Class / Patent application number | Description | Number of patent applications / Date published |
398077000 | Code division multiplexing | 25 |
20090169210 | DIGITAL ENCODING OF LABELS FOR OPTICAL PACKET NETWORKS - Methods and apparatuses are provided for transmitting labels in an optical packet network. Groups of K payload bits are encoded into blocks of N bits by using a code in which each of the groups of K payload bits is represented by a corresponding one of at least two distinct codewords of differing weights to form coded payload packet data, where K and N are integers and K07-02-2009 | |
20090175621 | Optical code division multiplexing module and method - An optical code division multiplexing module includes a superstructured fiber Bragg grating having equally spaced unit fiber Bragg gratings that convert an optical pulse into an optical chip train with equal inter-chip phase differences. A thermo-module heats or cools the mounting plate to which the superstructured fiber Bragg grating is secured. A temperature sensor measures the temperature of the mounting plate, and a temperature controller adjusts the temperature, thereby adjusting the inter-chip phase difference. The optical code division multiplexing module can be used for both coding and decoding. The inter-chip phase difference defines the code. Operation is stable despite environmental variations, and the code can be changed by changing the temperature setting, without replacement of any physical parts. | 07-09-2009 |
20090190927 | OPTICAL CODE DIVISION MULTIPLEXING TRANSMISSION AND RECEPTION METHOD AND OPTICAL CODE DIVISION MULTIPLEXING TRANSCEIVER - An object of the present invention is to provide an OCDM transceiver with which the reduction amount of the intensity of the correlation waveform signal is smaller than that of a conventional device of the same type in the decoding step that comprises a time gate processing step. Hence, in the OCDM transceiver of the present invention that comprises an encoding portion and a decoding portion, the decoding portion is constituted comprising a decoder, clock extractor, and time gate. The decoder decodes an encoded optical pulse signal and separates the encoded optical pulse signal into a clock signal extraction signal and an optical pulse signal playback signal. The clock extractor extracts a clock signal from the clock signal extraction signal. Further, the time gate removes only the auto-correlation waveform component from the optical pulse signal playback signal. The auto-correlation waveform component is converted to an electrical signal by means of an optical receiver and generated as a reception signal. | 07-30-2009 |
20090202246 | Passive optical network communication system - A passive optical network communication system includes a number of subscribers' units connected to a central line termination unit through a passive optical coupler. The line termination unit includes a first section that transmits and receives a code division multiplex (CDM) signal, a second section that transmits and receives a time division multiplex (TDM) signal, and a wavelength multiplexing filter that combines the transmitted CDM and TDM signals into a single downstream optical signal, and separates the CDM and TDM components of an upstream signal received from the subscribers' units through the passive optical coupler. The CDM signal provides channels for digital video transmission to CDM-capable subscribers' units. | 08-13-2009 |
20090208213 | Code division multiplex signal receiving apparatus and code division multiplex transmitting and receiving system - In a code division multiplex transmitting and receiving system, the transmitting apparatus inserts a clock signal in the code division multiplex signal. The clock signal has a frequency equal to a null frequency in the frequency spectrum of the code division multiplex signal. The receiving apparatus extracts this frequency component from the received signal and recovers the clock signal, using an ordinary clock recovery device of the type designed to recover a clock signal from a bi-level signal. The recovered clock signal is used as a synchronizing signal in the processing of the received signal. | 08-20-2009 |
20090220232 | Code division multiplex communication system - A code division multiplex (CDM) communication system transmits frames including a preamble and its end bit pattern followed by a CDM signal and its end bit pattern in respective time slots. A clock recovery device at the receiving end recovers a clock signal from the preamble during the preamble time slot and continues to output the clock signal in free run mode during the CDM signal time slot. The clock signal is used to gate the output of a decoder that decodes the received signal, so that the decoded CDM signal is output as a received data signal. The preamble is a bi-level signal, so an ordinary clock recovery device can be used. | 09-03-2009 |
20090257750 | Optical code division multiplex communication method, system, and module - An optical communication system uses superstructured fiber Bragg gratings (SSFBGs) to encode and decode an optical pulse signal transmitted between two optical communication devices. Each SSFBG has uniformly spaced fiber Bragg gratings, producing a chip pulse train with a uniform phase difference between chips. The phase difference defines a code. There is one SSFBG at one of the two devices and two or more SSFBGs at the other device, using different codes to encode or decode the same optical signal. Using one code to encode and multiple codes to decode, or multiple codes to encode and one code to decode, provides a high signal-to-noise ratio and permits stable performance despite environmental temperature variations. For bidirectional communication, each communication device has at least three SSFBGs, divided into a transmitting group and a receiving group, mounted on a mounting plate with a negative thermal expansion coefficient. | 10-15-2009 |
20100074620 | RECEIVER FOR A MODULATED LIGHT SIGNAL AND METHOD FOR RECEIVING A MODULATED LIGHT SIGNAL - 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. | 03-25-2010 |
20100074621 | OPTICAL DIVISION MULTIPLEXING TRANSMISSION AND RECEPTION METHOD AND OPTICAL DIVISION MULTIPLEXING TRANSMISSION AND RECEPTION DEVICE - An OCDM signal generation section generates an encoded optical pulse signal by encoded an optical pulse signal. The encoded optical pulse signal is then inputted to a wavelength disperser and the time waveform of the encoded optical pulse signal is shaped to be outputted as a shaped and encoded optical pulse signal. A WDM signal generation section generates an optical wavelength division multiplexing signal. A OCDM signal extraction section then decodes the OCDM reception signal by using the same code as the time-spreading/wavelength-hopping code for each channel and generates a decoded OCDM reception signal. | 03-25-2010 |
20100215370 | OPTICAL CODE DIVISION MULTIPLEX SIGNAL GENERATOR - An optical code division multiplexing signal generator provided with an optical pulse light source, a first encoder to an N | 08-26-2010 |
20110013909 | Optical Code Division Multiplexing Access System - Problem An object of the present invention is to provide an optical code division multiple access system which is used by many people. | 01-20-2011 |
20110069958 | OPTICAL FREE SPACE DATA TRANSMISSION - The invention relates to an aircraft data communication system as well as an aircraft comprising such a data communication system, in particular a wireless optical communication system inside an aircraft cabin and outside for aircraft services. The aircraft data communication system comprises a first sending unit | 03-24-2011 |
20120076497 | Method and Apparatus for Loading, Detecting, and Monitoring Channel-Associated Optical Signals - A method and apparatus for loading, detecting, and monitoring channel-associated signals are provided. Channel-associated signals are identified with spread spectrum codes in the electrical domain, and after being modulated to an optical service signal at respective loading points separately, the channel-associated identification signals are transmitted in the optical channel along with the optical signal. At any downstream detecting point, passing optical signals can be converted through photoelectric conversion, and the channel-associated identification signals are de-spread. By detecting the channel-associated signals, it is possible to learn about whether the upstream loading point work normally, whether the optical channel operates normally, etc., and thereby to find possible failures, solve problems, and monitor quality parameters of optical signals in real time, and improve reliability of the optical signal transmission. | 03-29-2012 |
398078000 | Multiple Access (e.g., CDMA) | 12 |
20080304828 | OPTICAL COMMUNICATION SYSTEM USING WDMA AND CDMA - In a PON system, an OLT periodically transmits a channel resource information block specifying a carrier wavelength and a spreading code on a first downstream channel to which a spread-spectrum spreader having a first spreading code is applied; one of ONUs receives the channel resource information block with a spread-spectrum despreader having the first spreading code and transmits a connection request to the OLT, using the carrier wavelength and the spreading code specified by the channel resource information block; the OLT having received the connection request transmits a new channel resource information block specifying a carrier wavelength and a spreading code to be used on an upstream data channel to the requester ONU through the first channel; and the requester ONU transmits data, using the carrier wavelength and the spreading code specified by the new channel resource information block. | 12-11-2008 |
20090196613 | METHOD AND DEVICE FOR MODULATING THE LIGHT EMISSION OF A LIGHTING DEVICE - The invention relates to controlling a lighting device, particularly to the modulation of light generated by a solid state lighting (SSL) device. The invention provides a method and device for modulating the light emission of a lighting device by keying each pulse ( | 08-06-2009 |
20090196614 | ACOUSTO-OPTIC FILTER AND OPTICAL CDMA SYSTEM USING THE SAME - Provided are an acousto-optic filter and an optical code division multiple access (CDMA) system using the acousto-optic filter. The acousto-optic filer includes: an acousto-optic mode converter (AOMC) converting an optical signal of a specific optical frequency corresponding to a frequency of an electric signal of an optical signal of a first mode having a predetermined optical frequency band; and a mode stripper (MS) stripping an optical signal of the optical signal of the first mode that has been converted to a second mode. | 08-06-2009 |
20090208214 | EXTINCTION RATIO CONTROL USING A FREQUENCY SPREAD TONE TO MODULATE OPTICAL SIGNAL POWER LEVELS - An optical transmitter that controls the extinction ratio by modulating a power level of an optical signal using a frequency spread tone. An electro-optic transducer driver generates an electrical signal that is to be converted into an optical signal. Meanwhile, a tone generator generates an electrical tone having a relatively narrow frequency spectrum. A frequency spreading circuit frequency spreads the electrical tone. A modulator modulates a power level of the electrical signal using the frequency spread electrical tone. An electro-optic transducer then converts the modulated electrical signal into a corresponding optical signal. An optoelectronic transducer recovers the modulated electrical signal by monitoring the optical signal. The tone is then recovered from the signal, and demodulated. The demodulated tone is then used to control the extinction ratio. | 08-20-2009 |
20090252496 | COMMUNICATION NETWORK USING CODE DIVISION MULTIPLEXING TECHNOLOGY - A communication network which can use communication bandwidth effectively. Spreading codes of a first and a second code length are assigned for every communication terminal interfaces connected to the same communication network. The spreading codes of the first code length are used for data communications. The spreading codes of the second code length are used for the control communications between the interfaces and the sever. The interfaces and the server receives mixed signals of the data and the control signals. When the received signals are decoded using the spreading code of the first code length, control signal components became equal to or lower than the noise level. When the received signals are decoded using the spreading code of the second code length, data components became equal to or lower than the noise level. Therefore, the interfaces and the server can extract one of these signal components. | 10-08-2009 |
20090269064 | Optical CDMA by Self Heterodyne Filtering - A new method and system for Optical Code Division Multiple Access (OCDMA) transmission, in which channel selection and rejection are based on dynamic self-heterodyne filtering using differential time delays applied to the data-modulated signals to code and decode the transmissions in each channel. Mach-Zender Interferometers having characteristic delays between their arms are a simple way of performing this coding and decoding. The technique enables the use of narrow linewidth sources and low spectrum spreading. Consequently this technique can be used in next-generation all-optical dynamic networks allowing bandwidth sharing on the one hand, while at the same time eliminating the need for network management and optical switching. Preliminary theoretical calculations predict the system support of up to 15 channels at a data rate of 1 GHz. | 10-29-2009 |
20100003031 | VARIABLE SPECTRAL PHASE ENCODER/DECODER BASED ON DECOMPOSITION OF HADAMARD CODES - The invention is directed toward a variable spectral phase encoder. The variable spectral phase encoder includes a plurality of switches and at least one encoder. The encoder is coupled between a first switch and second switch among the plurality of switches. The first switch selectively routes an optical signal to some combination of fixed encoders such that their collective product applies one of the Hadamard sequences to the optical signal. | 01-07-2010 |
20100074622 | LINE-OF-SIGHT OPTICAL DETECTION SYSTEM, AND COMMUNICATION SYSTEM - A line-of-sight optical detection system comprises: a plurality of dimmable light sources ( | 03-25-2010 |
20100158527 | OPTICAL COMMUNICATION SYSTEM USING WDMA AND CDMA - In a PON system, an OLT periodically transmits a channel resource information block specifying a carrier wavelength and a spreading code on a first downstream channel to which a spread-spectrum spreader having a first spreading code is applied; one of ONUs receives the channel resource information block with a spread-spectrum despreader having the first spreading code and transmits a connection request to the OLT, using the carrier wavelength and the spreading code specified by the channel resource information block; the OLT having received the connection request transmits a new channel resource information block specifying a carrier wavelength and a spreading code to be used on an upstream data channel to the requester ONU through the first channel; and the requester ONU transmits data, using the carrier wavelength and the spreading code specified by the new channel resource information block. | 06-24-2010 |
20110170872 | APPARATUS AND METHOD FOR PROVIDING SYNCHRONIZED DATA BY USING VISIBLE LIGHT COMMUNICATION - An apparatus and a method for providing synchronized data by using visible light communication includes, receiving a synchronization channel from a mobile communication base station using a specific mobile communication network, by a Light Emitting Diode (LED) lighting; analyzing the received synchronization channel, and extracting a synchronization signal for synchronizing the LED lighting with at least one LED lighting adjacent to the LED lighting; selecting a specific time slot of the synchronization signal based on IDentifications (IDs) of the LED lightings; and including a data frame of the LED lighting in the specific time slot, and transmitting the specific time slot, which includes the data frame of the LED lighting, to a mobile terminal. | 07-14-2011 |
20110311228 | Communication Apparatus for Communication in a Medium and a Manufacturing Method - Invention shows an electro-optical key arrangement comprising for a key of the key arrangement comprises: a transmitter (LED | 12-22-2011 |
20130294777 | Reconfigurable Optical Transmitter - The present disclosure includes systems and techniques relating to reconfigurable optical transmitters. In some implementations, an apparatus, systems, or methods can include multiple ports to receive independent optical data signals or independent electrical signals that are converted into independent optical data signals, at least one optical pump laser, and one or more nonlinear optics elements configured and arranged to generate a phase conjugate for each of the independent optical data signals at least by combining the respective independent optical data signal with an output of the optical pump, and generate an output optical signal from the independent optical data signals at least by combining each of the independent optical data signals with its corresponding generated phase conjugate. | 11-07-2013 |