Patent application number | Description | Published |
20100039794 | TRAFFIC LED LAMP WITH INTERNAL CIRCUIT BACKUP SYSTEM - In accordance with one aspect of the present exemplary embodiment, an LED lamp is provided. In one embodiment, the LED lamp is made to be mounted in a traffic signal housing that includes other lamps, where the LED lamp can be red, yellow, green or another color and can represent a full ball aspect, an arrow aspect or another aspect. The LED lamp is adapted to be powered by an external power source and includes an input power circuit receiving an input voltage from the external power source. The input power circuit includes a power detection circuit that is adapted to determine a power state of the traffic LED lamp. The LED lamp further includes an LED load and a battery powered driving circuit. The battery power driving circuit drives the LED load if the power state of the LED lamp is in a power failure state. | 02-18-2010 |
20120154176 | LED TRAFFIC SIGNAL COMPENSATION AND PROTECTION METHODS - According to one aspect of the present disclosure, systems and methods for monitoring one or more operating parameters of a traffic lamp and adjusting light output of one or more light sources thereof to correct for one or more degradation factors are provided. According to another aspect of the present disclosure, systems and methods for monitoring one or more operating parameters of a traffic lamp and generating an indication if end of life is detected with the traffic lamp, where end of life is determined based on the one or more operating parameters. According to another aspect of the present disclosure, systems and methods for monitoring one or more operating parameters of a traffic lamp and entering the traffic lamp into a self-protected mode if a fault is detected with the one or more operating parameters. | 06-21-2012 |
20120161641 | SAFETY FLASHING DETECTOR FOR TRAFFIC LAMPS - A safety flashing detector that suitably detects unintentional flashing of the LED light engine in a traffic lamp is provided. The LED light engine may flash unintentionally when there are failures (hardware or software) inside a traffic lamp. In certain embodiments, unintentional flashing may be detected using a current sensor. If unintentional flashing is detected, the flashing detector may activate and shut down the LED light engine to remove the hazardous failure and eventually triggers the fuse blowout circuit. Hardware circuitry is suitably employed for both reliability and safety purposes, but software may also be employed. | 06-28-2012 |
Patent application number | Description | Published |
20080199191 | MAXIMUM LIKELIHOOD SEQUENCE ESTIMATION FOR HIGH SPECTRAL EFFICIENCY OPTICAL COMMUNICATION SYSTEMS - Severe inter-symbol interference (ISI), introduced by narrow-band optical filtering in high spectral efficiency wavelength-division multiplexed (WDM) systems to avoid coherent WDM crosstalk, can be substantially mitigated by the use of maximum-likelihood sequence estimation (MLSE) reception. Compared to conventional threshold detection, the use of an MLSE receiver allows, for example, a 22% reduction in optical receive filter bandwidth. For tight optical filtering, the MLSE receiver benefits from taking into account noise correlation. MLSE receivers with one and with two samples per bit are described and it is shown that while oversampling is beneficial for wide-band optical filters, the benefit goes away for narrow-band optical filtering, thereby facilitating MLSE design for rates beyond 10 Gb/s. | 08-21-2008 |
20100111542 | Intra-Channel Nonlinearity Compensation For Optical Data Communications - An arrangement is described for compensating intra-channel nonlinearities in an optical communications system which combines optical dispersion compensation with electronic pre-distortion (EPD). EPD with moderate lookup table size can effectively suppress intra-channel nonlinearities over optical transmission links incorporating optical dispersion compensation. The arrangement can be implemented for a variety of optical communications systems, including 10 Gb/s, 40 Gb/s and higher bit rate systems as well as single-channel and wavelength-division multiplexing (WDM) systems. | 05-06-2010 |
20100150559 | Time-interleaved polarization-division-multiplexed transmission systems and transmitters - A WDM system having at least two channels, each of which employs two polarizations, is arranged so that the start times of symbols carried by one polarization of a channel are displaced in time from the start times of symbols carried by the other polarization of that channel, e.g., the start time for each symbol on one polarization is not substantially synchronized with the closest-in-time symbol start time on the other polarization of that channel. Preferably, the data signals are modulated using a return-to-zero (RZ) format and the start times of the symbols of the data signal carried by one polarization of a channel is offset from the start time of the symbols data signal carried by the other polarization of that channel by between 20% to 80%—preferably 50%—of the symbol period of the data signals, when the data signals have the same symbol period. | 06-17-2010 |
20100150577 | Communication System and Method With Signal Constellation - An example method includes modulating an optical signal using a Phase Shift Keying (PSK) signal constellation, wherein signal points of the PSK signal constellation are located on at least two rings. The first ring has a first radius r | 06-17-2010 |
20100329670 | RECEIVER FOR OPTICAL TRANSVERSE-MODE-MULTIPLEXED SIGNALS - A representative optical receiver of the invention receives an optical transverse-mode-multiplexed (TMM) signal through a multimode fiber that supports a plurality of transverse modes. The optical receiver has a plurality of optical detectors operatively coupled to a digital signal processor configured to process the TMM signal to determine its modal composition. Based on the determined modal composition, the optical receiver demodulates each of the independently modulated components of the TMM signal to recover the data encoded onto the TMM signal at the remote transmitter. | 12-30-2010 |
20100329671 | TRANSVERSE-MODE MULTIPLEXING FOR OPTICAL COMMUNICATION SYSTEMS - An optical communication system having an optical transmitter and an optical receiver optically coupled via a multi-path fiber. The optical transmitter launches, into the multi-path fiber, an optical transverse-mode-multiplexed (TMM) signal having a plurality of independently modulated components by coupling each independently modulated component into a respective transverse mode of the multi-path fiber. The TMM signal undergoes inter-mode mixing in the multi-path fiber before being received by the optical receiver. The optical receiver processes the received TMM signal to reverse the effects of inter-mode mixing and recover the data carried by each of the independently modulated components. | 12-30-2010 |
20110211828 | Flexible Dispersion Mapping - One method configures an all-optical network such that at least eighty percent of optical fiber spans of a portion of a first all-optical path of the network have substantially a first residual dispersion per span and at least eighty percent of optical fiber spans of a remainder of the first all-optical path have residual dispersions per span substantially differing from the first residual dispersion per span. The remainder of the first all-optical path includes an overlap between the first all-optical path and a second all-optical path of the network. The second all-optical path has a plurality of optical fiber spans and a substantially singly periodic dispersion map. | 09-01-2011 |
20110243574 | MULTIMODE OPTICAL COMMUNICATION - An optical transmitter includes a set of optical waveguides and first, second, and third optical modulators. Output ends of the optical waveguides of the set form a two-dimensional array capable of end-coupling the optical waveguides of the set to a multimode optical fiber in response to the array being located to optically face one end of the multimode optical waveguide. The first optical modulator is optically connected to a first of the optical waveguides of the set, and each of the second and third optical modulators is optically connected to the second and third of the optical waveguides of the set. The set of optical waveguides is configured to provide a coupling matrix of rank three or more between the optical modulators and optical propagation modes in the multimode optical fiber. | 10-06-2011 |
20120170943 | Configuring optical launch powers in optical fiber transmission lines - A method includes transmitting optical signals through a heterogeneous sequence of spans of an all-optical transmission line. Each span has an optical transmission fiber connected to an optical amplifier. Each amplifier launches the signals into a sequential remainder of the line. The transmitting includes launching the optical signals into the highest loss fibers with substantially equal average optical launch powers or operating the spans with the highest loss fibers to have substantially equal quality products. The average optical launch powers are substantially equal to the inverse of a sum of (1−T | 07-05-2012 |
20130230319 | MULTIMODE OPTICAL FIBER, MODE DELAY ADJUSTER FOR FIBER SYSTEMS, AND METHODS TO USE SUCH FIBERS, ADJUSTERS, AND SYSTEMS - An apparatus includes a multi-mode optical fiber having a selected plurality of optical propagating modes. The selected plurality may include only a proper subset of or may include all of the optical propagating modes of the multi-mode optical fiber. Each optical propagating mode of the selected plurality has a group velocity that varies over a corresponding range for light in, at least, one of the optical telecommunications C-band, the optical telecommunications L-band, and the optical telecommunications S-band. The ranges corresponding to different ones of the modes of the selected plurality are non-overlapping. The ranges of a group velocity-adjacent pair of the ranges are separated by a nonzero gap of less than about 10,000 meters per second. | 09-05-2013 |
20130336649 | ADAPTIVE CONSTELLATIONS AND DECISION REGIONS FOR AN OPTICAL TRANSPORT SYSTEM - An optical transport system in which (i) an optical transmitter is configured to adaptively change an operative constellation to use a constellation that provides optimal performance characteristics for the present optical-link conditions and/or (ii) an optical receiver is configured to change shapes of the decision regions corresponding to an operative constellation to adapt them to the type of signal distortions experienced by a transmitted optical signal in the optical link between the transmitter and receiver. Under some optical-link conditions, the optical receiver might use a decision-region configuration in which a decision region corresponding to a first constellation point includes an area that is closer in distance to a different second constellation point than to the first constellation point. | 12-19-2013 |
20140079392 | Multi-Mode Optical Transmission Line With Differential Modal Group Delay Compensation - An apparatus includes an all-optical transmission line having, at one wavelength, a pair of relatively orthogonal optical propagating modes whose local group velocities differ along a part of the all-optical transmission line. The all-optical transmission line is formed by a sequence of optically end-connected multi-mode fiber segments. The segments include, at least, 80% of the optical path length of the all-optical transmission line. Each segment is configured such that a differential group delay between the pair varies monotonically there along and changes by, at least, 200 pico-seconds thereon. | 03-20-2014 |
20140153922 | Multi-Mode Optical Communication With Mode Mixtures - An apparatus includes an optical transmitter having a plurality of optical data modulators and an end-face coupler. Each of the optical data modulators is configured to output a corresponding data-modulated optical carrier. The optical end-face coupler is configured to direct the data-modulated optical carriers into a pattern of light beams to illuminate an end-face of a multi-mode optical fiber with a pattern of light spots. The optical end-face coupler is configured to cause each of the data-modulated optical carriers to excite a set of orthonormal optical propagating modes of the multi-mode optical fiber. Some of the orthonormal optical propagating modes of the set have nontrivially differing intensity and/or phase profiles. | 06-05-2014 |
20140186024 | OPTICAL RECEIVER HAVING A MIMO EQUALIZER - An optical receiver comprising an optical-to-electrical converter and a digital processor having one or more equalizer stages. The optical-to-electrical converter is configured to mix an optical input signal and an optical local-oscillator signal to generate a plurality of electrical digital measures of the optical input signal. The digital processor is configured to process the electrical digital measures to recover the data carried by the optical input signal. At least one of the equalizer stages is configured to perform signal-equalization processing in which the electrical digital measures and/or digital signals derived from the electrical digital measures are being treated as linear combinations of arbitrarily coupled signals, rather than one or more pairs of 90-degree phase-locked I and Q signals. The latter feature enables the digital processor to more-effectively mitigate the receiver-, link-, and/or transmitter-induced signal impairments because various orthogonality-degrading effects can be mitigated in a relatively straightforward manner. | 07-03-2014 |
20150085352 | OPTICAL AMPLIFIER FOR SPACE-DIVISION MULTIPLEXING - In an example embodiment, an optical amplifier comprises a doped multi-core optical fiber and two optical couplers placed at the ends of the doped multi-core fiber, with each optical coupler having a respective plurality of optical waveguide cores optically coupled to the optical waveguide cores of the doped multi-core fiber. The spatial arrangement of the cores at the input end of the first optical coupler is configured for low-loss intake of the optical energy from the input transmission line. The spatial arrangement of the cores at the output end of the first optical coupler and the spatial arrangement of the cores at the input end of the second optical coupler match the spatial arrangement of the cores in the doped multi-core fiber. The spatial arrangement of the cores at the output end of the second optical coupler is configured for low-loss transfer of the optical energy into the output transmission line. | 03-26-2015 |
20150086201 | Data Multiplexing And Mixing Of Optical Signals Across Propagation Modes - An apparatus, e.g. an optical device, includes an optical transmitter and a mixer. The transmitter is configured to transmit a plurality of optical data channels that each include at least one spectral component at a same frequency. The mixer is configured to combine a first data channel with a second data channel. The combining is such that first and second optical channels output by the optical transmitter each include contributions from the first and second data channels at the same frequency. | 03-26-2015 |