Code Division Multiplexing Patents (Class 398/77)
  • Patent number: 7813652
    Abstract: The present invention is an optical pulse time spreading device comprising a plurality of optical pulse time spreaders that output an input optical pulse as a series of chip pulses stream that are sequentially arranged time-spread on a time axis in accordance with optical phase code. Each of the optical pulse time spreaders comprises phase control means that supplies a phase difference between adjacent chip pulses. Identification parameters are introduced to realize channel discrimination by changing the phase difference conditions supplied between adjacent chip pulses for each of the phase control means. The phase control means have a structure in which an SSFBG is fixed to the core of the optical fiber, for example. The SSFBG has unit FBGs that are arranged in series in the waveguide direction of the core. The code values of the optical phase code established for the phase control means correspond each one-on-one with each of the unit FBGs.
    Type: Grant
    Filed: May 15, 2006
    Date of Patent: October 12, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kensuke Sasaki
  • Patent number: 7809267
    Abstract: The present invention is directed to a coherent gated receiver. The receiver includes a decoder operable to receive an optical signal and generate a decoded optical signal, the decoder comprises a demultiplexer operable to spatially distribute the optical signal, a phase mask operable to decode the spatially distributed optical signal, and a multiplexer operable to combine the decoded spatially distributed optical signal. The receiver also includes a laser source operable to provide a pulse signal, a combiner coupled to the laser source and the decoder operable to combine the decoded optical signal and the pulse signal, and a detector operable to detect an output from the combiner.
    Type: Grant
    Filed: June 1, 2006
    Date of Patent: October 5, 2010
    Assignee: Telcordia Technologies, Inc.
    Inventor: Ronald Charles Menendez
  • Patent number: 7809266
    Abstract: A DWDM optical system in a first embodiment includes a plurality of scramblers on the transmit side and a plurality of corresponding de-scramblers on the receiver side of the DWDM system. Each scrambler includes an input for an encryption key with the corresponding de-scrambler including an input for the same encryption key. In accordance with the pseudorandom encryption key, input data channels are scrambled onto output optical channels to provide data security across the optical path. With a suitable algorithm, this technique can provide very strong data confidentiality. The strength of the technique of the embodiments of the invention resides in the scrambling algorithm that is used to scramble the data over the optical carriers. Preferably the scrambling algorithm is very unpredictable and does not repeat for a very long time.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: October 5, 2010
    Assignee: Ciena Corporation
    Inventor: Michael Lee
  • Patent number: 7792427
    Abstract: An OCDMA system is disclosed that provides for storage and retrieval of OCDMA data while maintaining OCDMA encoding and signaling information. The system includes a wavelength demultiplexer that optically receives an OCDMA signal having a plurality of wavelengths of light. A plurality of light detectors is optically interconnected with the wavelength demultiplexer, with each of the light detectors being associated with a unique wavelength of light. Each of the light detectors respectively communicates with a plurality of storage volumes. For example, each storage volume is associated with a unique wavelength of light and is configured for storing optical data electronically converted from an optical data stream having a unique wavelength of light. Such a process may substantially eliminate the need for OCDMA conversion during electronic storage of the OCDMA data. Stored OCDMA data may be rapidly retrieved and configured as an OCDMA signal because OCDMA coding is maintained.
    Type: Grant
    Filed: January 30, 2006
    Date of Patent: September 7, 2010
    Assignee: Lockheed Martin Corporation
    Inventors: Brian L. Uhlhorn, Howard J. Schantz
  • Publication number: 20100215370
    Abstract: An optical code division multiplexing signal generator provided with an optical pulse light source, a first encoder to an Nth encoder, a first optical modulator to an Nth optical modulator, and a first optical circulator to an Nth optical circulator. The first optical circulator inputs an input optical pulse train to a first encoder, and inputs a first encoded optical pulse train output by Bragg reflection from the first encoder to the first optical modulator. The kth optical circulator inputs an input (k?1)th optical pulse train which has passed through the (k?1)th encoder to a kth encoder, and inputs a kth encoded optical pulse train output by Bragg reflection from the kth encoder to the kth optical modulator. Herein k takes all integers from 2 to N, and N is a positive integer of 2 or more.
    Type: Application
    Filed: January 28, 2010
    Publication date: August 26, 2010
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventors: Shuko KOBAYASHI, Kensuke Sasaki
  • Patent number: 7778547
    Abstract: The invention is directed to code labeling in an optical network. The network includes a transmitting station operable to transmit an optical signal. The network also includes an encoder coupled to the transmitting station operable to label the optical signal composed of a group of codes. A receiving station operable to receive the labeled group of optical codes is also provided. The receiving station is operable to read the optical signal if the label of the received group of codes corresponds to the group of codes assigned to the receiving station.
    Type: Grant
    Filed: June 1, 2006
    Date of Patent: August 17, 2010
    Assignee: Telcordia Technologies, Inc.
    Inventor: Ronald Charles Menendez
  • Patent number: 7778546
    Abstract: Methods and apparatus are described for transmitting and receiving data. A method includes a process of transferring data over a coaxial network at a bandwidth above 1000 MHz, wherein the process of transferring data transfers the data between an optical node and a plurality of cable modems of a hybrid fiber-coaxial cable network. An apparatus includes a data transfer system which sends and receives data over a coaxial network at a bandwidth above 1000 MHz, wherein the data transfer system is located at an optical node of a hybrid fiber-coaxial cable network.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: August 17, 2010
    Assignee: Aurora Networks, Inc.
    Inventors: Guy Sucharczuk, Oleh J Sniezko, Krzysztof Pradzynski, Thomas K Fong
  • Patent number: 7773882
    Abstract: Communication is provided between at least two of a plurality of stations. A signal is received from a first one of the plurality of stations, and the signal is coded using a first code that is assigned to that station. The coded signal is converted to obtain a further coded signal that is decodable using a further code that is assigned to at least a second one of the plurality of stations. The further coded signal is transmitted for delivery to at least the second one of the plurality of stations.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: August 10, 2010
    Assignee: Telcordia Technologies, Inc.
    Inventor: Ronald Charles Menendez
  • Patent number: 7773881
    Abstract: 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.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: August 10, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Naoki Minato, Takeshi Kamijoh
  • Patent number: 7769301
    Abstract: Technology is provided in which, by performing time gate processing using a clock signal with time jitter suppressed, time and intensity fluctuations which in the prior art had been observed in auto-correlated signals after time gate processing are reduced. In a decoder, received optical code division multiplexed signals are divided into two, one of which is reflected as a decoded signal, and the other of which is transmitted as an encoded signal in the encoded state. In the clock extraction circuit, encoded signals are divided into first encoded signals and second encoded signals. In the first clock signal generation portion, first clock signals are generated from the first encoded signals, and optical pulses synchronized with the first clock signals are extracted from the second encoded signals, and second clock signals are generated from the extracted optical pulses.
    Type: Grant
    Filed: September 18, 2006
    Date of Patent: August 3, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Hideyuki Iwamura
  • Patent number: 7755073
    Abstract: 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.
    Type: Grant
    Filed: January 28, 2009
    Date of Patent: July 13, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bong Kyu Kim, Sang Jo Park, Heuk Park, Kwang Joon Kim
  • Patent number: 7751718
    Abstract: An efficient means for transmitting digitized return path signals over a cable television return path is disclosed. In one embodiment of the invention, the cable television return path includes a node that receives an analog return signal from a subtree of the cable television system and generates a digital transport signal representative of the analog return path signal. The digital transport signal, however, is not a digitized form of the analog return signal. Rather, the digital transport signal is encoded such that fewer bits are used to represent the analog return signal without substantially impacting the accuracy and dynamic range of the signal. At the hub, the digital transport signal is decoded and converted to produce an analog signal that is a close approximation of the analog return signal.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: July 6, 2010
    Assignee: Finisar Corporation
    Inventor: Gerald F. Sage
  • Patent number: 7747170
    Abstract: A transmission unit comprises an optical pulse train generation unit, first channel encoded optical pulse signal generation unit, second channel encoded optical pulse signal generation unit, third channel encoded optical pulse signal generation unit, and fourth channel encoded optical pulse signal generation unit; the second and fourth channels further comprise polarization controllers respectively. By means of these polarization controllers, a polarization control step is executed in which the planes of polarization of first encoded optical pulse signals of the second and fourth channels are rotated by 90°. By executing the polarization control step, the directions of the planes of polarization of the first decoded optical pulse signals of adjacent channels in the reception unit can be caused to be mutually orthogonal.
    Type: Grant
    Filed: November 22, 2006
    Date of Patent: June 29, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Hideaki Tamai
  • Patent number: 7746805
    Abstract: In a communication network which performs transmission from a plurality of first communication devices to a single second communication device using a synchronous code division multiplexing technique, the phases of signals transmitted from the first communication devices are synchronized easily. The first communication devices control the transmission phase of spread modulated signals using phase control information received from the second communication device. A repeater generates a code division multiplexed signal by superposing the spread modulated signals transmitted respectively from the first transmission devices. The second transmission device demultiplexes the code division multiplexed signal received from the repeater, determines the optimum phase of the demultiplexed signals, and transmits the determined optimum phase to the first transmission devices as the phase control information.
    Type: Grant
    Filed: November 30, 2006
    Date of Patent: June 29, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Hideaki Tamai, Masayuki Kashima
  • Patent number: 7729616
    Abstract: Apparatus and system for transmitting and receiving optical code division multiple access data over an optical network. The apparatus comprises a spectral phase decoder for decoding the encoded optical signal to produce a decoded signal, a time gate for temporally extracting a user signal from the decoded signal, and a demodulator that is operable to extract user data from the user signal. The system preferably comprises a source for generating a sequence of optical pulses, each optical pulse comprising a plurality of spectral lines uniformly spaced in frequency so as to define a frequency bin, a data modulator associated with a subscriber and operable to modulate the sequence of pulses using subscriber data to produce a modulated data signals and a Hadamard encoder associated with the data modulator and operable to spectrally encode the modulated data signal to produce an encoded data signal.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: June 1, 2010
    Assignees: Telcordia Technologies, Inc., University of Central Florida
    Inventors: Shahab Etemad, Paul Toliver, Janet Lehr Jackel, Ronald Charles Menendez, Stefano Galli, Thomas Clyde Banwell, Peter Delfyett
  • Patent number: 7725036
    Abstract: An efficient means for transmitting digitized return path signals over a cable television return path is disclosed. In one embodiment of the invention, the cable television return path includes a node that receives an analog return signal from a subtree of the cable television system and generates a digital transport signal representative of the analog return path signal. The digital transport signal, however, is not a digitized form of the analog return signal. Rather, the digital transport signal is encoded such that fewer bits are used to represent the analog return signal without substantially impacting the accuracy and dynamic range of the signal. At the hub, the digital transport signal is decoded and converted to produce an analog signal that is a close approximation of the analog return signal.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: May 25, 2010
    Assignee: Finisar Corporation
    Inventors: Gerald F. Sage, Randy Ichiro Oyadomari
  • Patent number: 7702245
    Abstract: Utility data modulation is superimposed on a payload data modulator optical signal by exploiting spread spectrum techniques by virtue of one embodiment of the present invention. Utility data transmission rates of e.g., 200 Kbps, can be achieved without impairment to payload data transmission. The utility data modulated signal spectrum overlaps or is entirely within the payload data modulation spectrum, therefore, overcoming problems with optical amplifier gain control and pink noise.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: April 20, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Goran Mork, Johan Martensson, Dan Wahlbeck
  • Patent number: 7702240
    Abstract: The present invention is an optical multiplex communication system in which an optical wavelength division channel and an optical code division channel can coexist, wherein a WDM channel section 86 has a wavelength demultiplexer 36 and WDM channels W1 to W4. An optical pulse string 83-3 is demultiplexed by the wavelength demultiplexer 36, and for channel W1, an optical pulse 37 with wavelength ?1 is input to an intensity modulator 114 and converted into an optical pulse signal of channel W1, and is output as a wavelength division optical pulse signal 115, where transmission information of channel W1 is reflected.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: April 20, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Naoki Minato
  • Publication number: 20100091990
    Abstract: A high data rate optical signal is inverse multiplexed into a multitude of lower-rate tributaries, each of which is coded by its unique OCDM code, and the combined coded tributaries are injected into a common phase scrambler. Coherent summation of these optically encoded tributaries pass through a shared phase or phase and frequency scrambler before exiting the secure location. The setting of the scrambler acts as the key. The authorized recipient with the correct key retrieves the ones and zeros of the several decoded signals.
    Type: Application
    Filed: September 21, 2009
    Publication date: April 15, 2010
    Applicant: TELCORDIA TECHNOLOGIES, INC.
    Inventors: Shahab Etemad, Janet Jackel, Sarry Habiby
  • Publication number: 20100080559
    Abstract: A synchronized CDM communication system performs 1-to-N communication by CDM between a central office and first to N-th optical network units (ONU). The synchronized CDM communication system adds structural elements for realizing a connection state acquisition section to a conventional synchronized CDM communication system. A central office includes a presence check section, a ranging processing section and the connection state acquisition section. The presence check section checks the ONUs that are connected with the central office and the ONUs that are not connected. The ranging processing section performs transmission timing adjustments for the ONUs that are connected. The connection state acquisition section verifies whether all of ONUs are connected with the central office, and performs a discovery of a ONU, among the ONUs that were not connected at the time of the check, that has resumed participation in communication since the check ended.
    Type: Application
    Filed: July 16, 2009
    Publication date: April 1, 2010
    Applicant: OKI ELECTRONIC INDUSTRIES CO., LTD.
    Inventor: Masahiro Sarashina
  • Patent number: 7689124
    Abstract: Disclosed herein are a CDMA optical system and encoder and decoder included therein. Time domain encoding means creates a time domain code having a sequence according to inputted data bits or a complementary code which is complementary to the time domain code. An optical modulation means selectively outputs lights, in which the lights are incident upon the optical modulation means from the outside, to two output leads, respectively, according to chip bits of the time domain code or the complementary code. A wavelength domain encoding means encodes the light outputted from a first output lead of the optical modulation means to a wavelength domain sequence (two dimensional code), transmits the wavelength code to the base station, encodes the light outputted from a second output lead to a complementary sequence of the wavelength domain sequence, and transmits the complementary code of the two dimensional code to the base station.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: March 30, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Young Hee Yeon, Bong Kyu Kim, Sung Chan Cho, Byoung Whi Kim, Sang Jo Park
  • Publication number: 20100074620
    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.
    Type: Application
    Filed: October 29, 2007
    Publication date: March 25, 2010
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventor: Johan Paul Marie Gerard Linnartz
  • Publication number: 20100074621
    Abstract: 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.
    Type: Application
    Filed: September 18, 2009
    Publication date: March 25, 2010
    Applicant: Oki Electric Industry Co., Ltd.
    Inventors: Naoki Minato, Takeshi Kamijoh
  • Patent number: 7684713
    Abstract: A calculation processing unit controls temperature of a Peltier device based on a slope of a waveform obtained by subtracting a waveform of a B-arm monitoring signal from a waveform of an A-arm monitoring signal and a value obtained by subtracting a value B of the B-arm monitoring signal from a value A of the A-arm monitoring signal. Similarly, the calculation processing unit controls a phase of the A-arm and a phase of the B-arm. An A-arm side micro-controller controls temperature of an A-arm side heater 22 based on the value of the A-arm monitoring signal, and controls the phase of the A-arm. A B-arm side micro-controller controls temperature of a B-arm side heater based on the value B of the B-arm monitoring signal, and controls the phase of the B-arm.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: March 23, 2010
    Assignee: Fujitsu Limited
    Inventors: Yoshikazu Terayama, Noriaki Mizuguchi, Eiji Ishikawa, Takashi Toyomaki, Kenichi Kaburagi, Takeshi Hoshida, Jens Rasmussen, Akihiko Isomura
  • Patent number: 7680415
    Abstract: 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.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: March 16, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Naoki Minato, Akihiko Nishiki, Hideyuki Iwamura, Takashi Ushikubo
  • Patent number: 7676127
    Abstract: 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.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: March 9, 2010
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Masahiko Mizutani, Toshiki Sugawara, Tohru Kazawa, Yoshihiro Ashi
  • Patent number: 7660536
    Abstract: An optical modulating circuit realizing a PPM is constituted by circuit parts having a frequency band equal to a data rate to provide a technique which increase the data rate. A first light source generates a first single wavelength signal serving as a continuous light having a first wavelength ?1 as a wavelength of a carrier wave. A second light source generates a second single wavelength signal serving as a continuous light having a second wavelength ?2 different from ?1 as a wavelength of a carrier wave. For the first single wavelength signal and the second single wavelength signal, according to a transmission electric signal having information 0 or 1, an optical switch outputs a first single wavelength signal as an input optical signal when the information is 0. On the other hand, when the information is 1, the optical switch outputs the second single wavelength signal as an input optical signal.
    Type: Grant
    Filed: December 11, 2006
    Date of Patent: February 9, 2010
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Naoki Minato
  • Patent number: 7646980
    Abstract: 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.
    Type: Grant
    Filed: May 8, 2006
    Date of Patent: January 12, 2010
    Assignee: Telcordia Technologies, Inc.
    Inventor: Ronald C. Menendez
  • Patent number: 7630641
    Abstract: One method embodiment for monitoring an optical pathway includes emitting an optical signal from an optical emitter, encoding the optical signal with a monitoring optical code division multiple access (OCDMA) code, directing the optical signal with the monitoring OCDMA code into the optical pathway, receiving reflected light associated with the monitoring OCDMA code from the optical pathway, and determining a status of the optical pathway based on the reflected light.
    Type: Grant
    Filed: August 2, 2006
    Date of Patent: December 8, 2009
    Assignee: Lockheed Martin Corporation
    Inventor: Brian L. Uhlhorn
  • Patent number: 7630642
    Abstract: In 1 to N communication based on code division multiplexing, ranging is performed by following the first to ninth steps. First step: all the optical network units are set to standby status. Second step: first and second optical network units are set to transmission enable status. Third step: the phase shift amount is set for the variable phase shifters of the first and second optical network units. Fourth step: reception of a fixed signal is attempted in the optical line terminal. Fifth step: if the fixed signal is not received, processing returns to the second step, and if received, the phase amount of the variable phase shifter is defined and fixed. In the sixth to ninth steps, an operation the same as the first to fifth steps is performed for the third to N-th optical network units.
    Type: Grant
    Filed: January 16, 2007
    Date of Patent: December 8, 2009
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Hideaki Tamai, Masayuki Kashima
  • Patent number: 7620324
    Abstract: An object of the present invention is to implement optical multiplexing transmission and reception in which an OCDM channel is added without changing the used wavelength bandwidth of the existing WDM channel or without changing the time slot allocated to the existing OTDM channel. Hence, one of the embodiments of the present invention is constituted as follows. The OCDM signal generation section generates an encoded optical pulse signal by encoding an optical pulse signal. The encoded optical pulse signal is inputted to the 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. The WDM signal generation section generates an optical wavelength division multiplexing signal. The OCDM signal extraction section 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.
    Type: Grant
    Filed: February 24, 2006
    Date of Patent: November 17, 2009
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Naoki Minato, Takeshi Kamijoh
  • Publication number: 20090257750
    Abstract: 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.
    Type: Application
    Filed: March 5, 2009
    Publication date: October 15, 2009
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventors: Shuko Kobayashi, Kensuke Sasaki
  • Publication number: 20090232494
    Abstract: An optical network having a tree-like structure with a main line and a plurality of branches, at least two of the branches comprising a monitoring unit for upstream signalling to the main line, wherein each of the monitoring units comprises a signal generation unit with a light source for generation of a pre-defined optical signal, and the monitoring units are construed to generate pre-defined optical signals which are different from each other, as well as a monitoring unit for generating a periodic upstream signal in such an optical network and a method for monitoring such an optical network.
    Type: Application
    Filed: April 23, 2008
    Publication date: September 17, 2009
    Applicant: Alcatel Lucent
    Inventors: Jorg HEHMANN, Harald SCHMUCK, Michael STRAUB
  • Publication number: 20090220232
    Abstract: 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.
    Type: Application
    Filed: January 22, 2009
    Publication date: September 3, 2009
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventor: Masahiro Sarashina
  • Publication number: 20090208213
    Abstract: 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.
    Type: Application
    Filed: January 27, 2009
    Publication date: August 20, 2009
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventor: Masahiro Sarashina
  • Publication number: 20090202246
    Abstract: 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.
    Type: Application
    Filed: December 22, 2008
    Publication date: August 13, 2009
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventor: Masayuki Kashima
  • Publication number: 20090190927
    Abstract: 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.
    Type: Application
    Filed: January 16, 2009
    Publication date: July 30, 2009
    Applicant: Oki Electric Industry Co., Ltd.
    Inventors: NAOKI MINATO, Akihiko Nishiki
  • Publication number: 20090175621
    Abstract: 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.
    Type: Application
    Filed: November 18, 2008
    Publication date: July 9, 2009
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventors: Shuko Kobayashi, Satoko Katsuzawa, Kensuke Sasaki
  • Publication number: 20090169210
    Abstract: 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 K<N. Composite packet data is produced by choosing among the at least two distinct codewords according to a value of chip data based, at least partly, on label data. An optical signal for transmission via the optical network is produced by applying the composite packet data to an optical transmitter.
    Type: Application
    Filed: February 16, 2009
    Publication date: July 2, 2009
    Applicant: AT&T Corp.
    Inventors: Mark David Feuer, Vincent Anant Vaishampayan
  • Patent number: 7555216
    Abstract: The invention dispenses with calibration of the optical frequency of the light source and permits the use of many codes without increasing the transmission bandwidth used. Let the optical frequency width of the light source be represented by FSR and the code length of every code be represented by FSR, the codes are made to be orthogonal to each other. The optical intensity-frequency characteristic of an n-th optical code signal is set to Cn(f)=(1+cos(2?sf/FSR+r?/2))/2 (where s is an integer in the range from 1 to maximum number of codes/2, and r=0 or 1) to provide orthogonality between the optical code signals.
    Type: Grant
    Filed: July 16, 2004
    Date of Patent: June 30, 2009
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Manabu Yoshino, Noriki Miki
  • Patent number: 7555214
    Abstract: A method of managing forward error correction (FEC) initialization and auto-negotiation in ethernet passive optical networks includes receiving FEC data from an optical network unit (ONU 105), and the optical line terminal (OLT 103) responds to the ONU with FEC data. Upon receiving data not forward error corrected from an ONU. The OLT responds with data not coded for FEC (203). Similarly, upon receiving forward error corrected data from the OLT, the ONU responds with forward error corrected data (503); and upon receiving data not forward error corrected from the OLT, the ONU responds with data not forward error corrected (203). The communications quality from the ONU is monitored (501), if the communications quality is not sufficient, the OLT transmits forward error corrected data to the ONU; otherwise, the OLT transmits non-FEC data to the ONU.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: June 30, 2009
    Assignee: PMC-Sierra Israel Ltd.
    Inventor: Lior Khermosh
  • Patent number: 7536105
    Abstract: A W-CDMA base station is disclosed in which a base band processing device and a plurality of remote radio devices are provided and downward data is transmitted from the plurality of remote radio devices at the same time. The base band processing device inserts a synchronous signal into downward data, and transmits the downward data to the remote radio devices. The remote radio device extracts the synchronous signal from the downward data transmitted from the base band processing device, inserts the synchronous signal into the upward data at an insertion timing based on an extraction timing when the signal is extracted, and transmits the upward data to the base band processing device.
    Type: Grant
    Filed: February 10, 2006
    Date of Patent: May 19, 2009
    Assignee: NEC Corporation
    Inventor: Tomoyuki Teramoto
  • Patent number: 7525944
    Abstract: Techniques for delivering data recovered by a HARQ entity in proper order to higher layers in a CDMA system. In a method, packets are received from the HARQ entity by the re-ordering entity and missing packets among the received packets are detected. Packets may be transmitted in a sequential order based on transmission sequence numbers (TSNs) assigned to the packets, and missing packets may be detected based on the TSNs of the received packets. Delivery of received packets later than the missing packets are stalled because higher layers expect data in-order. A determination is thereafter made whether each missing packet is (1) subsequently received from the HARQ entity or (2) lost, by successively eliminating HARQ channels that may be used to send the missing packet. Received packets previously stalled by each missing packet are delivered after the missing packet is determined to be lost or received.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: April 28, 2009
    Assignee: QUALCOMM Incorporated
    Inventors: Alkinoos Hector Vayanos, Durga P. Malladi, Sai Yiu Duncan Ho
  • Patent number: 7512342
    Abstract: 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 K<N. Composite packet data is produced by choosing among the at least two distinct codewords according to a value of chip data based, at least partly, on label data. An optical signal for transmission via the optical network is produced by applying the composite packet data to an optical transmitter.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: March 31, 2009
    Assignee: AT&T Intellectual Property II, L.P.
    Inventors: Mark David Feuer, Vincent Anant Vaishampayan
  • Patent number: 7433603
    Abstract: In one embodiment, the present invention includes a network hub having an active optical encoder where the network hub is to generate a plurality of addressed optical data signals, each having a common carrier wavelength and a different address corresponding to a network node coupled to the network hub. Other embodiments are described and claimed.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: October 7, 2008
    Assignee: Intel Corporation
    Inventors: Alan Johnson, Michael Munroe, Eric Maniloff, Shasi Raval
  • Patent number: 7421203
    Abstract: A method for transmitting a packet in a wireless access network based on a wavelength identification code scheme. The method comprises the steps of connecting n number of RNCs (Radio Network Controllers) to one sub-ring where the “n” is a positive integer, and assigning a unique wavelength to each RNC; identifying a packet to be transmitted between the RNCs located within a same sub-ring using the assigned unique wavelength, and transmitting the packet through an SRC (Sub-Ring Controller); connecting m number of SRCs to one main-ring where the “m” is a positive integer, and assigning a unique wavelength to each SRC; and detaching a wavelength identification code from the packet to be transmitted between the RNCs located within different sub-rings, and transmitting the packet having the encapsulated wavelength identification code through an MRC (Main-Ring Controller).
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: September 2, 2008
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Byoung Whi Kim, Jea Hoon Yu, Min Ho Kang
  • Patent number: 7421204
    Abstract: A method and system for increasing the spectral efficiency of binary coded signals includes encoding an input binary bit sequence such that the input binary bit sequence is converted into a series of rectangular pulses having varying repetition rates. A continuous wave carrier signal is then modulated via a control signal representative of the encoded signal. The modulated optical signal is filtered by a narrow band optical filter to generate a minimum shift keying (MSK) encoded optical signal. In accordance with the present invention, an input binary bit sequence is encoded via a minimum shift keying (MSK) modulation format to improve the spectral efficiency of a binary coded digital signal and to contemporaneously limit distortion of the optical signal induced by optical nonlinear effects during transmission in an optical transmission system.
    Type: Grant
    Filed: September 2, 2004
    Date of Patent: September 2, 2008
    Assignee: Lucent Technologies Inc.
    Inventor: Jean Gerardus Leonardus Jennen
  • Patent number: 7421202
    Abstract: A photonic label switching architecture. The architecture includes a photonic label extractor to split an externally input first optical packet data into a photonic label and a payload. Then, the photonic label is input to a photonic label processing and swapping device to duplicate as a plurality of parallel copies for decoding and producing an auto-correlation output. According to the auto-correlation output, a photonic label swapping path is chosen, a new photonic label is produced, and an output port of an optical switch is chosen. A new optical packet data which is the result of the new photonic label adjoining the payload is output to the chosen output port of the optical switch.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: September 2, 2008
    Assignee: Industrial Technology Research Institute
    Inventor: Dar-Zu Hsu
  • Patent number: 7418205
    Abstract: An optical spread spectrum communication system includes a tunable laser which sequentially outputs optical signals having different wavelengths. The laser produces a frequency spectrum having a plurality of closely spaced modes relative to optical frequencies. The system further includes an optical modulator and a frequency synthesizer. The frequency synthesizer controls the optical modulator to allow specific modes from the frequency spectrum to pass through. Additionally, the system includes a tunable filter and a phase locked loop (PLL) control circuit. The PLL control circuit controls the filter to select specific channels. The selection of the specific modes by the modulator and the selection of channels by the tunable filter are performed independent of each other and are based on randomly assigned codes generated in accordance with one or more algorithms.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: August 26, 2008
    Assignee: General Instrument Corporation
    Inventor: Kerry I. Litvin
  • Patent number: 7403713
    Abstract: Quantum source coding apparatus for communication of quantum information comprising: a quantum state preparation device for converting input messages into block messages; a coding device for producing coded signals by compressing the block messages prepared by the quantum state preparation device; and an output device for outputting the coded signals produced by the coding device.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: July 22, 2008
    Assignees: University of Hertfordshire, National Institute of Information and Communications Technology, University of Strathelyde
    Inventors: Masahide Sasaki, Yasuyoshi Mitsumori, Atsushi Hasegawa, Masahiro Takeoka, John A. Vaccaro, Stephen M. Barnett, Erika Andersson