein the corrective signal causes the detected signal to be redirected, and measures a signal-to-noise ratio of the detected signals. The method then establishes the terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio.

Abstract: A wavelength sensing lighting system may include a light source, a sensor and a controller. One or more light sources and sensors may be included in an array. The light source may emit an illuminating light and the sensor may sense an environmental light. The illuminating light may include data light. The lighting system may include a plurality of nodes connected in a network. The nodes may communicate by emitting and receiving the data light, which may be analyzed by the controller. The light source and the sensor may be provided by a light emitting semiconductor device that is capable of emitting illuminating light and receiving environmental light. A conversion material may convert the wavelength of a source light into a converted light. The conversion material may increase the wavelength range of light emittable and detectable by the lighting system.

Abstract: Method to personalize a workspace, including: receiving via a first communication channel an information message comprising an identification of the workspace; sending via a second communication channel: an identity of a user; the identification of the workspace; and a request to personalize the workspace according to settings associated with the user; and sending via the second communication channel an optional confirmation message confirming a personalization of the workspace. Another embodiment to personalize a workspace may comprise: receiving a command from a user to personalize the workspace; sending via a first communication channel an information message comprising an identification of the workspace; and receiving personalization data via a second communication channel, wherein the personalization data is used to personalize the workspace.

Abstract: A system comprises a transmitter including a laser configured to generate a laser beam directed at a spot on a surface, and a laser driver connected to the laser and configured to modulate input data onto the laser beam. The system may further comprise a receiver including an optical detector configured to decode received light into raw data, a signal processor configured to decode the raw data into the original input data, and telescope optics configured to receive light reflected from the spot on the surface, collimate the light and converge the light onto the optical detector.

Abstract: A system for open space data communication comprising a transmitting device and an optical receiver using multiple varying levels of emitted radiation output. The transmitting device includes multiple emitter groups that are capable of being switched on and off and each of which can be activated in parallel to emit fixed, varying radiation outputs. A total radiation output emitted by the transmitting device is defined by a sum of the emitted radiation outputs of the emitter groups, wherein to transmit a bit vector (b0 . . . bn) an emitter group assigned to a most significant bit (b0) emits a maximum radiation output Pmax and emitter groups assigned to the less significant bits (b1 . . . bn) of the bit vector emit radiation outputs: Px=Pmax/2x where x=1 . . . n.

Abstract: A directional control/transmission system adapted with a directional light projector to mark the direction of signal control or transmission; comprised of a control or transmission system having a directional infrared or ultrasonic waves as a carrier adapted with a light projector to output a visible light-spot target to indicate control or transmission direction of directional infrared or ultrasonic waves; or to project the target on a monitor for auxiliary help; or to serve as a lighting beam; or to adjust focus for functioning as the light-spot target or selection of the lighting beam.

Abstract: A data center for executing a data processing application includes processing units, sub-units or servers. Each of the processing units, sub-units or servers can execute a part or all of the data processing application. The processing units, sub-units or servers are electrical disjoint with respect to data communications, but can communicate with each other over free space optical links.

Abstract: A data center for executing a data processing application includes processing units, sub-units or servers. Each of the processing units, sub-units or servers can execute a part or all of the data processing application. The processing units, sub-units or servers are electrical disjoint with respect to data communications, but can communicate with each other over free space optical links.

Abstract: An apparatus comprises a platform, an optical transmitter associated with the platform, an optical detector associated with the platform, a sensor associated with the platform, a phase-locked loop circuit, and a processor unit associated with the platform. The optical transmitter is configured to transmit first optical signals. The optical detector is configured to receive optical signals. The phase-locked loop circuit is configured to indicate a presence of second optical signals in the optical signals indicating a time interval to transmit information in the first optical signals. The processor unit is electrically connected to the optical detector, the optical transmitter, and the sensor. The processor unit is associated with the phase-locked loop circuit. The processor unit is configured to transmit the information in the first optical signals using the optical transmitter during the time interval.

Abstract: For setting a tag ID in association with a content supposed to be provided to a portable terminal, the server acquires the location information of an illumination device of which the content is already stored in the memory and sets a tag ID in association with an illumination device that is away from the location presented by the location information by a given or longer distance. Then, the server associates and stores in the memory the set tag ID, location information of the illumination device transmitting the tag ID, content supposed to be provided. Subsequently, the server receives the tag ID and location information transmitted from a portable terminal, determines the content to transmit based on the received location information and the element stored in the memory, and transmits the determined content to the portable terminal.

Abstract: Provided is an apparatus and method for transmitting and receiving data in a visible light communication system, the apparatus including a visible light communication (VLC) transceiver for converting a visible light signal received from a counterpart into an electrical signal and outputting the electrical signal, by using a light receiving device during a reception operation, and converting an electrical signal containing information into a visible light signal and transmitting the visible light signal to the counterpart, by using a light emitting device during a transmission operation, a VLC controller comprising a visible frame engine (VFE) for generating a visible frame and outputting the visible frame to the VLC transceiver, in which the VFE generates the visible frame for transmission to a counterpart during non-transmission of respective frames for communication at a sender and a receiver in order to provide visibility to a communication link, and a host controller for controlling the VLC controller and

Abstract: An optical transmission module includes an optical transmitting unit and an optical receiving unit. The optical transmitting unit includes a first laser diode and a second laser diode. The optical receiving unit includes a first photo diode and a second photo diode, in which the second photo diode is electrically connected to the first photo diode. The second photo diode converts the light energy of the light transmitted by the second laser diode into electrical energy to drive the first photo diode so as to convert the optical signal transmitted by the first laser diode into an electrical signal.

Abstract: A wireless light communication system and method using a plurality of light transmitting units driven by a same alternating current (AC) power, and a light receiving unit for receiving optical signals transmitted by the plurality of light transmitting units are provided. The wireless light communication method includes setting a channel for each of the plurality of light transmitting units such that light transmitting units having an overlapping area that is reachable by optical signals use different channels, detecting zero crossing of the AC power, synchronizing channels by using the detected zero crossing, and transmitting an optical signal through the set channel by using the plurality of light transmitting units, and receiving the optical signal transmitted by each of the plurality of light transmitting units by using the light receiving unit, and analyzing information included in the received optical signal.

Abstract: A data center for executing a data processing application includes processing units, sub-units or servers. Each of the processing units, sub-units or servers can execute a part or all of the data processing application. The processing units, sub-units or servers are electrical disjoint with respect to data communications, but can communicate with each other over free space optical links.

Abstract: A radial optical data interchange packaging comprises a central core; a plurality of central core photo transceivers emerging from an exterior side surface of the central core; a mother board coupled to the central core, wherein the mother board is perpendicularly oriented below and abutting the central core; a plurality of retention slots on the mother board, wherein the retention slots radially extend away from the central core; and a plurality of cards held by the retention slots, wherein each of the plurality of cards comprises a set of card photo transceivers that optically communicate with the central core photo transceivers.

Abstract: Disclosed is a multimedia data transmitter that can transmit multimedia data such as image, voice and control signal whose media are different from each other through an optical transmission medium such as plastic or glass optical cables to a short or long distance area. The multimedia data transmitter includes: a digital signal processing logic, converting multimedia data transmitted in different transmission formats into data of a single transmission format, converting parallel image data into serial image data; an interface control logic, generating a control signal for transmission of the data converted by the digital signal processing logic, interfacing interface data; an optical driver, performing optical transmission of the serial data generated by the digital signal processing logic according to the control signal generated by the interface control logic, processing an optical-to-electrical converted signal.

Abstract: An apparatus comprises a housing, a bearing member, and a transmission system. The housing has a channel in communication with an opening at a first end of the housing and a first surface at a second end of the housing. The first surface is substantially perpendicular to a rotation axis through the channel. The bearing member is capable of rotating in the channel around the rotation axis. The bearing member has a second surface substantially perpendicular to the rotation axis and substantially parallel to the first surface. The transmission system is coupled to the first surface and the second surface. The transmission system has a transmitter and a receiver. The transmission system is capable of emitting an electromagnetic radiation in a beam that is capable of being received by the receiver, while a rotation occurs between the transmitter and the receiver about the rotation axis.

Abstract: Disclosed is a visible light communication system including a transmission device, including multiple light emitting units emitting light of different colors and mapping transmission data to a chromaticity point, calculating luminescence of each of the light emitting units, generating a preamble signal for channel matrix estimation, and emitting light based on the preamble signal and calculated luminescence amount. A reception device of the visible light communication system includes multiple light receiving units and estimates a channel matrix based on a corresponding optical signal when an optical signal corresponding to the preamble signal is received in each light receiving unit, compensates the optical signal corresponding to the chromaticity point for a propagation path based on the estimated channel matrix, detects a chromaticity point on the chromaticity coordinates based on a signal after the propagation path compensation, and demodulates the transmission data.

Abstract: A method and an apparatus are provided for guaranteeing terminal mobility in a time division visible light communication system. In resource assignment in a position where the visible light communication terminal changes a cell, the terminal is assigned a resource to be used in a next cell in a cell boundary area from a communication coordinator, thereby guaranteeing the continuous mobility. The visible light communication system informs the terminal of cell boundary notice information for easily informing the terminal of the cell definition so that the terminal can recognize that the terminal is currently located in the cell boundary and is necessary to change the resource.

Abstract: A visible light communication apparatus of the present invention includes: a target signal receiver filtering only a signal having a target wavelength from a visible light received signal received from a transmitting terminal; a signal generator judging a reception quality of the visible light received signal by using characteristics of the signal having the target wavelength and generating a visible signal by using at least one light source having a wavelength different from the target wavelength in accordance with the reception quality; and an optical signal transmitter transmitting the signal having the target wavelength for transmitting data together with the visible signal and changing a light emitting color of a visible light transmitted signal.