Abstract: A system and method for optimizing signal recognition in a light communication system by approximately maximizing the minimum distance between received constellation points; the method comprising identifying the constellation region containing points for transmitting symbols, identifying channel impairments, transforming the constellation region according to the channel impairments into a constellation region of potential received symbols, using signal processing circuitry to apply an algorithm that operates to maximize the minimum distance between constellation points to obtain a symbol constellation in the receiver constellation region, and inverting the transformation to obtain the designed transmitted-symbol constellation. The system comprises signal processing circuitry for performing a preferred methodology.

Abstract: Aspects of the present invention provide a multi-band hybrid Gigabit wireless communication system which is enabled by a number of different complementary access technologies to realize ubiquitous hyper-connectivity, true broadband, seamless operation and low power consumption. The system is capable of serving fixed, nomadic and mobile scenarios. The multi-band wireless system is a low power wireless system which operates in different frequency bands covering the spectrum from radio wave to optical wave by making use of both regulated bandwidths and unregulated bandwidths. Using low power distributed antenna and low power indoor and outdoor antennas enables the use of unregulated bandwidths as well as regulated bandwidths as the low power nature of the signals reduces the possibility of interference with the regulated use of the signals.

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: In one aspect, the present disclosure relates to a method for broadcasting a modulated digital pulse recognition signal from a light source. In some embodiments, the method includes selecting one or more digital pulse recognition tones to broadcast, determining a desired brightness level for the light source, generating a digital pulse recognition signal having a duty cycle based on the desired brightness level and a frequency based on the one or more digital pulse recognition tones, and driving the output of the light source with the digital pulse recognition signal. In some embodiments, selecting one or more digital pulse recognition tones to broadcast includes generating a single periodic tone for differentiating the light source from a nearby light source. In some embodiments, selecting one or more digital pulse recognition tones to broadcast includes generating a sequence of periodic tones.

Abstract: A Visible Light Communication (VLC) method in a VLC terminal, in which the VLC terminal requests initial access to an Access Point (AP) on a selected mini-slot among a plurality of mini-slots constituting a control slot, based on control information in a frame, sends an association request to the AP on an allocated uplink time slot, if the uplink time slot allocated to correspond to the selected mini-slot exists in control information in a next frame, and transmits data at a data rate appointed to the VLC terminal included in control information in the current frame using an association Identifier (ID) included in a response received in reply to the association request and the allocated uplink time slot.

Abstract: A visible light wireless communication receiver includes: a source code recognizing unit that receives a source bit stream and recognizes the source bit stream as source codes of a unit of a first number of bits; and a line coding unit that encodes each of the source codes into an encoding code of a unit of a second number of bits, the second number being larger than the first number. In particular, in the encoding code, the number of bits corresponding to 1 is the same as the number of bits corresponding to 0. Therefore, the change in brightness of lighting may be minimized in the visible light wireless communication.

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: Noise may be received through a microphone included in a lighting apparatus. The noise may then be analyzed to determine if a human being may have been the source of the noise, and a message sent over a network alerting other devices that a human-caused noise was detected.

Abstract: Both ends of an interface may each be configured by an interface device including a light emitting unit that emits light into a textile, a light diffusion unit that widely diffuses the emitted light onto the textile and extends a light receiving range of a light receiving unit, and a light receiving unit for receiving an optical signal of the other party unlike the existing method using electromagnetic inductive coupling in the wearable computing system and a method of performing communication by using light such as infrared rays, visible light, laser, or the like as a medium is provided.

Abstract: In a method for transmission of digital data in an optical free-space transmission system in which a binary code sequence produced from the digital data is used to transmit amplitude-modulated light waves across an optical free space between a transmitter and a receiver, according to a first aspect, the binary code sequence is produced such that a modulation frequency of the light waves determined by the binary code sequence has a value of 70 Hertz. According to a second aspect, ‘t’ light waves are modulated with the binary code sequence and binary data are transmitted in blocks during a first time period, and non-modulated light waves are emitted during second time periods, wherein the light intensities of the time periods are selected so that the quantities of light transmitted in two periods correspond to predetermined quantities of light.

Abstract: In accordance with some embodiments of the present disclosure, a method for spectrally spacing carrier waves comprises determining a frequency offset between a first frequency of a first optical carrier wave and a second frequency of a second optical carrier wave. The method further comprises adjusting the second frequency of the second optical carrier wave according to the frequency offset. The method additionally comprises combining a first optical signal associated with the first carrier wave and a second optical signal associated with he second carrier wave into a multi-frequency signal.

Abstract: A method and apparatus for allocating resources of a Visible Light Communication (VLC) terminal in a VLC system. The VLC terminal receives a beacon message from a base station, coordinates time synchronization with the base station, searches for an available wavelength channel, constructs available wavelength channel information, and transmits an initial access request using a basic time slot channel and a basic wavelength channel. The base station considers the available wavelength channel information and a current channel allocation condition, allocates an appropriate channel, and transmits channel allocation information to the VLC terminal. The VLC terminal and the base station communicate data with each other using an allocated time slot channel included in the channel allocation information and an allocated wavelength channel included in the channel allocation information.

Abstract: A method and apparatus are provided for outputting a visibility frame for a communication link connection during a communication link release in a Visible Light Communication (VLC) system. A transmitting-side VLC device determines a visibility frame output type according to a communication mode to be performed. The communication mode and the visibility frame output type are transmitted to a receiving-side VLC device. The receiving-side VLC device is communicated with according to the communication mode and it is determined whether a communication link is released while performing communication according to the communication mode. When the communication link is released, outputting a visibility frame according to the visibility frame output type.

Abstract: In one aspect, the present disclosure relates to a method for broadcasting a modulated digital pulse recognition signal from a light source. In some embodiments, the method includes selecting one or more digital pulse recognition tones to broadcast, determining a desired brightness level for the light source, generating a digital pulse recognition signal having a duty cycle based on the desired brightness level and a frequency based on the one or more digital pulse recognition tones, and driving the output of the light source with the digital pulse recognition signal. In some embodiments, selecting one or more digital pulse recognition tones to broadcast includes generating a single periodic tone for differentiating the light source from a nearby light source. In some embodiments, selecting one or more digital pulse recognition tones to broadcast includes generating a sequence of periodic tones.

Abstract: A method for generating a visible signal for a data transmission frame in a visible-light communication system includes: receiving specific data constituted by a plurality of frames from a sender; checking and converting a received signal strength indication (RSSI) signal measured from the sender; whenever each frame of the specific data is consecutively received, checking the converted RSSI, determining a level of a visible signal for distinctively displaying a state of a corresponding communication channel, and transmitting the level of the visible signal to the sender; and when reception of the specific data has finished, transmitting a corresponding response message to the sender, according to whether the specific data has been successfully received.

Abstract: There is disclosed a visible light communication technology capable of intuitively recognizing a transmission speed, an alignment status, a communication status, or a transmission rate. A visible light communication apparatus according to an embodiment of the present invention includes: a light source selecting unit selecting at least one light source of a plurality of light sources generating lights having different wavelengths by considering intuitive information distinguished depending on a wavelength in a visible light band; and a visible light communication unit performing visible light communication by at least one selected light source to allow the intuitive information to be recognized by a color corresponding to at least one selected light source. Accordingly, a user using the visible light communication can intuitively know an optimal communication status or transmission speed.

Abstract: There is disclosed a visible light communication technology capable of intuitively recognizing a transmission speed, an alignment status, a communication status, or a transmission rate. A visible light communication apparatus according to an embodiment of the present invention includes: a light source selecting unit selecting at least one light source of a plurality of light sources generating lights having different wavelengths by considering intuitive information distinguished depending on a wavelength in a visible light band; and a visible light communication unit performing visible light communication by at least one selected light source to allow the intuitive information to be recognized by a color corresponding to at least one selected light source. Accordingly, a user using the visible light communication can intuitively know an optimal communication status or transmission speed.

Abstract: A method is described for driving a light source, particularly a HID lamp (2), the method comprising the steps of: providing a commutating DC current for supplying the lamp; and varying a commutation period (T) in order to transmit data. In an embodiment, the duration of each commutation period (T) is set to be equal to one of two possible values (T1, T2) such as to encode a digital bit.

Abstract: Lighting apparatuses and LED modules capable of both illumination and data transmission are disclosed. An exemplifying lighting apparatus has a LED module and a modulator. The LED module comprises a plurality of LED cells connected as a LED chain having two conductive pads. The light emitted from the LED module is visible. The modulator provides driving current to the LED module to transmit data.

Abstract: A visible light communication receiver increases a communication distance from a transmitter to a receiver while realizing high transmission speed. The visible light communication receiver includes a receiving unit that receives a visible light signal from a blue light-excited white LED driven by a driving current signal generated by adding rising and falling pulses to respective rising and falling edges of a transmission data encoded according to a DC-free RLL code having a minimum run of 1 and NRZI-modulated prior to adding the rising and falling pulses; a photoelectric converter that converts the visible light signal into an electrical signal; an equalizer that equalizes the electrical signal to a duobinary signal; a discriminator that discriminates the duobinary signal to generate a 3-value signal; a maximum-likelihood decoder that ML-decodes the 3-value signal to output a decoded signal; and a decoder that RLL decodes the decoded signal.

Abstract: The invention relates to receiving of a modulated light signal from a lighting device, particularly from a solid state lighting (SSL) device. It is an object of the present invention to provide a receiver and a receiving method which are primarily designed to operate efficiently for light (wave) signals that adhere to specific constraints. In order to achieve this object, the invention provides a receiver for a modulated light signal which is keyed with a code sequence of a predefined number of chips, comprising —a light sensor adapted to receive the modulated light signal and to convert it into an electrical signal, —sampling means adapted to take several consecutive samples of the electrical signal during a chip period, and —processing means adapted for calculating for each sample of a chip period an inner product with the chip.

Abstract: An optical-information transmitting, lighting apparatus 2 is installed in a place where a lighting apparatus of the existing type for applying light generally used is provided. The lighting apparatus 2 comprises an illumination light source 4 for applying light and an information-transmitting unit 5 for transmitting optical information. A person who may receive information from the lighting apparatus 2 has a mobile terminal 3, which receives the optical information transmitted from the information-transmitting unit 5. Since the lighting apparatus of the existing type is widely used in our living space. Hence, the optical-information transmitting, lighting apparatus 2 can convert every place where an existing type lighting apparatus is used, into an optical communications space.

Abstract: A light source control section 15 selects a first light emitting device arrangement (color combination device group) in which LEDs 19 make a particular visible light color by color synthesis and form one optical communication channel, and then causes the first light emitting device arrangement to emit light, and selects a second light emitting device arrangement so that a light quantity of a light source 18 as a whole becomes uniform, and then causes the selected second light emitting device arrangement to emit light when the first light emitting device arrangement does not emit light. As a result, upon performing optical communication, an optical transmitting apparatus and an optical communication system that can emit an illumination light at a uniform light quantity without generating a flicker of illumination can be realized.

Abstract: A transmitter apparatus to transmit information to a receiver apparatus by using visible light emitted from a plurality of light sources includes at least a first light source to transmit user data; at least a second light source to transmit a pilot signal; and at least a third light source to transmit notice information that is necessary for receiving the user data in the receiver apparatus, the third light source being placed at a position determined by the position of the second light source.

Abstract: A visible light communication system and method for transmitting and receiving an information symbol in a visible light communication system for a Color Code Modulation (CCM) scheme using a chromaticity diagram. The method includes determining a first coordinates value corresponding to an information symbol to be transmitted on the chromaticity diagram; determining a first color ratio corresponding to the first coordinates value; determining a second coordinates value corresponding to a compensation symbol for compensating for the first color ratio into a color white and determining a second color ratio corresponding to the second coordinates value; and emitting a visible ray corresponding to each of the first color ratio and second color ratio. The first and second coordinates values are located on a line on the chromaticity diagram.

Abstract: An LED light and communication system includes at least one optical transceiver, the optical transceiver including a light support and a processor. The light support has a plurality of light emitting diodes and at least one photodetector attached thereto, the light emitting diodes receiving power from a power source. The processor is in communication with the light emitting diodes and the at least one photodetector, the processor capable of illuminating the light emitting diodes to simultaneously create at least one first light signal, and at least one second light signal, the first light signal being observable to the unaided eyes of an individual and the second light signal not being observable to the unaided eyes of the individual. The second light signal includes at least one data packet. The at least one data packet comprises global positioning system (GPS) location information.

Abstract: An LED light and communication system includes at least one optical transceiver, the optical transceiver including a light support and a processor. The light support has a plurality of light emitting diodes and at least one photodetector attached thereto. The processor is in communication with the light emitting diodes and the at least one photodetector, where the processor is constructed and arranged to illuminate at least one of the light emitting diodes to generate a light signal which in turn includes at least one embedded data packet. The at least one embedded data packet communicates global positioning system (GPS) location information.

Abstract: Systems and methods for data reporting in electronics devices are disclosed. An exemplary system may include a processor configured to encode a bit stream representing information from at least one subsystem in the electronics device. The system may also include an output device in the electronics device. The output device outputs the bit stream for decoding with a receiving device while being ordinarily visually imperceptible to an end-user without the receiving device.

Abstract: A server device to transmit a message through a visible light communication, in which the server includes a visible light communication unit to transceive data through visible light communication; a message reception unit to receive a message; a message identification unit to identify a receiving object, a message type, and a transmission characteristic of the message; and a message transmission unit to transmit the message to the receiving object according to the transmission characteristic of the message. A method for transmitting a message though visible light communication, in which the method includes receiving a message; identifying a receiving object of the message, a message type and a transmission characteristic of the message; and transmitting the message to the receiving object according to the transmission characteristic of the message using the visible light communication.

Abstract: Disclosed herein is a visible light communication system, in which the visible light emitted from the light-emitting element is superposed with a signal in order to accomplish communication. The system has a transmitter and a receiver. The transmitter has a modulation circuit whose the demodulating mode can be changed during the communication in accordance with the state of the visible light. The receiver receives the visible light emitted from the transmitter and has a demodulation circuit that demodulates the modulated signal received from the transmitter.

Abstract: Disclosed herein is a visible-light communication system according to one embodiment of the invention. The system comprises two apparatus. One apparatus emits a visible light beam on which is superimposed transmission data. From the void data represented by the visible light beam, the other apparatus generates a retroflected light beam, superimposes transmission data on the retroflected light beam, and applies the retroflected light beam to the apparatus. On receiving the retroflected light beam, the apparatus identifies the transmission data coming from the other apparatus, on the basis of the identification data superimposed on the retroflected light beam.

Abstract: The invention relates to A method for a lighting device, in particular for a display device such as a LCD-TV, projector etc., generating radiation including at least visible light for illumination with at least one light-emitting element (1) being a LED (1) or an OLED, emitting radiation comprising an average light intensity for illumination purpose, a controller (2) coupled to the light-emitting element (1) modulating said radiation for a data transfer simultaneously to the illumination purpose, wherein the controller (2) is configured in such a way, that simultaneously data signals are transmitted via the generated radiation of said light-emitting element (1) and said modulation is not visible by an observer, wherein the data signals are transmitted to a detecting unit (3).

Abstract: The present invention relates to the dual-use of radiation, for example, but not limited to, visible or infrared light, for both a conventional application, e.g., illumination, combined with the additional or “dual-use” application of transmitting information without wires.

Abstract: A visible light communication apparatus is constituted with a transmitter for illuminating and projecting visible light on which an information signal is superimposed from a lamp fitting and a receiver for receiving the visible light to take out the information signal superimposed on the visible light. The transmitter modulates a transmission information signal, driving a light projecting element of the lamp fitting so as to superimpose the transmission information signal on the visible light of the lamp fitting, thereby radiating white light containing a blue light component as visible illumination light. The receiver receives the white visible light containing the blue light component radiated from the transmitter and generates a receiving information signal from the light receiving signal on a receiving circuit. A blue light photodiode which receives blue light at the highest sensitivity to output a light receiving signal is used as a light receiving element of the light receiving unit.

Abstract: A method and system for visible light communication (VLC) for use in a dimmable lighting environment is provided. The method includes transmitting data using light from at least one light source, a brightness of the light reduced below a maximum level. The method also includes compensating or accommodating for the reduced brightness of the light at a VLC circuitry to maintain communication. The method further includes transmitting data to at least one VLC receiver using the light from the at least one light source.

Abstract: There is provided a transmission device including an optical signal generation section configured to generate an optical signal formed by arranging one or more of each of a plurality of kinds of same-color light beams each having different phase, and a transmission section configured to transmit the optical signal generated by the optical signal generation section.

Abstract: Provided is a method for broadcasting visible light information in visible light communication. The method includes determining a time interval for a simultaneous signal and a time interval for an individual signal of information to be displayed on a display device; simultaneously modulating output signals of three Red-Green-Blue (RGB) Light Emitting Diodes (LEDs) making up one pixel, and transferring the modulated information to the display device; individually modulating output signals of the three RGB LEDs and transferring the modulated information to the display device; and displaying the modulated information for any selected one of the time interval for the simultaneous signal and the time interval for the individual signal.

Abstract: A data signal to be transmitted is supplied to a modulator of a transmitter, and the modulator modulates the output of a blue light-excited white LED and outputs blue LED light and phosphor light. The modulated blue light enters to a photo-electric converter through an LED light transmission color filter. The modulated phosphor light on the other hand enters to another photo-electric converter through a phosphor light transmission color filter. The photo-electric converters convert incident light to electric signals. The converted signals are amplified by amplifiers. Then, equalizers emphasize the harmonic component therein according to the response characteristic of the blue light and the response characteristic of the phosphor light for reduction of the dullness of waveforms.

Abstract: An illumination light receiver includes: a wavelength separation mechanism separating visible light containing optical signal data distributed among wavelengths corresponding to three primary colors into the wavelengths corresponding to the three primary colors; a dispersion restraining mechanism restraining dispersion of light outputted from the wavelength separation mechanism; and a light receiving portion illuminated, separately for each of the separated wavelengths corresponding to the three primary colors, by the light outputted from the dispersion restraining mechanism, the light receiving portion converting the optical signal data into and extracting an electrical signal.

Abstract: Disclosed is a method for processing incoming signals of photo-detectors in a visible light communication system. The method includes: dividing symbol duration into divided durations according to an equal time interval to set the divided durations to a plurality of time slots, the symbol duration being a time required to transmit one of a symbol and a bit; receiving visible light signals through a photodiode array in a receiver; determining a gain value of each of the photodiodes during a time slot, in consideration of each photodiode area on the photodiode array during the time slot and the time slot position within the symbol duration; multiplying a gain value of each of the photodiodes by an output value of a corresponding photodiode; and summing up output values of each of the photodiodes by which the gain value has been multiplied and calculating a total of output values of the time slot.

Abstract: A visible ray communication system and method that improve transmission rate and remove an influence of inter-color interference to improve the communication quality. A transmission apparatus included in the visible ray communication system allocates each carrier signal component of an OFDM signal, which is modulated into transmission information, to a plurality of LEDs of different colors. The information is added to a combination of a carrier frequency and an LED wavelength, when a carrier signal is allocated to an, in addition to each carrier signal being modulated into the information.

Abstract: A method of providing a visible light communication in a data link layer of a visible light communication system adopting an infrared communication link connection protocol includes: broadcasting a discovery exchange station identification (D-XID) frame; generating a visible frame to provide a visibility to a link for a specified waiting time period for responding to the broadcast D-XID frame; exchanging a set normal response mode (SNRM) frame and an unnumbered acknowledgement (UA) frame for requesting a link setting between the transmitting and receiving terminals; generating visible frames for a waiting time for receiving the SNRM frame and the UA frame; exchanging an information transfer frame (I-frame) and a receive ready (RR) frame, which is a response to the I-frame, between the transmitting and receiving terminals; and generating visible frames for a specified waiting period for receiving the I-frame and the RR frame.

Abstract: A visible light communication apparatus enables an operator to visually recognize a communication state during visual light communication. The apparatus includes a light emitting section which emits visible light and which includes a modulator, a visible light emitter, a light emitting element and an emission control section which includes a controller and which controls an emission state of the visible light from the light emitting section. The apparatus controls the emission state according to the communication state. It is hence possible for the operator to visually perceive the communication state during the visible light communication.

Abstract: A digital camera 800 receives from lighting units 120a-120l lights temporarily changing in luminance and produces a coordinates data list 8031 of the lighting units. Decoding unit 804 reads change in luminance at each luminance-point coordinates of the lighting unit to decode information. It is judged based on the decoded information of a data format 900, whether plural luminance-point coordinates having the same guidance point ID information 902 are found. When the plural luminance-point coordinates having the same guidance point ID information are found, a location of the plural luminance-point coordinates is analyzed to draw and display a circumscribed polygon having its vertices at these coordinates on a through image in an overlapping manner. A hatched area is set inside the circumscribed polygon and the decoded information is displayed within the hatched area.

Abstract: A laminated body comprises: a particle dispersion layer comprising a first material and particles dispersed in the first material, the first material being changed from a gel state to a sol state upon increase in temperature; and a coated layer comprising a second material, the second material is changed from a gel state to a sol state upon increase in temperature, is changed from a gel state to a sol state upon decrease in temperature, and shows a hysteresis behavior in sol-gel change upon change in temperature, wherein the particle dispersion layer in a sol state and the coated layer in a gel state are laminated in contact with each other, and in a state where each of the particle dispersion layer and the coated layer contains a solvent, a maximum temperature T1 where the first material maintains a gel state is less than a maximum temperature T2 where the second material maintains a gel state upon increase in temperature (T1<T2).

Abstract: A reconnection method and device for a peripheral interface using VLC provide a protocol for when a communication link between a primary device and a secondary device is disconnected. The primary device generates an R-XID message including reconnection information and a warning indication signal indicating the disconnection. The secondary device aligns the communication link with the primary device using the warning indication signal, receives the R-XID message from the primary device by the secondary device, and transmits an R-XID response message for the R-XID message to the primary device.

Abstract: Disclosed are an apparatus and a method for visible light communication, which apparatus uses an illuminator equipped with a plurality of light sources, so that the apparatus can be used for illumination, as well as for visible light communication. The visible light communication apparatus includes an illuminator for generation of the illumination light, the illuminator including a plurality of light sources with luminescence center wavelengths on mutually different visible regions; a communication amount adjuster for receipt of the plurality of communication data signals, and generation of each dummy data so that data to be transmitted through each of the plurality of LEDs has an equal communication amount; and a modulator for receipt of the plurality of communication data signals and their corresponding dummy data, and modulation of the received communication data signals and their corresponding received dummy data into driving signals for a plurality of LEDs configured as a light source.

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: A navigation system and a navigation method inside of a building using Visible Light Communications (VLC) are provided. The navigation system includes a map server, in which map information required to provide a navigation function is stored, for transferring the map information to each lamp, a plurality of lamps, installed in each zone inside of the building and having their respective identifiable and unique IDentifications (IDs), for receiving the map information required to provide the navigation function from the map server, and for generating a visible light signal in response to the received map information by using a VLC module, and a mobile terminal, equipped with a visible light Rx module, for being provided with the map information upon receiving the visible light signal generated from the lamp, and for displaying a map image in response to the provided map information.