Industrial Technology Research Institute

National Yang Ming Chiao Tung University

Institute for Information Industry

Chi-Wai Chow

Chien-Hung Yeh

Jiun-Yu Sung

Sien Chi

Yen-Ting Chen

Wei-Chung Wang

Chia-Wei Chen

Yen-Liang Liu

Hsiang-Chin Hsieh

Hsiang-Chain Hsieh

Chung-Yen Chen

Hung-Yu Chen

Chia-Hsuan Wang

Kevin Liang

Fu-Yuan Shih

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.

Visible light communication system and method

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.

Optical communication system and optical transmission device

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.

Visible light communication method

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.

Transmitting apparatus and receiving apparatus for visible light communication, and visible light communication system

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.

Integrated passive optical network (PON) system

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.

Wavelength-division multiplexing (WDM) optical fiber network system

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.

Optical fiber communication system and methods having a reflective optical network unit

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.

Fiber sensing systems and fiber sensing methods

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.

Head-end circuit and remote antenna unit and hybrid wired/wireless network system and transceiving method using thereof

An optical network and an optical signal modulation method thereof are provided. The optical network includes an optical fiber and a remote node (RN). The RN receives a continuous carrier wave from the optical fiber and modulates the continuous carrier wave to generate a first frequency offset carrier wave The frequency of the first frequency offset carrier wave is different from that of the continuous carrier wave. A first user device re-modulates and loads data to the first frequency offset carrier wave to generate a first upstream signal. The frequency of the first upstream signal is the same as that of the first frequency offset carrier wave. The RN inputs the first upstream signal into the optical fiber.

Optical network and optical signal modulation method thereof

The present invention discloses a fiber sensing system with self-detection mechanism which utilizes a central office to control secondary ring architecture formed by fiber sensor, remote node and optical coupler primarily. The secondary ring architecture is connected serially to form a primary ring architecture. The central office has a tunable laser light source that can deliver the light source to the fiber sensor. Since the fiber sensor has reflective ability, all light source signal sent by the tunable laser light source will be detected and measured by the fiber sensor. Thus central office can detect all signals reflected by the fiber sensor and produce a spectrum for analyzing fault point locations. The present invention can greatly enhance survivability and sensing capacity of all fiber sensors, so that when a fault point caused by environmental change within the fiber, it will not effect the overall operation of the sensing mechanism. The application of fiber sensor can also reduce cost and complexity of the overall fiber network topology.

Growing community of inventors

Hong Kong, China

Chi-Wai Chow