Abstract: Disclosed are a visible light communication system and a visible light communication method. In this system, a signal transmitter sends a visible light signal, and a signal light receiver capture an image of the visible light signal to recover the visible light signal according to the captured image. The signal receiver includes an image capturing module, an image processing module and a signal recovery module. The method includes: capturing an image of a visible light signal; processing the captured image of the visible light signal; determining whether there is a complete packet according to the processed image; if yes, directly recovering the visible light signal according to the processed image; but if no, executing a packet recovery process according to the processed image of the visible light signal, then obtaining the complete packet and recovering the visible light signal transmitted from the signal transmitter.

Abstract: Disclosed are a visible light communication system and a visible light communication method. In this system, a signal transmitter sends a visible light signal, and a signal light receiver capture an image of the visible light signal to recover the visible light signal according to the captured image. The signal receiver includes an image capturing module, an image processing module and a signal recovery module. The method includes: capturing an image of a visible light signal; processing the captured image of the visible light signal; determining whether there is a complete packet according to the processed image; if yes, directly recovering the visible light signal according to the processed image; but if no, executing a packet recovery process according to the processed image of the visible light signal, then obtaining the complete packet and recovering the visible light signal transmitted from the signal transmitter.

Abstract: The present invention relates to an optical communication system and an optical transmission device. By changing the ratio between the first segment and the segment or/and the amplitude of the second segment, the digital signal is modulated and transmitted in the form of an optical signal. Then a solar panel, which is used as the receiver for the optical signal, can receive the optical signal and give directly the one or more digital signal without demodulation. Thereby, the costs of using a solar panel as the optical receiver may be reduced and the transmission rate may be enhanced.

Abstract: The present invention relates to an optical communication system and an optical transmission device. By changing the ratio between the first segment and the segment or/and the amplitude of the second segment, the digital signal is modulated and transmitted in the form of an optical signal. Then a solar panel, which is used as the receiver for the optical signal, can receive the optical signal and give directly the one or more digital signal without demodulation. Thereby, the costs of using a solar panel as the optical receiver may be reduced and the transmission rate may be enhanced.

Abstract: A visible light communication method. Firstly, a plurality of binary logic streams is sequentially received and a serial-to-parallel conversion is performed on them to obtain a plurality of binary signal sets corresponding to each binary logic stream. Then, all the binary signal sets are respectively mapped to obtain the first OFDM symbols in frequency domain. The first OFDM symbols are respectively transformed into the second OFDM symbols in time domain. Then, a parallel-to-serial conversion is performed on the second OFDM symbols. Adequate cyclic prefix is added in each of the second OFDM symbols. Next, the relative intensity of each of the second OFDM symbols is regulated, and then a digital-to-analog conversion is performed on the second OFDM symbols to obtain analog electrical signals. Finally, visible lights respectively corresponding to the analog electrical signals are generated.

Abstract: According to embodiments of the invention, systems, apparatuses, methods and devices are provided for controlling accidental discharge of pressurized gases from entry point of a pressurized tubular member containing the pressured gases. In one embodiment, an apparatus is provided that includes a tubular member and a tubular port body. The tubular member holds the pressurized gases in an at least a partial gas phase and the tubular port body is threaded to an upper part of the tubular member in a sealed position. The apparatus may also have a dual channel valve top assembly and a discharge route. The dual channel valve top assembly can be disposed within the tubular port body. A first port is utilized to fill the tubular member with a pressurized gas, and a second port in gas communication with an entry point of the tubular member to discharge the pressurized gas.

Abstract: A transmitting apparatus and a receiving apparatus for visible light communication, and a visible light communication system are provided. The visible light communication system includes a transmitting apparatus and a receiving apparatus. The transmitting apparatus includes two transmitting modules. The transmitting modules include a plurality of visible light sources and a transmitting polarization plate. Polarizations of the two transmitting polarization plates are orthogonal to each other. The receiving apparatus includes two receiving modules. The receiving modules include a plurality of light detecting diodes and a receiving polarization plate. Polarizations of the paired receiving polarization plate and transmitting polarization plate are the same.

Abstract: A visible light communication method. Firstly, a plurality of binary logic streams is sequentially received and a serial-to-parallel conversion is performed on them to obtain a plurality of binary signal sets corresponding to each binary logic stream. Then, all the binary signal sets are respectively mapped to obtain the first OFDM symbols in frequency domain. The first OFDM symbols are respectively transformed into the second OFDM symbols in time domain. Then, a parallel-to-serial conversion is performed on the second OFDM symbols. Adequate cyclic prefix is added in each of the second OFDM symbols. Next, the relative intensity of each of the second OFDM symbols is regulated, and then a digital-to-analog conversion is performed on the second OFDM symbols to obtain analog electrical signals. Finally, visible lights respectively corresponding to the analog electrical signals are generated.

Abstract: An integrated passive optical network system is disclosed. The system comprises an optical distribution network (ODN), a time-division multiplexing (TDM)-optical line terminal (OLT), a wavelength-division multiplexing (WDM)-optical line terminal (OLT), a plurality of time-division multiplexing (TDM)-optical network units (ONUs), and at least one wavelength-division multiplexing (WDM)-optical network unit (ONU) comprising a first filter. The TDM-OLT and the WDM-OLT respectively transmit a first optical signal carrying a first downstream signal and a second optical signal carrying a second downstream signal to the ONUs through the ODN, and wavelengths of the second optical signal and the first optical signal are different. The TDM-ONUs respectively retrieve the first downstream signal. The WDM-ONU uses the first filter to retrieve the second downstream signal.

Abstract: A transmitting apparatus and a receiving apparatus for visible light communication, and a visible light communication system are provided. The visible light communication system includes a transmitting apparatus and a receiving apparatus. The transmitting apparatus includes two transmitting modules. The transmitting modules include a plurality of visible light sources and a transmitting polarization plate. Polarizations of the two transmitting polarization plates are orthogonal to each other. The receiving apparatus includes two receiving modules. The receiving modules include a plurality of light detecting diodes and a receiving polarization plate. Polarizations of the paired receiving polarization plate and transmitting polarization plate are the same.

Abstract: A wavelength-division multiplexing (WDM) optical fiber network system is disclosed, which comprises a signal provider generating at least one set of wavelength signals of a plurality of different wavelengths and coupled to a plurality of modulation modules. The modulation modules respectively coupled to a user receiver. The modulation module comprises a control unit generating a random sequence and a control signal corresponding to the random sequence, and transmitting the control signal to a first modulation unit. The control unit is coupled to the signal provider to receive the wavelength signals and controls the first modulation to retrieve a wavelength signal according to the control signal. The control unit rapidly changes the control signal according to the random sequence whereby the first modulation unit rapidly retrieves the wavelength signals of different wavelengths and transmits them to the user receiver, so as to prevent a specific wavelength from attack.

Abstract: A VLC (Visible Light Communication) modulation system and method thereof, which includes a visible light generating device and a visible light receiving device. The visible light generating device includes a visible light emitting module and an arbitrary waveform generator. The arbitrary waveform generator further includes a first finite impulse response filtering unit, a pre-distortion amount control unit, and a second finite impulse response filtering unit.

Abstract: A wavelength-division multiplexing (WDM) optical fiber network system is disclosed, which comprises a signal provider generating at least one set of wavelength signals of a plurality of different wavelengths and coupled to a plurality of modulation modules. The modulation modules respectively coupled to a user receiver. The modulation module comprises a control unit generating a random sequence and a control signal corresponding to the random sequence, and transmitting the control signal to a first modulation unit. The control unit is coupled to the signal provider to receive the wavelength signals and controls the first modulation to retrieve a wavelength signal according to the control signal. The control unit rapidly changes the control signal according to the random sequence whereby the first modulation unit rapidly retrieves the wavelength signals of different wavelengths and transmits them to the user receiver, so as to prevent a specific wavelength from attack.

Abstract: An integrated passive optical network system is disclosed. The system comprises an optical distribution network (ODN), a time-division multiplexing (TDM)-optical line terminal (OLT), a wavelength-division multiplexing (WDM)-optical line terminal (OLT), a plurality of time-division multiplexing (TDM)-optical network units (ONUs), and at least one wavelength-division multiplexing (WDM)-optical network unit (ONU) comprising a first filter. The TDM-OLT and the WDM-OLT respectively transmit a first optical signal carrying a first downstream signal and a second optical signal carrying a second downstream signal to the ONUs through the ODN, and wavelengths of the second optical signal and the first optical signal are different. The TDM-ONUs respectively retrieve the first downstream signal The WDM-ONU uses the first filter to retrieve the second downstream signal.

Abstract: A driving device adapted to at least one light emitting diode, includes a clock recovery unit, a modulation unit, and a bias tee unit. The clock recovery unit receives a first alternating current signal, and generates a square wave signal according to the first alternating current signal. The modulation unit is coupled to the clock recovery unit, for receiving the square wave signal and a signal source, and for generating a message signal by using the square wave signal and the signal source. The bias tee signal is coupled to the modulation unit, for receiving a second alternating current signal and the message signal, and for outputting a driving signal to at least one light emitting diode by using the second alternating current signal and the message signal, in order to make at least one light emitting diode generate an optical signal.

Abstract: An optical fiber communication system is provided, including a central office and an optical network unit. The central office generates a first downstream signal and a second downstream signal according to a radio frequency signal and a baseband signal, respectively. The optical network unit is coupled to the central office to receive the first downstream signal and the second downstream signal through a first fiber and a second fiber different from the first fiber, respectively, such that the optical network unit only modulates the second downstream signal to generate an upstream signal and then delivers the upstream signal to the central office through the first fiber, thereby decreasing signal Rayleigh backscatter noise.

Abstract: A VLC (Visible Light Communication) modulation system and method thereof, which includes a visible light generating device and a visible light receiving device. The visible light generating device includes a visible light emitting module and an arbitrary waveform generator. The arbitrary waveform generator further includes a first finite impulse response filtering unit, a pre-distortion amount control unit, and a second finite impulse response filtering unit.

Abstract: A background noise-immune LED-based communication device comprises at least one LED signal transmitter emitting a Manchester code signal generated by a Manchester coding technology; and at least one optical receiver receiving the Manchester code signal from the LED signal transmitter. The present invention applies the Manchester coding technology to visible-light communication devices, enabling the LED-based communication device to transmit the Manchester code signal, whereby is decreased noise and promoted signal quality.

Abstract: A fiber sensing system is provided, including a plurality of ring structures, an optical coupler and a switching unit. Each of the ring structures has at least one fiber sensor to receive and reflect a light source signal. The optical coupler is directly connected to the ring structures thereby injecting the light source signal into the ring structures to form a plurality of loops. The switching unit is disposed in a central office having two output terminals coupled to the ring structure respectively by the optical coupler, thereby forming a first path and a second path in the loops, such that the light source signal is injected into the first path and the second path sequentially by the switching unit.

Abstract: A head-end circuit comprises first and second continuous light sources, first and second modulators. The first and the second continuous light sources provide first and second optical signals respectively corresponding to first wavelength and second wavelength, which is different from the first wavelength. The first modulator modulates the first optical signal based on first clock signal to generate an optical clock signal. The second modulator modulates the second optical signal based on downlink data to generate optical downlink data with the carrier of the second optical signal. The optical clock signal and the optical down link data are outputted to a remote antenna unit via first fiber path.